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DON’T FORGET ABOUT
THE STEAM GENERATOR
Although we have focused upon
methods to maximize heat extraction
from the steam generation process,
it is important to remember that heat
input efficiency should be maximized
as well. Poor makeup water treatment
and water/steam chemistry programs
can lead to deposition and corrosion
in steam generators. While boiler tube
failures often result from poor chem-
istry, even in units with seemingly
good treatment programs, problems
can arise. The most common deposit
on steam generator tubes and internals
consists of iron oxide particulates that
are generated in the condensate/feed-
water system. (The concentration can
be very large in systems equipped with
air-cooled condensers.) So, it is abso-
lutely vital to operate with the proper
feedwater chemistry, and to have the
ability to immediately detect impurity
ingress from a leaking condenser tube
or other source. [2] For units with
ACCs, a condensate particulate filter is
an absolute must.
Periodic removal of boiler tube de-
posits by chemical cleaning is often a
necessary procedure to improve heat
transfer. Not only will deposits reduce
heat transfer in general, they will also
cause an increase in tube metal tem-
peratures which can lead to accelerated
metal deformation known as “creep.”
Finally, and often most important, is
that some deposits, and most notably
transported iron oxides, are porous and
can allow impurities in the bulk boiler
water to concentrate underneath the de-
posits. Local and rapid corrosion may
be the result. In fact, the Electric Power
Research Institute (EPRI) now recom-
mends a normal (and very low) limit
of 2 parts-per-billion for chloride and
sulfate in condensate, precisely because
these impurities, and chloride in partic-
ular, can generate severe under-deposit
corrosion in the steam generator.
1 psia (approximately 2 inches of mer-
cury). Again assuming an ideal turbine,
the enthalpy of the turbine exhaust is
904.9 Btu/lbm. The unit work output
equates to 1474.1 – 871.0 = 603.1 Btu/
lbm. At 1,000,000 lb/hr steam flow,
the total work is 603,100,000 Btu/hr =
176.7 MW. This represents a 32 percent
increase in available work from the
previous example. Obviously, conden-
sation of the steam has an enormous
effect upon turbine efficiency.
One can also look at this example
from a physical perspective. Calcula-
tions indicate that the steam quality
at the turbine exhaust pressure of 1
psia is 77 percent. (In actuality, this
would be excessive moisture that could
damage low-pressure turbine blades.
Techniques such as steam reheating are
common for reducing moisture in the
low-pressure turbine.) This means that
23 percent of the steam has condensed
to water. However, the remaining
steam takes up a specific volume of 257
ft3
/lbm. The corresponding volume of
water in the condenser hotwell at sat-
uration temperature is 0.016136 ft3
/
lbm. Thus, the condensation process
reduces the fluid volume nearly 16,000
times. The condensing steam generates
the strong vacuum in the condenser,
which actually acts as a driving force
to pull steam through the turbine.
(The strong vacuum also pulls in air
from outside sources, where excessive
air in-leakage can seriously affect heat
transfer.)
In the next example, we can see why
it is important to maintain proper
cleanliness in condensers and heat ex-
changers. Consider again a condensing
turbine, but where waterside fouling or
scaling (or excess air in-leakage) caus-
es the condenser pressure to increase
from 1 psia to 2 psia.
Thermodynamic calculations show
that the work output of the turbine
drops from 603.1 to 569.2 Btu/lbm.
So, at 1,000,000 lb/hr steam flow, a
rise from 1 psia to 2 psia in the con-
denser backpressure equates to a loss
of 33,900,000 Btu/hr or 9.9 MW of
work. This is a primary reason why
proper cooling water chemical treat-
ment and condenser performance
monitoring are very important. Severe
fouling may require a reduction in unit
load. If this occurs on a hot summer
day with emergency power pricing in
effect, the financial consequences can
be enormous. Techniques continue
to emerge to improve condenser, heat
exchanger, and cooling tower perfor-
mance. These include more effective
biocides, improved cooling tower film
fill, more rugged condenser tube ma-
terials, and enhanced instrumentation
for monitoring physical and chemical
operating parameters.
Similarly, for co-generation and CHP
facilities it is important to keep heat ex-
changers free of deposits and corrosion
to ensure maximum efficiency and
equipment availability.
Often, cooling towers are neglected
because they may be isolated from the
main equipment. Improper chemistry
control in chillers and building heat
systems may lead to severe corrosion.
The list goes on.
POWER PLANT OPTIMIZATION
Fouled Cooling
Tower Film Fill
3](https://image.slidesharecdn.com/201509powereng-160314132915/75/2015-09-Power-Engineering-47-2048.jpg)
Uploaded byLuiz Carlos Martinelli Júnior
2015 09 Power Engineering
The document summarizes several recent developments in the power industry: 1) PJM Interconnection announced a 37% increase in payments to power generators, to $164.77/MWh, due to new rules allowing penalties for generators that fail to supply promised power. 2) Regulators in Washington D.C. rejected a proposed $6.8 billion merger between Exelon and Pepco, questioning whether it would benefit the public. 3) Xcel Energy achieved a 20% reduction in carbon emissions since 2005 and is on track for a 30% cut by 2020, becoming the first utility to register a decade of emissions data with The Climate Registry. 4) President Obama announced over $
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- 2. YEARS 119 THE 316(B) RULE ONEYEAR LATER SMALL GAS TURBINES ONE OF THE BIGGEST TRENDS IN DISTRIBUTED GENERATION EMISSIONS CONTROL MULTI-POLLUTANT COMPLIANCE OPTIONS SPECIAL REPORT: BIG Solar September 2015 • www.power-eng.com
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- 4. CHIEF EDITOR —Russell Ray (918) 832-9368 russellr@pennwell.com ASSOCIATE EDITOR — Sharryn Dotson (918) 832-9339 sharrynd@pennwell.com ASSOCIATE EDITOR — Tim Miser (918) 831-9492 tmiser@pennwell.com CONTRIBUTING EDITOR—Brad Buecker CONTRIBUTING EDITOR—Brian Schimmoller CONTRIBUTING EDITOR—Robynn Andracsek CONTRIBUTING EDITOR—Wayne Barber (540) 252-2137 wayneb@pennwell.com CONTRIBUTING EDITOR—Barry Cassell (804) 815-9186 barryc@pennwell.com GRAPHIC DESIGNER — Deanna Priddy Taylor (918) 832-9378 deannat@pennwell.com SUBSCRIBER SERVICE P.O. Box 3264, Northbrook, IL 60065 Phone: (847) 763-9540 E-mail: poe@halldata.com MARKETING MANAGER — Rachel Campbell (918) 831-9576 rachelc@pennwell.com SENIOR VICE PRESIDENT, NORTH AMERICAN POWER GENERATION GROUP — Richard Baker (918) 831-9187 richardb@pennwell.com NATIONAL BRAND MANAGER — Rick Huntzicker (770) 578-2688 rickh@pennwell.com CHAIRMAN — Frank T. Lauinger PRESIDENT/CHIEF EXECUTIVE OFFICER — Robert F. Biolchini CHIEF FINANCIAL OFFICER/SENIOR VICE PRESIDENT — Mark C. Wilmoth CIRCULATION MANAGER — Linda Thomas PRODUCTION MANAGER — Katie Noftsger POWER ENGINEERING, ISSN 0032-5961, USPS 440-980, is published 12 times a year,monthly by PennWell Corp.,1421 S.Sheridan Rd.,Tulsa, OK 74112; phone (918) 835-3161. ©Copyright 2015 by PennWell Corp. (Registered in U.S. Patent Trademark Office). All Power Engineering published content is copyright protected by law. PennWell Corporation must grant proper authorization to reuse any article, photograph or illustration. Foster Printing is the exclusive reprint provider for Power Engineering and gains copyright permissions for published content. For copyright permissions, call 866-879-9144 x194. Prior to photocopying items for educational classroom use, please contact Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923 USA 978-750-8400. Periodicals postage paid at Tulsa, OK and additional mailing offices. Subscription: U.S.A. and possessions, $111 per year; Canada and Mexico, $124 per year; international air mail, $300 per year. Single copies: U.S., $18, Outside U.S. $29. Back issues of POWER ENGINEERING may be purchased at a cost of $18 each in the United States and $29 elsewhere. Copies of back issues are also available on microfilm and microfiche from University Microfilm, a Xerox Co., 300 N. Zeeb Rd.,AnnArbor,MI 48103.Available on LexisNexis,Box 933,Dayton, OH 45402; (800) 227-4908. POSTMASTER: Send change of address, other circulation information to POWER ENGINEERING, PO Box 3271, Northbrook, IL 60065-3271. “POWER ENGINEERING” is a registered trademark of PennWell Corp. Member American Business Press BPA International PRINTED IN THE U.S.A. GST NO. 126813153 Publications Mail Agreement No. 40052420 CORPORATE HEADQUARTERS—PennWell Corp. 1421 South Sheridan Road • Tulsa, OK 74112 P.O. Box 1260, Tulsa, OK 74101 Telephone: (918) 835-3161 • Fax: (918) 831-9834 E-mail: pe@pennwell.com World Wide Web: http://www.power-eng.com Power Engineering® Power Engineering is the flagship media sponsor for FEATURES 119VOLUME POWER ENGINEERING ONLINE : www.power-eng.com Newsletter: Stay current on industry news, events, features and more. Newscast: A concise, weekly update of all the top power generation news Industry News: Global updates throughout the day DEPARTMENTS 2 Opinion 4 Industry News 8 Gas Generation 10 View on Renewables 11 Energy Matters 46 What Works 48 Products and Literature 56 Ad Index 18 Circulating Fluidized Bed Scrubber vs. Spray Dryer Absorber In response to more stringent air emissions regulations,utilities are under pressure to add flue gas desulfurization to their coal-fired units.Power Engineering investigates the differences between state-of-the-art circulating fluidized bed scrubbers and the latest advanced spray dryer absorber designs. 34 316(b): One Year Later As the one-year anniversary of the EPA’s newest 316(b) regulations approaches, Power Engineering examines the details of the rule and how power producers can best meet the revised mandates. 42 Maintaining Maximum Efficiency in Power Generation Units Pressure to lower industrial carbon dioxide emissions continues to foster increased interest in improved efficiency at steam generating facilities.Read about some of the issues operators face in their quest for more efficient plants. 24 Improving the Flexibility and Efficiency of a Gas Turbine-Based Distributed Power Plant By building smaller,more flexible gas-fired power plants closer to actual load centers,network operators can better satisfy their customers’power demands. Learn how an efficient and flexible distributed generation model can help power producers meet the challenges of today’s power landscape. 38 Turbine Oils: A Key Factor in System Reliability Turbine lubricants must perform under the hostile conditions of heat,friction,and chemical degradation.Learn how the right mix of oil and additives,combined with a disciplined program of testing and maintenance,can prevent unwanted varnish and forestall premature equipment wear. 12 Large-Scale Solar on the Rise The cost of generating electricity from utility-scale solar power has plummeted in recent years,but the possible end of federal investment tax credits threatens to temper an otherwise sunny outlook for the industry.Find out what the future holds for solar in NorthAmerica. No.9,September 2015
- 5. 2 OPINION www.power-eng.com In another bizarretwist, the CO2 lim- it for existing plants is 1,307 pounds per megawatt-hour while the CO2 lim- it for new plants is 1,400 pounds per MWh. Under the final rule, the stan- dard for an existing plant is more strin- gent than the standard for a brand new plant. What gives? The new standards can’t be achieved without installing a carbon capture and storage system, an expensive and questionable technology. “We just commissioned the most efficient coal-fired power plant in the country in Arkansas and its CO2 emis- sions are just under 1,800 pounds per megawatt-hour,” said Mark Mc- Cullough, executive vice president of Generation at American Electric Power. The new CO2 standards are among a host of new, costly requirements faced by coal-fired power plants. The new rules mean as much as 90,000 MW of coal-fired generation will be retired be- tween now and 2040. Most of those re- tirements are expected to be achieved by 2020. The only real option for replacing that dispatchable output is power fu- eled with natural gas. “The risk profile of coal and nuclear, from a utility per- spective, is just too high,” McCullough said. But too much reliance on natural gas could lead to serious economic and security issues for the nation’s power sector, McCullough said. “Absence of diversity is a recipe for a big problem,” he said. If you have a question or a comment, contact me at russellr@pennwell.com. Follow me on Twitter @RussellRay1. T he minute the Obama admin- istration unveiled its final plan to cut greenhouse gas emis- sions from U.S. power plants, oppo- nents launched the first of many legal efforts to kill what some have described as the most prejudicial regulation ever proposed by the U.S. Environmental Protection Agency (EPA). The Clean Power Plan calls for sweep- ing new requirements to cut carbon di- oxide (CO2 ) emissions 32 percent below 2005 levels by 2030. The rule will require a massive restructuring of the power sector. It will decimate coal by establish- ing unattainable CO2 standards for coal plants. It does nothing to promote the use of cleaner-burning natural gas, but it will stimulate the deployment of intermittent wind and solar power with new incen- tives. What’s more, it will require states to spend billions to comply with a rule that may ultimately be vacated by the U.S. Su- preme Court. Several states have asked a federal ap- peals court to stay the controversial plan until the courts decide whether the EPA has the authority to force states to limit CO2 from U.S. power plants. More states are expected to join a lawsuit challeng- ing the rule, a case that will likely end years from now at the Supreme Court. What are the plaintiffs’ chances of winning the case against the EPA? Bet- ter than average, I would say. On June 29, the high court struck down the EPA’s Mercury and Air Toxics Standard, better known as the MATS rule, which established the first limits on mercury, arsenic and acid-gas emis- sions from coal-fired power plants. The final MATS rule was issued back in 2012 and became effective earlier this year. However, the Supreme Court remanded the rule to the D.C. Circuit Court, saying the EPA failed to consid- er the $9.6 billion cost of implement- ing the new rule when drafting it. The industry spent billions to comply with the MATS rule, which now faces the possibility of being vacated. How the Supreme Court will rule on the Clean Power Plan is anyone’s guess, but its ruling on the MATS rule is com- pelling evidence the high court may reject the plan. The states’ case against the Clean Power Plan centers on the EPA’s au- thority to regulate greenhouse gas emissions from power plants under section 111(d) of the Clean Air Act (CAA). The states contend power plant emissions are already regulated under section 112 of the CAA. The CAA pro- hibits the EPA from regulating power plant emissions under more than one section of the law. What’s more, opponents of the plan argue the EPA is already regulating pow- er plant emissions under the MATS rule and, thus, does not have the authority to regulate such emissions under section 111(d) of the CAA. However, if the MATS rule is vacated by the D.C. Circuit Court, that legal argument will vanish. “That may undermine one of the key legal challenges to the EPA’s Clean Power Plan,” said Andy Byers, associate vice president at Black & Veatch. “A lot of folks are speculating the EPA may go back to the circuit court and ask them to overturn their (MATS) rule.” What You Need to Know About the Clean Power PlanBY RUSSELL RAY, CHIEF EDITOR
- 6. Indeck Group ofCompanies Indeck Keystone Energy LLC • Indeck Power Equipment Co. • Indeck Boiler Corp. • Indeck Energy Services Inc. (814) 464-1200 • 24-HR Parts: (800) 322-5995 • www.indeck-keystone.com • info@indeck-keystone.com For info. http://powereng.hotims.com RS#2
- 7. 4 INDUSTRY NEWS www.power-eng.com PJM IncreasesPayments to Power Producers 37 Percent PJM Interconnection, the largest electric grid in the U.S., will increase payments to power generators 37 per- cent. The company said the increase will begin in June 2018, and will be $164.77 per megawatt (MW) per day, as deter- mined in a capacity auction held last month. The price is almost $45 above the previous 12 months reached in an auction last year. Precipitating the increase was a deci- sion by federal regulators to allow PJM to penalize generators that fail to sup- ply promised power. The decision was intended to prevent unplanned shut- downs and fuel shortages, like those that greatly inflated prices during the winter of 2014. Capacity costs were set at higher lev- els for two regions because of supply constraints. The eastern mid-Atantic region, including New Jersey, Delaware and Pennsylvania, finalized a price of $225.42/MW/day, while prices in Ex- elon Corp.’s ComEd utility territory rose to $215.Under the new rules, the grid operator can impose penalties of about $2,800 per megawatt-hour on generators who fail to deliver promised power during emergency hours. Exelon-Pepco Merger in Doubt After Regulators Reject Proposal The D.C. Public Service Commis- sion last month rebuffed a multi-bil- lion dollar proposed merger between power companies Exelon and Pepco. The three-member commission unani- mously rejected the $6.8 billion merger. Chicago-based Exelon announced in April 2014 plans to acquire Washing- ton-based Pepco Holdings. The deal would have created the largest electric and gas utility in the region with about 10 million customers in cities includ- ing Baltimore, Chicago, Philadelphia and Washington. Despite garnering the approval of several surrounding states, Exelon and Pepco failed to reach settlements with regulators in Washington D.C. Chairwoman Betty Ann Kane said in a statement the companies failed to show the merger was a benefit to the public. “The evidence in the record is that sale and change in control proposed in the merger would move us in the oppo- site direction,” Kane said. The companies expressed disap- pointment in the decision and said the commission did not recognize the ben- efits of the merger. Excel Energy Cuts GHG Emissions 20 Percent Xcel Energy has become the first utility in the nation to register nearly a decade’s worth of greenhouse gas emissions data with The Climate Registry, a nonprofit organization that operates voluntary and compliance greenhouse gas report- ing programs throughout the world. The company pledged to begin re- ducing emissions in 2005, according to Xcel Energy Vice President Frank Prag- er. In the years since, the utility has seen more than a 20-percent reduction in carbon dioxide emissions and is on track to achieve a 30-percent reduction companywide by 2020. Xcel Energy reached Climate Regis- tered status by measuring and report- ing the company’s emissions from 2005 to 2011. The data was then ver- ified by a third party. The company’s emissions from 2012 to 2014 are being verified and regis- tered with The Climate Registry. Obama Announces $1 Billion in DOE Initiatives President Obama last month an- nounced more than $1 billion in initia- tives promoting clean energy. The president’s Clean Power Plan per- mits the Department of Energy’s Loan Programs Office to guarantee up to $1 billion for commercial-scale distributed energy projects like rooftop solar, smart grid technology and methane capture for oil and gas wells. Distributed energy technologies reduce greenhouse gas emissions while strength- ening energy security and creating eco- nomic opportunity, but projects often encounter roadblocks when it comes to lenders who are unwilling to take on the risk of a new technology. Additionally, the DOE is awarding $24 million through the Advanced Re- search Projects Agency – Energy for 11 high-performance solar power projects aimed at lowering the cost and improv- ing the performance of solar photovol- taic power systems. GE Signs its Largest Battery Storage Deal to Date GE announced it will provide Coachel- la Energy Storage Partners (CESP) with a 30-MW battery energy storage system as part of CESP’s supply contract with the Imperial Irrigation District (IID). Representing GE’s largest energy stor- age project to date, the plant will be built in California’s Imperial Valley, 100 miles east of San Diego. The facility will aid grid flexibility and increase reliability on the IID network by providing solar ramping, frequency regulation, power balancing, and black start capability for an adjacent gas turbine. GE will provide CESP with an integrat- ed energy storage solution, configured
- 8.
- 9. 6 www.power-eng.com using GE’sMark VI plant controls, GE Brilliance MW inverters, GE Prolec trans- formers, medium-voltage switchgear, and advanced lithium ion batteries housed in a GE purpose-built enclosure. The plant will be operated by ZGlobal, an engineer- ing collaborator with CESP, for the first 18 months, after which control will transfer to the IID. Construction is expected to begin early next year, with commercial operation scheduled for the third quarter of 2016. NRC Issues Corrective Actions Against Millstone 2 Nuclear Unit Dominion is implementing a range of corrective actions at the Millstone Unit 2 nuclear plant in Connecticut to address violations. In September 2011, the NRC became aware that Dominion had submitted re- quests for approval of amendments to the Millstone 2 operating license that were incomplete and inaccurate. The requests were to modify requirements for Unit 2’s charging pumps and irra- diated fuel decay time. NRC’s Office of Investigations began an investigation the following November to determine if there was any wrongdoing. On April 29, 2015, NRC notified Dominion that the violations were considered for esca- lated enforcement. The first violation was for a will- ful violation for changes made to the plant’s Updated Final Safety Analysis Report, without a license amendment, that removed credit for a specific type of safety-related pump in the mitiga- tion of a plant accident. The second vi- olation was a non-willful violation for a failure to provide complete and accu- rate information to the NRC pertain- ing to the changes. The third violation, related to the utility’s failure to obtain a license amendment prior to making changes related to spent fuel pool heat- load analysis, was not considered for escalated enforcement. Louisiana Regulators Approve Merger of Entergy Utilities The Louisiana Public Service Commis- sion approved the merger of Entergy Lou- isiana LLC and Entergy Gulf States Louisi- ana LLC into a single utility. The new utility will operate under the name Entergy Louisiana LLC after the deal closes Oct. 1. It will have over $16.5 billion in assets and 66,194 GWh in com- bined sales. Louisiana’s utilities provide electricity to more than one million cus- tomers, and natural gas service to over 93,000 customers in the greater Baton Rouge area. The merged company will be a unit of Entergy Corp. GE’s Gas Turbine Surpasses 75 Million Operating Hours GE’s LM2500 aeroderivative gas tur- bine has reached a milestone of 75 mil- lion combined operating hours. The current fleet of gas turbines totals more than 2,800 turbines across six con- tinents. Main features includes reaching full power within 10 minutes, direct drive for 50-hertz and 60-herts power genera- tion, variable speed for mechanical drive, dual-fuel capability for distillate or natu- ral gas, reduced NOx with dry low emis- sions combustor and natural gas fuel and optional steam or water injection system for NOx control. The first LM2500 gas turbine began op- erating on a U.S. Navy cargo ship, GE said in a release. The turbine consists of a 16 or 17-stage axial flow compressor, annular combustor, two-stage, high-pressure, sin- gle rotor gas turbine and efficient six-stage power turbine. DOE Picks 8 Projects to Receive Funding for Cutting Cost of CO2 Capture and Compression The U.S. Department of Energy’s (DOE) National Energy Technology Laboratory has selected eight projects to receive funding to construct small- and large-scale pilots for reducing the cost of carbon dioxide (CO2) capture and com- pression through DOE’s Carbon Capture Program. The Carbon Capture Program is de- veloping technologies that will enable cost-effective implementation of carbon capture and storage (CCS) in the pow- er generation sector and ensure that the U.S. will continue to have access to safe, reliable and affordable energy from fossil fuels. The program consists of two core research technology areas, post-combus- tion capture and pre-combustion capture, and also supports related CO2 compres- sion efforts. Current research and devel- opment efforts are advancing technol- ogies that could provide step-change reductions in both cost and energy pen- alty compared to currently available tech- nologies. MidAmerican Building Iowa Wind Farms for $900 Million MidAmerican Energy says it will build its next two wind farms in northwest Iowa. The company says there will be 134 generators at the Ida County site and 104 at the site in O’Brien County, providing a combined capacity of 552 megawatts. The estimated investment for the two projects is $900 million. A MidAmeri- can vice president, Mike Gehringer, says that by the end of the year, more of Mi- dAmerican’s electricity will come from wind than from any other single source. MidAmerican spokeswoman Ruth Com- er says that by the end of 2016, when both projects are completed, the Berkshire Ha- thaway-owned company will have more than 2,000 wind turbines across Iowa.
- 10. NOx Reduction Catalyst Bringdown NOx and mercury emissions Regulators worldwide are clamping down on mercury emissions, and complying with the latest standards can be a costly burden. Topsoe’s DNX® series NOx reduction catalysts can help you meet today’s tough standards without breaking the bank. A unique tri-modal pore structure and specialized additives enable superior mercury oxidation, while also ensuring high activity and durability, outstanding poison resistance and low SO2 oxidation. www.topsoe.com For info. http://powereng.hotims.com RS#4
- 11. 8 GAS GENERATION www.power-eng.com complete borescopeinspections at recom- mended intervals. Although not a precise indicator of part condition, signs of major damage such as large crack indications, excessive wear or oxidation, foreign object damage, tip rubbing, and missing coating should be explored. It is important to document damage that occurs over time in order to track the progression of known conditions. During major overhauls, users should conduct cycling-targeted, non-destructive testing (NDT), particularly on rotating hardware. Depending on material, there are multiple NDT techniques that can identify cracks. These include liquid pen- etrant, magnetic particle, and eddy cur- rent inspections. Users should complete pre- and post-repair inspections, especial- ly if weld repair is required. In addition, they should inspect the integrity of the coating and determine if new coatings are required. Always review repair inspection reports for non-conformances so as to un- derstand the condition of hardware prior to reuse. ASSESSMENT FOR PART REUSE With inspection results in hand, it must then be determined if it is safe to continue to use hardware. Recall the difference in failure modes between base loaded and cycling machines and the fact that many parts are life limited by time at tempera- ture failure modes. When coupled with the results of the cycling targeted failure mode inspections, knowledge of the ac- cumulated operating hours of hardware enables educated decisions concerning part reuse. Given the cost of replacement hardware, significant monetary benefits can be realized using this strategy. G as turbine maintenance inter- vals are determined by hours, starts, or a combination of both. The latter is often referred to as equivalent operating hours (EOH). The increasing integration of renewable energy sourc- es into generation portfolios has meant changes in dispatch, and many tradition- ally base-loaded assets are being forced to load follow and on-off cycle, as seen in many gas turbine and combined-cycle arrangements across the country. With such shifts in operational patterns comes a shift in the failure modes that manifest, as well as the inspection techniques required to effectively diag- nose these respective modes. Given the competitive marketplace, it is valuable to understand applicable failure modes and inspection techniques to effective- ly balance the fine line between scrap- ping parts prematurely and running hardware beyond safe conditions. CYCLING VS. BASE LOAD FAILURE MODES When a unit starts and stops, it is ex- posed to significant cyclic stresses in ad- dition to large thermal transients in the high-temperature sections of the engine. This can lead to thermal mechanical fa- tigue or low-cycle fatigue cracking. After cracks begin, they continue to propagate with each new cycle. If not addressed in time, liberation of a rotating blade can lead to substantial forced outage time and repair costs. For cycling units, it is also common to sustain damage at interface or contact sur- faces. Damage occurs from the repetitive relative movement between surfaces, or as a result of increased deflection of the rotor through critical speeds. Some examples of these surfaces include rotor to blade root interfaces, tip contact faces on adja- cent shrouded blades, and compressor or turbine blade tips. In addition, cycling has been shown to increase coating spallation rates for coated parts, thus leading to pre- mature oxidation of the hardware. The impact of cycling is not limited to a sin- gle section of the gas turbine. TG Advisers has been involved in root cause failure analyses ultimately attributed to cycling in the compressor, combustion, and hot sections of gas turbines. It is also important to understand base load failure modes. Base loaded machines are mainly limited by failure modes that result from prolonged operation at ele- vated temperatures. These failure modes include creep, coating/surface oxidation damage, and embrittlement. Creep dam- age is very difficult to detect non-destruc- tively. As a result, hot section rotating blades often have conservative life guide- lines. This design philosophy is under- standable given the scatter in material properties, difficulty of detecting creep, and severity of a blade failure. The risk for failure modes that require extended time at high temperatures, such as creep, is less in gas turbines that exhibit cycle dominat- ed maintenance intervals. CYCLING-TARGETED INSPECTIONS The key to effective inspections is un- derstanding the applicable failure modes and how they manifest. This holds true for broad condition inspections such as in-situ borescope inspections, as well as for detailed inspections completed during major outages. Prior to overhaul, and as a routine maintenance practice, users should Renewable Energy – Pushing Gas Turbine Components to Their Cycling Limit! BY THOMAS R. REID,TG ADVISERS, INC.
- 12. magnetrol.com • 1-630-969-4000• info@magnetrol.com © 2015 Magnetrol International, Incorporated Safety Measures Remote Mount Capability Keeps Workers Off Top of Tank for Switch Modification Advanced Self Diagnostics Assures Reliable Performance Dual-Point Option for Two-Alarm Safety Protocol Best-in-Class Safe Failure Fraction >91% Goggles Hard Hat High-Visibility Vest Insulated Gloves Safety Harness Steel-Toed Boots Protect your plant with Echotel® Ultrasonic Level Switches ECHOTEL liquid level control technology measures up to the most rigorous safety standards, with intelligent design that ensures outstanding quality, reliability and overfill prevention. echotel.magnetrol.com For info. http://powereng.hotims.com RS#5
- 13. 10 VIEW ON RENEWABLES www.power-eng.com –sweeping a greater area to make the most of the available wind resource. At an average wind speed of 7.5 me- ters per second (nearly 17 miles per hour), the Siemens SWT-2.3-120 yields an increase of nearly 10 percent in an- nual energy production (AEP) com- pared to that of its pioneering prede- cessor under the same conditions – helping to deliver higher re- turns and a decrease in the Levelized Cost of Energy . Production of this new wind turbine will begin in 2017, and we are pleased that its production will support clean energy jobs here in the U.S., where we have close to 2,000 workers in our new unit and service businesses. The nacelles and hubs will be as- sembled at our facility in Hutchinson, Kansas, and the blades will be manu- factured at our blade factory in Ft. Mad- ison, Iowa. And our national network of wind service technicians is ready to keep these turbines running optimally throughout their lifecycle. With more than 5,000 wind turbines installed in the U.S., Siemens is leading the effort to ensure that wind power is an increasingly important part of the nation’s energy mix. At Siemens, we have more than 30 years of global experience in onshore wind – and this new turbine is the lat- est example of our strong commitment to the growth of wind energy in the United States. T he Department of Energy’s Wind Vision report recently laid out a plan to double wind ener- gy in the U.S. by 2020, double again to 20 percent by 2030, and expand to over one third of energy production by 2050. With policymakers in Washington focusing on reducing greenhouse gas emissions, wind power is a natural com- plement to fast-growing natural gas – a prime building block for lowering car- bon emissions. The U.S. already leads the world in the amount of electricity that is produced by wind – with more than 181 million megawatt hours in 2014 – and the cost of wind energy has dropped by half over the past five years. As a share of the nation’s energy mix, wind has grown from under 1 percent to nearly 5 percent over the past eight years – competing with natural gas for the top spot of new power added to the system. Because it is a low-cost solution with zero emissions, it is clear that wind ener- gy will play an important role in cost-ef- fectively meeting the goals set forth by the Obama administration. In order to continue to reduce the cost of wind energy, ongoing technol- ogy enhancements are essential. Be- cause of performance enhancements, onshore wind is nearly reaching grid parity. At Siemens, we are committed to continually enhancing our technol- ogy in order to grow the wind indus- try here in the U.S. Earlier this year, at the 2015 AWEA WINDPOWER Con- ference & Exhibition in Orlando, Sie- mens announced the latest addition to our G2 product platform. This new SWT2.3-120 wind turbine builds upon the proven design principles of our G2 platform. Nearly 8,000 units have been installed globally. With wind power becoming an increasingly important part of the U.S. energy mix, this new turbine was designed in America specifically to meet the needs of the American market. The SWT- 2.3-120 offers proven technology tailored to local requirements and designed to lower the levelized cost of energy. Building upon the achievements of the SWT-2.3-108, the new SWT-2.3-120 features a high-perfor- mance 120-meter rotor that enables en- hanced energy production, lower sound power levels and improved operating temperature and altitude capabilities. At our aerodynamic R&D center in Boulder, Colorado, the new blade type was designed to optimize the perfor- mance of next generation wind com- ponents – resulting in an aero-elastic blade design that improves efficiency and reduces loads through intelligent use of the blade’s flexing capabilities. This allows for the SWT-2.3-120’s larg- er rotor size without a proportional in- crease in structural loading – decreas- ing wear and tear on the turbine. The new blade was designed with the goal of increasing energy production for sites with medium to low wind con- ditions, which comprise a significant part of the U.S. market. The 59-meter blades extend the reach of the rotor WIND POWER: Made for American NeedsBY JACOB ANDERSEN, CEO ONSHORE AMERICAS, SIEMENS WIND POWER & RENEWABLES DIVISION “As a share of the nation’s energy mix, wind has grown from under 1 percent to nearly 5 percent over the past eight years.”
- 14. 11 ENERGY MATTERS www.power-eng.com April EscamillaRobynnAndracsek communities were the least likely to mount a serious challenge to the industry because low income people are often less well-educated, have less access to computers and internet technology, are less knowledgeable of how to access and interpret environmental data, and are the least likely to have the resources for a time consuming legal battle.” The Freedom of Information Act (FOIA), enacted in 1967, is the usual method to obtain records about a plant’s operation: emissions, limits, or almost anything needed to demonstrate compliance (other than business confidential information). For larger, more publically sensitive projects such as those at power plants, many states have already adopted a policy of creating websites where the most requested documents can be downloaded by the public. This simple action saves the agency manpower in fulfilling repetitive FOIA requests. However, FOIA requests and state websites put the burden of transparency on the government and not the regulated entity. By requiring each coal plant to post their compliance information on the internet, neighbors, activists, and other interested parties can play armchair watchdog. For now, EPA seems to have met the needs of all parties involved. Citizens can scrutinize their local utility, state agencies can redirect their budgets to enforcing other regulations, and EPA can stay neutral until they are dragged into action by a lawsuit. And the utilities? While they are busy managing ash and protecting the environment, citizen groups will be watching every move. T he new rules on Coal Com- bustion Residuals (CCR) have a novel requirement aimed at making compliance efforts transparent: many records must be posted on the in- ternet to allow easy public accessibility. Requiring a website is an interesting de- velopment and is an obvious next step in regulatory communication. On April 17, 2015, the Environmental Protection Agency (EPA) published the final version of the federal CCR rule on the storage and disposal of CCRs generated by electric utilities. The CCR rule is expected to affect more than 1,000 active CCR management units throughout the U.S, particularly the owners and operators of CCR landfills and surface impoundments. The new rule includes provisions addressing the potential for catastrophic failure of CCR containments, groundwater monitoring, operational requirements, recordkeeping and reporting, as well as closure procedures for inactive or failing facilities. Under the rule, there are numerous requirements that must be performed by a professional engineer, and others by a qualified individual. The rule will require installation of groundwater monitoring wells, and a groundwater monitoring program for taking samples and assessing that data. In addition to thorough recordkeeping and notification requirements, owners and operators of CCR sites are now required to maintain a public website hosting all compliance information, including monitoring reports. The rule also outlines timeframes and procedures for site closure, and also details closure consequences for sites failing to meet these criteria. The first provisions of this rule are expected to take effect on October 19, 2015. As part of these provisions, all owners and operators of over 1,000 identified active landfills and surface impound- ments, currently receiving CCRs are now required to establish and maintain a website of CCR facility operation- al compliance data called “CCR Rule Compliance Data and Information.” The website must be made publically available, and host items identified in the CCR rule are required to be publi- cally accessible. Some of the items that must be included are annual ground- water monitoring results, corrective ac- tion reports, fugitive dust control plans, structural stability assessments, emer- gency action plans, and closure com- pletion notifications. As information is uploaded to the site, notifications must be sent to the state and local tribal au- thorities. The requirement for a website stems from another unusual aspect of the CCR rule: the rule does not require permits, does not require states to adopt or implement these requirements, and EPA cannot enforce these requirements. EPA has promulgated a rule that relieves itself of the burden of assessing compliance. Commenters on the draft rule fell on both sides of the argument as to whether or not civilian enforcement would be effective. Some were encouraged by the opportunity to enforce the rule themselves since “…citizens have shown no reluctance to challenge companies that they believe are not responsibly following environmental regulations.” Others felt “environmental justice Kicking Ash and Taking Names BY APRIL ESCAMILLA, BURNS & MCDONNELL, AND ROBYNN ANDRACSEK, P.E., BURNS & MCDONNELL AND CONTRIBUTING EDITOR
- 15. 12 www.power-eng.com RENEWABLE POWER T heutility-scale solar en- ergy industry is feeling its oats. The cost of gen- erating electricity from solar power has plum- meted in recent years, and experts say it will continue to drop. Utility-scale solar is on par with, if not cheaper than, power produced with fossil fuel in many markets in the U.S., and there are more than 27 GW of solar projects either under construction or in the planning stages. Yet, there are a few clouds darken- ing the utility-scale solar market. The darkest being the possible sun setting of federal investment tax credits (ITC) at the end of 2016. Solar has about 1 percent of the power generation market in the U.S., but the industry is scoring some his- toric firsts. Georgetown, Texas, about 50 miles north of Austin, recently an- nounced that it will use solar and wind power to become one of a handful of U.S. cities running on 100 percent re- newable energy. The solar power will come from a 150 MW project in West Texas, accord- ing to John Lamontagne, senior direc- tor of corporate communications at SunEdison. What’s interesting about the announcement is why the city chose SunEdison: price. “They did it because we were the lowest cost option for local ratepayers,” Lamontagne says. “In other words, solar energy (along with wind power) were the cheapest ways to power that town.” PROJECT PROFILE There are two main ways to gener- ate solar power: photovoltaic cells or concentrated solar power (CSP). CSP uses mirrors to focus solar energy to create heat, which can then power a traditional steam turbine. Photovoltaic cells use an electronic process to con- vert sunlight into electricity. The Ivanpah Solar Electric Generat- ing System uses solar thermal technol- ogy to produce energy. Unlike tradi- tional solar farms, more than 300,000 computer-controlled mirrors track the sun and reflect it towards boilers that sit atop immense towers. Steam is cre- ated when the concentrated light hits the boilers. The steam is piped to a tur- bine where it creates electricity. Ivanpah, which has been live since January 1, 2014, has three units with a total generating capacity of 377 MW. Units 1 and 3 provide power for Pa- cific Gas & Electric while unit 2 sends electricity to Southern California Edi- son. The plant has a 30-year license to operate on public land in California’s Mojave Desert, 45 minutes southwest of Las Vegas. About 65 full-time op- erations and maintenance employees work at the plant. Ivanpah, a partnership between BrightSource Energy, Google and Large-Scale Solar on the RiseBY ROBERT SPRINGER NRG called Solar Partners, was built by Bechtel. NRG Energy Services han- dles the plant’s operations and main- tenance. The plant reaches full load during sunny days, says Mitchell Samuelian, vice president of operations and main- tenance for NRG Renew and the former general manager of Ivanpah. “On sun- ny days we’ve made over 103 percent of our estimated energy that we were supposed to reach in the year,” he says.
- 16. 13www.power-eng.com The challenge ishow to produce the most electricity during partly cloudy weather. The goal, explains David Knox, senior director, wholesale and new business communications at NRG, is to “collect as much solar en- ergy as you can to start it up as quickly as you can, and then to continue that throughout the day, whether it be high noon or early evening and optimizing that throughout the entire day.” This is technically very challenging to do, according to Samuelian, “Be- cause you’ve got clouds moving in and out and you’ve got a steam plant with thermal inertia and the parts and piec- es move around,” he says. In the early morning, virtually all of the mirrors are aimed at the tower, but as the day goes on some go into a standby position so the tower doesn’t overheat. The process is regulated by infrared cameras, Samuelian says. “They monitor the boilers surface with infrared cameras, and they balance turbine load with the amount of solar they’re putting in and with how much sunlight’s in the sky,” he says. The boiler has three sections – super heat, reheat and evaporator – and mul- tiple mirrors heat a different section of the boiler. Supercomputers balance the energy on the three spots and give aiming signals to each unit every 10 sec- onds, according to Samuelian. “I think that people don’t understand The Ivanpah Solar Electric Generating System uses mirrors to direct concentrated solar power at a boiler,which produces steam to power a turbine and produce clean electricity for Northern and Southern California.Photo Courtesy:Ivanpah Solar Electric Generating System Author Robert Springer is an Oregon-based freelance journalist covering the energy industry. His work has been published in several publications, including Renew- ableEnergyWorld.com and Power Engi- neering magazine.
- 17. 14 www.power-eng.com RENEWABLE POWER thecomplexity associated with that. I mean these are actually run by big su- percomputers that control the system,” says Samuelian. The plant uses recycled water, and is using much less than originally thought, at about 40 percent of the 100 acre feet allotment for all three units, ac- cording to Samuelian. Using air-cooled condensers helps, as does having “a closed loop cooling system that ejects the heat to the air rather than evaporat- ing water. There’s a golf course next to us out in the desert, and I think we use the amount of water equal to two holes on the golf course,” Samuelian says. Another challenge is the sheer size of the plant. A coal-fired plant of similar size would have a much smaller foot- print, Samuelian says. Ivanpah’s three units cover about 3,000 acres and is about five miles end to end. “So if I’ve got someone working in the solar field on one end of the plant and I need them to go look at something else on the oth- er end of the plant, there’s restrictions on what speed you can drive onsite, for wildlife considerations, and creating dust, and so, the speed limits like 10 miles an hour,” says Samuelian. It takes about half an hour to go from one end of the plant to the other. FOLLOWING THE PHOTONS: SOLAR IS MORE THAN PANELS Solar panels get the lion’s share of the publicity, but they’d just be large, shiny mirrors without the ability to take the electricity the solar panels pro- duce from the panel to the grid. ABB, a global provider of power and automa- tion technologies, manufactures and installs the equipment that allows util- ities to get solar energy onto the grid. ABB’s products take over once the solar panels have converted the ener- gy from photons into DC power, says Bob Stojanovic, ABB’s director of solar power for North America. “What ABB makes is everything from the connec- tors that connect the cabling to the de- vices,” he says. Groups of solar panels (or “strings”) run in a series and in parallel until they get the maximum voltage they’re de- signed for, and the electricity is taken to a combiner box, which is a group of fuses and switches that take the input from the strings and combine it into a single output, according to Stojanovic. “And that typically runs back to another larger combiner box, which is typically a bunch of breakers or large fuses that take the rest of these strings and com- bine it into one big DC input into an inverter,” he says. The DC power needs to be converted to AC to reduce losses and because that’s what the North American grid supports. Stojanovic says they typically get somewhere around 300 to 690 volts of AC out of the inverter, and “then it goes through what’s called an inverter step-up transformer” or padmount transformer, he says. The transformer typically boosts the voltage up to 34.5 KV. Although there are small losses during the conversion process, the fi- nal boost to 34.5 KV will decrease the loss as the power is sent to the substa- tion, according to Stojanovic. “Inside the substation you’ll typically string, depending on the plant design, some- where between, five to eight converters together on the same circuit, and you’ll bring it back to a main breaker, a feeder breaker which will then feed it into the main power transformer,” he says. ABB manufactures turnkey substa- tions and almost all of the equipment that’s in the substations, Stojanovic says, “Everything from the reclosers to the tank breakers to the power trans- formers, the current transformers, and the instrument transformers where you measure power and voltage.” Stojanovic says that ABB has no ABB provides concentrated solar power and thermal automation solutions for solar farms around the world,including this customized application with eSolar’s Sierra SunTower facility in Southern California.Photo Courtesy:ABB
- 18. exist? No, definitelynot. It has become very competitive to the point where I think it would certainly cause a consid- erable slowdown in the industry, but I’m confident that the industry can ab- sorb it if it’s forced to,” he says. “It will certainly spur a high level of consolida- tion in the industry and only the very strong and very efficient will survive the expiration of the ITC. “ David Feldman, senior financial an- alyst at the National Renewable Ener- gy Laboratory, notes that the personal homeowner credit completely goes away, so the distributed market could be harder hit than the utility-scale one. He also thinks it’s time for the ITC to go away entirely, albeit gradually. “The best thing that I think that could hap- pen is that they just agree to somehow put some sort of orderly ramp-down in place rather than just a hard cliff; but I OXAMINE.THE POWERHOUSE MICROBICIDE. © 2014 Buckmuckman LLaboraboratoratoriesies InteInternational, Inc.nc. All righrights reserved.ved. MORE POWER TOYOUR POWER PLANT. Oxamine® from Buckman works better than conventional oxidizing microbicides in high demand systems to keep condensers cleaner, reduce the use of corrosive chlorides, and improve the overall efficiency of your operation. Check out all the ways Buckman’s advanced technologies are helping power plants reduce costs and generate bigger returns. For info.http://powereng.hotims.com RS#6 desire to enter the solar panel market, although the company looked into it a few years ago, as they realized it was not a core competency. “What we manufacture is power and automation equipment. That’s really where we can add value,” he says. WHAT HAPPENS IN 2017? There are a myriad of predictions for what would happen to the U.S. solar industry if the federal investment tax credit were to decrease from the cur- rent 30 percent to 10 percent in 2017. The predictions range from an extreme disruption of the industry to a 12 to 18 month hiccup in the industry’s rapid growth of the past few years. “I think right now people are pro- ceeding with cautious optimism,” says Katherine Gensler, director of gov- ernment affairs for the Solar Energy Industries Association (SEIA). “This is in contrast to say the last five or six years, where there was sort of a boom- ing industry and a growing industry.” Gensler adds that the eight year ITC extension that the industry received in 2008 allowed the industry to grow and especially helped larger utility-scale projects that had long lead times. Charles Pimentel, Solar Frontier’s chief operating officer, is not optimis- tic that congress will extend the ITC in its current form, although he is “con- fident that congress will provide some kind of interim solution, whether it be a complete extension, or whether it be some kind of safe harbor, or some kind of grandfathering in of projects com- pleted by the end of 2016,” he says. He doesn’t foresee long term damage to the industry if the ITC is allowed to expire. “Will the industry cease to
- 19. 16 www.power-eng.com RENEWABLE POWER commissionto leave things as they are, while Pacific Gas & Electric and South- ern California Edison want payments lowered to new net metered installa- tions. FUTURE OF SOLAR IN N.A. While experts agree that solar has a place at or near the head of the table of renewable energy options for North America, the industry has some sub- stantive challenges in addition to the possible expiration of the ITC at the end of 2016. ABB’s Stojanovic is an “optimist” when it comes to technological innova- tions that will continue to drive down equipment costs and increase efficien- cies in the next few years. “They’ve ba- sically proven everybody wrong over the last five years by blowing away whatever cost curves they thought they think whoever’s in office, it’s going to take congress as well as the president to decide what the policy is going for- ward. But all energy is policy, so it’s not just solar,” he says. NET METERING: A DEBATE IN MANY STATES Net metering, or the process of selling excess electricity generated on-site back to a utility at retail power rates, is an issue that utilities and solar-using rate payers are passionate about. The rate at which customers are paid for energy sold back to a utility impacts its bottom line and the cost effectiveness of a roof- top solar installation, experts say. Pimentel says that while net meter- ing does impact a utilities bottom line, it won’t destroy their business model as rooftop solar is such a tiny percent- age of the energy generated in North America. “If a homeowner is typically paying the utility $250 every month and all of a sudden the utility is only getting $15 a month, that impacts their reve- nue,” he says. However, if a utility has 2 million customers and only 5,000 use solar “it’s not going to destroy the utili- ty. It will affect their revenue and their economics, but it’s certainly not going to destroy them,” he says. It makes sense for customers to be paid the retail rate, according to Feld- man, as utilities don’t have to pay for pay transmission charges, the facili- ties are collocated and there are other benefits which make distributed solar worth a higher value price. The solar industry itself is of two minds about net metering. In Califor- nia, the SEIA and the Alliance for Solar Choice have asked the public utilities Solar Frontier’s CIGS solar modules provide 82.5 MW of the Catalina Solar Project’s 143 MW.The project is near Bakersfield,California.Photo Courtesy:Solar Frontier
- 20. Lapeyre Stair... We don’tmiss a step. Lapeyre Stair serves all your stair needs quickly and precisely. In-house detailing and design ensure project accuracy – every time, on time. Choose from our expanding product line to meet your on-site assembly requirements. www.lapeyrestair.com Welded Egress Stairs • Alternating Tread Stairs • Platform Systems • Bolt-together StairsW lW lW lW ldeddeddedded Eg s Ss Ss Staitaitaitaitai • Alte m S BolBol thethethethether Sr Sr Sr Sr Staiting Tg Tg T d Stai • P• P• P• P• Platlatlatlatform Sm S Accurate and timely advanced stair building technology since 1981. Send us your plans or email us at ls.sales@lapeyrestair.com to learn how you can experience the ease of working with long-time stair building professionals. Or, to immediately consult a knowledgeable customer service agent, call 800-535-7631. 17www.power-eng.com For info.http://powereng.hotims.com RS#7 plants are not being planned for post 2016 until the ITC debate is resolved. “There’s a lot more uncertainty about the near-term future, but then once we get through the uncertainty, the indus- try is strong and will continue to grow,” she says. had in line,” he says. Solar’s biggest challenge going for- ward is making energy that’s affordable in the daytime also affordable at night, Stojanovic said. “I don’t think cost for solar is the issue anymore,” he says. Interconnection continues to be an issue, according to Feldman. Putting the right amount of solar technology in the right location at the right cost is a challenge. He says that a utility indus- try that has placed a high premium on reliability (a good thing) might be act- ing too conservatively when it comes to solar. In addition to reliability, flexi- bility and storage are important factors for utilities to consider, Feldman says. Samuelian thinks era of the me- ga-solar projects is over, as the low price of oil and natural gas is “really kind of driving the energy market in general,” he says. Knox sees the home solar market as “an incredible growth market,” he says. “We just really see a huge potential for the home solar mar- ket, not instead of but in addition to the utility-scale market.” Many different technologies – in- cluding wind, storage, diesel genera- tors and solar – could converge to help create a self-sustaining micro grid, Samuelian says. The number of states that have ag- gressive solar and renewables programs has grown exponentially, Pimentel says, with North Carolina being the poster child for this group. “Two years ago, nothing was going on in North Carolina, and now North Carolina will do gigawatts next year,” he says. Geor- gia is also getting into solar in a big way, according to Pimentel. New markets will be important for the industry, Feldman says, as states start to satisfy their Renewable Port- folio Standards (RPS). If Arizona, for example, hits its RPS, utility-scale so- lar might not make sense there as the demand will have evaporated. On the other hand, states like California and Hawaii have very aggressive RPS’, which could balance out the demand. Solar is also competing against wind, Feldman notes. Gensler says that there is “still some trajectory” left in the market through 2016, but large utility-scale solar
- 21. 18 www.power-eng.com EMISSIONS CONTROL JEA’sNorthside Generating Station includes two Amec Fos- ter Wheeler CFB boilers,each producing 831,000 ACFM of flue gas.Each boiler uses a single SDA followed by a pulse jet fabric filter to treat the flue gas produced by the pet coke- and coal-fired unit.SO2 emissions are reduced up to 90 percent and SO3,HCl,and HF emissions are reduced up to 99 percent.The plant has been in operation since 2002. Photo Courtesy:Amec Foster Wheeler Circulating Fluidized Bed Scrubber vs. Spray Dryer AbsorberBY MATTHEW FISCHER AND GREG DARLING Toxics Standards or MATS), Regional Haze (RH), and SO2 , NOx, and partic- ulates (Cross-State Air Pollution Rule or CSAPR) have ratcheted up the pres- sure on coal-fired generators to quickly reduce a variety of pollutants. The EPA estimates that CSAPR alone requires more than 3,000 units at more than 1,000 plants located in 28 states to re- duce emissions that cross state lines and contribute to ground-level ozone and fine particle pollution. CSPAR Phase 1 compliance takes effect this year while MATS and RH reduction are ongoing programs. The debate over what limits will be imposed has now shifted to how indi- vidual units will comply with the pre- scribed deadlines. There are as many technical approaches to meeting new emission limits as there are differences in plant designs. Adding to the com- plexity of any solution is the uncertain- ty of future rules that will require fur- ther reductions of an expanding range of pollutants. In the past, SO2 capture on a large scale was the province of wet flue gas desulfurization (WFGD) technology. It has the advantage of a relatively low operating cost and uses readily available limestone as the reagent, which can be recycled into a number of useful prod- ucts to offset operating costs. However, WFGD scrubbers do have disadvantag- es, such as large capital and high main- tenance costs. By design, many WFGD systems require periodic discharge of the scrubber liquor to maintain solids M any utilities are under pressure to add flue gas desul- furization to their coal-fired units in response to more stringent air emis- sions regulations. There are a number of multi-pollutant compliance options available that have an edge over wet flue gas desulfurization systems. This article sorts out the difference between state- of-the-art circulating fluidized bed scrubbers and the latest advanced spray dryer absorber designs. By Matthew Fischer and Greg Dar- ling, Amec Foster Wheeler The converging U.S. Environmental Protection Agency (EPA) rules for re- ducing mercury, metals, acid gases, and organic compounds (Mercury and Air Author Matthew Fischer is Product Leader, Dry FGD Systems, and Greg Darling is Prod- uct Leader, CFBS Systems, for Amec Fos- ter Wheeler North America Corporation Global Power Group – Environmental Systems.
- 22. 1SDA Design Details Source:Amec Foster Wheeler The SDA uses hydrated lime to treat flue gas.The heat of the flue gas evaporates the droplets, which cools the flue gas. Cooled flue gas with the dried products is directed to a fabric filter. Solids Discharge Hopper Perforated Distribution Plate & Flow Straightener Flue Gas In Reaction Vessel Two-Phase Reaction Process Two Fluid Nozzles Flue Gas Out 19www.power-eng.com Source: Amec Foster Wheeler The optimized two-fluid nozzle design ensures balanced atomizing air distribution in order to produce a consistent droplet size, and reduced compressed air consumption by a quarter.Also, tungsten carbide inserts have significantly reduced nozzle wear. Two-Fluid Nozzles Released 2 Inserts Nozzle Shroud Lime Slurry Atomizing Air Shroud Air Lance Assembly Two Fluid Nozzle Lime Slurry Atomizing Air Air Reservoir absorber (SDA), which sprays atom- ized lime slurry droplets into the flue gas. Acid gases are absorbed by the atomized slurry droplets while simul- taneously evaporating into a solid par- ticulate. The flue gas and solid partic- ulate are then directed to a fabric filter where the solid materials are collected from the flue gas. Amec Foster Wheeler has installed 60 SDA units represent- ing over 4,500 MW of plant capacity. The second is the circulating fluidized bed scrubber (CFBS, which circulates boiler ash and lime between a scrubber and fabric filter. Amec Foster Wheeler has install 78 CFB scrubber units rep- resenting over 7,000 MW of capacity in the power and industrial industries. Spray dryer absorber SDA technology operates using ab- sorption as the predominant collec- tion mechanism. In general, the acid gas dissolves into the alkaline slurry droplets and then reacts with the alka- line material to form a filterable solid. Intimate contact between the alkaline sorbent (hydrated lime) and flue gases make the gas removal process effective. and/or chlorides. This effluent requires additional treatment which adds capital and operating costs. Also the uncertain- ty of future regulations, specifically the Steam Electric Power Generating Efflu- ent Limitation Guidelines (ELG), may require additional discharge treatment. WFGD is also limited in its ability to capture mercury and SO3 . Some plants have reported increased mercury re- moval as a desirable, but expensive co-benefit when a selective catalytic re- duction (SCR) system for NOx removal was installed upstream of the WFGD scrubber. Other plants have also add- ed injection of one or more proprietary reagents into the furnace, such as dry sorbent injection (DSI), as a means to increase the mercury removal co-ben- efit. Stacking technologies is not a cost effective long-term strategy to reduce pollutants—it’s unnecessarily expen- sive and reduces the overall reliability of the entire unit. A more holistic solution is preferred. TECHNOLOGY COMPARISON Interest in dry or semi- dry FGD scrubbers is in- creasing due to its ability to capture mercury, acid gases, dioxins, and fu- rans, in addition to SO2 and particulates. These multi-pollutant technol- ogies also have added benefits: no liquid dis- charge and significantly reduced water consump- tion, which is increas- ingly important to pow- er plants that are under pressure to reduce water consumption. Two multi-pollutant technologies dominate the utility sector. The fundamental difference between the two tech- nologies is the manner in which the re- agent is mixed with the incoming flue gas to remove the desired pollutants. The first technology is the spray dryer
- 23. Source: FWEC The principaloperating steps is recycling a solids/hydrated lime and water mixture in the flue gas flow to capture pollutants, cool the gas, and then capture solids in a fabric filter. Other reactive absorbents like activated carbon can be added to target specific pollutants. CFBS Design Details 3 Inlet Flue Gas and Ash CFB Scrubber Fabric Filter Air Air Water Hydrated Lime Solid By- Product Reactor Ash Drain 20 www.power-eng.com EMISSIONS CONTROL frequency (1–3 weeks continuous operation), reduced cost of operation (20-25 percent less compressed air consumption), and longer life with its new tungsten carbide inserts. In addition no special tools are required for routine maintenance. The SDA design also provides additional operating flexibility for the entire plant. For example, any two-fluid nozzle can be removed for maintenance without decreasing boiler load. Emissions performance is maintained even when multiple two- fluid nozzles are taken out of service. The SDA is also capable of high unit turndown, down to 25 percent of rated flue gas flow without recirculation of the flue gases while maintaining emission requirements. The design of the unit also provides for fast load response enabling unit cycling or load following. An added advantage is low absorber pressure drop that keeps the parasitic fan power loss to a minimum. The key to efficient performance is the means used to atomize the lime slurry into droplets within the gas stream. The SDA offered by Amec Foster Wheeler uti- lizes a two-fluid nozzle to atomize the lime slurry. The fine spray provides in- creased contact area in order for gas ab- sorption to occur compared to the CFBS (it’s easier to mix a gas with a liquid than with a solid). Acid gases are then absorbed onto the atomized droplets. Evaporation of the slurry water in the droplets occurs simultaneously with acid gas absorption. The cooled flue gas carries the dried reaction product downstream to the fabric filter. This dried reaction product can be recycled to optimize lime use. Industry experience with earlier SDAs was they were expensive to operate and maintain regardless of the atomization mechanism used. Amec Foster Wheeler has redesigned its two-fluid nozzle to improve the distribution and mixing of atomizing air with lime slurry, which improves mixing efficiency and decreases operating and maintenance costs. The optimized nozzle design delivers even atomizing air distribution to produce a consistent droplet size while providing longer nozzle life. In 14 field applications, the optimized nozzle has demonstrated low cleaning The 420MW-rated coal-fired unit at Basin Electric’s Dry Fork Station has operated the world’s largest CFBS since it entered service in June 2011. Since it began operation,the CFBS has exceeded its design performance reducing SO2 by 95 percent to 98 percent.Photo Courtesy: Basin Electric Co-Op and Wyoming Municipal Power Agency
- 24. 21 ( 8 77 - 4 S I - P O W E R ) 8 7 7 - 4 7 4 - 7 6 9 3 Scan the QR Code for more information www.structint.com/power-eng Structural Integrity’s engineering strength comes in many forms -- from our team of over 200 engineering experts, to applying our knowledge at many power plants and pipelines in the industry, to our 30+ years of experience. You can also look to us in the following areas for our ability to link theory and practice: • Knowledge of power plants, codes, and how things work. • Extensive experience and leadership. • High quality, hard work, and responsiveness. • Custom, integrated equipment, software and solutions. Call us today to put our engineering strength to the test. ENGINEERINGSTRENGTH NEW www.structint.com www.power-eng.com For info.http://powereng.hotims.com RS#8 Circulating fluidized bed scrubber Boiler flue gas enters the CFBS (with or without ash) at the bottom of the up-flow vessel, flowing upward through a venturi section that accelerates the gas flow rate, causing turbulent flow. The turbulator wall surface of the vessel causes highly turbulent mixing of the flue gas, solids, and water for 4 to 6 seconds to achieve a high capture efficiency of the vapor phase acid gases and metals contained within the flue gas. The gas and solids mixture then leaves the top of the scrubber and the fabric filter removes the solid material. Recycled solids/hydrated lime and water mix with the turbulent flowing gas moving vertically through the vessel, which provides gas cooling, reactivation of recycled ash, and capture of pollutants. The CFBS process achieves a very high solids-to-gas ratio, which dramatically improves the ability of vapor phase pollutants to find adsorption sites on the colliding solid particles. The water plays the important role of cooling the gas to enhance the adsorption of the vapor phase pollutants onto the solid particles. The gas and solids mixture exit at the top of the scrubber and enter the fabric filter where solids entrained in the flue gas are captured and recycled back
- 25. Source: FWEC Flue gasenters vertically upward into the scrubber and through a set of venturis that accelerate the gas flow.Wall turbulators increase flue gas and reagent mixing efficiency.Multiple venturis allow a single scrubber to be scaled up to 600 MW in unit capacity. Turbulent Mixing 4 Absorber Bottom Recycled Solids Multiple Venturi Design CFB Scrubber Dry Flue Gas with Solids Raw Flue Gas & Ash Hydrated Lime Water 22 www.power-eng.com EMISSIONS CONTROL scrubbing performance over a wider range of fuel sulfur content. SDA sys- tems are temperature limited because fresh lime is introduced as slurry (lime and water). In addition, due to water being introduced independently and purely for temperature control, the CFBS can utilize lower quality water, as it is not used for pebble lime hydration. The CFBS has the ability to effective- ly treat more flue gas volume than an SDA. The multiple venturis present al- low a single CFBS vessel to be scaled up to almost twice that of the SDA vessel option. Turndown capability is built into the SDA design, where a CFBS requires a flue gas recirculation system in or- der to achieve equivalent turndown. An SDA utilizing the two-fluid nozzle design can maintain required emis- sion levels down to approximately 25 percent of MCR. In a CFBS at lower loads additional recirculated flue gas is required to maintain bed velocities in order to maintain required emission levels. If turndown during non-peak power demands is a consideration the additional parasitic load is an operat- ing cost consideration for the CFBS. The CFBS provides greater sor- bent utilization compared to a once- through SDA system as reagent recycle is incorporated into the design. How- ever, due to the difference in hydration efficiency, a SDA equipped with recy- cle offers greater overall sorbent utili- zation compared to CFBS. In an SDA the recycled solids are slurried within a tank providing essentially 100 percent hydration. In a CFBS water spray noz- zles wet the dry recirculated solids as it passes through the vessel. This hydra- tion process is less efficient due to the quantity of recycled solids and the lack of sufficient wetting time. All the other performance character- istics are relatively equivalent including net auxiliary power. The pressure drop in the SDA (10 inches H2 O) is much to the scrubber to capture additional pollutants. A portion of the recycled solids is removed from the fabric filter in order to maintain the right quantity of material in the circulating loop. The effectiveness of the sorbent is largely a function of residence time. A CFBS can keep solids in the system from 20 to 30 minutes. This is a sufficient period of time for the sorbent to react with the acid gases. Two independent control systems maintain the dry flue gas at optimum temperature and at adequate removal efficiency by controlling the amount of water added and the amount of fresh sorbent added separately. As a result, unlike the SDA scrubber, pollutant capture is not limited by inlet flue gas temperature. TECHNICAL COMPARISON Table 1 summarizes the important technical differences between the SDA and CFBS options. Table 2 summariz- es the performance differences. In gen- eral, the CFBS is slightly better at SO2 control, with up to 98+% capture with high amounts of sulfur in the fuel. Plant turndown capability is equiva- lent, when the CFBS is equipped with flue gas recirculation. In general, the CFBS offers slightly greater SO2 removal flexibility when compared to SDA. The amount of fresh lime injection is not limited by flue gas temperature thus allowing greater SO2
- 26. 23www.power-eng.com Source: Amec FosterWheeler Performance characteristic SDA CFBS Fuel sulfur content < 2.5% < 3.5% SO2 removal % 95 – 97 % 95 – 98+ % Capacity per vessel 40,000 – 1,000,000 acfm 75,000 – 1,800,000 acfm Turndown capability, % of MCR flue gas flow 25% without FGR 50% without FGR Sorbent Calcium hydroxide slurry 25% with FGR Sorbent Treatment Slaker Dry calcium hydroxide Sorbent Utilization (Molar Ca/S ratio) 1.4 – 1.5 (without recycle) 1.3 – 1.4 1.15 – 1.25 (with recycle) Control flexibility Temperature limited Temperature independent Water quality Medium Low Capital cost Slightly lower Slightly higher Footprint,includes fabric filter Large in power island, small overall Moderate in power island,small overall KeyTechnical Characteristics of SDA and CFBS 1 Notes:MCR = maximum continuous rating; FGR = flue gas recirculation; acfm = actual cubic feet per minute Source: Amec Foster Wheeler Parameter SDA CFBS SO2 removal efficiency,% 95 98 Expected SO2 removal,% 97 98+ SO3 removal,% 95+ 95+ HCl/HF removal,% 99 99 Total PM Removal efficiency,% 99+ 99+ Mercury removal efficiency,% (with or without PAC) Equal Equal Pressure drop,inches H2 O 10 16 Auxiliary power consumption Higher Lower Total power consumption (including ID fan) Equal Equal Availability,% 99 99 Water consumption Equal Equal Noise Equal Equal Key Performance Characteristics of SDA and CFBS 2 Notes:ID = induced draft; PAC = powdered activated carbon; PM = particulate matter approximately equivalent. However, depending on the unit capacity, pres- sure drop may have a greater operating cost impact compared to the additional auxiliary power of an SDA. Both technologies are simple, reli- able, and robust. When maintenance of the CFBS is required, the accumu- lated solids can easily be removed through the bottom of the scrubber. Also, the water nozzles are low main- tenance and can be replaced with the unit in operation. SDA two-fluid noz- zles may also be removed and main- tained during plant operation without loss of unit capacity. NO ONE SIZE FITS ALL TECHNOLOGY In the past, dry scrubbing technol- ogy was typically chosen over WFGD technology for its much lower capital cost and water usage, provided that the boiler size was not too large and the fuel sulfur content was not too high. Today, CFBS technology has broken through these limitations with single unit designs up to 600 MW backed by operating units coal-fired units of over 500 MW and on fuels with sulfur levels above 4 percent by weight. SDA have also been deployed on equal-sized units but are less tolerant to fuel sulfur content change. The utility retrofit market has leaned more toward the CFBS technology of late due to the higher SO2 removal perfor- mance. The limited turndown without flue gas recirculation and use of hydrat- ed lime is also viewed as a disadvantage. However, the new generation of SDA nozzles now available has significant- ly reduced cleaning frequency, which was a major criticism by early adopters. With extended nozzle life and reduced compressed air consumption, the perfor- mance gap between the SDA and CFBS has narrowed. Specific site and environ- mental permit requirements will be the determining factor. less than the equivalent sized CFBS (16 inches H2 O), which is proportional to ID fan power consumed. However, the auxiliary power used by the SDA, principally for compressed (atomizing) air, exceeds that required by the CFBS. The net result is that the total auxilia- ry power used by the either option is
- 27. 24 www.power-eng.com A 6MWe ORC installation with air-coled condenser in Germany.Photo courtesy:Siemens SMALL GAS TURBINES
- 28. 25www.power-eng.com Improving the Flexibility and Efficiencyof Gas Turbine-Based Distributed Power Plants F or the past 100 years across most of the world, consumers have re- ceived their electricity from large central power plants, which provide energy to the en- tire system from a single location via a network of transmission lines. This model, which relies heavily on fossil fuels, is facing an increasing number of challenges. The major initial efforts to reduce the environmental impact of power generation centered on fuel switching from coal to natural gas, with plans for massive centralized coal-fired power stations giving way to more efficient, less polluting, natural gas-fired power plants in the so-called “dash for gas,” changing the power mix from predom- inantly thermal coal-fired steam tur- bine plant to a more even split between coal and combined cycle gas turbines. With increasing global efforts to re- duce greenhouse gas emissions, there is an increasing penetration of inter- mittent and variable renewable energy. BY MICHAEL WELCH AND ANDREW PYM Both wind and solar generation out- put vary significantly over the course of hours to days, sometimes in a pre- dictable fashion, but often imperfectly forecast. This intermittency and vari- ability of wind and solar power gener- ation presents challenges for grid op- erators to maintain stable and reliable grid operation, especially in countries where renewable power is given dis- patch priority, requiring redundancy and flexibility in fossil-fueled power generation so that the system can re- spond quickly to these fluctuations, outages and grid support obligations. Predominantly to date this has been achieved by operating central power plant so that they maintain their con- nection to the grid but run at part-load so that they can rapidly respond to transients on the system network. Without sufficient system flexibility, system operators may need to curtail power generation from wind and solar sources. The centralized power generation model has created a trend over the past century towards ever
- 29. 26 www.power-eng.com Renewables ImpactonAvailable Power Generation Over aWeek In Germany In 2013 1 Pumped Storage Gas 70.000 60.000 50.000 40.000 30.000 20.000 10.000 0 MW 23.06. (Sun.) 22.06. (Sat.) 21.06. (Fri.) 20.06. (Th.) 19.06. (Wed.) 18.06. (Tue.) 17.06. (Mon) Hydro Nuclear Lignite Coal Hard Coal Wind Solar the ability to operate at low output lev- els, while still maintaining high effi- ciencies, low emissions and low power plant maintenance downtimes. Dis- tributed Generation is also enabler for enhanced smart grid capabilities. FLEXIBILITY OF A MULTIPLE GAS TURBINE SOLUTION Conventional modern large-scale Combined Cycle Gas Turbine power plant (CCGT) are usually based on a single gas turbine with a single steam turbine (1+1 configuration), or two gas turbines with a common steam turbine (2+1 configuration). While this con- figuration offers very high efficiencies at full load, in excess of 60 percent to- day, the efficiency falls as load reduc- es. There is also a minimum emissions compliance load, which limits the op- erating range of the power plant. With around 1/3 of the total station power generated by the steam turbine, it can take over 30 minutes to achieve full station load. In addition, with the gas turbine shut down for main- tenance in a 1+1 configuration, the complete station is offline, whereas in a 2+1 configuration, an outage of one gas turbine will reduce station power generation to less than 50 percent of its rated output. A solution based on multiple gas turbines may offer much greater flexibility, improved efficiency across the power range and enhanced operability compared to a convention- al CCGT solution. The Advantages of Modularity Modularity can help enhance plant flexibility and reliability. By having multiple units, load can be shared across them, and units switched on and off to match the required load. This enables the power plant to oper- ate efficiently over a much wider load range within the permitted emissions limits than a conventional CCGT can achieve. Future plant expansion is easy increasing unit sizes, based on the assumption that larger units and bigger plant provided lower cost power generation due to economies of scale, with small increases in power generation efficiency also contributing to this. The accepted penalty was losses in the transmission and distribution networks, and the potential for consumers to lose their power supply in case of transmission or distribution system outages. However, maximum efficiency occurs at full-load, so operating a large central plant at part-load reduces the efficiency of power generation considerably, and the need for part-load operation may impact on the operational range of the power station due to the need to comply with emissions legislation. In addition, cycling of the units, ramping up and down in load, can create the need for more frequent maintenance and power station outages. A large utility-scale turbine undergoing major maintenance can require around two to three weeks outage for disassembly, inspection, parts replacement and reassembly. Cycling also reduces part life and severely impacts plant economic returns and in some cases, overall viability. Another issue facing centralized power generation is water usage. In manypartsoftheworld,waterisascarce resource for which power generation competes with agricultural, industrial and domestic needs. In 2010, World Bank estimates indicated 15 percent of the world’s water withdrawals were used for energy production, and with electricity demand expected to grow 35 percent by 2035, water usage for power generation will increase significantly, especially in systems relying on the centralized generation model. Distributed Generation can help ad- dress all the above issues. By building smaller, more flexible power plants closer to the actual load centers, net- work operators can better compensate for the intermittency of renewables, reduce transmission system losses and improve security of supply and reduce capital expenditure on capacity expan- sion/augmentation while the power plant operators by using multiple units can optimize the plant design to meet the needs of the network operators with fast ramp up and turn down and SMALL GAS TURBINES
- 30. Typical Modular Outdoor GasTurbineGenerator Set Installation 2 3Typical StartTimes for Open Cycle GasTurbines PowerOutput(%) 100 80 60 40 20 0 Trent SGT-800 Minutes 1 2 3 4 5 6 7 8 9 10 27www.power-eng.com second and 200 kW/second. However, gas turbines can also ac- cept step load applications while still maintaining power generation with- in the required frequency and voltage limits. The maximum acceptable step load depends on the gas turbine design – a single shaft gas turbine can accept a larger single load application than a twin-shaft variant – but this ability to step load enables the turbines to reach full load much faster than by employing a simple ramp rate for load- ing. Figure 4 shows the comparison of time taken for a twin-shaft 12MW gas turbine to reach full load using the maximum permissible load steps for this particular gas turbine model – full load can be achieved in half the time by applying load in steps. Single-shaft gas turbine designs can accept greater step loads, varying from 50 percent to 100 percent de- pending on the model, rating and site conditions. In the case of a 50MW sin- gle-shaft gas turbine, it is possible to load the unit from zero to full load in two steps within 30 seconds. Reducing Maintenance Outages When scheduled maintenance is re- quired and parts need to be replaced, to achieve simply by adding one or more units whenever required, either at the same location or at a different tactical point in the power network, rather than having to build a new large power plant and associated transmis- sion system. By distributing capacity in this way a ‘virtual generation’ benefit is also achieved via loss offset in the transmission network. The modular at- tributes also enable plant to be moved easily if market conditions change or the plant is sold. This reduces opera- tional and financial risk which is ben- eficial for accessing finance at more favorable terms. Small gas turbines tend to come in pre-designed, pre-as- sembled standardized packages which have undergone significant levels of factory testing and require only a sim- ple concrete foundation. This reduces the amount of planning, engineering, site installation and construction work required compared to a conventional power plant, enabling the power plant to be brought online faster, while still maintaining a competitive first cost, and reduces the risk of construction delays and associated contract penal- ties in addition to lost revenue. In ad- dition, these packages can be supplied with weather-proof acoustic enclo- sures, eliminating the need for build- ings. All the auxiliary systems required for turbine operation – including the control system - can be mounted ei- ther within the enclosure, adjacent to the enclosure or on the enclosure roof, minimizing the number of intercon- nections required. Having multiple units also helps maintain high power plant availabil- ity and output. As mentioned earlier, with a single gas turbine installation, a maintenance outage means that the entire power station has to be taken of- fline. A power plant of similar output but based on, say, 5 smaller gas tur- bines can still generate 80 percent of rated station output with one turbine out of service, 60 percent with two turbines out etc. Decentralized power plant using this concept have been used for many years in the Oil & Gas industry for on- shore fields and offshore platforms with no possibili- ty to connect to a power grid, with many Oil & Gas operators choos- ing the so-called ‘N+1’ configura- tion so that there is a spare unit to ensure 100 per- cent power output is available even with one gas tur- bine out of ser- vice. Ramp Rate The ability of a power plant to re- spond rapidly to variable grid demands is critical in today’s power environ- ment with a high percentage of inter- mittent renewable power generation. Multiple small gas turbines allow the full plant load to be achieved relatively quickly from pushing the start button as the units can ramp up in parallel. The ramp rates of small gas tur- bines typically range between 100 kW/ SMALL GAS TURBINES
- 31. A 7.7 MWTri-FuelGasTurbine Installed in a Cogeneration Plant in the U.S. 5 Expected Ramp Rate and Step LoadAcceptance for aTwin-Shaft 12-MW GasTurbine 4 PowerOutput(MW) 14 12 10 8 6 4 2 0 Seconds Ramp Step 0 5 10 15 20 25 30 35 40 45 50 55 60 28 www.power-eng.com reducing the maintenance require- ments still further. FUEL FLEXIBILITY While Utility-scale gas turbines are designed primarily for operation on pipeline quality natural gas with a pre- mium liquid fuel such as diesel as an alternative or back-up fuel, the major- ity of smaller gas turbine models are able to operate on a much wider range of gaseous and liquid fuels. Low emissions combustion systems have also been developed that will operate on non-standard gas fuels, including those with variable compo- sitions. This is a potentially important feature for decentralized power plant as it enables the power plant to oper- ate on a locally available fuel, which, as some of these are classified as waste gases, may also be more economical than utilizing pipeline quality nat- ural gas. Examples of such potential gas fuels are landfill gas, digester gas, high hydrogen content gases such as refinery gas or syngas, ethane and pro- pane. It is potentially possible to use two completely different gas fuels and switch between these fuels as neces- sary, determined by fuel availability or pricing. Most gas turbines are available in dual fuel configuration, able to oper- ate on either gas fuel or liquid fuel. The the large utility scale gas turbines re- quire considerable downtime as the unit has to be disassembled on site, parts changed and then the unit reas- sembled. The smaller gas turbines are generally of Light Industrial or Aerod- erivative designs which, while many variants have the capability for on- site maintenance as well, are primar- ily designed for off-site maintenance employing gas generator and turbine module exchange programs. This re- duces the turbine outage times for ma- jor inspections from several weeks per unit to between one day and five days depending on the gas turbine model and the type of maintenance interven- tion required. Meanwhile in a power plant based on multiple units, the re- maining units are still available to gen- erate power, enabling the power sta- tion to stay online generating revenue, with only a relatively small percentage of total plant output unavailable. Routine maintenance require- ments during plant operation are also low, with no requirement for highly skilled maintenance personnel to be permanently based on site and low consumption of consumables such as lubricating oil. The various gas turbine OEMs are all working on further developments to improve system reliability and remote monitoring systems to enable unmanned operation for prolonged periods of time. As has been well-document- ed elsewhere, the output of a gas turbine is dependent on ambient temperature: as ambi- ent air temperature rises, a gas turbine’s power output reduc- es. Conversely this means that if you design a power plant to give a specific output at the maxi- mum ambient temperature foreseen, on cooler days more power is available for dispatch. If there are distribution or transmission system constraints that limit the amount of power that can be exported, then on cooler days, while still producing maximum station out- put, the gas turbines will operate at part-load. Most GT OEMs calculate the time between overhaul (TBO) for the various different gas turbine mod- els based on an Equivalent Operat- ing Hours (EOH) formula – part-load operation can help extend the TBO SMALL GAS TURBINES
- 32. 6Efficiency vs.Load Comparison Efficiencyversus load comparison for a 50-MW gas turbine (light blue line) and 4 x 12.5-MW gas turbines (dark blue line) in open cycle at 40oC ambient temperature. 4 x 12.5-MW gas turbines PowerOutput(%) 40 30 20 10 0 Power Plant Output (MW) 0 10 20 30 40 50-MW gas turbine Efficiencies 7 Typical gas turbine nominal efficiencies (vertical axis) by power output (horizontal axis) with complex cycle designs indicated by circles. 50 45 40 35 30 25 20 15 10 5 0 Seconds 0 20 40 60 80 100 120 29www.power-eng.com environmentally friendly manner for base load, load following and peak- ing service. Figure 6 compares the net plant efficiency of a single 50MW class aero-derivative gas turbine in open cycle with four open cycle 12.5 MW class gas turbines with performance data calculated for an ambient air tem- perature of 40° C. While at high loads the single unit is more efficient, once the power plant output drops below 50% of rated plant output, the multi- ple unit solution has a higher efficien- cy as units can be turned on and off to maximize efficiency. The multiple unit solution also offers a wider power plant operating range from a combus- tion emissions perspective. Most gas turbine models guarantee nitrous ox- ide (NOx) and carbon monoxide (CO) from 50% of rated load to 100% of rated load, as required by most global legislation, although some units offer these guarantees down to 30% or 40% load. Therefore a single unit solution at low loads will start to exceed the per- mitted emissions. A multiple unit solu- tion though enables the power plant to have a greater turn-down capability Smaller open cycle (simple cy- cle) gas turbines have been used for peaking ap- plications for many years be- cause they can be started quickly and ramped up and down rap- idly to meet the grid demands. In open cycle, a gas turbine is rela- tively inefficient with efficiencies varying from around 28% for a small industrial gas turbine to just over 40 percent for the larger aero-derivative gas turbines. In peaking applications, this is perhaps not so much of an issue as the price of electricity is very high during the periods of gas turbine operation, but with increasing demand for flexible power generation across the whole day, a power plant today needs to be able to operate efficiently and in an turbines can operate on 100 percent gas fuel or 100 percent liquid fuel, with rapid automatic changeover between the fuels with no requirement to tem- porarily reduce load to undertake the fuel change. The liquid fuels that may be considered are typically #2 diesel, kerosene, LPG and naphtha, although there are gas turbine models available that can utilize Light, Intermediate and Heavy Fuel Oils, Residual Oils, Bio-Oils and even Heavy Crude Oils. On some gas turbines it is possible to simultaneously operate on both gas and liquid fuels – commonly referred to as bifueling or mixed fuel operation - using one fuel type to compensate for shortage of another. There are examples of tri-fuel gas turbine installations, with units capa- ble of operating on a gas fuel and two different liquid fuels, or a liquid fuel and two different gas fuels. Figure 5 is a gas turbine installed in a cogeneration plant at a university in the U.S. and configured to operate on either pipe- line quality natural gas or a processed landfill gas, with diesel as a back-up fuel in case of loss of gas supplies, while still meeting strict emissions limits. Improving Part-Load Efficiency and Emissions Performance SMALL GAS TURBINES
- 33. 8EfficiencyVariations NetPlantEfficiency(%) 41 40 39 38 37 36 35 34 33 32 31 33 66 100 Comparisonof variation of efficiency with load based on a 25-MW power plant using multiple small turbines and ORC or 42 bar, 400oC steam to create a combined cycle plant. ORC Steam Cycle 30 www.power-eng.com temperature heat recovery steam gen- erators (HRSGs) and steam turbine sys- tems required to achieve this efficien- cy level adds considerable cost. Lower cost solutions using low pressure steam systems can be employed, but this re- duces the plant efficiency. In addition, for decentralized plant located close to load demand, the availability of water may be an issue, or the operation and maintenance level required by classical steam solution cannot be easily accom- modated, so an alternative tech- nology to generate electricity from the wasted energy in the gas turbine exhaust needs to be considered. Organic Ran- kine Cycle (ORC) Technology The Rankine Cy- cle is a thermody- namic cycle which converts heat into work. For power generation, by ap- plying heat exter- nally to a closed loop, the working fluid is heated till it becomes a vapor, expands across a turbine to drive a generator and is then cooled and condensed ready to commence the cycle again. Water is normally the working fluid used, and the water (steam)-based Rankine Cycle provides approximately 85 percent of worldwide power generation. A utility scale gas turbine tends to have a high exhaust gas temperature, typically between 530°C (990°F) and 640°C (1180°F), as the designs are optimized for combined cycle applications with multi-pressure level multi-pass boilers producing high pressure, superheated steam (up to 160 bar and 600°C) for inlet to steam tur- bines with reheat between different while still complying with applicable emissions legislation. In the example in Figure 6, and assuming 50 percent turndown limit, the power plant will still meet emissions requirements down to 12.5 percent of rated pow- er plant output. However, for a truly flexible power plant, the efficiency of the gas turbines needs to be as high as possible as well as providing as wide an operating range for the power plant as possible. While there are complex cycle gas turbines on the market with recu- perators and intercooling to improve efficiency, the simplest, most effective and most proven way to improve effi- ciency is to use a combined cycle con- figuration with energy recovered from the exhaust of the gas turbine to gen- erate additional power. Water (steam) is the obvious choice as a working flu- id to generate additional power via a steam turbine, just as in a conventional large-scale CCGT. However, smaller gas turbines are not optimised for com- bined cycle applications, having rela- tively low exhaust mass flows and ex- haust gas temperatures, and although combined cycle efficiencies in excess of 55 percent can be achieved, the complexity of the high pressure, high pressure levels within the steam tur- bine. This is how a modern CCGT achieves the high full load efficiencies quoted, and produces electricity at competitive prices through economies of scale. Smaller gas turbines have lower exhaust gas temperatures, typically between 460°C (870°F) and 550°C (1025°F) as they are optimized for maximum open cycle efficiency. This reduces both the volume and tem- perature of high pressure superheated steam that can be produced, reducing cycle efficiency. It is also not cost-effec- tive to use the same Waste Heat Recov- ery Unit and Steam Turbine technology as developed to go with a 300 MW gas turbine on a 10 MW gas turbine. Therefore if a power plant is to be based on multiple small units, effi- ciency must be sacrificed to ensure cost-effectiveness, so lower pressure non-reheat steam systems are used, of- ten with much simpler Once Through Steam Generators (OTSGs) that re- spond much more rapidly to changes in steam demand. However, at low pressures, there is a large enthalpy drop experienced when water is the working fluid, and a degree of superheat is re- quired to avoid the risk of condensa- tion, and associated erosion, inside the steam turbine. By changing the working fluid, a low enthalpy drop can be achieved, the need for superheating eliminated, as condensation within the turbine can be avoided, and the same efficiency achieved at a lower working pressure. Improved efficiencies at part-load are also attainable using ORC turbogene- rators compared to conventional steam turbines. Organic Rankine Cycles for small gas turbines tend to use a high molecu- lar weight hydrocarbon (organic) fluid such as cyclopentane, or silicone oil, as the working fluid for the turbine. This SMALL GAS TURBINES
- 34. 10Efficiency vs.Load Comparison Efficiencyversus load comparison for a 50-MW class gas turbine and 4 x 12.5 MW class gas turbines in open cycle, with 4 x 12.5 MW class gas turbines with ORC at 40oC ambient temperature. 4 x 12.5-MW gas turbines with ORC Efficiency(%) 50 40 30 20 10 0 MW 0 10 20 30 40 50 31www.power-eng.com turbines are not optimised for combined cycle applications, gen- erally having low- er exhaust tem- peratures than the utility scale gas turbines, and so they have re- duced high pres- sure steam raising capabilities. How- ever, the lower exhaust tempera- tures at both full and part-load en- able ORC technol- ogy to be readily employed to im- prove overall plant efficiency while still enabling multiple units to be installed to maintain the overall power station flexibility and operability. This config- uration also has the additional advan- tage of being able to be ‘water free’ as air cooling can be used throughout the installation. Returning to our power plant capa- ble of producing 40 MW at 40°C re- ferred to in Figure 6, the addition of an ORC turbogenerator to the smaller gas allows high efficiency, larger diameter turbines to be utilized, operating at lower speeds, typically 3000rpm, with low mechanical stress – unlike small steam turbines which operate at speeds up to around 10000rpm. The combina- tion of working fluid and turbine speed leads to much reduced maintenance re- quirements, as well as eliminating the need for water in the process. ORC systems can use either directly or indirectly heat the working fluid. In both cases the Waste Heat Recovery Unit (WHRU) installed in the gas tur- bine exhaust system is a simple once through design, but in the indirectly heated system, heat is transferred from the gas turbine exhaust to the ORC working fluid via a secondary closed loop using a thermal oil. Directly heat- ed systems offer better efficiency of the ORC cycle (see Figure 10 below) and reduce the initial capital cost, while an indirectly heated system allows for en- ergy to be recovered from higher tem- perature heat sources than a directly heated system. Combining Gas Turbines + ORC to Maximize Performance As mentioned earlier, smaller gas turbines has quite a considerable im- pact, as can be seen in Figure 12. Firstly, it can be seen that the ORC system adds about 25% additional power output for the multiple small units for no additional fuel input. Sec- ondly, this additional power improves the plant efficiency so that at full load the overall net plant efficiency is in excess of 40%, even on a hot day. This efficiency improvement makes a nomi- nal 50MW plant based on multiple gas turbines more efficient and more flexi- ble than a plant based on a single open cycle gas turbine across the whole load range, and with the ability to achieve load turn-down to around 10 percent of rated station power output while still maintaining an acceptable com- bustion emissions profile. Multiple gas turbines can be con- nected to a single ORC turbogenerator, providing the maximum output rating of the ORC turbogenerator is not ex- ceeded. This helps reduce the cost/kW of a power plant based on multiple gas turbines as the cost of the ORC system is spread across multiple units. In addi- tion, thanks to ORC working fluid pe- culiarities, the plant flexibility and ef- ficiency at part load is not reduced. The ORC unit can be operated at between SMALL GAS TURBINES 9Comparison of ORC System Efficiency for a Direct Heated and Indirect Heated System Efficiency(%) 25 20 15 10 5 0 10 30 50 Direct – 2 GTs Oil – 2 GTs Ambient Temperature (oC)
- 35. 12Efficiency vs.Load Comparison Efficiencyversus load comparison for a 50-MW class gas turbine in open cycle (blue line) with 4 x 12.5MW class gas turbines with ORC (red line) and a 50MW class gas turbine with ORC (green line) at 40oC ambient temperature 4 x 12.5-MW gas turbines with ORC Efficiency(%) 50 40 30 20 10 0 MW 0 10 20 30 40 50 32 www.power-eng.com ORC is better. This suggests that for larger power plant of, say, 200 MW or 250 MW design output, a combination of 50 MW class and smaller 12.5 MW class gas turbines would give the opti- mum plant efficiency across the widest load range. The gas turbine plus ORC combination helps maintain a high output power and high net plant effi- ciency across a wide temperature range. 10 percent and 110 percent of its nomi- nal load automatically, while still main- taining high efficiency even at partial load - as shown in the Figure 13, at 50 percent of the load, the ORC still has an efficiency of 90 percent of nominal full load efficiency). Obviously it is also possible to add an ORC system onto the larger gas turbine considered to improve efficiency but it is most likely in these cases that a con- figuration based on each gas turbine having its own ORC turbogenerator sys- tem will be needed. As for the multiple small units, the addition of the ORC system boosts both power and efficiency considerably. At nearly 47 percent net power output on a 40°C ambient day with all site losses accounted for, a 50MW class gas tur- bine with ORC offers a better efficiency than large (100MW) complex cycle gas turbines (which are quoted as having an ISO, zero loss efficiency of 44%). It is interesting to note that while the ef- ficiency of the single larger gas turbine plus ORC is higher for station loads over 60 percent, at lower loads the effi- ciency of the multiple small units plus In the example given in Figure 14, the ORC system is air-cooled, with the Air Cooled Condenser (ACC) designed for an average 30º C ambient temperature. The shape of the power output and ef- ficiency curve can be altered by the design temperature used for the ACC: designing the ACC for the maximum ambient temperature will impact plant performance at lower temperatures, so it is important to consider and define the correct design point. Conclusions Combining multiple small gas tur- bines with ORC technology permits engineers to design a very load flexi- ble power plant with optimal efficien- cy and emissions compliance across a wide load range. With no requirement for a water supply, such modular pow- er plant potentially offer a simple way to meet the demands on the electrici- ty grid caused by the large amounts of intermittent renewable power genera- tion with high power plant reliability, availability and low maintenance in a cost-effective manner. By building such flexible distributed plant close to the actual load centers, investment in the power system infrastructure can also be reduced. SMALL GAS TURBINES Efficiency vs.Load 11 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Steam ORC Direct comparison in efficiency versus load for similarly-sized steam turbine generator and ORC turbogenerator. ActualEfficiency/NominalEfficiency 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Actual load/Nominal Load
- 36. www.roxul.com Industrial Insulation Shapedby Experts We share our knowledge to your advantage. The key to ROXUL Technical Insulation’s success is the combination of high-grade products and dedicated people. Thanks to our expertise and 75+ years of experience our customers can count on sustainable ProRox stone wool solutions that offers great protection against fire, heat, noise and energy loss. Like us to share our knowledge with you? Call (800) 265-6878 or visit www.roxul.com for the latest in a series of expert tools that help your business shape up. www.roxul.com 1.800.265.6878 Order your ProRox Process manual at www.roxul.com der your ProRox Industrial insulation Process Manual Technical guidelines for the insulation of industrial installations EXPERT TOOL For info. http://powereng.hotims.com RS#9
- 37. 34 www.power-eng.com ENVIRONMENTAL ISSUES 316(b): OneYear LaterBY TIM WOODROW application of a plant’s National Pollut- ant Discharge Elimination System (NPDES) permit. The 316(b) ruling pro- vides a date (July 14, 2018) that dictates the timeline of compliance which all qualifying plants need to follow with re- gard to the renewal of their NPDES. Per- mit renewal is required every five years. Whether a permit is due for renewal be- fore or after this date (or if it is working on an administratively extended permit) will determine the actions a plant must take over the upcoming period. Plants will have to sub- mit a host of reports to state agencies, including section 122.21 (r2-8) among others. For permit applications after July 14, 2018, plants that withdraw more than 125 MGD must submit application with the appropriate reports (section 122.21 (r9-12)).These re- ports will enable the permit director to understand both the social and economic costs and benefits that a selected solution may have. If renewal is due before July 14, 2018, a plant will negotiate a separate timeline for compliance. SCREEN OPTIONS In all likelihood, installing and opti- mizing traveling fish protection screens will be the lowest cost option for the ma- jority of power plants. However, there is concern that operating traveling water screens whenever drawing water will dra- matically increase operational and me- chanical costs. This is where the industry may be missing an opportunity. While plants are preparing to submit their per- mit applications with the required data, they must ensure that they have studied the various BTA options from a mechani- cal performance perspective. Currently, power plants operate their W e are rapidly ap- proaching the one year anni- versary of the publication of the U.S. Environmental Protection Agen- cy’s (EPA) new regulations under Section 316(b) of the Clean Water Act for Ex- isting Facilities and New Units at Ex- isting Facilities. According to the EPA, the final rule affects 544 existing power generating facilities that withdraw more than 2 million gallons of water per day (MGD) from U.S. waters and use at least 25 percent of the water they withdraw for cooling purposes. The rule requires that the location, design, construction, and capacity of cooling water intake structures reflect the Best Technology Available (BTA) for minimizing negative environmental impacts. Compliance with the rule requires all permit applicants to select an impinge- ment compliance approach from seven options. Applicants with actual intake flows exceeding 125 MGD must first complete and file several study reports (§122.21(r9-12)) that will provide permit directors with the engineering, biological, and economic information necessary for an entrainment BTA determination. Following this determination, these applicants will then select their cho- sen impingement compliance approach from the BTA compliance options. The required studies, as well as the timely selection of a compliance option, will be a challenge for the industry, requiring the latest information on fish protection technologies (cost and performance); bi- ological sampling methods and interpre- tation of results; and practical approaches and supporting information for assessing economic social costs and benefits. WHERE ARE WE NOW? One of the fundamental requirements of the final rule is the parameters under which a plant must select a BTA to reduce the impact of impingement and entrain- ment. The timing of compliance also rep- resents another major change from the draft rule. Compliance is tied to the renewal Hydrolox traveling water screens like the one in operation at Xcel Energy’s Wilmarth Station,Mankato,Minnesota,have very low associated O&M costs.Photo courtesy:Hydrolox. Author Tim Woodrow is the U.S. Commercial Manager for Hydrolox, a manufacturer of traveling water screens.
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- 39. ENVIRONMENTAL ISSUES WEBCAST REGISTER TODAY THETOTAL CONDENSER PERFORMANCE WORKSHOP™: NON-DESTRUCTIVE TESTING SEPTEMBER 1, 2015 | 2:00PM CDT For info. http://powereng.hotims.com RS#11 solution. Another streamlined option requires facilities to achieve an actual through screen velocity of 0.5 ft/s by in- creasing the screening area or via unit re- tirements. Additionally, the two stream- lined options above can be combined to create an additional option for the streamlined approach. The final BTA option requires facilities to maintain less than 24 percent mortal- ity in aquatic life as a result of impinge- ment. This option would require a plant to install modified traveling screens, as well as monitor and report their impinge- ment mortality every month for the life of the plant—an option so tedious and expensive that most will not consider it. 316(B) IMPACT ON POWER PLANTS Power plants have been approaching 316(b) in different ways. First and fore- most, plants are assessing where they screens two to three times a day, about 20 minutes at a time, for a total of about an hour a day. Even with this reduced usage, they are still spending anywhere from $20,000 to $50,000 a year to keep the screens operating. Under the new rule, any time a plant turns on its water circulation pumps, it must also rotate its screens. In order to comply with the rule, then, these plants must now operate their screens up to 24 hours a day, seven days a week; this has many plant operators wor- ried about costs. The total cost of a screen is not entire- ly accounted for by its up-front capital expenditure. Operational and main- tenance costs must also be added into this equation. Traditional screens are driven by large side chains which repre- sent a large maintenance burden. A new screen technology has made it possible to eliminate this chain, making the screen nearly maintenance-free, which can dramatically lower maintenance costs, even when screens must run 24/7. There are pros and cons related to each BTA, pre-approved and streamlined, and their associated costs and benefits. Pre-approved BTA options include the use of an existing closed-cycle cooling system, or the installation of a new one. This can be very expensive to retrofit with costs ranging from $50 million to $300 million. Another pre-approved option involves the design of a cooling wa- ter intake structure that has an actual through screen velocity lower than 0.5 feet per second (ft/s), which would in- volve increasing the surface area of the screening system by a factor of two- to five-fold, an undertaking with signifi- cant associated costs. The streamlined approach has a few options. The first option involves the installation of modified traveling water screens, perhaps the lowest capital-cost
- 40. For more than25 years, Sealeze has helped design and manufacturing engineers design solutions. Adaptive Brush Seal Solutions for Air Preheaters ᣝᣞᣞᣟᣠᣡᣢᣣᣤᣠᣞᣥᣦᣧᣞᣦᣨᣩᣣᣠᣥᣪᣥᣫᣠᣞᣬᣧᣢᣭᣣᣠᣮᣡᣞᣥᣯᣞᣯᣰᣠᣞᣯᣱᣧᣭᣦᣨᣠᣞᣰᣢᣱᣡᣦᣨᣫᣞ gland seal ᣝᣞᣞᣲᣦᣮᣬᣣᣳᣞᣮᣢᣱᣨᣯᣡᣞᣯᣢᣞᣯᣰᣠᣞᣯᣱᣧᣭᣦᣨᣠᣞᣰᣢᣱᣡᣦᣨᣫᣞᣦᣨᣞᣥᣞᣡᣦᣨᣫᣣᣠᣞᣡᣰᣦᣴᣯ ᣝᣞᣟᣠᣡᣯᣢᣧᣠᣞᣤᣥᣵᣱᣱᣮᣞᣥᣨᣞᣢᣱᣯᣬᣱᣯᣞᣵᣥᣬᣥᣵᣦᣯᣳ ᣝᣞᣞᣢᣨᣴᣢᣧᣮᣡᣞᣯᣢᣞᣡᣠᣥᣣᣦᣨᣫᣞᣡᣱᣧᣴᣥᣵᣠ ᣝᣞᣞᣥᣵᣰᣞᣣᣥᣮᣠᣨᣯᣞᣦᣡᣞᣠᣦᣭᣣᣠᣞᣵᣢᣨᣴᣢᣧᣮᣦᣨᣫᣞᣯᣢᣞᣤᣥᣧᣳᣦᣨᣫᣞᣫᣥᣬᣞᣡᣦᣠᣡᣞ and surface irregularities for a continuous seal ᣝᣞᣞᣰᣢᣱᣡᣥᣨᣡᣞᣢᣴᣞᣣᣥᣮᣠᣨᣯᣡᣞᣨᣠᣡᣯᣣᣠᣞᣯᣦᣫᣰᣯᣣᣳᣞᣯᣢᣫᣠᣯᣰᣠᣧᣞᣵᣧᣠᣥᣯᣦᣨᣫᣞ ᣥᣞᣰᣦᣫᣰᣞᣦᣨᣯᣠᣫᣧᣦᣯᣳᣞᣡᣠᣥᣣᣞᤀᣨᣠᣧᣞᣬᣧᣠᣡᣡᣱᣧᣠᣞᣯᣰᣠᣡᣠᣞᣣᣥᣮᣠᣨᣯᣡᣞ ᣬᣥᣵᣪᣞᣠᣤᣠᣨᣞᣯᣦᣫᣰᣯᣠᣧ High performance. Long life. ᤁᤂᤃᣟ 800.787.7325 ᣠᣩᣮᣥᣦᣣᤄᣞᣬᣢᤅᣠᣧᤆᣡᣠᣥᣣᣠᣠᣵᣢᣮ ᤅᤅᤅᣡᣠᣥᣣᣠᣠᣵᣢᣮ ᤇᣲᤂᣞᤈᤉᤉᤊᣞᣠᣧᣯᣦᣠ Turbine Brush Seals Sealeze’s patented brush-based high-temp sealing solution delivers reliability and extended functional service life Visit Us at PowerGen Middle East BOOTH: J21 www.power-eng.com are on the NPDES timeline to determine the urgency of compliance and whether their facilities fall in the impinge- ment or entrainment category. Plants with permit renewal deadlines that fall before July 14, 2018 will negotiate a sep- arate compliance timeline, but those with permits due for renewal after July 14, 2018 will need to submit their data/ reports and select one of the approved BTA technologies, as well as their entrainment solutions, if applicable. After reviewing data from studies and analysis, some plants have already proactively installed fish screens and tested them for both aquatic protection and operating costs so that they have a clear understanding of the costs and work associated with living with traveling fish screens in a post-316(b) envi- ronment. 316(B) IMPACT ON STATE REGULATORY AGENCIES Just as power companies and individual plants are assessing their positions and the workloads ahead of them, so too are state agencies. State agencies have been tasked with enforc- ing numerous new EPA regulations, including MATS and the Clean Power Plan under the Clean Power Act. Section 316(b) is just another regulation to be considered in this mix. Response from state regulators has been mixed. Some reg- ulators are only just getting up to speed on the regulation, while some are even proactively writing 316(b) regulation into their current NPDES permits. Others are asking the EPA for an extension beyond July 14, 2018. For the majority of states, the expectation is that the state permit writer will fol- low the guidelines as laid out in the rule. The relationship that a plant has with their local state permit writer will be crucial in determining the smoothness of the compliance process. WHERE DO WE GO FROM HERE? Plants are currently engaging in contracts with inde- pendent consultants to prepare the paperwork and con- duct the studies necessary to submit their applications at the appropriate times. As mentioned, the compliance schedule for facilities is driven by where their NPDES permit renewal date falls in relation to the July 14, 2018 deadline. All facilities are required to comply with one of the seven standards of im- pingent mortality. Proactive plants will install test equipment ahead of their submission timeline to determine the most cost ef- fective and reliable compliance option. With the modern technology available, plants will actually have the oppor- tunity to reduce their operation and maintenance costs while meeting 316(b) compliance guidelines, depending on the BTA they choose. For info. http://powereng.hotims.com RS#12
- 41. TURBINE OILS: A KeyFactor in System Reliability 38 www.power-eng.com Temperature fluctuation in the turbine oil can result in oxidation and thermal deg- radation initially caused by elevated tem- peratures of the oil, followed by the depo- sition of varnish on critical valves as the oil cools to lower temperatures. Resulting stuck valves can in turn cause unplanned downtime, added maintenance costs, and lower productivity. The survey also indicated that end us- ers are interested in extended oil drainage service intervals to reduce maintenance. In addition, the oil must provide adequate I n a recent Shell global survey, turbine oil end users indicated that their biggest concern was unplanned downtime during turbine operation. The cost of downtime can be significant if a power company is unable to provide power. To- day’s turbine systems are operating under increasingly severe conditions including wider temperature variances due to stop/ start cyclic operation, which has resulted in some instances in varnish formation on critical turbine component surfaces. Pearl GTL Plant located in Qatar manufactures GTL base oils.Source: Shell BY ROB PROFILET, PH.D. rust and corrosion inhibition, separate water quickly, be compatible with seals, not foam, and be readily filterable. These challenging operating requirements and the desire to extend the lifetime of the turbine oil require robust turbine oil tech- nology in combination with a good oil maintenance program. Turbine oil formulations must possess very specific properties if the oil is to provide adequate protection for the tur- bine. To prevent metal-to-metal contact, oils need to have the correct viscosity for
- 42. 39www.power-eng.com Author Rob Profilet has22 years of experience in the field of industrial lubricants. He serves as Shell’s Product Application Specialist for industrial products for the Americas. a given application in order to provide a good oil film for bearings. Oils must release air rapidly to help prevent cavi- tation, but must also not cause excessive foaming. Rust and corrosion inhibition is a necessity to ensure all key components of a system are protected. In steam tur- bines, or in other systems where water contamination can be a concern, the tur- bine oil must separate water very rapidly. If water cannot separate from the oil, an oil-in-water emulsion can form which will interfere with the oil film needed to support loads carried by the bearings. The oil must also act to some degree as a coolant. The internal surfaces inside a tur- bine become very hot, and the oil must absorb this heat without thermally de- grading or oxidizing prematurely. FORMULATION OF TURBINE OILS So how is turbine oil formulated? Un- like motor oils, which may contain 20 to 30 percent additives, typical turbine oil formulations contain approximately 99 percent base fluid and only one percent additive. Both the base oil and additive play very critical roles in the performance of the lubricant. The additive itself is a delicate balance of antioxidants, rust and corrosion inhibitors, demulsifiers, de- foamants, and pour point depressant. In the case of turbine systems with gears, an anti-wear additive is often present as well. The right combination of additives and base oil is critical to minimize the impact of oxidation and thermal degradation which can lead to the formation of sludge and varnish. The most common lubricants used in gas, steam, and combined-cycle turbines today are based on formulations utilizing mineral oils in combination with an ad- ditive system. The mineral base oils uti- lized are API Group I, II, or III. The base oil can have a significant impact on the performance of the turbine oil. When combined with appropriate additive tech- nology, Group II and III base oils exhibit extended oxidation life compared to tur- bine oils formulated with Group I base oils. Turbine oils formulated with Group III base oils have an advantage over those formulated with Group II base oils be- cause they have a naturally higher viscosi- ty index. This higher viscosity index helps maintain the thickness of the oil film at the bearing during times of elevated tem- peratures. Group III oils also help provide enhanced surface properties in the fin- ished lubricant. GAS TO LIQUID BASE OILS Base oil technology has evolved re- cently to help improve turbine oil perfor- mance. Shell recently introduced Gas to Liquid (GTL) base oil which is considered an API Group III base oil. The use of Shell GTL technology represents an exciting step change in technology for turbine oils. Shell GTL technology involves the con- version of natural gas into high-quality products including transport fuels, wax- es, chemicals, and lubricants. Research into GTL for Shell began in Amsterdam in 1973, and now after many patents, is produced in Qatar. Shell GTL base oil has been shown to enhance motor oil for- mulations with better volatility control, better low temperature performance, and enhanced oxidation stability. The benefits of GTL technology are a natural fit for turbine oil formulations. Enhanced oxidation protection helps the turbine oil last longer and resist the for- mation of oxidation byproducts which ultimately lead to the formation of var- nish. Rapid air release properties of GTL base oils also enable the turbine oil to operate more efficiently by minimizing the chance for the oil film to be broken, which is critical in the lubrication of the bearings. GTL base oils also have a higher viscosity index, which helps maintain the optimum viscosity and film thickness re- quired for the bearings in a turbine across a wider range of temperatures. Maintain- ing film thickness and reducing the for- mation of varnish can help reduce bear- ing temperatures. OIL ADDITIVES Although small in quantity, the addi- tive used in turbine oils has a big job to do. Turbine oil additive systems are de- signed to minimize foam, provide rust
- 43. 40 www.power-eng.com A severemethod to measure thermal stability is the MAN Thermal Stability Test. The test is conducted by heating the test oil in a static oven at 180°C for a period of two days. The amount of sludge formed is then measured, which helps to assess the thermal sta- bility and short-term deposit resistance when the oil is exposed to very high temperatures. IN THE FIELD After laboratory testing is complet- ed, turbine oil suppliers will often conduct field demonstrations of their product. Field demonstrations allow for careful monitoring of the fluid in real-world applications. The fluid is introduced and monitoring is conduct- ed on a scheduled basis that is agreed upon with the end user. All turbine oils should be subjected to a proactive oil analysis monitoring system. There are many published tur- bine oil condition monitoring guide- lines available from industry bodies such as ASTM and ISO. Original equip- ment manufacturers (OEM) also publish guidelines to help the end user monitor the turbine oil and get the most efficient performance. Lubricant suppliers will also provide guidance to help suggest a schedule for testing. Test schedules will often include vis- cosity, total acid number (TAN), water and corrosion protection, and help sep- arate water very quickly so it can be re- moved. Because turbine oils are expected to last a long time (7+ years for gas tur- bines and up to 20+ years for steam tur- bines) the additive must contain a robust antioxidant system. THE PERILS OF VARNISH Due to the high operating tempera- tures found in turbine systems, im- properly formulated oils can thermally degrade, oxidize, and form varnish. Varnish is found on critical turbine surfaces and starts as a soft film, grad- ually hardening into a lacquer which is not easily removed. The lacquer can act as an insulating film that interferes with heat transfer. It can also trap par- ticulates such as wear metals. In ad- dition, the varnish can cause valves to stick, causing the turbine not to start. The varnish layer which forms on bear- ings takes up critical clearance space for the oil film, which can result in higher temperatures and the formation of more varnish. Varnish precursors form when polar long chain acids, aldehydes, and ke- tones form in the oil from oxidation and thermal degradation of the lubri- cant. These precursors eventually com- bine or react with each other and form longer chain polymeric species. The oil will hold this material in solution until a saturation point is reached and the resulting “sludge” drops out on cooler parts of the system (often during shut- down). Overtime, the sludge turns into varnish and eventually a lacquer as temperatures increase. IN THE LAB Once a fluid has been developed, several tests are conducted in the lab- oratory to assess the performance of a product. Common physical property tests such as viscosity, flash point, pour point, and density are measured along with performance tests. Performance tests include water separation proper- ties, resistance to rust and corrosion, air release, filtration performance, foaming tendencies, and thermal and oxidation stability tests. A common method used to measure resistance to oxidation is the ASTM D943 Turbine Oxidation Stability Test. This test is commonly listed on suppli- er Technical Data Sheets. In this test, a mixture of oil and water is heated to 95°C in the presence of a catalyst and bubbling oxygen to expedite the oxidation process. The oil is moni- tored by total acid number, and the test is stopped when oils reach 2.0 mg KOH/g. The more hours in this test the better; long life turbine oils will have a value of >10,000 reported hours. There are other oxidation tests which can also assess turbine oil performance. These include ASTM D4310 (1000 hour TOST) which measures sludge forma- tion, ASTM D2272 Rotating Pressure Vessel Oxidation Test (RPVOT), and the Dry TOST Test (ASTM D7873). The Dry TOST Test (ASTM D7873) promotes the oxidation of the turbine oil in the presence of heat (120°C), metals (steel and copper coils), but no water. The test is conducted for a pe- riod of 1008 hours, and is designed to measure the sludging tendency of the fluid by measuring the RPVOT reten- tion and insoluble oxidation products. The test is a useful method to predict turbine oil performance in the field. Thermal stability in turbine oils can vary based on results of the MAN LTAT thermal stability test.Source: Shell Global Solutions
- 44. 41www.power-eng.com used to helpremove varnish precursors from turbine oils or other lubricating oils. Popular methods include the use of electrostatic filters, balanced charge agglomeration systems, electro-phys- ical separation processes (ESP), depth filtration, and filters which minimize electrostatic discharge. The best route to minimize varnish formation involves a two-pronged strategy. First, a high-quality turbine oil should be selected. The oil should not only have excellent oxidation re- sistance, but should also be resistant to deposit formation. Second, a proactive oil monitoring program can go a long way in minimizing problems resulting from oil degradation, extending the life content, elemental analysis by ICP, oil cleanliness (particle count), RPVOT, de- mulsibility, foam performance, RULER Test, and either MPC (membrane patch colorimetry) or QSA (quantitative spec- trophotometric analysis) to assess var- nish potential in the fluid. Varnish potential screening meth- ods have been successful in identifying a system with a high potential to var- nish by isolating insoluble oxidation products and measuring their concen- tration in the system. By assigning a rating system, an end user can take dif- ferent courses of action to help protect their system. If a high rating is observed, there are many systems available which can be of the oil, and providing a higher level of protection for the system. Down- time and unplanned maintenance can be reduced or eliminated. CONCLUSION Shell recently introduced a new line of turbine oils which provide a very high level of performance for steam, gas, and combined-cycle turbines. The technology is based on the use of Shell GTL Group III base oils in combination with a specially developed additive sys- tem. Testing in the laboratory and in the field has shown that these products have a very high resistance to oxidation and thermal breakdown, minimizing the formation of sludges and varnish on critical turbine surfaces. These products have very rapid air release and are low foaming, helping to improve the overall efficiency of the turbine operation. The use of Shell Turbo S4 X or Shell Turbo S4 GX (for turbines requiring protection of gears) in combination with a suitable oil-monitoring program can help to ex- tend the life of critical turbine compo- nents and help extend the life of the tur- bine oil. This can result in lower costs, less unplanned downtime, and higher efficiency. Predicting the Onset of Varnish 2 MPC Normal <15 Monitor 15-29 Abnormal 30-40 Critical >40 Turbine oils can be tested using the MPC test to help predict the onset of varnish. Increasing varnish potential results in a darker filter patch. Source: Shell Global Solutions Test Steam Turbine Gas Turbine Suggested Limits Viscosity Quarterly/Bi-annual Quarterly +/- 5% of fresh oil value Total Acid Number (mg KOH/g) Quarterly/Bi-annual Quarterly Caution:0.1-0.2 over new oil value; Warning 0.3-0.4 over new oil value Water Content (KF,ppm) Quarterly Quarterly <0.1% for steam; <0.05% for gas Elemental Analysis (ICP) Quarterly Quarterly Check contamination Oil Cleanliness (ISO 4406) Quarterly/Bi-annual Quarterly Follow OEM Limits RPVOT (min) Annual Quarterly <25% of fresh oil Demulsibility (ASTM D1401) Annual --- >40-37-3 (40 minutes) MPC or QSA (varnish formation) --- Quarterly <40 MPC; <60 QSA Foaming (mL-mL) Annual Annual 450/10 max Turbine oils should be tested on a regular basis to help extend the life of the fluid and the system. TypicalTesting Schedule forTurbine Oils 1 Source: Shell Global Solutions
- 45. 42 www.power-eng.com Maintaining Maximum Efficiency in Power Generation UnitsBYBRAD BUECKER, CONTRIBUTING EDITOR QB = heat input to the steam generator QC = heat extracted in the condenser WP = work done by the feedwater pump (usually negligible in this particular cal- culation) The diagram also indicates a key com- ponent of the second law; for any pro- cess that produces work, not all of the heat input can be utilized for work, some heat must be extracted as waste energy. We will later examine how this thermo- dynamic aspect makes condensers, and proper operation of them, so important for power generation. In the meantime, let’s consider anoth- er important issue from Figure 1. If the steam from this simple system were to be immediately injected into a turbine, very little work would occur, as the steam would immediately begin condensing to water upon passage through the blades. For this reason among others, all utility steam generators include superheaters to raise the steam temperature well above saturation and allow much more work from the turbine. Even so, the net effi- ciency of Rankine-cycle only plants rang- es from 1/3 in the least efficient plants V irtually everyone in the power, chemical pro- cess, and other indus- tries is no doubt aware of the greatly expanded efforts to lower carbon dioxide emis- sions from industrial sources. This con- cern continues to lead increased efforts into maximizing plant efficiency both through good operating principles and through design improvements. This arti- cle examines several of these issues with regard to steam-generating facilities. AN OVERVIEW OF THE RANKINE CYCLE Power production via steam generation to drive a turbine is based on the Ran- kine cycle, whose fundamental outline is shown below. Even this simple diagram (Figure 1) clearly illustrates several fundamental aspects from the first and second laws of thermodynamics. First, and for the time being ignoring entropy increases due to heat losses, friction, and other mecha- nisms,thetheoreticalworkavailablefrom the turbine (WT ) can be approximated by the following straightforward equation. WT = m(h2 – h1 ) Eq. 1, where m = mass flow rate of steam through the turbine h1 = enthalpy of turbine exhaust steam h2 = enthalpy of turbine inlet steam POWER PLANT OPTIMIZATION Author Brad Buecker is a process specialist with KiewitEngineeringandDesignCompany in Lenexa, Kansas. A Basic Rankine Cycle WP WP QB QC Boiler Condenser Condensate High-Pressure Steam Turbine Turbine exhaustFeedwater FW Pump 1
- 46. 43www.power-eng.com to keep condensersand heat exchangers clean from chemical and biological de- posits, and also operating properly from a mechanical perspective to avoid costly impacts. We will examine heat transfer issues below, starting with a non-con- densing steam turbine. Equation 1 approximates the heat transfer in an ideal steam turbine, while in actuality turbines are typically 80 to 90 percent efficient. To simplify the dis- cussion, we will consider an isentropic (no energy losses) turbine, as this exam- ple is still quite sufficient to outline the principles intended. Conditions for the non-condensing steam turbine example are: Main Steam (Turbine Inlet) Pressure – 2000 psia Main Steam Temperature – 1000o F Turbine Outlet Steam Pressure – Atmo- spheric (14.7 psia) The steam tables show that the enthal- py of the turbine inlet steam is 1474.1 Btu per pound of fluid (Btu/ lbm). Thermodynamic calculations indicate that theexitingenthalpyfrom the turbine is 1018.4 Btu/ lbm (steam quality is 86%). Per Equation 1 the maximum unit work available from this ideal turbine is (1474.1 Btu/ lbm – 1018.4 Btu/lbm) = 455.7 Btu/lbm. To put this into practical per- spective, assume steam flow to be 1,000,000 lb/hr. The overall work is then 455,700,000 Btu/hr = 133.5 megawatts (MW). At this point, if the exhaust steam were transported for co-generation or CHP purposes, excellent efficiency would be possible. However, in the power industry steam condensation is a very important step. Therefore, consider a second exam- ple, where the unit has a condenser that reduces the turbine exhaust pressure to to perhaps a bit above 2/5 for the most efficient plants. The primary reason re- garding this seemingly low efficiency is that the usable energy is contained in the superheat of the steam, perhaps 500 to 600 Btu/lbm is not as large as the steam latent heat, approximately 1000 Btu/lbm. We will examine several examples short- ly, when examining condenser and heat exchanger cleanliness. This then is one aspect, among sever- al, that is driving industry towards higher efficiency machines. The two processes that stand out are combined-cycle power generation and combined heat and power (CHP) or co-generation. We will consider CHP/co-generation first. The previous example from the Ran- kine cycle showed that much heat is lost during the condensation process in the condenser. This lost energy represents the latent heat of the exhaust steam. Howev- er, if in place of the condenser which sim- ply exhausts the heat to a cooling tower or other heat sink, the steam is transport- ed to heat exchangers to drive chemical processes or even simply to warm water for district heating systems, much of the latent heat is productively utilized. Con- sider 100,000 lbm/hr of saturated steam flowing to a heat exchanger with water as the process fluid, say for building heat. Energy transfer from condensation alone could warm approximately 3,000,000 lbm/hr of the water from 70o F to 100o F. On the flip side, heat is a requirement for such devices as absorption-refrigeration chillers, which are common devices for cooling large office buildings. Again, la- tent heat is a potential source of energy for these systems. Net efficiencies of up to 80 percent have been reported for co-generation pro- cesses. The power industry continues to see steady installation of combined-cycle power plants, which also offer increased efficiency. These plants, of course, use combustion turbines for partial power production with heat recovery steam gen- erators (HRSG) for additional power gen- eration from a steam turbine or turbines. This is truly a combined cycle process, as the HRSGs operate on the Rankine cycle while the combustion turbines operate on the Brayton cycle. Maximum efficien- cies in some units have now topped 60 percent, which is immensely better than efficiencies for some of the old coal plants that are still operating. From a combus- tion turbine aspect, the key limiting factor to efficiency is the para- sitic power requirement for the inlet air compres- sor. But much energy is, of course, regained by converting the combus- tion turbine exhaust heat into steam for Rankine cycle power generation. But, even with these de- sign efficiency improve- ments, it is still very im- portant to maintain top efficiency from an oper- ating standpoint. This is particularly true when it comes to proper cooling water and steam generator cleanliness. KEEP THE HEAT EXCHANGERS CLEAN A thread through all of the technol- ogies mentioned above is that the ex- haust heat from the steam generation process must be transferred in one or more heat exchangers. It is paramount Fouled CondenserTubes 2 “This is truly a combined cycle process, as the HRSGs operate on the Rankine cycle while the combustion turbines operate on the Brayton cycle.”
- 47. 44 www.power-eng.com DON’T FORGETABOUT THE STEAM GENERATOR Although we have focused upon methods to maximize heat extraction from the steam generation process, it is important to remember that heat input efficiency should be maximized as well. Poor makeup water treatment and water/steam chemistry programs can lead to deposition and corrosion in steam generators. While boiler tube failures often result from poor chem- istry, even in units with seemingly good treatment programs, problems can arise. The most common deposit on steam generator tubes and internals consists of iron oxide particulates that are generated in the condensate/feed- water system. (The concentration can be very large in systems equipped with air-cooled condensers.) So, it is abso- lutely vital to operate with the proper feedwater chemistry, and to have the ability to immediately detect impurity ingress from a leaking condenser tube or other source. [2] For units with ACCs, a condensate particulate filter is an absolute must. Periodic removal of boiler tube de- posits by chemical cleaning is often a necessary procedure to improve heat transfer. Not only will deposits reduce heat transfer in general, they will also cause an increase in tube metal tem- peratures which can lead to accelerated metal deformation known as “creep.” Finally, and often most important, is that some deposits, and most notably transported iron oxides, are porous and can allow impurities in the bulk boiler water to concentrate underneath the de- posits. Local and rapid corrosion may be the result. In fact, the Electric Power Research Institute (EPRI) now recom- mends a normal (and very low) limit of 2 parts-per-billion for chloride and sulfate in condensate, precisely because these impurities, and chloride in partic- ular, can generate severe under-deposit corrosion in the steam generator. 1 psia (approximately 2 inches of mer- cury). Again assuming an ideal turbine, the enthalpy of the turbine exhaust is 904.9 Btu/lbm. The unit work output equates to 1474.1 – 871.0 = 603.1 Btu/ lbm. At 1,000,000 lb/hr steam flow, the total work is 603,100,000 Btu/hr = 176.7 MW. This represents a 32 percent increase in available work from the previous example. Obviously, conden- sation of the steam has an enormous effect upon turbine efficiency. One can also look at this example from a physical perspective. Calcula- tions indicate that the steam quality at the turbine exhaust pressure of 1 psia is 77 percent. (In actuality, this would be excessive moisture that could damage low-pressure turbine blades. Techniques such as steam reheating are common for reducing moisture in the low-pressure turbine.) This means that 23 percent of the steam has condensed to water. However, the remaining steam takes up a specific volume of 257 ft3 /lbm. The corresponding volume of water in the condenser hotwell at sat- uration temperature is 0.016136 ft3 / lbm. Thus, the condensation process reduces the fluid volume nearly 16,000 times. The condensing steam generates the strong vacuum in the condenser, which actually acts as a driving force to pull steam through the turbine. (The strong vacuum also pulls in air from outside sources, where excessive air in-leakage can seriously affect heat transfer.) In the next example, we can see why it is important to maintain proper cleanliness in condensers and heat ex- changers. Consider again a condensing turbine, but where waterside fouling or scaling (or excess air in-leakage) caus- es the condenser pressure to increase from 1 psia to 2 psia. Thermodynamic calculations show that the work output of the turbine drops from 603.1 to 569.2 Btu/lbm. So, at 1,000,000 lb/hr steam flow, a rise from 1 psia to 2 psia in the con- denser backpressure equates to a loss of 33,900,000 Btu/hr or 9.9 MW of work. This is a primary reason why proper cooling water chemical treat- ment and condenser performance monitoring are very important. Severe fouling may require a reduction in unit load. If this occurs on a hot summer day with emergency power pricing in effect, the financial consequences can be enormous. Techniques continue to emerge to improve condenser, heat exchanger, and cooling tower perfor- mance. These include more effective biocides, improved cooling tower film fill, more rugged condenser tube ma- terials, and enhanced instrumentation for monitoring physical and chemical operating parameters. Similarly, for co-generation and CHP facilities it is important to keep heat ex- changers free of deposits and corrosion to ensure maximum efficiency and equipment availability. Often, cooling towers are neglected because they may be isolated from the main equipment. Improper chemistry control in chillers and building heat systems may lead to severe corrosion. The list goes on. POWER PLANT OPTIMIZATION Fouled Cooling Tower Film Fill 3
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- 49. www.power-eng.com46 WHAT WORKS allowed alarger Combustion/Explosion Hazard Area (CEHA) that would likely meet worst-case requirements. (We used applicable Jamaican fire codes that were based on standards of the U.S. National Fire Prevention Association (NFPA) Code, Sections 57 through 59, for han- dling of LPG and LNG.) The relatively congested areas adjacent to the Bogue Plant, on the other hand, would likely require double-walled tank construction as a safety precaution. Using a double- walled tank would both lengthen the construction timeline and increase cost. The use of portable ISO LNG contain- ers is common but not at this scale. In addition, transporting them overland presented significant safety risk. Staging, filling, transporting, unloading, purging and inspecting a proposed fleet of 350 ISO containers – based on consumption of 22 containers per day – would likely constitute a ‘fatal flaw.’ We investigated the market for deliv- ering relatively small quantities of bulk LNG in the Caribbean and found it to be still in the early stages of development. We did identify two suppliers that are pre- paring to offer such service to the region in the near term, but found no companies currently able to deliver bulk LNG at this small a scale. Although it lay outside the scope of this review, we advised the cli- ent to complete a thorough financial and technical due diligence of potential sup- pliers – and sign a firm supply agreement with a credit-worthy supplier – before moving ahead with any plan that relied on bulk LNG delivery. OUR RECOMMENDATION AND LOGIC While we advised the client that ei- ther plan was feasible as proposed, we recommended significant modifications to both. For the LNG solution, we rec- ommended relatively small-scale LNG import; extensive due diligence before contracting with any supplier; port-side storage; and overland transport of the A s many who work in the Ca- ribbean energy markets know, Jamaica has been trying for years to import liquefied natural gas (LNG). Unfortunately, suppliers have deemed the Jamaican market too small to support a full-scale LNG storage and regasification facility, so the need has remained unmet. To answer the call, Marubeni, a stake- holder in the Caribbean power-generat- ing industry asked our Engineering Ser- vices team to review the technical and safety risks of two alternate plans for re- fueling the Bogue Power Station, a light distillate oil-fired, combined-cycle facility near Montego Bay, Jamaica. (Note: As one of several investors in Jamaica Public Service Co. Ltd. (JPS), Marubeni engaged NAES for an inde- pendent study and does not speak for the other investors or for JPS.) Designed for a net capacity of 120 MW, the refueled Bogue plant is equipped with two GE MS6001B gas turbines, two HRSGs and a single steam turbine. Although it did not af- fect the scope of this review, Marubeni elected to retain the capability to oper- ate on oil as a backup in the event of disruption to the LNG supply chain. Option 1: Small-Quantity LNG Ship Delivery and ISO Container Overland Transport This plan would be based on small- scale ship delivery of LNG with overland transport via a fleet of small-volume ISO containers. Once the LNG was pumped from the ship to the containers, the containers would then be loaded onto flatbed tractor-trailers using truck- mounted cranes, and transported two ki- lometers inland to the plant. They would be stockpiled plant-side, and the LNG va- porized to a gaseous state by skid-mount- ed electric vaporizers. Once the contain- ers were empty, they would be sent back to the port to be refilled. While this solu- tion would present obvious operational challenges, it would likely be the quickest way to repower the plant and would also reap the financial and environmental benefits of burning LNG. Option 2: Large-Quantity LPG De- livery and Refrigerated Tank Storage This solution would be based on un- loading liquefied petroleum gas (LPG) from a large-volume refrigerated ves- sel into a large, stationary, refrigerated tank(s) located at the port-side terminal – or transported to a plant-side tank(s) via a cryogenic pipeline. In addition to comparing the merits of the LNG and LPG solutions, we were asked to advise on which LPG tank location – port-side or plant-side – presented less technical, financial and safety risk. A UNIQUE SET OF CHALLENGES The geographical complications – an island location with an inland plant re- quiring both port-side and plant-side facilities – in addition to the regional market conditions and economics made this an interesting assignment. The port- side area offered a fair amount of vacant property for siting of storage tanks. This Risk Review Leads to Alternative Plan for Jamaica Fuel ConversionBY ANDREW MARKLE, P.E. Author Andrew Markle is Senior Engineer for NAES Engineering Services
- 50. www.power-eng.com 47 and gravelfoundation, and moisture barrier to improve protection from fire, hurricanes and earthquakes. While this installation would have a larger footprint than the single large tank, we believe the CEHA would still be confined to the va- cant property and adjacent water at port- side, although a more detailed engineer- ing investigation would be required to verify this. To confirm feasibility of the bullet- tank solution, we researched a similar installation currently under construc- tion on the island of St. Thomas in the U.S. Virgin Islands, and forwarded our findings to the client. We also noted that larger bullet tanks are available – up to 5,000 m3 capacity with dimen- sions of 40 x 160 feet. However, we have not seen tanks this large used on land and do not know of many shops that have the capability to roll steel for a 40-foot-diameter pressure vessel. THE CHOSEN SOLUTION Ultimately, the client elected to go with an LNG solution, which was likely prompted by fuel-pricing analysis that lay outside the scope of NAES’ investi- gation. Based on small-quantity ISO- container shipment, the fuel would be vaporized at the terminal and trans- ported to the plant via a pressurized, ambient-temperature pipeline. To facil- itate the supply, Marubeni has contract- ed with a vendor to transport the ISO containers weekly from its small-scale liquefaction facility in Florida. fuel to the plant in a gaseous state via pressurized pipeline. For the LPG option, we favored the large-volume, refrigerated, port-side LPG tank(s) with a port-side va- porization facility that would also trans- port the fuel to the plant in gaseous form via pressurized pipeline. Our modification of the LNG option called for replacement of overland trans- port in ISO containers with a pressur- ized, ambient-temperature pipeline. ISO containers at the scale required to supply Bogue would introduce substantial safety risk to personnel as well as considerable operational complexity. While the in- frastructure for delivering and receiving bulk shipments of LNG in the quantities required to operate Bogue could be erect- ed in the near term, no vendor we con- tacted was able to make such shipments to the port of Montego Bay at the time of inquiry. However, if a suitable small-scale supplier could be found, we advised that keeping the LNG terminal facility small would reduce the construction schedule from an estimated two-year duration to a single year. As for the proposed LPG plan, the established supply chain for delivering LPG in bulk quantities to the Caribbean market eliminates much of the risk posed by an LNG solution, at least in the near term. By opting for the port-side stor- age tank location, the client could likely achieve compliance (pending a more detailed engineering investigation) with a single-walled tank design due to the larger expanse of available CEHA. This would also shorten the construction timeline and substantially reduce capital expense. Vaporizing the fuel port-side would eliminate the need for a cryogenic pipeline with all of its attendant capital and O&M expenses. AN ALTERNATIVE LPG SOLUTION In response to our recommendations, the client requested an estimated end-to- end construction time to fabricate, erect and bring online a 13,000 m3 refriger- ated, vertical-cylinder LPG tank based on three possible configurations: single-wall, double-wall and full-containment. Our estimates were to reflect current market conditions and any existing bottlenecks that could impact construction time. Based on our consultation with three tank suppliers (one of which is currently doing business in the Caribbean market) and our own experience, we proposed a third alternative: a port-side installation of 10 cylindrical, horizontally erected bullet tanks measuring 21 x 180 feet, each with a capacity of 1,400 m3 at 80 percent full. The estimated construction time would compare very favorably with estimates for a vertical cylinder of single- wall, double-wall or full-containment construction: • Refrigerated bullet tanks: 10 x 1,400 m3 = 8 to 12 months • Single-wall vertical cylinder: 1 x 13,000 m3 = 18 months • Double-wall vertical cylinder: 1 x 13,000 m3 = 24 months • Full-containment vertical cylinder: 1 x 13,000 m3 = 24 months With the bullet-tank solution, the foundation-building and tank fabrica- tion could proceed concurrently, which would substantially reduce construction time. In addition, several tank fabricators located on the U. S. Gulf Coast could ship directly to Jamaica. We also recommended mounding the bullet tanks with an engineered soil, sand Mounding of LPG bullet tanks (as shown in this example) to further reduce risk from fire, hurricanes and earthquakes. A portside tank location,where the surrounding Combustion/Explosion Hazard Area encompasses uninhabited property and water.
- 51. 48 www.power-eng.com PRODUCTS Battery thermalprotection T E Connectivity’s business unit, TE Circuit Protection, introduced the new MHP-TAM series. The MHP-TAM device features an ultra-low-profile (L: 5.8mm x W: 3.85mm x H: 1.15mm max.) package and a high (9VDC) rating. The devices in the series offer a choice of two different levels of current-carrying capacity and multi- ple cut-off temperature ratings. The device provides a space-efficient thermal cutoff (TCO) solution that helps designers meet the demanding peak-current requirements of consumer products. Utilizing innovative metal hybrid PPTC technol- ogy, the MHP-TAM device combines a bimetal pro- tector in parallel with a PPTC (polymeric positive temperature coefficient) device. In battery applica- tions, the MHP-TAM device helps provide resetta- ble over-temperature protection to shut down the battery when a fault is detected. The device rests when the fault is removed. The devices in the MHP- TAM series feature different open temperatures, ranging from 72°C to 90°C (typical), which are ap- propriate for the battery market. They also offer two levels of hold currents: low-current (approximately 6A at 25°C) and high-current (approximately 15A at 25°C). TE Circuit Protection Info http://powereng.hotims.com RS# 400 Film capacitor series A VX Corp. launched the new FRC Series me- dium power DC-link film capacitors, which feature a wide range of capacitance and voltage values in ad- dition to self-healing properties. Designed for use in DC filter circuits, power supplies, in- dustrial inverters, UPS systems, motor drives, power converters, and solar inverters, the capacitors are available in nine volt- ages spanning 400V-1500V, two tolerances (±5% and ±10%), two lead lengths (4mm and 8mm), and with capacitance values spanning 4.7µF to producing highly accurate and reliable cryogenic flow measurement, a direct result of the emphasis they put on extensive research and development. Turbines Inc. Info http://powereng.hotims.com RS# 403 Front-end power supply T ectrol announce the availability of their TFE- 1800-48 1800W output power, 48VDC out- put front-end power supply designed in a sub-1U horizontal package for integration into a Tectrol power shelf or other end-user system. The power supply includes secondary isolation from chassis >1500VRMS with output adjustable to 54VDC for PoE (Power over Ethernet) requirements and is suitable for ATCA (Advanced Telecommunications Computing Architecture) applications. This high reli- ability power supply features universal AC input, ac- tive PFC and I2C Interface for advanced status and control functions. The Tectrol TFE-1800-48 offers a very compact footprint of just 1.60-inch x 4.00-inch x 11.00-inch (40.64 x 101.60 x 279.40 mm), provides full power output of 1800W over the range 180-264VAC and 1000W over the range 90-180VAC and offers high efficiency of 85 percent minimum at 90 VAC. Tectrol Info http://powereng.hotims.com RS# 404 Compact digital thermocouple gauge T he Sensor Connection expanded its line of tem- perature measurement and control instrumenta- tion with the addition of the model DPG-SD-2 series dual channel digital Type K thermocouple tem- perature gauge. This microproces- sor-based gauge is packaged in a compact 52mm O.D. round hous- ing with an IP65 rated face ideal for use in harsh industrial environments. The dual line bright red LED numeric display is easy to read, even at a distance. During a high temperature alarm condition the dis- play flashes and an internal 2 Amp relay circuit is activated. Programming of the gauge is quick and easy using the front panel membrane keypad. The Sensor Connection Info http://powereng.hotims.com RS# 405 35µF. Housed in size A cylindrical cases measuring 54mm (L) x 36mm (OD) x 5.1mm (P1), the RoHS- compliant series is rated for operating tempera- tures spanning -40°C to +105°C and exhibits long lifetime performance of 100,000 hours at rated voltage and 70°C. AVX Corp. Info http://powereng.hotims.com RS# 401 Corrosion protection C ortec Corp. introduces environmentally safe BioCortec range of corrosion control products. BioCortec is a green response to hazardous oil derived corrosion preventatives and offers eco-ef- ficient, compostable and biodegradable solutions made from sustainable materials. Utilizing new technologies, Cortec is continuously developing biobased chemicals. These products do not destroy the natural bal- ance of the environment, are functionally superior to conventional petroleum derived products as well as cost efficient making them a far more econom- ical solution. Cortec Corp. Info http://powereng.hotims.com RS# 402 Turbine flow meter T urbines Inc. expands its comprehensive cryo- genic monitoring capabilities with the availability of its cryogenic turbine flow meter for bulk and mi- cro-bulk transports. Turbines Inc.’s cryogenic flow meters for bulk and micro-bulk transports appli- cations feature the same advanced technology of their liquid flow measurement products, but are specifically built for low-temperature requirements. The compa- ny’s cryogenic flow meters are widely known for
- 52. 49www.power-eng.com radiation environments atextra cost. Alliance Sensor Group Info http://powereng.hotims.com RS# 408 Infrared surveillance system H GH Infrared Systems offers their latest Spynel model, the Spynel-M. With dimensions of less than 12x20 cm and weight of only 1.8 kg, the Spynel-M is a cost-effective, rugged, and compact solution for wide area surveillance. One single Spynel-M sensor effectively replaces up to 16 traditional infrared cameras and is able to per- form 24/7 early human intrusion alerts over a 1.5 km-diameter area. The Spynel-M continuously cap- tures full panoram- ic, high-resolution infrared images every second to provide real-time security against conventional and asymmetrical threats including hardly detectable targets such as UAVs, RHIBs, or crawling men. Easily transportable, it can be carried in a backpack and quickly deployed on a light mast or fixed atop a building for superior wide area surveillance. While requiring only 8 watts of power, Spynel-M can also be operated with solar or alternate power supply systems to allow for a remote operation. Unlike radar, the system is completely passive, requires no addi- tional light source and cannot be jammed. The intuitive advanced intrusion detection software, Cyclope, automatically tracks and detects an unlimited number of targets from any direction at any time of day or night and under any type of weather conditions. As versatile as it is mobile, the system can also be paired with other systems such as radars and PTZs for data integration and target identification. HGH Infrared Systems Info http://powereng.hotims.com RS# 409 Thermal flow meter M agnetrol has released of the Thermatel TA2 thermal dispersion mass flow meter with FOUNDATION fieldbus digital output communi- cations. This addition signifies the growth of the THERMATEL TA2 mass flow technology offering Refractometers E riez HydroFlow Refractometers are simple yet rugged instruments that give users the ability to quickly determine the concentration of metal- working coolants and cleaners, heat-treating flu- ids, water-based hydraulic fluids and plating baths. Portable Refractometers require no batteries. They feature a large, easy-to-read scale that is available in two ranges: 0-10° Brix and 0-32° Brix. Automatic Temperature Compensating Refractometers provide an ideal solution for sit- uations in which the temperature of certain fluids can affect the refractive index reading of the mix. They have a large, easy-to-read scale available in two ranges: 0-20° Brix and 0-30° Brix. Extremely accurate, hand-held Digital Refractometers are also available. They feature an easy-to-read LCD readout with a 0-52° Brix range. Eriez HydroFlow Info http://powereng.hotims.com RS# 406 Position sensors A lliance Sensors Group expanded its in-cylin- der position sensor product line to include the MHP series linear induc- tive sensors. These com- pact inductive linear sensors were de- signed to be installed into the rear end- cap of hydraulic cylinders for operation at pres- sures up to 5000psig. Their 1-inch hex aluminum or stainless steel housing are ideal for oil and gas exploration equipment, and mount to the cylinder with a standard male o-ring port thread. The MHP series sensors are based on a pro- prietary contactless inductive sensing technology with a short stroke to length ratio. They employ a 7 mm diameter probe inserted into an 8 mm (5/16 inch) gun-drilled hole in the cylinder rod to measure position rather than a ring magnet or pot contact spool. They are offered in ranges from 50 to 600mm (2 to 24 inches) full scale with a wide variety of on analog I/Os and either connector and cable terminations. The MHP series also includes the MR and ME series for larger cylinders and actuators. Alliance Sensors Group Info http://powereng.hotims.com RS# 407 Linear position sensors T he Alliance Sensors Group PG Series LVDT linear position sensors are designed and en- gineered specifically for valve position sensing applications for steam turbine control systems in electric power generation plants. Alliance Sensors Group’s approach to their PG series LVDT design for the power generation industry started with the premise that the LVDT must be extremely rugged, so these units feature a large diameter housing with a very thick wall and a versatile mounting configuration. A PG se- ries LVDT’s 3/8 inch diameter operating rod cap- tivates the LVDT’s core so that it can never come out or vibrate loose. This rod is offered with either a rigid coupling or a ball joint coupling that can be helpful in installations where there is a minor mis- alignment with the attachment mechanism on the steam valves. PG series LVDTs utilize materials and manufacturing processes that can be certi- fied for use in mild radiation environments found in boiling water reactor nuclear power plants. Alliance Sensors Group PG Series LVDTs are available in five full scale ranges from 0-to-3 to 0-to-15 inches (75 to 380 mm). Models include the PGHD Heavy Duty series LVDT with a 1-1/16 inch body diameter and the PGSD Super Duty se- ries LVDT with a 1-5/16 inch body diameter. Either series is available certified for operation in mild
- 53. 50 www.power-eng.com and theMAGNETROL commitment to con- tinued development in flow measurement and control solutions. The THERMATEL TA2 with FOUNDATION fieldbus offers all of the advan- tages of the standard TA2 model. Magnetrol Info http://powereng.hotims.com RS# 410 HART flow meters protocol option U niversal Flow Monitors, Inc. now offers a HART protocol option on all of its variable area and piston style flowmeters designed to perform in challenging lu b r i c a t i o n environments. These meters are optimized for specific lubrication flu- ids. There is an additional option of a mechanical switch to back up the transmitted signal. HART is a digital communication signal super- imposed on top of the 4–20 mA standard analog signal that provides additional digital information to the controller. The HART option is offered on all variable area vane and piston style flowmeters. These simple low maintenance meters come in 12 sizes and go up to 2000 PSI pressure for flow ranging up to 500 GPM. They have CSA and CE certifications. Universal Flow Monitors Inc. Info http://powereng.hotims.com RS# 411 Terminal blocks D ue to their compact size and ease of use, WAGO Corp.’s new 2059 SMT PCB terminal blocks offer a cost-effective alternative to solder- ing leads. With a height of merely 2.7 mm, the extremely compact 2059 reduces the space required for the connection technology. Designed for the smallest installation spaces, the light color and low profile of the PCB terminal block substantially reduce on- board LED shadowing. The 2059 Series features a PUSHWIRE connection of solid or pre-bonded conductors, with a tool-operated release slot, en- abling a high-quality and maintenance-free connec- tion between drivers and LED modules. Wire remov- al capability (in case of wiring errors or at the end of module life) is an exclusive feature in this size. Surface-mount terminal blocks are especially suited for solid state lighting applications that often utilize metal-core PCBs, including compact or miniaturized LED modules and LED ‘bulbs’. Available in 1-, 2- and 3-pole configurations, group arrange- ment is also possible without losing any poles. Offering similar functionality as the field-proven 2060 Series, the 2059 accom- modates conductors 26-22 AWG with pin spacing of 3 mm, and is available in tape-and-reel pack- aging for automated assembly. The 1-pole variant is rated for 3A/600V; the 2- and 3-pole variants are rated for 3A/250V. Wago Corporation Info http://powereng.hotims.com RS# 412 Diesel mobile generators K ohler Power Systems is adding two new mod- els to its line of diesel-powered mobile gen- erators. The two new units Kohler’s 145REOZT4 and 175REOZT4 diesel mobile generators offer quiet and reliable operation while delivering de- pendable power wherever it’s needed and meet all emissions standards. Kohler Power Systems offers mobile generators for any application from industrial power to public events. The company’s 145REOZT4 and 175REOZT4 are EPA-emission certified for non-road use and come equipped with a rugged DOT-certified trailer and durable enclosure. Both units utilize John Deere Tier 4 Final 6.8L engines that help lower operating costs with efficient performance and fuel savings. Kohler Power Systems Info http://powereng.hotims.com RS# 413 Input-Output modules I ndustrial automation manufacturer Opto 22 has released the SNAP-AIMA-iH and SNAP-AOA-23- iH two-channel analog input and output modules, each with HART communications. Both SNAP I/O modules use the HART communications protocol to extract sta- tus, diagnos- tics, and other in f o r m a t i o n from smart de- vices such as field-mounted process trans- mitters and analyzers. This information can be used by the automation system and/or the asset manage- ment system to increase uptime, improve productivi- ty and enhance safety. The SNAP-AIMA-iH analog input module has two isolated 4-20 mA input channels, and the SNAP- AOA-23-iH output module has two isolated 4-20 mA output channels. Each channel features an integrat- ed HART modem that allows the channel to commu- nicate digitally with the HART frequency-shift keying signal imposed on the 4-20 mA current loop, en- abling communication with the target smart device. Opto 22 Info http://powereng.hotims.com RS# 414 Chip resistor with Kelvin 4 wire T he CSSK Series from Stackpole offers a 0612 size chip resistor with Kelvin 4 wire connec- tion. The robust all metal construction withstands pulses and environmental stresses with mini- mal resistance shift. The low resistance values down to 0.75 milliohms and the terminations on the long side of the part handle high currents with relatively low self-induced heating for high efficiency. The CSSK0612 is available in resistance values from 0.75 milliohms to 2 milliohms in 1 percent, 2 percent, and 5 percent tolerances. Pricing varies with tolerance and resistance and ranges from $0.25 to $0.40 each in full package quantities. Stackpole Electronics Inc. Info http://powereng.hotims.com RS# 415
- 54. SUPPLIER’SSHOWCASE|ShowcaSeadvertiSingcontactJennahall:918-832-9249,Jennah@pennwell.com www.power-eng.com 51 SUPPLIER’SSHOWCASE|ShowcaSeadvertiSingcontactJennahall:918-832-9249,Jennah@pennwell.com www.power-eng.com 51 WhyShould You Filter Your Water? ᣝᣞᣟᣝᣠᣡᣠᣢᣣᣠᣤᣥᣦᣧᣦᣨᣣᣠᣩᣪᣫᣬᣭᣠᣢᣮᣯᣠᣰᣧᣨᣦᣪᣦᣯᣭᣠᣤᣰᣠᣱᣲᣲᣳᣴᣠᣵᣡᣰ ᣲᣲᣠᣝᣝᣞᣱᣴᣝᣠᣠᣳᣲᣠᣳᣱᣝᣝᣠᣠᣠᣣᣠᣳᣲᣠᣳᣱᣞᣟ ᣦᤀᣪᣦᣦᣧᤁᣮᤂᣠᣠᣠᣠᣥᣧᤃᣮᤄᣦᤀᣪᣦᣦᣧᤁᣮᤂ The Best Engineered Water Filteration Solution Always Costs Less ᤅᤆᤇᤈᤉᣠ ᤊᤋᤌᤍᤇᤎᣡᤋᤏᣠ ᤌᤉᤐᤑᤆᤉᤒᣠ ᤎᤓᤉᣠ ᤓᤉᤇᤎᣠ ᤎᤌᤇᤏᤒᤊᤉᤌᣠ ᤌᤇᤎᤉᣠ ᤇᤏᤐᣠ ᣡᤏᤆᤌᤉᤇᤒᤉᤒᣠ ᤎᤓᤉᣠ ᣣᤇᤎᤉᤌᣠ ᤔᤌᤉᤒᤒᤑᤌᤉᣠ ᤐᤌᤋᤔᣠ ᤎᤓᤌᤋᤑᤕᤓᣠ ᤎᤓᤉᣠ ᤓᤉᤇᤎᣠ ᤉᤖᤆᤓᤇᤏᤕᤉᤌᣠᤇᤏᤐᣠᤔᣡᤔᤉᤗᣠᣡᤌᤎᤁᣠᣣᤇᤎᤉᤌᣠᣡᤒᣠᤇᤈᤒᤋᣠ ᤆᤇᤑᤒᣡᤏᤕᣠ ᤎᤋᣠ ᤑᤏᤒᤆᤓᤉᤐᤑᤈᤉᤐᣠ ᤒᤓᤑᤎᣠ ᤐᤋᣣᤏᣠ ᤊᤋᤌᣠ ᤍᤇᣡᤏᤎᤉᤏᤇᤏᤆᤉᣠᤊᤋᤌᣠᤆᤈᤉᤇᤏᣡᤏᤕᣠᤇᤏᤐᣠᤌᤉᤔᤈᤇᤆᣡᤏᤕᤘᣠ ᤔᤑᤍᤔᣠ ᤒᤉᤇᤈᤒᤘᣠ ᤔᤇᤆᣵᣡᤏᤕᤘᣠ ᤒᤓᤇᤊᤎᤘᣠ ᤎᤑᤌᣢᣡᤏᤉᤘᣠ ᤒᤔᤌᤇᤁᣡᤏᤕᣠ ᤏᤋᣬᣬᤈᤉᤒᣠ ᤇᤏᤐᣠ ᤍᤇᤏᤁᣠ ᤍᤋᤌᤉᤗᣠ ᤙᤓᤉᣠ ᤙᤉᣵᤈᤉᤉᤏᣠ ᤊᣡᤈᤎᤉᤌᣠ ᣡᤒᣠ ᤇᣠ ᤔᤌᤋᤚᤉᤏᣠ ᤇᤏᤐᣠ ᣣᤋᤌᣵᣡᤏᤕᣠ ᤒᤋᤈᤑᤎᣡᤋᤏᤗ Automatic Filters +1 (864) 476-7523 ᤛ info@terrasource.com a brand of TerraSource Global www.TerraSource.com/PE TerraSource Global is a wholly-owned subsidiary of Hillenbrand, Inc. (NYSE: HI) ©2015, TerraSource Global. All rights reserved. Handling a World of Materials BOILER FEED SYSTEMS Your source for custom-designed, ruggedly-built mechanical and pneumatic systems for feeding of biomass and alternative fuels directly into boilers and kilns. High-pressure, low-pressure and vacuum conveying components available. Boiler Feed Systems Damper Drive Solutions http://powereng.hotims.com RS#302http://powereng.hotims.com RS#301http://powereng.hotims.com RS#300 POWER PLANT Demolition, Environmental Remediation, Decommissioning, Retrofitting (800) 932-2869 | www.brandenburg.com Brandenburg® Brandenburg is the premier demolition and environmental remediation contractor for power plant decommissioning and retrofit- ting. Brandenburg services utility companies throughout the U.S. by performing demo- lition and repurposing projects ranging from selective removal of obsolete equipment to complete closure of power plant facilities. Demolition/Decommissioning http://powereng.hotims.com RS#303 SOLVAir Solutions was formed to help customers address the problems of SOX, HCl and other stack emissions, as well as help with the changing EPA regulations. SOLVAir Solutions is the market leader in providing sodium sorbents for use in DSI systems. Access our brochure on our Library page at www.solvair.us Contact Rosemary Dunn ardunadv@gmail.com 713.521.7450 Emission Control ᤓᤋᤋᤒᤉᣠᤕᤇᤒᣠᤎᤑᤌᣢᣡᤏᤉᣠᣡᤏᤈᤉᤎᣠᤜᤈᤎᤉᤌᤒᣠᤇᤏᤐᣠᤒᤁᤒᤎᤉᤍᤒᣠ ᤊᤌᤋᤍᣠᣞᤝᤞᣱᤞᣠᣳᤏᤐᤑᤒᤎᤌᣡᤇᤈᣠᤝᣡᤌᣠᤎᤋᣠᤓᤉᤈᤔᣠᤉᤏᤒᤑᤌᤉᣠ ᤔᤌᤉᤐᣡᤆᤎᤇᣢᤈᤉᤘᣠᤌᤉᤈᣡᤇᣢᤈᤉᣠᤋᤑᤎᤔᤑᤎᤗ ᣱᤑᤌᣠᤉᤏᤕᣡᤏᤉᤉᤌᤉᤐᣠᤜᤈᤎᤌᤇᤎᣡᤋᤏᣠᤒᤋᤈᤑᤎᣡᤋᤏᤒᣠᤓᤉᤈᤔᣠᤇᤆᤓᣡᤉᤚᤉ ï Optimized turbine performance ï Reliable MW output ï Decreased compressor degradation ï Reduced turbine fouling With 50 yearsí of gas turbine OEM expertise, ᣣᤉᣠᣵᤏᤋᣣᣠᤜᤈᤎᤉᤌᤒ ᣣᣣᣣᤗᤆᤈᤉᤇᤌᤆᤑᤌᤌᤉᤏᤎᤜᤈᤎᤉᤌᤒᤗᤆᤋᤍ Gas Turbine Inlet Filtration http://powereng.hotims.com RS#304 http://powereng.hotims.com RS#305
- 55. ShowcaSeadvertiSingcontactJennahall:918-832-9249,Jennah@pennwell.com|SUPPLIER’SSHOWCASE www.power-eng.com5252 ShowcaSeadvertiSingcontactJennahall:918-832-9249,Jennah@pennwell.com|SUPPLIER’SSHOWCASE Crown Electric Iso PhaseBus Fabrication Installation Upgrades & Uprates GSU Change Outs 175 Edison Dr. Middletown, OH 45044 www.crown-electric.com sales@crown-electric.com ext. 201513 539-7394 Iso Phase Bus Media Blasting Services www.molemaster.com ᣝᣞᣟᣟᣠᣡᣢᣣᣣᣤᣠᣥᣦᣦᣧᣨᣩᣩᣧᣪᣪᣫᣨᣠᣬᣠᣡᣭᣮᣤᣠᣯᣰᣦᣧᣨᣯᣰᣧᣫᣱᣦᣥ ᣲᣳᣴᣞᣵᣞᣟᣣᣭᣣᣢᣧᣞ ᣣᣭᣢᣟᣣᣠᣞᣴᣠᣣᣠᣢᣴᣭᣣᣠ ᤀᣞᣟᣣᣬᤀᣭᣣᣢᣠᣭᣠᣭᣠᣣᣲᣭᣠ ᤁᣟᣭᣲᣳᣠᣞᣟᣲᣞᣳᣠᣴᣞᣢᣠᤂᣞᣧ From Dry Ice to Walnut Shells, ᤀᣞᣟᣣᣬᤀᣭᣣᣢᣠᣞᣣᣠ Abrasive Blasting ᣭᣴᣣᣟᤂᣠᣭᣳᣠᣣᣴᤃᣲᣣᣳᣟᤂᣧ Media Blasting Services SolutionforExisting& EvolvingEnergyNeeds forandintheAmericas NOW www.mhpowersystems.com Power Systems http://powereng.hotims.com RS#306 http://powereng.hotims.com RS#308http://powereng.hotims.com RS#307 ProtectiveCoatingsAssociation 3 NuScale Power has attained the Triple Crown for Nuclear Plant Safety™. With NO operator action, NO AC or DC power, and NO added water, the NuScale Power Module™ will achieve safe, self-cooled shutdown, and maintain it indefinitely. Safety: the Element of Nu.™ nuscalepower.com © 2015 NuScale Power, LLC. All Rights Reserved. Safe Nuclear Power http://powereng.hotims.com RS#310http://powereng.hotims.com RS#309 For Classified Advertising Rates & Information Contact Jenna Hall Phone: 918-832-9249 Jennah@pennwell.com
- 56. CLASSIFIEDS|ClassifiedadvertisingContaCtJennaHall:918-832-9249,JennaH@pennwell.Com The Board ofDirectors of Sho-Me Power Electric Cooperative is seeking qualifed candidates for the position of General Manager. The General Manager reports to a nine- member Board of Directors that sets policy and approves electric rates for both members and non-members of Sho-Me Power. Sho-Me Power Electric Cooperative is a generation and transmission electric cooperative owned by nine distribution cooperatives who serve over 200,000 retail customers in southern Missouri. Sho-Me’s power requirements are supplied by Associated Electric Cooperative, Inc. (AECI), created by Sho-Me and fve other G&T cooperatives in 1961. Sho-Me Technologies, a wholly owned subsidiary of Sho-Me Power, provides fber optic broadband communication services to rural Missouri. Headquartered in Marshfeld, operations personnel are strategically located at 3 crew facilities to minimize emergency response times. Facilities include Marshfeld, Cuba and Willow Springs, Missouri. The cooperative has 150 employees, operating and maintaining over 1,800 miles of electric transmission line, operated at voltages from 69 kV to 345 kV, connecting 22 transmission and 133 distribution substations throughout south central Missouri. In 2014, the G&T had consolidated annual operating revenues of $207,058,927, total operating expenses of $201,091,540 and a total net utility plant of $265,717,000. Thirty-seven of the cooperatives’150 employees are assigned to its subsidiary Sho-Me Technologies which operates over 5,000 miles of fber optic communication equipment and provides services to cell towers, educational institutions, medical facilities, government, and fnancial institutions in Missouri. Candidates should have a minimum of ten years of electric utility experience, preferably within the rural electric program and at least fve years senior management experience. Candidates must have broad electric utility experience encompassing the areas of operations, fnance, engineering, technology, marketing, power supply, strategic planning, union relations, member communications and board relations. Excellent communication skills, proven leadership ability and a strong commitment to cooperative principles is required. A bachelor’s degree in an appropriate feld is required. Interested candidates should include a resume, cover letter and a minimum of three (3) professional references or letters forwarded to: Andereck, Evans, Widger, Johnson & Lewis, LLC, ATTN: Rodric A. Widger, 3816 South Greystone Court, Suite B, Springfeld, Missouri, 65804, 417-864-6401. Electronic copies should be forwarded to rwidger@lawofcemo.com. Applications will be accepted from September 1 through October 1, 2015. All inquiries and applications are confdential. Sho-Me Power Electric Cooperative is an equal opportunity provider and employer. All qualifed applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability status, protected veteran status, or any other characteristic protected by law. EOE AA M/F/Vet/Disability General Manager Sho-Me Power Electric Cooperative, Marshfeld, Missouri For info. http://powereng.hotims.com RS# 450
- 57. ClassifiedadvertisingContaCtJennaHall:918-832-9249,JennaH@pennwell.Com|CLASSIFIEDS REACH YOUR AUDIENCE ADVERTISE yourcareer opportunities, equipment, services, and training programs in Power Engineering’s Classifed Section. GET RESULTS Put your message in front of North America’s most qualifed circulation with Power Engineering’s classifeds. CALL NOW FOR DETAILS: JENNA HALL Phone: 918.832.9249 | Email: jennah@pennwell.com GEORGE H. BODMAN, INC. Chemical cleaning advisory services for boilers and balance of plant systems George H. Bodman Pres / Technical Advisor P.O. Box 5758 Office (281) 359-4006 Kingwood, TX 77325-5758 1-800-286-6069 email: blrclgdr@aol.com Fax (281) 359-4225 For info. http://powereng.hotims.com RS# 452 For info. http://powereng.hotims.com RS# 451 Tell Us What You Have For Sale WE BUY Help Us “Sniff Out” Quality Generators > 25 kW to 2000 kW > Diesel & Natural Gas > Caterpillar, Cummins, Kohler, and others... or call: 855-720-7825 www.aaronequipment.com/sniff GENERATORS For info. http://powereng.hotims.com RS# 453 POWER PROFESSIONALS Opportunities in Operations and Maintenance, Project Engineering and Project Management. Business and Project Development. First-line Supervision to Executive Level Positions. Employer pays fee. Send resumes to: P.O. BOX 87875, VANCOUVER, WA 98687-7875 email: dwood@staffing.net (360) 260-0979 • (360) 253-5292 www.powerindustrycareers.com For info. http://powereng.hotims.com RS# 454
- 58. CLASSIFIEDS|ClassifiedadvertisingContaCtJennaHall:918-832-9249,JennaH@pennwell.Com For Classified AdvertisingRates & Information Contact Jenna Hall Phone - 918-832-9249, Jennah@pennwell.com CONDENSER & HEAT EXCHANGER TOOLS CLEANERS, PLUGS, BRUSHES John R Robinson Inc PH # 800-726-1026 e-mail: sales@johnrrobinsoninc.com www.johnrrobinsoninc.com For info. http://powereng.hotims.com RS# 456 24 / 7 EMERGENCY SERVICE BOILERS 20,000 - 400,000 #/Hr. DIESEL & TURBINE GENERATORS 50 - 25,000 KW GEARS & TURBINES 25 - 4000 HP LARGEST INVENTORIES OF: Air Pre-Heaters • Economizers • Deaerators Pumps • Motors • Fuel Oil Heating & Pump Sets Valves • Tubes • Controls • Compressors Pulverizers • Rental Boilers & Generators 847-541-5600 FAX: 847-541-1279 visit www.wabashpower.com FOR SALE/RENT POWER EQUIPMENT CO. 444 Carpenter Avenue, Wheeling, IL 60090 wabash For info. http://powereng.hotims.com RS# 455 ESI Boiler Rentals, LLC RENTALEQUIPMENT - Rental Boilers - Economizers - Deaerator Systems - Water Softener Systems - 24/7 On-Call Service 1-800-990-0374 w w w . r e n t a l b o i l e r s . c o m For info. http://powereng.hotims.com RS# 461 ᣞᣟᣠᣡᣢᣡᣣᣤᣥᣦᣟᣧᣡᣨᣟᣩᣠᣢᣦᣡᣪᣫᣤᣠᣟᣡᣬᣥᣠᣭᣥᣩᣡᣤᣩᣟᣡᣭᣤᣫᣧᣡᣢᣠ ᣬᣬᣬᣮᣬᣢᣧᣟᣥᣩᣯᣮᣯᣤᣰᣱᣟᣲᣫᣥᣳᣰᣟᣩᣠᣡᣤᣧᣡᣯᣢᣦᣦᣡᣴᣵᣵᣴᣴᣴ For info. http://powereng.hotims.com RS# 457 CONDENSER OR GENERATOR AIR COOLER TUBE PLUGS THE CONKLIN SHERMAN COMPANY, INC. Easy to install, saves time and money. ADJUSTABLE PLUGS - all rubber with brass insert. Expand it, install it, reverse action for tight fit. PUSH PULL PLUGS - are all rubber, simply push it in. Sizes 0.530 O.D. to 2.035 O.D. Tel: (203) 881-0190 Fax: (203) 881-0178 E-mail: Conklin59@aol.com www.conklin-sherman.com Just Plugging Along For info. http://powereng.hotims.com RS# 462 1319 Macklind Ave., St. Louis, MO 63110 Ph: (314) 781-6100 / Fax: (314) 781-9209 www.ampulverizer.com / E-Mail: sales@ampulverizer.com Quality and Service Since 1908 Ring Granulators, Reversible Hammermills, Double Roll Crushers, Frozen Coal Crackers for crushing coal, limstone and slag. For info. http://powereng.hotims.com RS# 459 Get a thorough mix with: Pugmill Systems, Inc. P.O. Box 60 Columbia, TN 38402 USA Ph: 931-388-0626 Fax: 931-380-0319 www.pugmillsystems.com For info. http://powereng.hotims.com RS# 458 For info. http://powereng.hotims.com RS# 460
- 59. www.power-eng.com56 INDEX RS# COMPANY PG#SALES OFFICERS# COMPANY PG# 1421 S. Sheridan Rd., Tulsa, OK 74112 Phone: 918-835-3161, Fax: 918-831-9834 e-mail: pe@pennwell.com Sr.Vice President North American Power Group Richard Baker Reprints Foster Printing Servive 4295 Ohio Street, Michigan City, IN 46360 Phone: 866-879-9144 e-mail: pennwellreprint@fosterprinting.com National Marketing Consultant Rick Huntzicker Palladian Professional Park 3225 Shallowford Rd., Suite 800 Marietta, GA 30062 Phone: 770-578-2688, Fax: 770-578-2690 e-mail: rickh@pennwell.com AL, AR, DC, FL, GA, KS, KY, LA, MD, MO, MS, NC, SC, TN, TX, VA, WV Regional Marketing Consultant Dan Idoine 806 Park Village Drive, Louisville, OH 44641 Phone: 330-875-6581, Fax: 330-875-4462 e-mail: dani@pennwell.com CT, DE, IL, IN, MA, ME, MI, NH, NJ, NY, OH, PA, RI, VT, Quebec, New Brunswick, Nova Scotia, Newfoundland, Ontario Regional Marketing Consultant Natasha Cole 1455 West Loop South, Suite 400 Houston, Texas 77027 Phone: 713.499.6311; Fax: 713.963.6284 e-mail: natashac@pennwell.com AK, AZ,CA,CO,HI,IA,MN,MT,ND,NE,NM,NV, OK,OR,SD,UT,WA,WI,WY,AB,BC,SK, Manitoba, Northwest Territory, Yukon Territory Regional Brand Manager Kelly Balaskovits 1421 S. Sheridan Rd., Tulsa, OK 74112 Phone: 918-831-9129; Fax: 918.831.9834 e-mail: kellyb@pennwell.com AK, AZ,CA,CO,HI,IA,MN,MT,ND,NE,NM,NV, OK,OR,SD,UT,WA,WI,WY,AB,BC,SK, Manitoba, Northwest Territory, Yukon Territory International Sales Mgr Tom Marler The Water Tower Gunpowder Mills Powdermill Lane Waltham Abbey, Essex EN9 1BN United Kingdom Phone: +44 1992 656 608, Fax: +44 1992 656 700 email: tomm@pennwell.com Belgium, Czech Republic, Denmark, Finland, France, Germany, Hungary, Norway, Poland, Portugal, Slovenia, Spain, Slovakia, Sweden International Sales Mgr Roy Morris The Water Tower Gunpowder Mills Powdermill Lane Waltham Abbey, Essex EN9 1BN United Kingdom Phone: +44 1992 656 613, Fax: +44 1992 656 700 email: rmorris@pennwell.com UK, Austria, Africa, Holland, India, Italy, Ireland, Israel, Russia, Australia & New Zealand, Singapore, Scotland, Switzerland, Turkey, Greece, UAE/SAUDI and Iran Classifieds/Literature Showcase Account Executive Jenna Hall 1421 S. Sheridan Rd., Tulsa, OK 74112 Phone: 918-832-9249, Fax: 918-831-9834 email: jennah@pennwell.com Rentech Boiler Systems, Inc. DIGITAL EDITION-COVER www.rentechboilers.com 9 Roxul Inc 33 www.roxul.com 12 Sealeze,A Unit 37 of Jason, Inc www.sealeze.com 8 Structural Integrity 21 Associates www.structint.com/power-eng Sulzer Management Ltd DIGITAL EDITION-BELLY BAND www.sulzer.com 10 Sulzer Turbo Services 35 www.sulzer.com Advertisers and advertising agencies assume liability for all contents (including text repre- sentation and illustrations) of advertisements printed, and also assume responsibility for any claims arising therefrom made against the publisher. It is the ad- vertiser’s or agency’s responsibil- ity to obtain appropriate releases on any items or individuals pic- tured in the advertisement. 3 Brand Energy and 5 Infrastructure Services www.beis.com 6 Buckman 15 14 Cleaver-Brooks Inc C3 www.cleaverbrooks.com 4 Haldor Topsoe Inc 7 www.topsoe.com 2 Indeck Power Equipment3 www.indeck-keystone.com 7 Lapeyre Stair 17 www.lapeyrestair.com 5 Magnetrol International 9 www.magnetrol.com 1 Mitsubishi Power C2 Systems Americas Inc www.mhpowersystems.com 11 PennWell Corporation 36 www.power-eng.com/webcasts 13 POWER-GEN 45 International www.power-gen.com 15 ProEnergy Services LLC C4 www.proenergyservices.com
- 60. To find yournearest representative, visit cleaverbrooks.com or call 800.250.5883. When you need BIG POWER, total integration generates bigger and better results. No matter the business — refinery, utility, manufacturing or petrochemical — if you are in an industry that demands big power, you’ll want to check out the complete range of boiler systems from Cleaver-Brooks. For more than 80 years, we have set the industry standard in the design and production of boiler systems that continually maximize efficiency and deliver uncompromising reliability and the lowest possible emissions. Our total integration is that every component — from gas inlet to stack outlet — is designed, engineered and manufactured by just one company. ©2015 Cleaver-Brooks, Inc. Visit Stand F18 at the 2015 Power-Gen Middle East Show For info. http://powereng.hotims.com RS#14
- 61. US Corporate Office| 660.829.5100 proenergyservices.com Accelerate your next power project with ProEnergy’s EPC FastTrack. With ProEnergy’s full inventory of equipment, including turbine and generator packages, auxiliary skids, transformers and compressors, all of the pieces you need for your next EPC project are assembled and ready to go whenever you are. THE RIGHT PIECES WHEN YOU NEED THEM For info. http://powereng.hotims.com RS#15