Trends in process field devices for automation


Published on

Published in: Technology
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Trends in process field devices for automation

  1. 1. BY ARC ADVISORY GROUP DECEMBER 2001 Trends in Process Field Devices for AutomationExecutive Overview ................................................................................ 3New Field Measurements Needed .......................................................... 4Soft Sensors Stage a Comeback ............................................................. 6Innovative Uses of Ultrasonic Waves ....................................................... 8Old Measurements Go Mainstream ...................................................... 10Vertical Applications Key to Success of Model Based Systems.................. 11Benefits and Drawbacks of Inferential Measurement .............................. 13Enterprise & Automation Strategies for Industry Executives
  2. 2. ARC Strategies • December 2001 NEW MEASUREMENTS Real-time Corrosion Soft Sensors Interface Leak Detection Pressure Flow Model-based Multiphase Flow TRADITIONAL MEASUREMENTS Vertical Solutions Level Temperature Analytical Product Quality Viscosity Real-time Analytical Entrained Air2 • • Copyright © ARC Advisory Group
  3. 3. ARC Strategies • December 2001Executive OverviewDemanding measurement applications are growing rapidly across allindustries. Suppliers recognizing the enormous opportunity are developingnew and enhanced measurements. New measurement solutions hitting themarket include viscosity, corrosion, and vertical solutions.Soft sensors are a rapidly growing solution for measurement applications.Soft sensors are the only answer for many applications where hardmeasurements are unavailable. Today’s soft sensors are widely used in thepower industry to continuously monitor environmental dis- Despite the high level ofcharges such as the emissions from combustion units to meet commonality of measurements infederal, state, and local regulations. Soft sensors, however, are process systems between industries,gaining acceptance across all the process industries in a wide va- there are many unique processriety of applications. Obstacles still remain, however, including measurements needed in each.issues such as measurement validation.Ultrasonic technology is findings its way into virtually every processmeasurement. Most commonly used to measure flow rate, level, and density,ultrasonic techniques are now making inroads into temperature, and inter-face detection applications. Not only is ultrasonic technology capable ofmeasuring these parameters, it often exceeds the performance of the currentmainstream technologies.Corrosion measurement has been employed for decades to monitor corrosionrates of critical pipelines. Old corrosion instruments relied on off-line sampletechniques by measuring the reduction of weight of disposable coupons. Theimpracticality of making off-line measurements limited its use until IntercorrInternational met the challenge by releasing the first on-line real-timecorrosion monitor to measure localized corrosion of pipelines and equip-ment.Despite the high level of commonality of measurements in process systemsbetween industries, there are many unique process measurements needed ineach. Direct instrumentation, process analyzers or soft sensor sensors cannotmeasure many production specific parameters. Intangible parameters can bevery complex properties of a substance such as taste, creaminess, color orsoftness, which can only be subjectively defined. Comprehensive modelbased process applications are meeting the demand for industry specific Copyright © ARC Advisory Group • • 3
  4. 4. ARC Strategies • December 2001 solutions. When adopting these solutions, however, drawbacks of the solu- tion must be considered from the onset to have a successful implementation. New Field Measurements Needed Traditional process control field devices commonly known as the “four horsemen” provide four main categories of measurements: pressure, temperature, flow, and level. New faster response online analytical devices are providing near real-time measurements and increasingly have been used as a mainstream process measurement however, as broad as these measure- ments are, collectively they still cannot provide the total insight needed for today’s complex processes. Demanding applications are growing rapidly in all industries particu- larly in the emerging biotech industry, which now has over 4000 companies world-wide up from just a few hundred less than 3 years ago. This unprecedented growth offers an enormous opportunity for suppliers to develop new and enhanced measurements beyond the traditional four and analytical. Increasing cost reduction targets oc- curring in all industries is compounding the situation and rendering once satisfactory measurements and processes obsolete in the quest to increase margins. Additionally, recent biological terrorist events have renewed the push for faster development of vaccines and new drugs to combat the suddenly heightened worldwide threat.Pressure, Temperature, Flow, and Level Asset management solutions continue to be a hot topic due to its po- tential savings in time and labor in the day-to-day operation of the plant. Coined Plant Asset Management (PAM), asset management solutions have become a critical strategy in many plants that are trying to squeeze that extra bit of production from their plants. PAM applications have progressed sig- nificantly in recent years. Once used strictly to analyze trends using the automation system’s historian and identify abnormal trends, PAM ap- plications have expanded to embedding artificial intelligent model based solutions to obtain more accurate health status and, in some cases, extend the useful life of the measurement by quantifying the problems, correcting the output, and validating the signal while sending a low level alert highlighting potential issues with the unit.4 • • Copyright © ARC Advisory Group
  5. 5. ARC Strategies • December 2001Field device suppliers are taking up the slack by offering new innovativereal-time hard sensors coupled with intelligent software to provide themeasurement of desired property. More sophisticated field device solutionsare expected with the increasing adoption of fieldbus, which allows easyaccess to every online measurement on the bus. The rich data set offered byFieldbus, coupled with increased intelligence, will enable the local field de-vice to use model based techniques to infer the measurement of new parame-ters previously unavailable.Field devices are following a natural product life cycle evolution as they ex-pand functionally. For example, ultrasonic level principle is being used in anincreasing number of hard measurements ranging from flow, and tempera-ture, to leak detection and nondestructive vessel testing. Field devicesuppliers are breaking away from traditional roles and usingtechnology to broaden their appeal in the ever-tightening market.By developing products to go beyond their traditional roles, vi-sionary field device suppliers are creating a strong launch padinto future markets and other lines of business. Expect to see in-creasing growth in combined hardware and the softwaresolutions in this area. Needed MeasurementsDespite the improvements in analytical measurements, the lack Viscosityof appropriate on-line instrumentation and reliability of on-line Entrained Airinstruments have forced users to depend on laboratory analysesresulting in infrequent and irregular and long analysis delays. ConsistencyLaboratory analyses may also be subject to reliability problems. Measurement ValidationOn-line sensors may be available but suffer from long measure- Leak Detectionment delays (e.g. gas chromatographs) or subject to factors that Multi-Phase Flowaffect the reliability of the sensor (e.g. drifts and fouling). In Real-time Analyticaleither case, automatic control and optimization schemes cannot Product Qualitybe implemented and, as a result, process performance is de- Bio Cell Productiongraded. CorrosionLeft unattended, the problems of delays and unreliable meas- Pipe Coatingurement manifest themselves into critical problems that affectproduct quality and availability of production. Critical problemssuch as these can quickly devour the last bit of shrinking margin to drive en-terprises into the red. Fortunately, field device suppliers have recognizedthis need and are working hard to provide new online real-time measure-ments. Progress in many areas, however, continues to be slow compared todemand. Copyright © ARC Advisory Group • • 5
  6. 6. ARC Strategies • December 2001 Soft Sensors Stage a Comeback Automatic control enables and facilitates consistent production. To achieve these goals, however, controllers require regular and reliable measurements at the appropriate frequency. Some slow reacting processes can do with in- frequent sample measurements but most demand continuous attention to maintain a narrow band of uncertainty for consistent product quality. Processes are tough on instru- Technology Function Inferential Measurement mentation. Process pressure Ultrasonic Flow & Level Transit Time & Frequency shift and temperature can exceed limits of field devices, high am- Magnetic Flow Milli -Volts bient temperature can cook Orifice/Venturi/Pitot/Nozzle Flow Differential Pressure electronics, and the inaccessibil- Radar Level Frequency ity of the measurement location RTD Temperature Resistance may make physical measure- ments impractical. When hard Turbine & PD Flow Rotor Speed measurements are unavailable, Common Inferential Field Devices soft sensors may be the only answer. Soft sensors, also known as inferential model-based analyzers, are programs that primarily use secondary measurements combined with mod- eling methods to develop process input-output variable relationships. Soft sensors use mathematics to estimate either the value of product properties measured in the laboratory, properties measured infrequently on-line or that take an inordinate amount of time to measure, or properties not measured at all. Soft sensors utilize easy to measure process variables such as pressure, flow, density, or temperature to estimate the value of an important property and make the data immediately available to operators and control systems. Because many of the desired primary measurements are directly related to one or more secondary variables, measurement of previously unavailable parameters is readily possible by using secondary variables to infer the state of a quality or primary variable. For example, liquid composition can be de- fined by pressure and temperature, concentration by density, and biomass growth can be linked to CO2 evolution and feed rate. The process of inferential measurement is quite common and has been in use by suppliers for decades to measure flow and level. For example, magmeters measure electrical potential, orifices measure differential pressure, and ultra- sonic flowmeters measure transit time for both flow and level measurements.6 • • Copyright © ARC Advisory Group
  7. 7. ARC Strategies • December 2001What is different in today’s solution is the complex modeling techniques ap-plied to standard measurements.By modeling the relationship between a primary output and secondary out-put the response time can approach that of a typical online process meas-urement. Suppliers such as Pavilion, Aspen Technology, Optima PSE, andShell Global Systems are investing in this approach to provide soft sensorsto replace analytical measurements. Instead of waiting 15-30 minutes for agas chromatograph to complete its analysis, the inferential measurementsystem could be returning estimates of compositions every few seconds.Field device suppliers are also investigating the opportunities for these tech- Emissionsniques to provide enhanced performance such as increasing the low range Measurementmeasurement of vortex flow meters and modeling of fluid mixtures toenhance concentration measurements. Increasing sophistication of modelingtechniques now make them sufficiently accurate to use inferential measure-ment as direct feedback for automatic control. Despite their performance,many users continue to use inferential soft sensor measurement in conjunc-tion with traditional off line techniques to optimize measurements.Soft sensors are widely used in the power industry to continuously monitorenvironmental discharges such as emissions from combustion units to meetfederal, state, and local regulations. Typically software solutions extract datafrom the process historian to build the model. Once built, the soft sensor willmonitor and predict air emissions in real-time. Pavilions Soft Sensor tech-nology for air emissions, CEM Software, is typical of these solutions.Working with the EPA, Pavilion has installed 250 software solutionsthroughout the US. The documentation generated is a necessary step in theapproval process that, in many cases, must be replicated for each local utility.Using similar modeling techniques suppliers are developing measurementvalidation by employing rules at the lowest measurement level. To accom-plish this, automated program models are applied to key process variablesby taking advantage of redundant information contained in process instru-mentation. Predicted value is then compared against the actual measuredkey variable to determine if it is operating correctly or not. If the input issuspect, an alarm is triggered; signaling for maintenance attention and con-trol action can be programmed for application specific action whilepreventing the use of suspect data. Copyright © ARC Advisory Group • • 7
  8. 8. ARC Strategies • December 2001 Despite their benefits, operators typically still do not totally trust the reliabil- ity of soft sensors. Many users point to the inability to quickly test, check, and calibrate a soft sensor solution that is standard operating procedure rou- tinely performed on direct instrumentation. Previous initial solutions have also produced inconsistent readings and because instrumentation technicians grew up with physical measurements, they are biased toward hard meas- urements and suspect the readings of soft. Bad memories are hard to erase and for soft sensors to continue their move into mainstream applications, ad- ditional enhancements are needed to allow measurement checks to ease the fears of operators. Innovative Uses of Ultrasonic Waves Ultrasonic technology is findings its way into virtually every process meas- urement. Traditionally used to measure flow rate, level, and density, ultrasonic techniques are now being applied to measure temperature, viscos- ity, and interface detection. Not only is ultrasonic technology capable of measuring these parameters, it often exceeds the performance of the current mainstream technologies such as RTD temperature probes and vibration type viscometers. Temperature can be measured with a multitude of sensors such as thermo- couples, infrared, thermistors, and RTDs. Caldon, a niche ultrasonic supplier, utilizes ultrasonic technology in its LEFM meter to accurately measure feedwater temperature in nuclear power plants. Sound velocity of a fluid is determined by the ratio of its compressibility and its density. For specific liquids such as pure water, compressibility and density are linked to various characteristics like temperature and pressure. As a result of this interdependence, it is quite easy, with the right model, to infer temperature Ultrasonic from the sound velocity through the fluid and pressure. Technology Using mean pulsed time from its meter combined with an external pres- sure input Caldon’s LEFM meter precisely calculates the temperature of high temperature feed water exceeding 450 deg Fahrenheit. Sound velocity can be determined within 1 part in 1000 yielding an accuracy of +/- .3 percent, which is a significant improvement over the typical RTD performance of +/- 2.6 percent in this application. Other suppliers are investigating the use of high speed 22 bit software in a multi-input transmitter to approach fast re-8 • • Copyright © ARC Advisory Group
  9. 9. ARC Strategies • December 2001sponse highly accurate temperature measurement to within .0005 degreesCelsius for the semiconductor industry in the production of the next genera-tion of processors.Viscosity can be determined in a similar way by measuring the attenuationof ultrasonic signals as they pass through the viscous liquid. Despite thesimplicity of the concept for both temperature and viscosity measurement anumber of parameters such as distance of travel, sonic velocity, pressuremeasurement and the allowance for transmission delays in the liquid mustbe accurately determined. Ultrasonic technology is one of the fastest re-sponding measurement methods, which makes this technology ideal fordetermining the interface between two different fluids transported through Nuclear Powerpipelines carrying finished petroleum products coast to coast. ApplicationsCaldon’s Sountrack measures viscosity, density and interface using one ormultiple ultrasonic transducers mounted in a simple ring that is simply in-stalled between a pair of process pipe flanges. Interface can be detectedwithin one second and kinematic viscosity can be determined within +/-.04centistokes (cSt).Caldon, best known for pioneering approval from the Nuclear RegulatoryCommission (NRC) for power up rates in nuclear power plants based on im-proved feedwater flow measurement, introduced a new eight-path transittime flowmeter for custody transfer applications that may prove to be one ofthe most accurate meters in the world. Multipath ultrasonic technologygained user mass acceptance in the natural gas industry after approval by theAmerican Gas Association in 1998. Krohne, Daniels, FMC and Instromet allhave released products utilizing multipath technology. The combination ofno moving parts with high reliability and high performance is hard to ignore.Ultrasonic technology is increasingly the technology of choice for leak detec-tion of long pipelines. Krohne, Panametrics, and Controlotron offer leakdetection systems. Caldon’s new LineWatch dynamic leak detection systemsis a prime example of these solutions, which can be used on existing pipe-lines to cost-effectively comply with environmental guidelines and regula-tions. LineWatch can determine the location of a sudden break or leak in thepipeline by measuring and timing the pressure waves created by such anevent. Caldon also manufactures a static leak detection system used princi-pally for jet fuel delivery lines in commercial and military airports, whichrequires significantly less down time than other technologies. Copyright © ARC Advisory Group • • 9
  10. 10. ARC Strategies • December 2001 Old Measurements Go Mainstream Corrosion is not new and has been employed for decades to measure corro- sion rates of critical pipelines, the main artery of the oil & gas industry. Traditional instruments, however, relied on the reduction of weight of dis- posable coupons. The impracticality of making this off-line measurement limited its use to the detriment of equipment and the safety of the personnel running the plant. The increasing popularity of equipment condition moni- toring and plant asset management indirectly pushed corrosion monitoring into the spotlight. Intercorr International met the challenge by releasing the first on-line real-time corrosion monitor to measure general corrosion and, more importantly, the localized corrosion that represents the bulk of corro- sion failures. Intercorr’s SmartCET is a cost-effective electrochemical multi-technique corrosion monitoring instrument that measures corrosion using tech- niques such as electrochemical noise, Linear Polarization Resistance (LPR), Harmonic Distortion (HD), Galvanic Current (GC), and Hydrogen Per- meation Current (HP). The system consists of a wetted 2- or 3- electrode probe with a companion transmitter/computer to compute corrosion rate. By releasing the first online monitor, Intercorr has provided users a means to perform low cost corrosion measurements with information immedi- Real-Time Corrosion Monitoring ately available whether onshore or offshore, local or remote. SmartCET also provides users the opportunity for direct interfacing between corro- sion, chemical injection, process control, and maintenance management sys- tems to allow personnel to take appropriate remedial action Yamatake’s Smart Plus One gas chromatograph is the world’s smallest natu- ral gas analyzer that fits in the palm of your hand. Previous products needed large amounts of real estate and were typically the size of a small refrigera- tor. SmartPlus is one of the first introductions of the new trend of miniaturized analyzer on a chip. The small size of future field devices will expand measurement possibilities and include variables that were previously inconceivable.10 • • Copyright © ARC Advisory Group
  11. 11. ARC Strategies • December 2001Vertical Applications Key to Success ofModel Based SystemsDespite the high level of commonality of measurements in process systemsbetween industries, there are many unique process measurements needed ineach. Some of these go unattended and left for the operator to control thebest they can with limited knowledge by juggling seemingly contradictoryneeds. The resulting inefficiency wastes raw materials, finished productsand time that can never be recovered.Direct instrumentation, process analyzers, and soft sensor sensors cannotmeasure many production specific parameters. These intangible parameterscan be found in virtually every industrial segment with many concentratedin the oil & gas industry. Intangible parameters can be very complex proper-ties of a substance such as taste, creaminess, color or softness, which can onlybe subjectively defined. Although an intangible parameter can be tied tophysical properties of the substance, there is typically no known definition.Typically, intangible parameters must be measured without having any de-tailed knowledge of the parameter.Comprehensive model based process applications are meeting the demand tomeasure intangible parameters with industry specific solutions. Using infer-ential modeling techniques, industry specific systems takes soft sensortechnology to a much higher level that many times is a semi-customized so-lution for an industrial process or particular plant.Final product quality isn’t the only quality assurance necessary to meetcustomer standards and regulatory requirements, interim product qual-ity in the production is increasingly needed to allow time to take actionon off-spec products. With the high production rates mandated by effi-cient production, time is of the essence, making online real-time Model Based Softwarecontinuous measurements necessary.Complex non-linear models can be built using neural networks, genetic pro-gramming, partial least squares, algebraic, hybrid neural, and regressiontechnologies. PSE Optima offers Product Quality Estimator solutions an em-pirical modeling tool to develop on-line models for estimating productquality from process measurements in real-time or with engineering correla-tions or user engineering correlations. This approach has proven to be a veryeffective means for on-line estimation of polymer properties. Typically, his- Copyright © ARC Advisory Group • • 11
  12. 12. ARC Strategies • December 2001 torical process data is used to develop models of key process and quality variables to be placed on-line. These models are updated online with lab re- sults (or analyzers if available). Virtually all performance optimization companies are offering non-linear model solutions today for use in oil & gas, refining, food processing, petrochemical, power, chemicals, mining, and pulp & paper industries. Specific process parameters and quality measure-Suppliers Product ments inferred on-line are very dependent on theAspenTech AspenIQ specific process and product requirements. Today’sGensym NeurOn-line excellent examples of solutions include: Melt index,Pavilion Technologies Property Predictor Tray Temperature, Mooney, Naphtha 95% point,Shell Global Solutions RQE Catalyst Mileage, Polymer residence time and Sheet color and opacity.Honeywell Profit SensorEmerson Process Intelligent Sensor Toolkit Because these parameters can drastically changeManagement with process operational changes it may be neces-Invensys/Pacific FACTNET sary to use an adaptive inferential measurementSimulations scheme by augmenting the estimated parameter Typical Soft Sensor Solutions with slow off-line measurements. This will correlate values generated by the parameter estimator with measured values and compensate the measurement model to more represen- tative values. In this adaptive framework, the slower measured primary output is fed to the faster parameter estimator, which updates the inferential measurement model when available. An excellent example of a model based vertical application solution is ABB’s OptimizeIT Well Monitoring System for estimating the flow rates of oil, gas, and water from individual wells in an oil field. OptimizeIT Well may be used as a software multiphase flowmeter, as a Reliability Tool, and as a Pro- duction Allocation System. OptimizeIT Well can also detect water or gas breakthrough, predict the production rate with high accuracy, provide re- dundancy, and validate specific measurements from the well’s instrumentation. OptimizeIT Well is based on data from standard well instrumentation that is designed to handle any configuration of well instrumentation, making the solution easily transferable from region to region and, therefore, suitable for any user around the globe. Calculations are based on a mechanistic model for multiphase flow and a full, compositional model of the fluid. ABB’s ap- proach to calculating all fluid properties using the full model is superior to12 • • Copyright © ARC Advisory Group
  13. 13. ARC Strategies • December 2001methods based on interpolation of tabulated data most commonly used incommercially available multiphase fluid simulation programs.Model-based measurement products typically come from software optimiza-tion companies that take reams of data to predict the measurement withoutdirect knowledge of the sensor making the measurement. Direct involve-ment of sensor manufacturers such as ABB helps to expand this techniquefurther. With collaboration of sensor and software suppliers, development ofnew innovative measurements may result.Benefits and Drawbacks of InferentialMeasurementDespite the relatively simple concept of inferential measurement and thestraightforward inferential model building techniques given the abundanceof computer-aided tools, there are a number of important things to bear inmind when adopting inferential model based solutions.BenefitsHere are some of the benefits that you can expect from successful inferentialmeasurement and control scheme:• Faster return of information. Process upsets can be detected quicker and remedial action can be taken before it is too late. Validation Key For• Increasing standard “shrink wrapped” vertical solutions reduce model- Continued Adoption ing time and lowers implementation cost.• The inferential estimates carry a fair degree of feedforward in- formation. For example, disturbances affecting tray temperatures in a distillation column in a refinery may show up much later in the product compositions but will immediately be reflected in the composition esti- mates.• Reducing human involvement in the control loop increases consistent production.• Better process control can be achieved. Copyright © ARC Advisory Group • • 13
  14. 14. ARC Strategies • December 2001 • Increased scope for process optimization leading to higher profit-ability. Drawbacks Drawbacks are few. Here are the major issues that need consideration for successful implementation: • High cost model based solutions will not replace on-line field de-vices any time soon. They can, however, provide the only real alternative. • Data conditioning can be time consuming - Delete data with abnormali- ties since the old adage rubbish in, rubbish out applies. • Selection of appropriate secondary inputs can be difficult – Select the least number of variables to develop a model of sufficient accuracy. • Estimator testing must be rigorous- test model over a broad range and account for changing process conditions. • Measurement mistrust from operators and the inability to calibrate or to check the measurement. This, however, is becoming less of an issue now with measurement validation enhanced solutions.14 • • Copyright © ARC Advisory Group
  15. 15. ARC Strategies • December 2001Analyst: Wil ChinEditor: David ClaytonDistribution: All MAS-P & MAS-H ClientsAcronym Reference: For a complete list of industry acronyms, refer to our webpage at Artificial Intelligence EPA Environmental Protection AgencyANSIAmerican National Standards Institute ERP Enterprise Resource PlanningAPI Application Program Interface GC Galvanic CurrentAPS Advanced Planning & Scheduling HD Harmonic DistortionB2B Business-to-Business HP Hydrogen Permeation CurrentB2C Business-to-Consumer MRP Materials Resource PlanningBPR Business Process Reengineering OLE Object Linking & EmbeddingCAGRCompound Annual Growth Rate OPC OLE for Process ControlCAN Controller Area Network NRC Nuclear Regulatory CommissionCMM Collaborative Manufacturing PAM Plant Asset Management Management PD Positive DisplacementCNC Computer Numeric Control RTD Resistance Temperature DetectorCPG Consumer Packaged Goods SCE Supply Chain ExecutionCRM Customer Relationship Management SPC Statistical Process ControlEAI Enterprise Application Integration TMS Transportation Management SystemEAM Enterprise Asset Management WAH Web Application HostingEC Electronic Commerce WMS Warehouse Management SystemFounded in 1986, ARC Advisory Group is the leader in providing strategic plan-ning and technology assessment services to leading manufacturing companies,utilities, and global logistics providers, as well as to software and solution suppli-ers worldwide. From Global 1000 companies to small start-up firms, ARCprovides the strategic knowledge needed to succeed in today’s technology driveneconomy.ARC Strategies is published monthly by ARC. All information in this report is pro-prietary to and copyrighted by ARC. No part of it may be reproduced withoutprior permission from ARC.You can take advantage of ARCs extensive ongoing research plus experience ofour staff members through our Advisory Services. ARC’s Advisory Services arespecifically designed for executives responsible for developing strategies anddirections for their organizations. For subscription information, please call, fax, orwrite to: ARC Advisory Group, Three Allied Drive, Dedham, MA 02026 USA Tel: 781-471-1000, Fax: 781-471-1100, Email: Visit our web page at Copyright © ARC Advisory Group • • 15
  16. 16. Cambridge, U.K. Düsseldorf, Germany Munich, Germany Hamburg, Germany Tokyo, Japan Bangalore, India Boston, MA Pittsburgh, PA San Francisco, CA Visit for complete contact informationThree Allied Drive • Dedham, MA 02026 USA • 781-471-1000 • Fax 781-471-1100