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© 2012 Valerus. Confidential and proprietary. All rights reserved.
© 2012 Valerus. Confidential and proprietary. All right...
© 2012 Valerus. Confidential and proprietary. All rights reserved.© 2012 Valerus. Confidential and proprietary. All rights...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
OUTLINE
1. Selection Of A Reciprocating Or Centrifugal ...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
OUTLINE
2. High/Medium Speed Vs. Slow Speed
Comparison ...
© 2012 Valerus. Confidential and proprietary. All rights reserved.© 2012 Valerus. Confidential and proprietary. All rights...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
COMPRESSOR TYPES
Rolling Lobe (Roots)
Reciprocating
Sin...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
HISTORY
© 2012 Valerus. Confidential and proprietary. All rights reserved.
DEFINE THE QUESTION
• Plant or Site Parameters
• Projec...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PLANT OR SITE PARAMETERS
• Onshore / Offshore
• Elevati...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PROJECT PARAMETERS
• Anticipated life
• Required start ...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PROCESS PARAMETERS
• Gas analysis
• Suction pressure - ...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
MACHINERY PARAMETERS
• Initial cost
• Transportation/in...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
ELECTRIC OR GAS DRIVER
• Fuel gas availability & qualit...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
• Fuel gas availability & quality – Not Required
• Elec...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
• Two types of gas turbines
– Industrial
• steam turbin...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
• Fuel gas availability & quality –Required / high qual...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
• Complex start-up/stop sequencing
• Complex controls r...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
• Fuel gas availability & quality –Required / low quali...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
• Industry did not have a large industrial gas engine u...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
Turbine Engine
Available HP >30,000 >10,000
Temp. 22°C ...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
CENTRIFUGAL COMPRESSORS
WHY Centrifugal?
• Mature Techn...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
CENTRIFUGAL CHARACTERISTICS
• Dynamic compressor
Achiev...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
Flow:
Minimum flow is approx. 3 m3/min (100 acfm) into ...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS
Pressure...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
Temperature:
• Low temps. down to -75°C handled using h...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS
Compress...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS
Horsepow...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS
Rotative...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS
Efficien...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
RECIPROCATING COMPRESSORS
WHY Reciprocating?
• Large, o...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
RECIPROCATING CHARACTERISTICS
• Positive Displacement c...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS
Flow:
...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
Pressure:
• No minimum limit, can attain high vacuums. ...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS
Temper...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS
Compre...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS
Horsep...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS
Rotati...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
SEPARABLE / CENTRIFUGAL COMPARISION
Comparing the most ...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
SEPARABLE / CENTRIFUGAL COMPARISION
Coverage:
© 2012 Valerus. Confidential and proprietary. All rights reserved.
SEPARABLE / CENTRIFUGAL COMPARISION
Separable vs. Centr...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
SEPARABLE / CENTRIFUGAL COMPARISION
POWER COMPARISON:
3...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
SEPARABLE / CENTRIFUGAL COMPARISION
POWER COMPARISON:
P...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
SEPARABLE / CENTRIFUGAL COMPARISON
POWER COMPARISION:
R...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
SEPARABLE / CENTRIFUGAL COMPARISON
OPERATING COSTS:
Fue...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
EFFICIENCY COMPARISON
Turbine / Centrifugal Engine / Re...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
Reciprocating Compressor:
– piston rings and wear bands...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
AVAILABILITY
100%
Downtime)dUnschedulefromLossesProduct...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
AVAILABILITY
• Reciprocating
Rental fleet operators gua...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PIPELINE APPLICATION EXAMPLE
ASSUMPTIONS
• 7500 Bhp ins...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PIPELINE APPLICATION EXAMPLE
SOLAR CAT Wartsilla
Instal...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PIPELINE APPLICATION EXAMPLE
0
50
100
150
200
250
300
3...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PIPELINE APPLICATION EXAMPLE
Flow
MMSCFD
Suction Pressu...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PIPELINE APPLICATION EXAMPLE
Reciprocating
Centrifugal
...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PIPELINE APPLICATION EXAMPLE
ACTUAL Operating Condition...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PIPELINE APPLICATION EXAMPLE
Reciprocating
Centrifugal
...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
PIPELINE APPLICATION EXAMPLE
Percent Flow
0 20 40 60 80...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
OTHER CONSIDERATIONS
gas turbine driven
centrifugal com...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
OTHER CONSIDERATIONS
gas turbine driven centrifugal
com...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
OTHER CONSIDERATIONS
gas turbine driven centrifugal
com...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
RECIPROCATING / CENTRIFUGAL COMPARISON
Compressor Type ...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
CONCLUSIONS
• Best compressor choice depends on:
– Plan...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
CONCLUSIONS
Gas Turbine driven Centrifugal compressors ...
© 2012 Valerus. Confidential and proprietary. All rights reserved.
CONCLUSIONS
Separable compressors are best when:
• High...
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Selecting a reciprocating or centifugal compressor

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Selecting a reciprocating or centifugal compressor

  1. 1. © 2012 Valerus. Confidential and proprietary. All rights reserved. © 2012 Valerus. Confidential and proprietary. All rights reserved. Compression Split – Technical Seminar September 26, 2013 Tom Birney, Director of Business Development
  2. 2. © 2012 Valerus. Confidential and proprietary. All rights reserved.© 2012 Valerus. Confidential and proprietary. All rights reserved. OVERVIEW
  3. 3. © 2012 Valerus. Confidential and proprietary. All rights reserved. OUTLINE 1. Selection Of A Reciprocating Or Centrifugal Compressor a. Parameters b. Drivers c. Centrifugal Compressors d. Reciprocating Compressors d. Recip. vs. Centrifugal Comparison - Examples e. Conclusion
  4. 4. © 2012 Valerus. Confidential and proprietary. All rights reserved. OUTLINE 2. High/Medium Speed Vs. Slow Speed Comparison of API 11P (ISO-13631): High/medium speed compressors and API 618 slow speed compressors 3. Sizing, Selection and Applications 4. Packaging Considerations
  5. 5. © 2012 Valerus. Confidential and proprietary. All rights reserved.© 2012 Valerus. Confidential and proprietary. All rights reserved. COMPRESSION 1. Selection of a Reciprocating or Centrifugal Compressor
  6. 6. © 2012 Valerus. Confidential and proprietary. All rights reserved. COMPRESSOR TYPES Rolling Lobe (Roots) Reciprocating Single Screw Axial Liquid Ring Screw Vane Radial Positive Displacement Dynamic
  7. 7. © 2012 Valerus. Confidential and proprietary. All rights reserved. HISTORY
  8. 8. © 2012 Valerus. Confidential and proprietary. All rights reserved. DEFINE THE QUESTION • Plant or Site Parameters • Project Parameters • Process Parameters • Machinery Parameters
  9. 9. © 2012 Valerus. Confidential and proprietary. All rights reserved. PLANT OR SITE PARAMETERS • Onshore / Offshore • Elevation/Barometric Pressure • Ambient Temperature - design/range • Fuel Available - type, pressure, cost • Soil/Foundation conditions • Enclosure Required - open, partial, full • Manpower/Staffing Plans • Utilities - water, power, air • Environment - noise, air, effluents
  10. 10. © 2012 Valerus. Confidential and proprietary. All rights reserved. PROJECT PARAMETERS • Anticipated life • Required start up date & equipment deliveries • Economic evaluation criteria
  11. 11. © 2012 Valerus. Confidential and proprietary. All rights reserved. PROCESS PARAMETERS • Gas analysis • Suction pressure - design/range • Discharge pressure - design/range • Suction temperature - design/range • Flow rate - design/range • Extra process heat requirement • Operating flexibility required • Operating reliability required
  12. 12. © 2012 Valerus. Confidential and proprietary. All rights reserved. MACHINERY PARAMETERS • Initial cost • Transportation/installation cost & time • Compressor efficiency - kw/m3 • Specific fuel consumption over range • Power avail/power required match • Actual emissions/emissions allowed • Operation & maintenance cost • Flexibility to handle range of conditions
  13. 13. © 2012 Valerus. Confidential and proprietary. All rights reserved. ELECTRIC OR GAS DRIVER • Fuel gas availability & quality • Electricity availability • Speed control • Fuel gas vs electric cost • Maintenance vs initial cost • Emissions • Lead time
  14. 14. © 2012 Valerus. Confidential and proprietary. All rights reserved. • Fuel gas availability & quality – Not Required • Electricity availability - Required • Speed control – Additional VFD and Torsional Analysis • Fuel gas vs electric cost – varies • Maintenance vs initial cost – Maintenance Low / (high failure cost) Initial cost comparable • Emissions - None • Lead time – Long, built to order ELECTRIC DRIVER
  15. 15. © 2012 Valerus. Confidential and proprietary. All rights reserved. • Two types of gas turbines – Industrial • steam turbine technology • in-situ repair – Aero-derivative • replace - don’t repair COMBUSTION GAS TURBINE
  16. 16. © 2012 Valerus. Confidential and proprietary. All rights reserved. • Fuel gas availability & quality –Required / high quality • Electricity availability - No • Speed control – Usually ran at constant speed • Fuel gas vs electric cost – varies • Maintenance vs initial cost – Maintenance Low / (high failure cost) Higher Initial cost • Emissions - High • Lead time – Long TURBINE DRIVER
  17. 17. © 2012 Valerus. Confidential and proprietary. All rights reserved. • Complex start-up/stop sequencing • Complex controls required for fuel scheduling and emissions controls • Many critical monitoring points for gas turbine • Complicated surge control GAS TURBINE CONTROLS
  18. 18. © 2012 Valerus. Confidential and proprietary. All rights reserved. • Fuel gas availability & quality –Required / low quality • Electricity availability - No • Speed control – Included • Fuel gas vs electric cost – varies • Maintenance vs initial cost – Maintenance medium / Low Initial cost • Emissions - medium • Lead time – short RECIPROCATING ENGINE DRIVER
  19. 19. © 2012 Valerus. Confidential and proprietary. All rights reserved. • Industry did not have a large industrial gas engine until 1995. – Caterpillar G3616 in 1995 (4500 HP) – Caterpillar G16CM34 in 2001 (7670 HP) – Waukesha 16V-AT27 in 2000 (4500 HP) – Wartsila 18V34SG in 1997 (8000 HP) – Wartsila 20V34SG in 1998 (10600 HP) RECIPROCATING DRIVERS
  20. 20. © 2012 Valerus. Confidential and proprietary. All rights reserved. Turbine Engine Available HP >30,000 >10,000 Temp. 22°C 37.8°C Altitude Sea Level 1500m Intake Loss None allowed 1500mm WC Exhaust Loss None allowed 300mm WC Degradation Allow up to 10% 0% Weight / Footprint Low High RECIPROCATING ENGINE VS. GAS TURBINES DRIVERS
  21. 21. © 2012 Valerus. Confidential and proprietary. All rights reserved. CENTRIFUGAL COMPRESSORS WHY Centrifugal? • Mature Technology – Since 1940’s • Handles large capacities • High Horsepower • Small footprint • 99% Availability • Minimal Maintenance
  22. 22. © 2012 Valerus. Confidential and proprietary. All rights reserved. CENTRIFUGAL CHARACTERISTICS • Dynamic compressor Achieves pressure increase by controlling gas velocities • Narrow operating range Precise matching to design point • Minimal degree of capacity control • Large Volumetric flow rates
  23. 23. © 2012 Valerus. Confidential and proprietary. All rights reserved. Flow: Minimum flow is approx. 3 m3/min (100 acfm) into any impeller. As flow decreases toward this limit efficiency falls off dramatically. CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS
  24. 24. © 2012 Valerus. Confidential and proprietary. All rights reserved. CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS Pressure: • Lower limit, none with proper seals. • Upper limit, high discharge pressure not itself a limiting factor, just thicker components. This may reduce number of stages possible. • Most applications are below 350 bar. • Higher suction pressure are more difficult to seal. Most applications below 200 bar.
  25. 25. © 2012 Valerus. Confidential and proprietary. All rights reserved. Temperature: • Low temps. down to -75°C handled using higher cost materials of sufficient ductility. Special seals required. Upper limit set by shaft seals. • Temps. of 195°C are common & can be increased to 230°C with cool buffer gas. CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS
  26. 26. © 2012 Valerus. Confidential and proprietary. All rights reserved. CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS Compression Ratio or Head: • Determines the number of stages required. For dynamic compressors this is a function of pressure ratio, MW, temperature, compressibility and ratio of specific heats. Due to rotor stability 10 impellers is normal max. At 4,600 m kg/kg polytropic head per impeller this limits methane to 7.92 ratios in one casing and propane to 200 ratios. Correct MW is critical to proper selection.
  27. 27. © 2012 Valerus. Confidential and proprietary. All rights reserved. CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS Horsepower: • Applications less than 750 kw (~1000 hp) usually have some other limiting factor such as low flow or poor efficiency. • Upper limits are typically set by available drivers. • Centrifugal compressors can handle high powers.
  28. 28. © 2012 Valerus. Confidential and proprietary. All rights reserved. CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS Rotative Speed: • With dynamic compressors higher speed results in improved performance. Work per stage and flow increases with speed. Mechanical considerations limit tip speeds to 335 m/sec for open impellers and 425 m/sec for closed impellers.
  29. 29. © 2012 Valerus. Confidential and proprietary. All rights reserved. CENTRIFUGAL COMPRESSOR APPLICATION LIMITATIONS Efficiency: • Polytropic efficiency per stage of 85% is normal for quantity constant of 100 to 300 and declines to 70% as quantity constant drops to 35. Quantity Constant = ICFM X 1000 X 1728 RPM X IMP. DIA. (in)
  30. 30. © 2012 Valerus. Confidential and proprietary. All rights reserved. RECIPROCATING COMPRESSORS WHY Reciprocating? • Large, operating range / flow / pressure / variations in gas • +95% Availability • Portability • Ease of Start – Stop • Re-Application • Cost
  31. 31. © 2012 Valerus. Confidential and proprietary. All rights reserved. RECIPROCATING CHARACTERISTICS • Positive Displacement compressor Achieves pressure by reducing the volume • Wide operating range • Infinite capacity control • Efficiency improves with decreasing flow
  32. 32. © 2012 Valerus. Confidential and proprietary. All rights reserved. RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS Flow: • No minimum flow. Maximum flow limited by piston displacement of available cylinders.
  33. 33. © 2012 Valerus. Confidential and proprietary. All rights reserved. Pressure: • No minimum limit, can attain high vacuums. Maximum pressures can be ultra high for special processes. Separable applications are normally limited to 415 bar (6000 psi), at reduced rotative speeds. RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS
  34. 34. © 2012 Valerus. Confidential and proprietary. All rights reserved. RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS Temperature: Minimum limit is -30°C with standard material and -40°C with special alloys. Maximum limit is normally 175°C and preferably below 150°C.
  35. 35. © 2012 Valerus. Confidential and proprietary. All rights reserved. RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS Compression Ratio: • Normally limited by one of following; Max. discharge temp. Allowable rod load Low cylinder volumetric efficiency • Practical limits on natural gas are 4 - 5 on first stage and 3.5 - 4.5 on succeeding stages.
  36. 36. © 2012 Valerus. Confidential and proprietary. All rights reserved. RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS Horsepower: • Limited by frame ratings or driver ratings. Reciprocating (aka Separable) frames of 7500kw and gas engines of 6100 kw (8000 Bhp) are available.
  37. 37. © 2012 Valerus. Confidential and proprietary. All rights reserved. RECIPROCATING COMPRESSOR APPLICATION LIMITATIONS Rotative Speed: • Smaller compressors operate at speeds up to 1800 rpm with larger units in the 750 - 1200 rpm range. Speed is normally determined by available driver speed.
  38. 38. © 2012 Valerus. Confidential and proprietary. All rights reserved. SEPARABLE / CENTRIFUGAL COMPARISION Comparing the most abundant combination in the upstream gas field. • Reciprocating Compressor driven by a Gas Engine : Separable • Radial Compressor driven by a Gas Turbine : Centrifugal
  39. 39. © 2012 Valerus. Confidential and proprietary. All rights reserved. SEPARABLE / CENTRIFUGAL COMPARISION Coverage:
  40. 40. © 2012 Valerus. Confidential and proprietary. All rights reserved. SEPARABLE / CENTRIFUGAL COMPARISION Separable vs. Centrifugal Coverage:
  41. 41. © 2012 Valerus. Confidential and proprietary. All rights reserved. SEPARABLE / CENTRIFUGAL COMPARISION POWER COMPARISON: 3 2 1 Point Separable Centrifugal 1 5182kW 5660kW 2 5138kW 6129kW 3 4016kW 4685kW
  42. 42. © 2012 Valerus. Confidential and proprietary. All rights reserved. SEPARABLE / CENTRIFUGAL COMPARISION POWER COMPARISON: Point Separable Centrifugal 1 5182kW 5660kW 2 5138kW 6129kW 3 4016kW 4685kW DRIVER RATINGS: Derate Temperature 37C 18% Altitude 260m 4% GT intake losses 100mm 0.7% GT exhaust losses 100mm • Gas Turbine Derate: 22% + 10% degradation • Gas Engine Derate: 0%
  43. 43. © 2012 Valerus. Confidential and proprietary. All rights reserved. SEPARABLE / CENTRIFUGAL COMPARISON POWER COMPARISION: Required Driver Rating (from Point 1): • Gas Engine rating required: 5182 kw • ISO Gas Turbine rating required: 5660 ÷0.68 = 8323 kw • Turbine rating needs to be 60% more than gas engine rating to meet design flows Solar Titan 130
  44. 44. © 2012 Valerus. Confidential and proprietary. All rights reserved. SEPARABLE / CENTRIFUGAL COMPARISON OPERATING COSTS: Fuel: • Cost of fuel is the single largest operating cost. • Reciprocating uses 23% less fuel than the Gas Turbine. Reciprocating Turbine Site Rating 8.44 Mj/Kwh 10.09 Mj/Kwh Total 43736 Mj/hr 57109 Mj/jr
  45. 45. © 2012 Valerus. Confidential and proprietary. All rights reserved. EFFICIENCY COMPARISON Turbine / Centrifugal Engine / Reciprocating Driver Heat Rate Btu / (hp-hr) 8239 6400 29% Compressor Hp / MMSCFD 26.5 24.7 +7% Decreasing Driver Speed Increased Fuel Rate No Change or Decrease Total Difference +36%
  46. 46. © 2012 Valerus. Confidential and proprietary. All rights reserved. Reciprocating Compressor: – piston rings and wear bands 16000 hr – valve overhaul 8000 hr – packings 16000 hr – complete 70000 hr • Engine – spark plugs 2000 hr – top end 30000 hr – complete 60000 hr • Estimated cost $7.2/MWh MAINTENANCE COMPARISON Centrifugal Compressor: – minimal with high quality gas • Gas Turbine – major overhaul 32000 hr • Estimated Cost $6.4/MWh
  47. 47. © 2012 Valerus. Confidential and proprietary. All rights reserved. AVAILABILITY 100% Downtime)dUnschedulefromLossesProduction(Actual ProductionActual yReliabilit    100% scheduled)LossesdUnscheduleLossesProduction(Actual ProductionActual tyAvailabili   
  48. 48. © 2012 Valerus. Confidential and proprietary. All rights reserved. AVAILABILITY • Reciprocating Rental fleet operators guarantee 97 - 99% availability for separable units • Rotating 99% expected for gas turbine / centrifugal
  49. 49. © 2012 Valerus. Confidential and proprietary. All rights reserved. PIPELINE APPLICATION EXAMPLE ASSUMPTIONS • 7500 Bhp installed • Heat rates (btu / (hp-hr)) – CAT 3616TA: 6810 – Wartsila 34SG: 6400 – Solar Taurus: 8239 • Fuel Cost: $2.5 / MM btu • Interest rate: 10% • Project life: 18 years
  50. 50. © 2012 Valerus. Confidential and proprietary. All rights reserved. PIPELINE APPLICATION EXAMPLE SOLAR CAT Wartsilla Installed Cost $6,091,000 $5,642,000 $5,834,000 O&M ($/hp) 25 40 45 Yearly O&M ($) $200,000 $320,000 $360,000 Yearly Fuel ($) $1,160,000 $841,000 $909,000 NPV - O&M ($) $1,640,000 $2,624,000 $2,952,000 NPV - Fuel ($) $9,511,000 $6,896,000 $7,454,000 Life Cycle Cost ($) $17,242,000 $15,162,000 $16,240,000 % Difference 14% 0% 7%
  51. 51. © 2012 Valerus. Confidential and proprietary. All rights reserved. PIPELINE APPLICATION EXAMPLE 0 50 100 150 200 250 300 350 Flow(MMSCFD) Jan Mar May July Sept Nov During Engineering / Design:
  52. 52. © 2012 Valerus. Confidential and proprietary. All rights reserved. PIPELINE APPLICATION EXAMPLE Flow MMSCFD Suction Pressure PSIA Discharge Pressure PSIA 305 550 900 300 564 900 290 590 900 280 615 900 250 678 900 225 722 900 During Engineering / Design:
  53. 53. © 2012 Valerus. Confidential and proprietary. All rights reserved. PIPELINE APPLICATION EXAMPLE Reciprocating Centrifugal Percent Flow 0 20 40 60 80 100 120 140 CompressionRatio 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 During Engineering / Design:
  54. 54. © 2012 Valerus. Confidential and proprietary. All rights reserved. PIPELINE APPLICATION EXAMPLE ACTUAL Operating Conditions:
  55. 55. © 2012 Valerus. Confidential and proprietary. All rights reserved. PIPELINE APPLICATION EXAMPLE Reciprocating Centrifugal Percent Flow 0 20 40 60 80 100 120 140 CompressionRatio 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 Design vs Actual:
  56. 56. © 2012 Valerus. Confidential and proprietary. All rights reserved. PIPELINE APPLICATION EXAMPLE Percent Flow 0 20 40 60 80 100 120 140 CompressionRatio 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2 Reciprocating Units Reciprocating 1 Reciprocating Unit Centrifugal Design vs Actual:
  57. 57. © 2012 Valerus. Confidential and proprietary. All rights reserved. OTHER CONSIDERATIONS gas turbine driven centrifugal compressor gas engine driven reciprocating compressor operating pressure not flexible, has very limited pressure ratio very flexible, can be designed to cover broad range of pressures flow capacity typical 100%-60% with variable guide vanes Large Capacity typically 100% - 50% with clearance control 100%-0% with recycle 100%-0% with recycle gas gravity pressure ratio is sensitive to the gas gravity pressure ratio is not affected by the gas gravity modification not practical to modify for changing gas conditions can be modified for # stages and changing gas types and flows cannot readily change pressure ratio can be designed as 1 stage / 2 stage or 2 stage/3 stage, etc size, weight small and compact larger and heavier than centrifugal available in large powers but similarly sized standby needed if the service is critical Above about 4700 hp would require multiple units but costs and flexibility are improved
  58. 58. © 2012 Valerus. Confidential and proprietary. All rights reserved. OTHER CONSIDERATIONS gas turbine driven centrifugal compressor gas engine driven reciprocating compressor cost usually higher capital cost usually lower capital cost fuel consumption 3 - 4 times higher than gas engine as low as 6800 - 8000 btu/bhp/hr usually requires fuel conditioning for field gases tolerant of field gases reliability typically 99 - 99.8% typically 95-98.5% needs sophisticated controls and instrumentation off the shelf control and instrumentation maintenance requires special shop repair and skilled technicians common tools and oil-field mechanics usually requires special synthetic lubricants Uses locally available engine crankcase lubricants requires special tools and assembly fixtures common tools and assembly techniques parts low usage, high cost predictable usage, low cost special parts, expensive insurance spares common parts, no insurance spares
  59. 59. © 2012 Valerus. Confidential and proprietary. All rights reserved. OTHER CONSIDERATIONS gas turbine driven centrifugal compressor gas engine driven reciprocating compressor failure modes can be unexpected and catastrophic usually with early symptoms and limited to replaceable components delivery Can be very long 9 - 18 months Can be very short 14 - 36 weeks installation small footprint and close centerlines larger footprint unbalance and vibration are nil unbalanced forces and moments are low typically 4 - 8 weeks typically a few days to a week portability usually not portable since the compressor is designed for a specific set of conditions and gas below about 2,000 hp can operate without foundation site rating turbines lose power generally above 500 ft turbocharged gas engines maintain power up to about 5,000 ft
  60. 60. © 2012 Valerus. Confidential and proprietary. All rights reserved. RECIPROCATING / CENTRIFUGAL COMPARISON Compressor Type Separable Centrifugal kw/m3 1 3 Installed cost 1 2 Lead time 1 3 Fuel consumption 1 2 Waste heat avail. 3 1 Availability 2 1 O & M cost 2 1 Low emissions 2 2 Operating flexibility 1 3 Compare a natural gas engine driven separable compressor to a gas turbine driven centrifugal compressor. 1 = best 2 = not quite as good 3 = worst
  61. 61. © 2012 Valerus. Confidential and proprietary. All rights reserved. CONCLUSIONS • Best compressor choice depends on: – Plant or site parameters – Project parameters – Process parameters – Machinery parameters
  62. 62. © 2012 Valerus. Confidential and proprietary. All rights reserved. CONCLUSIONS Gas Turbine driven Centrifugal compressors are best when: • Large horsepower is required • Waste heat is required • Limited range of process conditions • Minimal foundation is required • Light weight is desired • Low fuel gas cost • Long lead time is possible
  63. 63. © 2012 Valerus. Confidential and proprietary. All rights reserved. CONCLUSIONS Separable compressors are best when: • High fuel cost • No waste heat required • Minimum initial cost required • 6000 kw or less increments required • Medium project life is required • Relocation or conversion may be required • Minimum shipping/construction schedule • Maximum operating flexibility

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