1 / 52

Lowering Your Compressed Air Energy Costs

Lowering Your Compressed Air Energy Costs . Trey Donze Mike Hotz Air Technologies. Why Care About Compressed Air?. Compressed air is expensive Compressed air is essential to plant productivity Compressed air systems can be effectively managed to improve plant operation

Pat_Xavi
Download Presentation

Lowering Your Compressed Air Energy Costs

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lowering Your Compressed Air Energy Costs Trey Donze Mike Hotz Air Technologies

  2. Why Care About Compressed Air? • Compressed air is expensive • Compressed air is essential to plant productivity • Compressed air systems can be effectively managed to improve plant operation • Compressed air systems usually have significant opportunities for efficiency improvement

  3. Compressed Air Use in Selected Manufacturing Industries Compressed Air Energy Use as a Percentage of Total Electricity Use Food Metals Paper Petroleum Chemicals

  4. Life Cycle Cost of an air compressor • Energy cost can account for up to 90% over a ten year working life • Within 12 months, the capital cost is usually exceeded by the running costs • First cost represents the lowest of the three costs • Energy consumption by far is the most significant factor in operating cost of an air compressor Energy consumption Installation Maintenance Investment

  5. Benchmark Your System’s Efficiency • To make an accurate determination of energy savings solutions, it is important to measure your system flow, pressure and kW as well as evaluate any plans for future expansion • This is accomplished by a flow and kW survey

  6. Benchmark Your System’s Efficiency • Measure your compressed air requirements • Flow • Pressure • Dew point • kW and kWh • Benchmark your current system’s efficiency kWh/MCF • Receive a detailed report outlining improvements

  7. KW Meters

  8. Typical 24 hrs/day operation with low night shift and high day shift consumption. Steady weekend consumption (leakages). • (64% of installations). time

  9. Five days/week operation, erratic demand fluctuations • (28% of installations). time

  10. Energy Reduction Opportunities • Use Efficient Compressor Controls • Reduce Compressed Air Usage • Lower Compressor Discharge Pressure • Efficiently Sequence Air Compressors • Operate and Maintain Compressed Air Equipment at Peak Efficiency

  11. % Power Input % Capacity

  12. Use Efficient Compressor Controls 75 HP Lubricated screw compressor w/ Modulation Control -vs.- 60 HP VSD Average electrical cost = $0.06 / KWHR A) 1st shift 250 CFM 2200 HRS/YR B) 2nd shift 175 CFM 2200 HRS/YR C) 3rd shift 100 CFM 2200 HRS/YR 75 HP unit @ 125 PSIG60HP VSD @ 125 PSIG 82.5 Bhp full load power 66 Bhp full load power 320 CFM 290 CFM 91.5% Motor eff. 94%

  13. Use Efficient Compressor Controls 75 Hp modulating60 Hp VSD 250 CFM: 250/320 = 78% (93% Bhp) 250/290 = 86% (86% Input kW) 175 CFM: 175/320 = 55% (86.5% Bhp) 175/290 = 60% (61% Input kW) 100 CFM: 100/320 = 31% (79% Bhp) 100/290 = 34% (38% Input kW)

  14. Use Efficient Compressor Controls 75 HP lubricated screw with modulation control A) First shift 250 CFM: 82.5 Bhp X (.93 factor) X .746kW X $.06 X 2200Hrs = $8,738 .915 Mtr. eff. Hp kWh B) Second shift 175 CFM: 82.5 Bhp X (.865 factor) X .746kW X $.06 X 2200Hrs = $8,127 .915 Mtr. eff. Hp kWh C) Third shift 100 CFM: 82.5 Bhp X (.79 factor) X .746kW X $.06 X 2200Hrs = $7,422 .915 Mtr. eff. Hp kWh Total = $24,287

  15. Use Efficient Compressor Controls 60 Hp Variable Speed compressor A) First shift 250 CFM: 66 Bhp x .746 kW x (.86 factor) x $.06 x 2200Hrs = $5,946 .94 ME. Hp kWh B) Second shift 175 CFM: 66 Bhp x .746 kW x (.61 factor) x $.06 x 2200Hrs = $4,217 .94 ME Hp kWh C) Third shift 100 CFM: 66 Bhp x .746 kW x (.38 factor) x $.06 x 2200Hrs = $2,627 .94 ME Hp kWh Total = $12,790

  16. Use Efficient Compressor Controls Total Power Savings: $24,287 - $12,790 = $11,497 per year 60 HP VSD costs $25,000 for a 2.17 year payback!

  17. Reduce Compressed Air Usage • Eliminate inappropriate air users • Use brushes, blowers, or vacuum systems instead of compressed air to clean parts or remove debris;  • Use blowers, electric actuators, or hydraulics instead of compressed air blasts to move parts; • Use high efficiency nozzles instead of open orifices

  18. Reduce Compressed Air Usage • Eliminate inappropriate air users • Use fans to cool electrical cabinets instead of compressed air vortex tubes • Apply a vacuum system instead of using compressed air venturi methods • Use blowers instead of compressed air to provide cooling, aspirating, blow guns, air lances, agitating, mixing, or to inflate packaging

  19. Reduce Compressed Air Usage • Minimize unregulated air users • Install regulators • Reduced pressure lowers air consumption • Unregulated users use 47% more compressed air at 110 vs. 70 PSIG • Less equipment wear and tear

  20. Reduce Compressed Air Usage • Shut off air to equipment that is shutdown or abandoned • Install automatic solenoid valves • Valve off idled sections of the plant

  21. Reduce Compressed Air Usage • Fix Leaks • Leaks can account for 10-50% of the total compressed air usage! 1/8 inch dia. hole = 25 SCFM = $3,000 1/4 inch dia. hole = 100 SCFM = $12,000 3/8 inch dia. hole = 230 SCFM = $26,000 * Based on 8,760 operating hrs/yr @ $0.07 per kWh energy cost

  22. Reduce Compressed Air Usage • Minimize Leaks • Measure leak load to quantify the opportunity • Find the leaks with an ultrasonic leak detector • Tag the leaks • Fix the leaks • Re-measure the leak load to quantify the savings • Develop and on-going leak reduction program

  23. Reduce Compressed Air Usage • Reduce plant system air pressure • Unregulated air users and air leaks use 28% more compressed air at 120 vs. 90 PSIG

  24. Reduce Compressed Air Usage • Reduce system air pressure • Evaluate the pressure requirements of all compressed air users • Put the small high pressure user on its’ own compressor • Install good compressor sequencing controls • Lower the system air pressure

  25. Reduce System Air Pressure • Measure system/component pressure drops • Minimize distribution and component pressure drops • Loop air header • Upgrade, repair or eliminate high delta P components • Upsize piping/hoses • Address large intermittent air “gulpers” that draw the system down with storage and metering valves • Decentralize compressors

  26. Receiver Sizing Useful Free Air Stored = V x P 14.7 V = storage volume (Ft3) P = pressure differential (Pressure Drop in Tank) Example: Pneumatic conveyor requires 200 cfm of 40 psig air for 2 minutes every 10 minutes. 200 X 2=400 CF required useful free air to be stored  P=100-40=60 400=V X 60/14.7 V= 400 X 14.7/60 = 98 CF = 735gallons 400 CF/8 minutes=50 CFM to refill System sees 50 CFM instead of 200 CFM!

  27. Lower System Pressure to Lower Air Consumption 95 psig – 950 CFM air usage 85 psig – 825 CFM air usage 70 psig – 700 CFM air usage

  28. Reduce Compressed Air Usage • Reduce system air pressure • Use intermediate controllers with storage to regulate system air pressure • Effective when part of the plant operates at a lower pressure • Lowers air consumption • Does not lower compressor pressure

  29. Reduce Compressed Air Usage • Reduce system air pressure • Use effective compressor sequencing, storage, and compressor controls to “regulate” system pressure • Lowers air consumption and compressor pressure • Most energy efficient

  30. Sequence Air Compressors

  31. Typical System Without a Sequencer Cascading Systems C1 C2 C3 C4 125 PSIG 125 unload 120 115 • Individual settings • Large pressure band • Multiple units at part load • Very inefficient 110 115 110 105 load 100 100 PSIG

  32. Sequencers Significantly Improve Efficiency to Minimize Energy Costs • Can regulate system pressure within 3-5 psi • Lower system pressure significantly reduces air demand (leaks and unregulated demand) • Operates the minimum # of compressors to meet the demand • Only one compressor trims at all times • Automatic scheduled system pressure changes and/or start/stop of system • Most efficient compressor sequence order determined from flow data • Can automatically select optimum sequence

  33. System Pressure remains consistent as flow rate varies

  34. Power consumption increases 1% for every 2 psi increase in compressor pressure RULE OF THUMB

  35. Sequencerspay for themselves in energy savings by reducing pressure band differentials and lowering air usage EXAMPLE- 4-100 Hp Compressors Required: 1700 SCFM at 100 Psig Pressure Switch Settings Between 95 to 125Psig Pressure Band of 30 Psig 400 Hp x .745 kW/Hp x 8800/year x .06 kWh = $167,387.00 .94 (motor Efficiency) Reduce Pressure Band by 25 Psig to save12%=$20,086.00

  36. Flow changes but kW does not change proportionally

  37. Poor efficiency of a cascaded system due to multiple units at part load

  38. Sequencers Can Significantly Improve Efficiency to Minimize Energy Costs Total system energy savings of 20-50% are expected

  39. kW/100 CF stays consistent even under varying loads .32 kW/100CF versus .85 kW/100CF (63% Savings!)

  40. Switch to LILO Sequencing with a 5 minute unloaded time

  41. Sequencing Significantly Improves Efficiency to Minimize Energy Costs • Basis 3 shift operation, $.06/kWhr, 20 PSI pressure band reduction

  42. Advanced sequencers provide system flow and pressure data to manage your 4th Utility • System flow and pressure are logged automatically • Determine the most efficient compressor sequence • Useful for peak load shedding • Measure leaks • Spot system/ production problems • Measure equipment/process air consumption

  43. ManagAIR® by Air Technologies® System Report for Ferro 9/7/01 1:59:05 PM Alarm: No Faults Detected Current System Readings- Pressure=108 Flowrate=1347 Sequence=2,1,3 Previous 8hrs Data: Hour1 Hour2 Hour3 Hour4 Hour5 Hour6 Hour7 Hour8 Min Pressure 104 104 104 104 104 104 104 104 Avg Pressure 108 108 109 109 109 109 109 109 Max Pressure 114 114 114 114 114 114 114 114 Min FlowRate 1274 1274 1311 1322 1324 1349 1311 1305 Avg FlowRate 1448 1468 1648 1647 1739 1870 1644 1718 Max FlowRate 2274 2298 2504 2485 2545 2629 2409 2432 Min DewPoint -44 -43 -43 -43 -40 -36 -32 -21 Avg DewPoint -41 -41 -36 -40 -37 -33 -25 -15 Max DewPoint -39 -39 -11 -37 -35 -30 -19 -10 Compressor Data #1 ZT25 #2 ZT25 #3 ZT25 NONE NONE NONE NONE Delivery Air Press 110 113 107 DP Air Filter -.01 -.1 .01 Intercooler Pressure -9 30 1 Oil Injection Press 28 28 0 Delivery Air Temp 93 93 86 Oil Injection Temp 122 124 90 LP Outlet Temp 351 352 95 HP Outlet Temp 363 372 91 HP Inlet Temp 99 104 91 Cooling Medium Inlet Temp 91 91 86 MD Regen Air Out Temp 129 162 84 MD Wet Air In Temp 97 99 81 LP Element Temp Rise 260 261 9 HP Element Temp Rise 264 268 0 Cooling Water Temp Rise Oil Cooler Approach Temp 31 33 4 Aftercooler Approach Temp 2 2 0 Intercooler Approach Temp 8 13 5 MD Regen Temperature Drop 234 210 7 MD Inlet Temperature Diff 4 6 -5 Loaded Hours 7358 7579 8773 Running Hours 11048 11616 12606 Compressor Status UNLOADED LOADED STOPPED Motor Starts 1717 1042 1060 Link Type MKIII MKIII MKIII Isolated/Integrated CENTRAL CENTRAL CENTRAL Full Feature Dew Point Oil Filter Remaining Lifetime 2423 1413 952 Oil Filter Total Lifetime 4000 4000 4000 Oil Remaining Lifetime 4952 4383 3475 Oil Total Lifetime 16000 16000 16000 Hours Until Regrease Bearings 848 286 3471 Hours Between Bearing Regreasing 4000 4000 4000 Daily System Report and graph faxed or e-mailed to you automatically

  44. Every 4 inches (water) pressure drop reduces the compressor capacity 1% A dirty inlet filter can rob you of 5% or more! Good Maintenance Saves Energy Inlet Filters

  45. Good Maintenance Saves Energy Dirty Coolers For every 11oF deterioration in the intercooler approach or increase in water temperature, the power consumption will increase by 1%.

  46. Good Maintenance Saves Energy Dirty Coolers For every 10oF deterioration of the after cooler approach temperature, the dryer load is increased by as much as 46%.

  47. Good Maintenance Saves Energy Dirty Oil Separator A dirty oil separator can increase your HP 5%

More Related