降低压缩空气能源费用 lowering compressed air energy

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 Compressed air systems usually have significant opportunities for efficiency improvement,Compressed Air Use in Selected Manufacturing Industries,Compressed Air Energy Use as a Percentage of Total Electricity Use,Chemicals,Petroleum,Metals,Food,Paper,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,Investment,Installation,Maintenance,Energy consumption,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,Benchmark Your Systems Efficiency,Measure your compressed air requirements Flow Pressure Dew point kW and kWh Benchmark your current systems efficiency kWh/MCF Receive a detailed report outlining improvements,Benchmark Your Systems Efficiency,KW Meters,Typical 24 hrs/day operation with low night shift and high day shift consumption. Steady weekend consumption (leakages). (64% of installations).,time,Five days/week operation, erratic demand fluctuations (28% of installations).,time,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,% Capacity,% Power Input,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 PSIG 60HP VSD 125 PSIG 82.5 Bhp full load power 66 Bhp full load power 320 CFM 290 CFM 91.5% Motor eff. 94%,Use Efficient Compressor Controls,Use Efficient Compressor Controls,75 Hp modulating 60 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),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,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,Total Power Savings: $24,287 - $12,790 = $11,497 per year 60 HP VSD costs $25,000 for a 2.17 year payback!,Use Efficient Compressor Controls,System running with (2)-125 HP OL/OL compressors 3.7 kWH/MCF Inconsistent efficiency,System running with (1)-125 HP OL/OL compressors and (1)-75 HP VSD 3.3 kWH/MCF Nearly constant efficiency,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,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,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,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,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,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,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,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,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,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 = 735 gallons 400 CF/8 minutes=50 CFM to refill System sees 50 CFM instead of 200 CFM!,Lower System Pressure to Lower Air Consumption,70 psig 700 CFM air usage,85 psig 825 CFM air usage,95 psig 950 CFM air usage,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,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,Sequence Air Compressors,Typical System Without a Sequencer Cascading Systems,C1,C2,C3,C4,unload,load,Individual settings Large pressure band Multiple units at part load Very inefficient,100 PSIG,110,105,115,110,120,115,125 PSIG,125,100,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,System Pressure remains consistent as flow rate varies,Power consumption increases 1% for every 2 psi increase in compressor pressure,RULE OF THUMB,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 save 12%=$20,086.00,Sequencers pay for themselves in energy savings by reducing pressure band differentials and lowering air usage,Flow changes but kW does not change proportionally,Poor efficiency of a cascaded system due to multiple units at part load,Sequencers Can Significantly Improve Efficiency to Minimize Energy Costs,Total system energy savings of 20-50% are expected,kW/100 CF stays consistent even under varying loads,.32 kW/100CF versus .85 kW/100CF (63% Savings!),Switch to LILO Sequencing with a 5 minute unloaded time,Sequencing Significantly Improves Efficiency to Minimize Energy Costs,Basis 3 shift operation, $.06/kWhr, 20 PSI pressure band reduction,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,Advanced sequencers provide system flow and pressure data to manage your 4th Utility,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