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• Total leakage calculation:
T = on-load time (minutes)
t = off-load time (minutes)
• Well maintained system: less than 10%
leakages
Leak Quantification Method
Assessment of CompressorsAssessment of Compressors
Leakage (%) = [(T x 100) / (T + t)]](https://image.slidesharecdn.com/compressors-130530033006-phpapp01/85/Compressors-19-320.jpg)
![21
• Compressor capacity (m3/minute) = 35
• Cut in pressure, kg/cm2 = 6.8
• Cut out pressure, kg/cm2 = 7.5
• Load kW drawn = 188 kW
• Unload kW drawn = 54 kW
• Average ‘Load’ time =1.5 min
• Average ‘Unload’ time = 10.5 min
Example
Assessment of CompressorsAssessment of Compressors
Leakage = [(1.5)/(1.5+10.5)] x 35 = 4.375 m3/minute](https://image.slidesharecdn.com/compressors-130530033006-phpapp01/85/Compressors-21-320.jpg)
Compressors
This document provides an overview of a training session on air compressors and compressed air systems. It discusses the different types of compressors including reciprocating, rotary, centrifugal and axial compressors. It also covers how to assess compressors and compressed air systems to determine capacity, efficiency and leaks. Finally, it outlines various energy efficiency opportunities such as optimizing pressure settings and intake air conditions, installing intercoolers and aftercoolers, minimizing leaks, and implementing proper maintenance practices.
Compressors
- 1. 1 Training Session onAir CompressorTraining Session on Air Compressor Compressors &Compressors & Compressed AirCompressed Air SystemsSystems
- 2. 2 Training Agenda: CompressorTrainingAgenda: Compressor Introduction Types of compressors Assessment of compressors and compressed air systems Energy efficiency opportunities
- 3. 3 • Compressors: 5to > 50,000 hp • 70 – 90% of compressed air is lost Significant Inefficiencies IntroductionIntroduction
- 4. 4(CompressedAir) • Electricity savings:20 – 50% • Maintenance reduced, downtime decreased, production increased and product quality improved Benefits of managed system IntroductionIntroduction
- 5. 5 • Intake airfilters • Inter-stage coolers • After coolers • Air dryers • Moisture drain traps • Receivers Main Components in Compressed Air Systems IntroductionIntroduction
- 6. 6 Training Agenda: CompressorTrainingAgenda: Compressor Introduction Types of compressors Assessment of compressors and compressed air systems Energy efficiency opportunities
- 7. 7 Two Basic CompressorTypes Types of CompressorsTypes of Compressors Type of compressor Positive displacement Dynamic Reciprocating Rotary Centrifugal Axial
- 8. 8 • Used forair and refrigerant compression • Works like a bicycle pump: cylinder volume reduces while pressure increases, with pulsating output • Many configurations available • Single acting when using one side of the piston, and double acting when using both sides Reciprocating Compressor Types of CompressorsTypes of Compressors
- 9. 9 Screw compressor • Rotorsinstead of pistons: continuous discharge • Benefits: low cost, compact, low weight, easy to maintain • Sizes between 30 – 200 hp • Types • Lobe compressor • Screw compressor • Rotary vane / Slide vane Rotary Compressor Types of CompressorsTypes of Compressors
- 10. 10 • Rotating impeller transfersenergy to move air • Continuous duty Centrifugal Compressor Types of CompressorsTypes of Compressors • Designed oil free • High volume applications > 12,000 cfm
- 11. 11 • Efficiency atfull, partial and no load • Noise level • Size • Oil carry-over • Vibration • Maintenance • Capacity • Pressure Comparison of Compressors Types of CompressorsTypes of Compressors
- 12. 12 Training Agenda: CompressorTrainingAgenda: Compressor Introduction Types of compressors Assessment of compressors and compressed air systems Energy efficiency opportunities
- 13. 13 • Capacity: fullrated volume of flow of compressed gas • Actual flow rate: free air delivery (FAD) • FAD reduced by ageing, poor maintenance, fouled heat exchanger and altitude • Energy loss: percentage deviation of FAD capacity Capacity of a Compressor Assessment of CompressorsAssessment of Compressors
- 14. 14 • Isolate compressorand receiver and close receiver outlet • Empty the receiver and the pipeline from water • Start the compressor and activate the stopwatch • Note time taken to attain the normal operational pressure P2 (in the receiver) from initial pressure P1 • Calculate the capacity FAD: Simple Capacity Assessment Method Assessment of CompressorsAssessment of Compressors P2 = Final pressure after filling (kg/cm2a) P1 = Initial pressure (kg/cm2a) after bleeding) P0 = Atmospheric pressure (kg/cm2a) V = Storage volume in m3 which includes receiver, after cooler and delivery piping T = Time take to build up pressure to P2 in minutes
- 15. 15 Compressor Efficiency Assessment ofCompressorsAssessment of Compressors • Most practical: specific power consumption (kW / volume flow rate) • Other methods • Isothermal • Volumetric • Adiabatic • Mechanical
- 16. 16 Isothermal efficiency P1 =Absolute intake pressure kg / cm2 Q1 = Free air delivered m3 / hr r = Pressure ratio P2/P1 Compressor Efficiency Assessment of CompressorsAssessment of Compressors Isothermal efficiency = Actual measured input power / Isothermal power Isothermal power (kW) = P1 x Q1 x loge r / 36.7
- 17. 17 Volumetric efficiency D =Cylinder bore, meter L = Cylinder stroke, meter S = Compressor speed rpm χ = 1 for single acting and 2 for double acting cylinders n = No. of cylinders Compressor Efficiency Assessment of CompressorsAssessment of Compressors Volumetric efficiency = Free air delivered m3/min / Compressor displacement Compressor displacement = Π x D2/4 x L x S x χ x n
- 18. 18 • Consequences • Energywaste: 20 – 30% of output • Drop in system pressure • Shorter equipment life • Common leakage areas • Couplings, hoses, tubes, fittings • Pressure regulators • Open condensate traps, shut-off valves • Pipe joints, disconnects, thread sealants Leaks Assessment of CompressorsAssessment of Compressors
- 19. 19 • Total leakagecalculation: T = on-load time (minutes) t = off-load time (minutes) • Well maintained system: less than 10% leakages Leak Quantification Method Assessment of CompressorsAssessment of Compressors Leakage (%) = [(T x 100) / (T + t)]
- 20. 20 • Shut offcompressed air operated equipments • Run compressor to charge the system to set pressure of operation • Note the time taken for “Load” and “Unload” cycles • Calculate quantity of leakage (previous slide) • If Q is actual free air supplied during trial (m3/min), then: Quantifying leaks on the shop floor Assessment of CompressorsAssessment of Compressors System leakage (m3/minute) = Q × T / (T + t)
- 21. 21 • Compressor capacity(m3/minute) = 35 • Cut in pressure, kg/cm2 = 6.8 • Cut out pressure, kg/cm2 = 7.5 • Load kW drawn = 188 kW • Unload kW drawn = 54 kW • Average ‘Load’ time =1.5 min • Average ‘Unload’ time = 10.5 min Example Assessment of CompressorsAssessment of Compressors Leakage = [(1.5)/(1.5+10.5)] x 35 = 4.375 m3/minute
- 22. 22 Training Agenda: CompressorTrainingAgenda: Compressor Introduction Types of compressors Assessment of compressors and compressed air systems Energy efficiency opportunities
- 23. 23 • Significant influenceon energy use Energy Efficiency OpportunitiesEnergy Efficiency Opportunities 1. Location 2. Elevation • Higher altitude = lower volumetric efficiency
- 24. 24 3. Air Intake •Keep intake air free from contaminants, dust or moist • Keep intake air temperature low Every 4 o C rise in inlet air temperature = 1% higher energy consumption • Keep ambient temperature low when an intake air filter is located at the compressor Energy Efficiency OpportunitiesEnergy Efficiency Opportunities
- 25. 25 4. Pressure Dropsin Air Filter • Install filter in cool location or draw air from cool location • Keep pressure drop across intake air filter to a minimum Every 250 mm WC pressure drop = 2% higher energy consumption Energy Efficiency OpportunitiesEnergy Efficiency Opportunities
- 26. 26 5. Use Interand After Coolers • Inlet air temperature rises at each stage of multi-stage machine • Inter coolers: heat exchangers that remove heat between stages • After coolers: reduce air temperature after final stage • Use water at lower temperature: reduce power Energy Efficiency OpportunitiesEnergy Efficiency Opportunities
- 27. 27 • Higher pressure •More power by compressors • Lower volumetric efficiency • Operating above operating pressures • Waste of energy • Excessive wear Energy Efficiency OpportunitiesEnergy Efficiency Opportunities 6. Pressure Settings
- 28. 28 a. Reducing deliverypressure Operating a compressor at 120 PSIG instead of 100 PSIG: 10% less energy and reduced leakage rate Energy Efficiency OpportunitiesEnergy Efficiency Opportunities 6. Pressure Settings b. Compressor modulation by optimum pressure settings Applicable when different compressors connected c. Segregating high/low pressur requirements Pressure reducing valves no longer needed
- 29. 29 d. Design forminimum pressure drop in the distribution line • Pressure drop: reduction in air pressure from the compressor discharge to the point of use • Pressure drop < 10% • Pressure drops caused by • corrosion • inadequate sized piping, couplings hoses • choked filter elements Energy Efficiency OpportunitiesEnergy Efficiency Opportunities 6. Pressure Settings
- 30. 30 D. Design forminimum pressure drop in the distribution line Energy Efficiency OpportunitiesEnergy Efficiency Opportunities 6. Pressure Settings Typical pressure drop in compressed air line for different pipe size (Confederation of Indian Industries)
- 31. 31 7. Minimizing Leakage •Use ultrasonic acoustic detector • Tighten joints and connections • Replace faulty equipment 8. Condensate Removal • Condensate formed as after-cooler reduces discharge air temperature • Install condensate separator trap to remove condensate Energy Efficiency OpportunitiesEnergy Efficiency Opportunities
- 32. 32 9. Controlled usage •Do not use for low-pressure applications: agitation, combustion air, pneumatic conveying • Use blowers instead 10. Compressor controls • Automatically turns off compressor when not needed Energy Efficiency OpportunitiesEnergy Efficiency Opportunities
- 33. 33 9. Maintenance Practices •Lubrication: Checked regularly • Air filters: Replaced regularly • Condensate traps: Ensure drainage • Air dryers: Inspect and replace filters Energy Efficiency OpportunitiesEnergy Efficiency Opportunities
- 34. 34 Training Session onEnergyTraining Session on Energy EquipmentEquipment Compressors &Compressors & Compressed AirCompressed Air SystemsSystems