1. A Trane Air Conditioning Clinic Centrifugal Water Chillers Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999

2. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Chilled Water System

3. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 absorption centrifugal helical-rotary

4. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Centrifugal Water Chillers

5. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Centrifugal Water Chillers period one Components

6. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 condenser compressor control panel evaporator components of a Centrifugal Water Chiller starter motor

7. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Compressor

8. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Impeller blades

9. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 volute diffuser passage impeller passages Centrifugal Compressor

10. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 centrifugal compressor Energy Conversion refrigerant enters diffuser path through compressor velocity static pressure refrigerant enters impeller refrigerant enters volute

11. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Multistage Compressor

12. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Condenser baffle tubebundle liquid refrigerant refrigerant vapor cooling tower water

13. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 toevaporator orifice plates H1H1H1H1 expansion device Orifice Plates

14. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 expansion device Orifice Plates H2H2H2H2 toevaporator orifice plates

15. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 2-stage chiller Economizer refrigerant vapor to second stage of compression liquid refrigerant to evaporator orifice liquid refrigerant from condenser

16. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 3-stage chiller Economizer liquid refrigerant to evaporator orifice orifice refrigerant vapor to second stage of compression refrigerant vapor to third stage of compression liquid refrigerant from condenser

17. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Evaporator eliminator liquiddistributor orifice system liquid refrigerant tube bundle chilled water return

18. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Motor impellers impeller motor motor gear-drive direct-drive gears

19. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Hermetic Motor Cooling stator rotor drain liquidrefrigerant

20. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Controls and Starter control panel starter

21. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Starters remote-mounted starter line power control power wiring unit-mounted line power control power wiring

22. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Centrifugal Water Chillers period two Refrigeration Cycle

23. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 2-stage centrifugal chiller Refrigeration Cycle condenser evaporator expansion devices economizer 2-stagecompressor

24. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Pressure-Enthalpy (p-h) Chart enthalpy subcooledliquid mixture of liquid and vapor 15.5 Btu/lb [201.0 kJ/kg] pressure superheatedvapor B A 5 psia [0.034 MPa] 92.4 Btu/lb [380.4 kJ/kg]

25. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 2-stage centrifugal chiller Refrigeration Cycle1 2 3 4 6 7pressure enthalpy evaporator condenser 2-stage compressor expansion devices 8 9 PePePePe PcPcPcPc P1P1P1P15economizer

26. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 2-stage centrifugal chiller Refrigeration Cycle1 2pressure enthalpy evaporator condenser PePePePe PcPcPcPc P1P1P1P1 CB A6 7 9 5 2-stage compressor economizer3 4 expansion devices 10 8

27. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 pressure temperature HCFC-22 HCFC-123 atmosphericpressure Refrigerant Operating Pressures HFC-134a

28. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Low-Pressure Chillers compressor suction elbow evaporator

29. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Purge System

30. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Purge Operation filtration canister refrigerant vapor from condenser to condenser filter drier purge evaporator coil purge tank to chiller vent line

31. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Centrifugal Water Chillers period three Compressor Capacity Control

32. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Inlet Vanes inlet vanes impeller

33. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Multistage Compressor inlet vanes impellers

34. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 VrVrVrVr R VtVtVtVt Impeller

35. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Impeller Dynamics diameter V r refrigerant flow rate V r  refrigerant flow rate V t rotational speed × diameter V t  rotational speed × diameter rotational speed VrVrVrVr R VtVtVtVt refrigerant flow rate

36. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Compressor Unloading VrVrVrVr R VtVtVtVt VrVrVrVr VtVtVtVt full load part load R

37. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 VrVrVrVr VtVtVtVt Surge V r < static pressure R

38. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Compressor Map 25 75 10 14 63 pressure difference refrigerant flow rate surge vane position (degrees) 90 36 51

39. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Operating Point pressure difference refrigerant flow rate operatingpoint

40. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 compressor map for a 2-Stage Compressor 25 75 10 14 63 pressure difference refrigerant flow rate surge 90 36 51 operatingpoint vane position (degrees)

41. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 compressor map for a 2-Stage Compressor 25 75 10 14 63 pressure difference refrigerant flow rate surge 90 36 51 C B A unloading line

42. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Adjustable-Frequency Drives power consumption load inlet vanes only AFD + inlet vanes

43. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Centrifugal Water Chillers period four Maintenance Considerations

44. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Maintenance Considerations s Operating log s Mechanical components s Heat-transfer surfaces s Fluid analysis

45. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 operating log ASHRAE Guideline 3 s Chilled water inlet and outlet temperatures and pressures s Chilled water flow s Evaporator refrigerant temperature and pressures s Evaporator approach temperature s Condenser water inlet and outlet temperatures and pressures s Condenser water flow s Condenser refrigerant temperature and pressures s Condenser approach temperature s Oil pressures, temperature, and levels s Addition of refrigerant s Addition of oil s Vibration levels

46. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 maintenance considerations Mechanical Components s Required maintenance u Compressor and motor: no maintenance required u Controls: no maintenance or calibration required s Recommended maintenance u Visually inspect overall unit u Inspect safety controls and electrical components u Tighten electrical connections u Check for leaks

47. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 s Other design-specific requirements u Change oil when oil analysis dictates u Replace oil filter periodically u Replace filter drier periodically u Clean oil strainers annually u Check shaft alignment annually u Check coupling annually u Replace shaft seal every 2 to 4 years u Compressor teardown inspection every 5 to 10 years maintenance considerations Mechanical Components

48. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 maintenance considerations Heat Transfer Surfaces s Recommended maintenance u Use a qualified water treatment specialist u Clean condenser tubes as needed u Clean water-side strainers u Test tubes every 3 years

49. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Fluid Analysis s Oil analysis u Conduct annual analysis to verify system integrity u Measure oil pressure drop to determine if filter needs changing u Measure charge s Refrigerant charge u Conduct analysis of refrigerant u Inspect purge system

50. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Oil Analysis s Why perform regular oil analysis? u Helps reduce maintenance costs u Detects problems without compressor disassembly u Extends service life of oil charge u Reduces environmental problems related to oil disposal u Helps maintain compressor efficiency and reliability u Helps lower refrigerant emissions

51. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Centrifugal Water Chillers period five Application Considerations

52. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Condensing Temperature Control 25 75 10 14 63 pressure difference refrigerant flow rate surge 90 36 51 B A C vane position (degrees) unloading line

53. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 condensing temperature control Cooling Tower Bypass condenser bypass cooling tower 55°F[13°C] 40°F [4°C] 65°F [18°C] divertingvalve

54. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 evaporator water flow Constant or Variable Flow variable- speed drive chilled water pump evaporator

55. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 variable evaporator water flow Limitations s Maintain minimum and maximum water flow rates through the chiller evaporator s Rate at which the evaporator water flow changes must be kept below the corresponding limit to: u Maintain the chilled water set point control u Keep the chiller on line u Protect the chiller from damage

56. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Short Evaporator-Water Loops load chilled water pump evaporator

57. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Short Evaporator-Water Loops load chilled water pump evaporator tank

58. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Heat Recovery heat-recovery condenser cooling tower water standard condenser

59. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 heat-recovery (dual) condenser auxiliary condenser u No extra condenser u Large base heating loads or continuous operation u High hot water temperatures u Controlled u Chiller efficiency preserved u Second, full- size condenser u Large heating loads u High hot water temperatures u Controlled u Degrades chiller efficiency u Second, smaller size condenser u Preheating loads u Moderate hot water temperatures u Uncontrolled u Improves chiller efficiency heat pump Heat-Recovery Chiller Options

60. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 air-side economizer strainer cycle u Potential fouling limited to heat exchanger u Requires additional heat exchanger, piping, valves, and controls u Can operate simultaneously with chiller u Most efficient u Requires larger outdoor air, return, and exhaust duct systems u Coldest water temperatures u Potential fouling in chilled water loop u Requires additional piping, valves, and controls plate-and-frame heat exchanger Free Cooling

61. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 free cooling Refrigerant Migration from compressor to compressor evaporator condenser

62. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 equipment certification standards ARI Standard 550/590 s Purpose u Establish definitions, testing, and rating requirements s Scope u Factory designed and prefabricated water chillers u Vapor-compression refrigeration u Air-cooled and water-cooled condensing

63. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 equipment certification standards ARI Standard 550/590 s Standard rating conditions u Common system conditions for published ratings u Fouling factor s Integrated Part Load Value (IPLV) u Part-load efficiency rating u Based on an “average” single-chiller installation u Standard operating conditions

64. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Centrifugal Water Chillers period six Review

65. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Review—Period 1 condenser compressor control panel evaporator starter motor

66. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Review—Period 21 2 3 4 6 7pressure enthalpy evaporator condenser 2-stage compressor expansion devices 8 9 PePePePe PcPcPcPc P1P1P1P15economizer

67. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Review—Period 3 inlet vanes impellers

68. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Review—Period 4 s Maintenance considerations u Operating log u Mechanical components u Heat-transfer surfaces u Fluid analysis

69. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999 Review—Period 5 s Application considerations u Condensing temperature control u Constant or variable evaporator-water flow u Short evaporator-water loops u Heat recovery u Free cooling u Equipment certification standards

70. Air Conditioning Clinic TRG-TRC010-EN © American Standard Inc. 1999