6. Chapter10 Refrigeration Cycle

7. 10-1 Vapor-Compression Cycle 10-1-1 The Reversed Carnot Cycle T s 4 1 2 3 THTH TLTL Coefficient of Performance

8. Disadvantages Process 2-3 is difficult to be Fulfill in compressor Process 4-1 will do harm to turbine

9. 10-1-2 The Ideal Vapor-Compression Refrigeration Cycle condenser Equipments: 1 2 3 4 compressor Expansion valve evaporator

10. T s THTH TLTL 1 2 3 4

11. condenser compressor evaporator Capillary tube

13. 10-1-3 The COP of 10-1-3 The COP of Vapor-Compression Cycle h-s diagram h s 1 23 4

14. Usually p 1, p 2 are available h s 1 2 3 4 From p 1, get h 1 ”, s 1 ” h 1 = h 1 ” s 1 = s 1 ” From p 2, s 1, get h 2 From p 2, get h 2 ’ h 3 = h 2 ’ h 4 = h 3

15. p-h diagram

16. p h 1 2 3 4

17. 10-2 Refrigerant Ammonia CFC(chlorofluorocarbons) water Good refrigerant High enthalpy of vaporization Not too low evaporator pressure Not too high condenser pressure Nontoxic Noncorrosive Chemically stable Low cost

18. 10-3 Heat Pump An equipment Absorbing heat from environment for heating purpose T s THTH T0T0 1 2 3 4

19. Heat pump for heating

20. Heat pump for refrigeration

21. 10-4 Innovative Vapor-compression Refrigeration Systems 10-4-1 Regenerative Vapor Compression cycle Equipments condenser evaporator Heat exchanger separator compressor

22. T s THTH TLTL 1 2 3 4 T-s Diagram 2’ 1’

23. 10-4-2 Cascade Refrigeration Systems condenser evaporator

24. T s T0T0 T-s Diagram

25. 10-4-3 Multistage Compression Refrigeration Systems condenser evaporator Flash chamber 1 2 3 heat exchanger 45 6 7 8 9 T s 1 2 3 4 5 6 7 8 9

26. 10-4-4 Multipurpose Refrigeration Systems with a Single Compressor condenser Freezer refrigerator 1 2 3 4 5 6 Alternative path T s 1 2 3 4 5

27. 10-4-5 Liquefaction of Gas Heat exchanger Make up gas Liquid removed Multistage compressor 1 2 3 4 5

28. T s 1 2 1 3 4 5

29. 10-5 Gas Refrigeration cycle 10-4-1 Equipments Heat exchanger QHQH QLQL compressor turbine

30. T s p2p2 p1p1 1 2 3 4 T0T0 TLTL

31. 10-4-2 COP of Gas Refrigeration Cycle T s 1 2 3 4 T0T0 TLTL

32. T s 1 2 3 4 T0T0 TLTL

33. Since To decrease compression ratio can increase COP To To decrease compression ratio will decrease power ratio

34. T s T0T0 TLTL

35. T s T0T0 TLTL 1 2 45 3 q 6 q 10-4-3 Regenerative Gas Refrigeration Cycle

36. Heat exchanger QHQH QLQL compressor turbine regenerator 1 2 3 45 6

37. 10-6 Absorption Refrigeration System heat condenser evaporator =compressor

38. Refrigerant: Ammonia Transport medium: Water Refrigerant: Water Transport medium: Lithium bromide

39. 10-6 Adsorption Refrigeration Solar energy Active carbon evaporator condenser

40. Cooling Tube Solar energy Night Cold air Active carbon Vacuum tube Cooling tower

41. The End of This Chapter Thank You