1. 1 Vapour compression cycle Refrigerator Air conditioning plant Heat pump (“ ENERGY MANAGEMENT HANDBOOK” Sixth Edition, Chapter 8)

2. 2 Refrigerator

3. 3 Electric-motor-driven vapour compression cycle

4. 4 Engine-driven vapour compression cycle

5. 5 Absorption heat pump

6. 6 Applications of Heat pumps space heating; heating and cooling of process streams; water heating for washing, sanitation and cleaning; steam production; drying/dehumidification; evaporation; distillation; concentration.

7. 7 Heat pump performance Heat source at 0 C

8. 8 Typical COP

9. 9 Temperature Pressure Heat Transformer

10. 10 Factors affecting heat pump performance the climate - annual heating and cooling demand and maximum peak loads; the temperatures of the heat source and heat distribution system; the auxiliary energy consumption (pumps, fans, supplementary heat for bivalent system etc.); the technical standard of the heat pump; the sizing of the heat pump in relation to the heat demand and the operating characteristics of the heat pump; the heat pump control system.

11. 11 How heat pumps achieve energy savings and CO 2 emissions reduction Heat pumps and energy saving An efficient technology A large and worldwide potential

12. 12 Heat sources Heat sourceTemperature Range (°C) Ambient air-10 +15 Exhaust air+15 +25 Ground water+4 +10 Lake water0 +10 Rock0 +5 Ground0 +10 Waste water >10

13. 13 Heat pump working fluids HFC-134a R-407C Natural working fluids

14. 14 Heat pumps in residential and commercial buildings

15. 15 Example of how the COP of a water-to-water heat pump varies with the distribution/return temperature.

16. 16 Fundamental physics for vapor compression cycles

17. 17 Constant-pressure change from liquid to vapour phase for a pure substance.

18. 18 Temperature change of substance at constant pressure and constant heat supply

19. 19 Temperature-volume diagram showing liquid and vapour phases for different constant pressures

20. 20 Temperature-volume diagram showing liquid and vapour phases

21. 21 Ideal vapour compression cycle

22. 22 Relations for the cycle

23. 23 Ideal cycle 1 2 4 3

24. 24 Log P vs Enthalpy diagram Constant Temperature Absolute Pressure Saturation area Saturated liquid Saturated vapour Constant Entropi Enthalpy

25. 25 Coefficient of performance The coefficient of performance of a refrigeration system is The coefficient of performance of a heat pump system is

26. 26 Efficiency of compressor

27. 27

28. 28 Sweden - Closed-cycle compression heat pump

29. 29

30. 30 Example refrigerator/Heat Pump An refrigerator has an cooling capacity of 500 W. Evaporator pressure 2 bar(a), Condenser pressure 10 bar(a). An ideal cycle is assumed Determine Power input to compressor Heat transfer rate from Condenser

31. 31 Solution