A VCC refrigerating machine using R-12 refrigerant produces 10 tonnes of refrigeration at 10 0C when the ambient is at 35 0C. A temperature difference of minimum 5 0C is required at the evaporator and condenser for spontaneous heat transfer. The refrigerant is dry saturated at the outlet and to the inlet of compressor. The adiabatic efficiency of the compressor is 90%. The enthalpy at the end of isentropic compression is estimated to be 370 kJ/kg.
Determine : 20
- COP
- Power of the compressor
- Capacity of the condenser
Represent the cycle on hand drawn T-S plane and show the refrigerating effect, compressor work and condenser capacity on the same. 30
|
Temperature
(0C)
|
Pressure (bar)
|
Specific Enthalpy, kJ/kg
|
|
|
|
Sensible
|
Evaporation
|
|
5
|
3.62
|
204.64
|
148.97
|
|
10
|
4.23
|
209.32
|
146.37
|
|
15
|
4.91
|
214.10
|
143.69
|
|
30
|
7.45
|
228.54
|
135.04
|
|
35
|
8.47
|
233.50
|
131.90
|
|
40
|
9.60
|
238.53
|
128.62
|