An ice making plant using refrigerant R-12 is having an evaporator saturation temperature of –250C and the condenser saturation temperature of 350C. The vapour is leaving the compressor of 650C. The following table shows the properties of the refrigerant.
|
Temp. 0C
|
Pressure (kPa
|
Saturation Enthalpy (kJ/kg)
|
|
Liquid
|
Vapour
|
|
–25
|
123.7
|
13.3
|
176.5
|
|
35
|
850.0
|
69.6
|
201.5
|
|
enthalpy of superheated refrigerant at 850 kPa and 650C = 225.5 kJ/kg
|
(a) Calculate the Coefficient of performance (COP) of this system
(b) If the capacity of the plant is 5 kW, calculate mass flow rate of refrigerant