Refrigerant 22 enters an air conditioner compressor at 6 bar

Refrigerant 22 enters an air conditioner compressor at 6 bars, 10 degree C, and is compressed at steady state to 14 bars, 45 degree C. The volumetric flow rate of refrigerant entering is 2.05 m^3/min. The power input to the compressor is 20.7 kJ per kg of refrigerant flowing. Neglecting kinetic and potential energy effects, determine the heat transfer rate, in kW.

Solution

From R-22 properties:

At 6 bar, 10 deg C we get enthalpy h1 = 255 kJ/kg, specific volume v1 = 0.0402 m^3/kg

At 14 bar, 45 deg C, we get enthalpy h2 = 269 kJ/kg

q - w = h2 - h1

q - 20.7 = 269 - 255

q = 34.7 kJ/kg

Massflow rate m = volume flow rate / v1

= 2.05 / 0.0402

= 51 kg/min

= 51/60 kg/s

= 0.85 kg/s

Heat transfer Q = q*m

= 34.7*0.85

= 29.5 kW