A Carnot refrigerator has working temperatures of -30°C and 35°C. If it operates with Refrigerant 502 as a working substance, calculate the work isentropic compression and that of isentropic expansion, and the refriger

A vapor compression refrigerator using R134a as the refrigerant operates under the following conditions: The refrigerant condenses at 50°C and is then sub-cooled by 10°C to 30°C before expansion. After an isenthalpic expansion, the refrigerant evaporates at -20°C and then superheated by 10°C to 0°C before compression. The refrigerant is compressed to 70°C with entropy of 1.0 kJ/kg.K at the end of the compression. a)With reference to the above operating conditions, draw the cycle on the R134a p-h diagram. b)Calculate the specific refrigerating effect at the evaporating temperature of -20°C. c)Calculate the work input for the compression process. d)Prove the vapor compression is not an isentropic process. e) Calculate the COP of the cycle. f)To produce 5kW cooling, what is the refrigerant flow rate required?

A surface condenser deals with 12000 kg of steam per hour. Air leakage into the condenser is found to be 4 kg/hr. The vacuum and temperature at the air pump suction are 700 mm of Hg and 36°C respectively. The barometric pressure is 760 mm Hg. Compute the volumetric capacity in m'/min of wet air pump.