In a conventional refrigeration cycle which uses Freon-12 as the refrigerant, the temperature of the evaporating fluid is -20°C. It leaves the evaporator as saturated vapor at -20°C and enters the compressor. The pressure in the condenser is 1.40 MPa. The liquid leaves the condenser and enters the expansion valve at 40°C. It is proposed to modify this cycle by adding a heat exchanger that would superheat the suction vapor to 25°C. Draw the schematic and ts diagram 2.1 Compare the coefficient of performance of these two cycles. 2.2 What is the temperature of the refrigerant entering the expansion valve with the heat exchanger? 2.3 For a load of 50 kW, determine the volume flow rate for both cycles.

In a conventional refrigeration cycle which uses Freon-12 as the refrigerant, the temperature of the evaporating fluid is -20°C. It leaves the evaporator as saturated vapor at -20°C and enters the compressor. The pressure in the condenser is 1.40 MPa. The liquid leaves the condenser and enters the expansion valve at 40°C. It is proposed to modify this cycle by adding a heat exchanger that would superheat the suction vapor to 25°C. Draw the schematic and ts diagram 2.1 Compare the coefficient of performance of these two cycles. 2.2 What is the temperature of the refrigerant entering the expansion valve with the heat exchanger? 2.3 For a load of 50 kW, determine the volume flow rate for both cycles.