A heat pump cycle is executed with R–134a under the saturation dome between the pressure limits of 1.2 and 0.16 MPa. The maximum coefficient of performance of this heat pump is (a) 5.7 (b) 5.2 (c) 4.8 (d) 4.5 (e) 4.1

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.22 MPa and 27 C at a rate of 0.07 kg/s, and it leaves at 1.2 MPa and 73°C. The refrigerant is cooled in the condenser to 44°C and 1.16 MPa, and t is throttied to 0.21 MPa. Disregarding any heat transfer and pressure drops in the connecting lines between the components, show the cycle on a T-s diagram with respect to saturation lines, and determine (a) the rate of heat removal from the refrigerated space and the power input to the compressor, (b) the isentropic efficiency of the compressor, and (c) the COP of the refrigerator.

An inventor claims to have developed a heat pump that runs between a sink at 273 K and a source at 298 K, with a COP of 11. Is this claim valid? No Yes

Refrigerant 134 A enters in a condenser of a heat pump at 180 kPa and -4 0C and exits with a quality of 0.8 and the same pressure of 180 kPa. The mass flow rate of the refrigerant is 65 kg/h, and the heat pump compressor consumes 45 kJ/min of power. Determine the coefficient of performance of the heat pump. Type your answer in the first box.