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Unformatted text preview: ) h = 4 W/m 2 ºC h = 6 W/m 2 ºC A i r a t º C Air at 20ºC 3 c m 5 c m 3. Two separate experiments are performed on a small refrigerator. The refrigerator is placed in ambient air at 20ºC. In one experiment, an electrical heater is suspended inside the refrigerator cavity with the door closed, while the refrigerator is unplugged. With the heater dissipating 20 W, a steady-state temperature of 90ºC is recorded within the cavity. With the heater removed and the refrigerator now in operation, the second experiment involves maintaining a steady-state cavity temperature of 5ºC for a fixed time interval and recording the electrical energy consumption. In such an experiment, the input electrical energy is 125 kJ over 12-hour period. Determine the refrigerator’s coefficient of performance (COP). (Answer: 1.48)...
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- Spring '11
- Heat Transfer