Question

5, (25 points) A Carnot heat pump is used to maintain a house at 20 °C in winter and consumes 8 kW of power (electricity) when operating. On a day temperature outside the house is -3 °C, the house is estimated to lose heat at an average rate of 80,000 kJ/h. (Sa). (2p) Please identify the hot reservoir and the cool reservoir of this heat pump. (5b). (2p) Please draw of schematic diagram of this heat pump-house heating system with all known inform clearly presented, and calculate the coefficient of performance (COP) of this heat pump. (Se). Bp) How long does he heat pump have to run to maintain the house at 20 °C on that day (during a period of 24 hours)? (5d). (3p) Please determine the total cost of electricity if the above-mentioned heat pump is used for heating this house with the assumption of 8.5 cents per k Wh for electricity. (5e). (2p) Calculate the electricity cost if a heat resister is used for heating this house, assuming 8.5 cents per kWh for electricity and 100% efficiency of heat resister in converting electrical energy to heat. (SD, Gp) Please comments if heat pump is more environment friendly than the resister heater regarding the greenhouse gas emissions if the electricity is generated by hurnine nal

Answer 1