1. A Carnot heat engine produces power of 2.5 kW. It rejects heat to a river that is flowing at 2 kg/s, resulting in a temperature increase of 2° C. The average temperature of the river is 20° C.
Determine (a) the heat transfer input required for the heat engine (b) the efficiency of the heat engine (c) the temperature at which heat transfer occurs to the engine
2. A retired engineer living in Arizona is attempting to heat her home by using a heat pump. She has determined the minimum heat transfer rate needed to heat her home to be 50 kJ/h. She has the opportunity to purchase a heat pump that has a COP of 5 and requires 2.75 W of electric power to run. Should she buy this heat pump? If the inside of the house is to be maintained at 70° F and the average low outside temperature is 40° F, how does the performance of the actual heat pump compare with the maximum possible performance?