An irreversible heat engine extracts heat from a high-temperature source at a rate of 100 kW and rejects heat to a sink at a rate of 50 kW. The entire work output of the heat engine is used to drive a reversible heat pump operating between a set of independent isothermal heat reservoirs at 17 C and 75 C. The rate (in kW) at which the heat pump delivers heat to its high-temperature sink is _______ A. 50 B. 250 C. 300 D. 360
Answer: Let's draw the entire system.
Out of the 100 kW heat supplied to the engine, 50 kW is rejected to sink hence work output is 50 kW. This work is supplied to a heat pump which in turn extracts heat from 17 C sink and supplies heat to a high temp source at 75 C.
It is given that the heat pump is reversible. Therefore, its entropy doe not change.
