Carnot cycle. if a boiler's heat source produces 10e btu/hr at 600f, what is the highest possible rate at which work may be produced? the ambient air is 70f. ans: w 5x10 btu/hr 2. two carnot engines are operated in series with the exhaust (heat output) of the first engine being the input of the second engine. the upper temperature of this combination is 260f, the lower temperature is 40f. if each engine has the same thermal efficiency, determine the exhaust temperature of the first engine (the inllet temperature of the second engine) ans: t 140f 3. a nuclear power plant generates 750 mw of power. the heat engine uses a nuclear reactor operating at 315c as the source of heat. a river is available (at 20c) which has a volumetric flow rate of 165 m/s. if you use the river as a heat sink, estimate the temperature rise in the river at the point where the heat is dumped. assume the actual efficiency of the plant is 60% of the carnot efficiency ans: t 22.6c