1. A heat engine operating in an environment at 298 K produces 5 kW of power output with a first law efficiency of 50%. It has a second-law efficiency of 80% and TL = 310 K. Find all the energy and exergy transfers in and out.
2. A flow of nitrogen, 0.1 kg/s, comes out of a compressor stage at 500 kPa, 500 K and is now cooled to 310 K in a counter flowing intercooler by liquid water at 125 kPa, 15?C that leaves at 22?C. Find the flow rate of water and the second-law efficiency for the heat exchanger.