The air flows through the turbine entering at a temperature of 1400K and a pressure of 20 bar, then enters a heat exchanger at a pressure of 5 bar operating countercurrent, the second stream of the exchanger consists of an air flow of 1200 kg/min, at 1480 K and 1.25 bar, there being a pressure drop in the pipes of 0.35 bar, finally the fluid exiting the first stream of the heat exchanger enters a second stage leaving at a temperature of 980K and a pressure of 1 bar, finally the fluid exiting the heat exchanger enters a second stage leaving at a temperature of 980K and a pressure of 1 bar. Finally, the fluid leaving the first heat exchanger stream enters a second stage leaving at a temperature of 980 K and a pressure of 1 bar. The turbine of the first stage drives a generator which has an efficiency of 97%, obtaining an output power of 10000 kW. The exchanger has an efficiency of 75% and the first turbine has an efficiency of 0,90. The effects of kinetic and potential energy can be neglected. Determine (a) the temperature at the inlet of the second stage, in K. (b) the power output of the first and second turbines, in kW. (c) the entropy production rates, each in kW / K, for the turbines and the heat exchanger, (d) calculate the exergy efficiencies in all equipment and the exergy destroyed.