Consider two geothermal wells whose energy contents are estimated to be the same. Will the exergies of these wells necessarily be the same? Explain.

1. A source of heat at 1000 K transfers 1000 kW of power to a power generation device, while producing 300 kW of useful work. Determine: a. The rate of exergy destruction in this process if the environment is at 300K. b. The second law efficiency of the system.

In an evaporator of an air conditioning system, R134a enters at a quality of 0.2 and exits as saturated vapor at a temperature of -10 C. Air enters the evaporator unit at a temperature of 33 C and exits at 17 C with a mass flow rate of 0.3 kg/s. Calculate the rate of exergy destroyed in the evaporator in kW. Take the surrounding temperature to be 35 C. Hint: You will need to calculate the refrigerant mass flow rate first by taking the entire evaporator as a system and writing the first law of thermodynamics.