Question

A 21 kg iron block initially at 365 C is quenched in an insulated tank that contains 123kg of water at 27 C. Assume the water that vaporizes during the process condenses back in the tank and the surroundings are at 15 C and 125 kPa. The specific heats of iron and water are 0.45 kJ/kgK and 4.18 kJ/kgK, respectively.

a. Determine the final equilibrium temperature.
b. Determine the entropy change of the combined system at the initial state.
c. Determine the exergy of the combined system at the initial state.
d. Determine the waste work potential during this process.

Answer 1

a) final equilibrium temperature = 306.1°C

b) Entropy change of the combined system at the initial state = 3.28 kJ/kgK

c) Exergy of the combined system at the initial state = 2152.46 kJ

d) Waste work Potential = 984 kJ

Explanations:

The complete explanations of each section are in the files attached to this solution.