Air at 128C, 1 atm, and 40% relative humidity enters a

Chapter 12, Problem 12.54

(choose chapter or problem)

Air at \(12^{\circ} \mathrm{C}\), 1 atm, and 40% relative humidity enters a heat exchanger with a volumetric flow rate of \(1 \mathrm{m}^{3} / \mathrm{s}\). A separate stream of dry air enters at \(280^{\circ} \mathrm{C}\), 1 atm with a mass flow rate of 0.875 kg/s and exits at \(220^{\circ} \mathrm{C}\). Neglecting heat transfer between the heat exchanger and its surroundings, pressure drops of each stream, and kinetic and potential energy effects, determine

(a) the temperature of the exiting moist air, in \({ }^{\circ} \mathrm{C}\).

(b) the rate of exergy destruction, in kW, for \(T_{0}=-12^{\circ} \mathrm{C}\).