Moist air at 158C, 1.3 atm, 63% relative humidity and a

Chapter 12, Problem 12.68

(choose chapter or problem)

Moist air at \(15^{\circ} \mathrm{C}\), 1.3 atm, 63% relative humidity and a volumetric flow rate of \(770 \mathrm{m}^{3} / \mathrm{h}\) enters a control volume at steady state and flows along a surface maintained at \(187^{\circ} \mathrm{C}\), through which heat transfer occurs. Liquid water at \(15^{\circ} \mathrm{C}\) is injected at a rate of 7 kg/h and evaporates into the flowing stream. For the control volume, \(\dot{W}_{\mathrm{cv}}=0\), and kinetic and potential energy effects are negligible. If moist air exits at \(45^{\circ} \mathrm{C}\), 1.3 atm, determine

(a) the rate of heat transfer, in kW.

(b) the rate of entropy production, in kW/K.