Moist air enters a duct at 10 oc, 70% relative humidity, and a volumetric flow rate of 150 m3/min. the mixture is heated as it flows in the duct and exits at 40oc. no moisture is added or removed, and the mixture pressure remains approximately constant at 1 bar. for steady-state operation, determine (a) the rate of heat transfer, in kj/min, and (b) the relative humidity at the exit. change in kinetic and potential energy can be ignored.

An open feedwater heater operates at steady state with liquid entering at inlet 1 with t? = 40°c and pl = 1 .2 mpa. water vapor att2-200°c and p2 = 1.2 mpa enters at inlet 2. saturated liquid water exits with a pressure of pa 1.2 mpa. neglect heat transfer with the surroundings and all kinetic and potential energy effects, determine the mass flow rate of steam at inlet 2 if the mass flow rate of liquid water at inlet 1 is given as 2 kg/s.