Hot exhaust gases of an internal combustion engine are to be used to produce saturated water vapor at 2 MPa pressure. The exhaust gases enter the heat exchanger at 400°C at a rate of 32 kg/min while water enters at 15°C. The heat exchanger is not well insulated, and it is estimated that 10 percent of heat given up by the exhaust gases is lost to the surroundings. If the mass flow rate of the exhaust gases is 15 times that of the water, determine
(a) The temperature of the exhaust gases at the heat exchanger exit and
(b) The rate of heat transfer to the water. Use the constant specific heat properties of air for the exhaust gases.

Transcribed Image Text:

Exh. gas 400°C Heat exchanger 2 MPa sat. vap. Water 15°C