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Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)
8th Edition
ISBN: 9781305387102
Author: Kreith, Frank; Manglik, Raj M.
Publisher: Cengage Learning
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
Transcribed Image Text:Problem 05.089 - Heat exchanger
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 the temperature of the exhaust gases at the heat exchanger exit and the rate of
heat transfer to the water. Use the constant specific heat properties of air for the exhaust gases. The constant pressure specific heat of
the exhaust gases is taken to be cp 1.045 kJ/kg "C. The inlet and exit enthalpies of water are 62.98 kJ/kg and 2798.3 kJ/kg.
=
Exhaust
gases
400°C
T
2 MPa
sat. vap.
Heat
exchanger
Water
15°C
The temperature of the exhaust gases is
The rate of heat transfer is
kW.
°C.
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