An Adiabatic Heat Exchanger Is Used to Heat Cold Water

Multiple Choice

An adiabatic heat exchanger is used to heat cold water at 8°C entering at a rate of 3 kg/s by hot air at 150°C entering also at rate of 3 kg/s. If the exit temperature of hot air is 30°C, the exit temperature of cold water is (use constant specific heats at room temperature)

A) 150°C
B) 30°C
C) 36.9°C
D) 28.6°C
E) 128°C