Question

Hot exhaust gases of a stationary diesel engine are to be used to
generate steam in an evaporator. Exhaust gases (cp = 1051 J/kg.
K) enter the heat exchanger at 550 oC at a rate of 0.25 kg/s
while water enters as saturated liquid and evaporates at 200oC (with
heat of evaporation hfg = 1941 kJ/kg). The heat transfer surface area
of the heat exchanger based on water side is 0.5 m2
and overall heat
transfer coefficient is 1780 W/m2
. K. Determine the rate of heat
transfer, the exit temperature of exhaust gases, and the rate of
evaporation of water.

Answer 1

Answer:

Hot exhaust gases of a stationary diesel engine are to be used to generate steam in an evaporator. Exhaust gases (cp = 1051 J/kg⋅K) enter the heat exchanger at 550°C at a rate of 0.25 kg/s while water enters as saturated liquid and evaporates at 200°C (hfg = 1941 kJ/kg). The heat transfer surface area of the heat exchanger based on water side is 0.5 m2 and overall heat transfer coefficient is 1780 W/m2⋅K. Determine the rate of heat transfer, the exit temperature of exhaust gases, and the rate of evaporation of water.