Cold water with a mass flow rate of 9800 kg/h is heated from 40 to 115 oC in a countercurrent flow double pipe heat exchanger, for which overall heat transfer coefficient is 1480 W/m2 K, with hot water having a flow rate of 4800 kg/h and inlet temperature of 295 oC . As time passed by, the performance of the heat exchanger and hence the heat transfer rate decreases by 30% due to the heavy fouling conditions in the system. a) Draw the temperature profile and fully label it. b) Calculate the necessary area to accomplish desired heat transfer. c) Calculate cold and hot water outlet temperatures in the case of fouling if the inlet temperatures for both fluids are the same as the given values above. d) Calculate the total (for inner and outer surface) fouling factor in the case of fouling. Note that heat capacity of both hot and cold fluids may be taken as the same; Cph=Cpc at all conditions, and in the case of fouling the heat capacity value is 4.183 kJ/kg oC for both fluids.
Cold water with a mass flow rate of 9800 kg/h is heated from 40 to 115 oC in a countercurrent flow double pipe heat exchanger, for which overall heat transfer coefficient is 1480 W/m2 K, with hot water having a flow rate of 4800 kg/h and inlet temperature of 295 oC .
As time passed by, the performance of the heat exchanger and hence the heat transfer rate
decreases by 30% due to the heavy fouling conditions in the system.
a) Draw the temperature profile and fully label it.
b) Calculate the necessary area to accomplish desired heat transfer.
c) Calculate cold and hot water outlet temperatures in the case of fouling if the inlet temperatures
for both fluids are the same as the given values above.
d) Calculate the total (for inner and outer surface) fouling factor in the case of fouling.
Note that heat capacity of both hot and cold fluids may be taken as the same; Cph=Cpc at all
conditions, and in the case of fouling the heat capacity value is 4.183 kJ/kg oC for both fluids.
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