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Water enters at 20 ℃ at a rate of 0.2 kg/s in a double-pipe parallel flow heat exchanger is to be heated to 80 ℃ by geothermal water that enters the heat exchanger at 160 ℃ at a rate of 0.3 kg/s. The overall heat transfer coefficient of the heat exchanger is 600 W/m2. ℃. The internal diameter of the tube is 1.4 cm. Determine the length of the heat exchanger. The specific heats of the water and geothermal water are given to be 4.18 and 4.31 kJ/kg.℃, respectively.
Select one:
a. 27.5 m
b. 20.7 m
c. 30.5 m
d. 23.5 m
Transcribed Image Text:Water enters at 20 °C at a rate of 0.2 kg/s in
a double-pipe parallel flow heat exchanger
is to be heated to 80 °C by geothermal water
that enters the heat exchanger at 160 °C at
a rate of 0.3 kg/s. The overall heat transfer
coefficient of the heat exchanger is 600 W/m2.
°C. The internal diameter of the tube is 1.4 cm.
Determine the length of the heat exchanger.
The specific heats of the water and geothermal
water are given to be 4.18 and 4.31 kJ/kg.°C,
respectively.
Select one:
a. 27.5 m
b. 20.7 m
c. 30.5 m
d. 23.5 m
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