In order to cool a mass flow rate of 25 Kg/h of air (cp = 1060 J/Kg oC) at 300 oC, it is passed through the tube side of a counter flow heat exchanger with a length of 2 m and 2.54 cm tube outer diameter. The cooling water, (cp = 4182 J/Kg oC and r = 1000 Kg/m3), enters the heat exchanger at a temperature of 30 oC with a volume flow rate of 0.3 Litre/min. If the overall heat transfer coefficient, U, is 5.83 W/m2 oC and the effectiveness of the heat exchanger 60 %, calculate the following: The heat transfer rate, The exit temperatures of both the water and the air, The surface area of the heat exchanger, The number of tubes used in the heat exchanger The capacity rate ratio.
Heat Exchangers
Heat exchangers are the types of equipment that are primarily employed to transfer the thermal energy from one fluid to another, provided that one of the fluids should be at a higher thermal energy content than the other fluid.
Heat Exchanger
The heat exchanger is a combination of two words ''Heat'' and ''Exchanger''. It is a mechanical device that is used to exchange heat energy between two fluids.
In order to cool a mass flow rate of 25 Kg/h of air (cp = 1060 J/Kg oC) at 300 oC, it is passed through the tube side of a counter flow heat exchanger with a length of 2 m and 2.54 cm tube outer diameter. The cooling water, (cp = 4182 J/Kg oC and r = 1000 Kg/m3), enters the heat exchanger at a temperature of 30 oC with a volume flow rate of 0.3 Litre/min. If the overall heat transfer coefficient, U, is 5.83 W/m2 oC and the effectiveness of the heat exchanger 60 %, calculate the following:
- The heat transfer rate,
- The exit temperatures of both the water and the air,
- The surface area of the heat exchanger,
- The number of tubes used in the heat exchanger
- The capacity rate ratio.
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