Problems in the heat exchanger course design
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I’m asking for help from all the experts! ! ! No matter how the heat exchanger design is adjusted, it still fails to meet the requirements; the area margin calculated using software as well as the pressure drop in the shell side also do not satisfy the specified criteria. Could someone please point out where the problem lies? Title: It is necessary to supply 60,400 kg/h of hot air at 120°C to a drying tower. To save energy, the waste gas from the drying tower at 40°C is reused; flue gas at 600°C is used to heat this air to 120°C, with the temperature of the flue gas after heating dropping to 140°C. Design a heat exchanger to accomplish this task. It is required that the pressure drop of the fluid in the tube side and the shell side be less than 2000 Pa.
😔 Does anyone have any materials, templates, drawings, etc. to share? I can’t get off in the forum
With such a large temperature difference and high temperature variations, conventional shell-and-tube heat exchangers are not sufficient; an air preheater is required
First, it is necessary to determine what type of heat exchanger can meet the process requirements; under these conditions, shell-and-tube heat exchangers are clearly not suitable.
For this operating condition, a box-type air preheater should be used: the flue gas flow on the hot side should flow inside the tubes, while the air flow on the cold side, being larger in volume, should flow outside the tubes!