The geometric parameters of the HTRI heat exchanger are fixed. Why does the heat exchange area change greatly when the flow rate is modified?
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The flow rate is 3000, and the heat exchange area is more than 300. The flow rate is 500, and the heat exchange area is less than 60:'(
Because the number, length and diameter of the heat exchange tubes are the same, the area of a single unit is the same. But the number of units you connect in series and parallel is different, one is 10 units, the other is 2 units, the relationship is 5 times the area.
This post was last edited by wanlirn on 2019-8-7 14:27. The calculation book does not have two units in parallel and one has 10 units in parallel. . . When the quantity is small, 10 tubes are connected in parallel. The inside of the tube is in the laminar flow zone. The heat transfer coefficient is low. When the quantity is large, only 2 tubes are used.
If the geometric structure remains unchanged, the heat transfer area will definitely increase as the flow rate increases!
It is determined by the flow rate, because your inlet and outlet temperatures are limited. Therefore, after the flow rate reaches a certain level, it is limited by the pipe diameter or length. To meet the inlet and outlet temperature requirements, after increasing the flow rate, you need to increase the diameter or the length of the heat exchange tube, or both.……