Plate heat exchanger for cooling circulating water, maximum temperature difference of circulating water
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Dear gods, please give me some advice.: We have a process requirement, the heat source flow is 30m3/h, and it is required to go from 90°C to 60°C in 1 hour. The cold source is a circulating water tower, designed according to 32/37. If so, the heat source temperature difference is 30°C, the cold source temperature difference is 5°C, the heat source is 30m3, and the cold source is 180m3. Should we increase the circulating water outlet temperature, such as 32/42, so that the flow rate on both sides will not differ so much?
This post was last edited by lupg on 2021-12-19 14:47 1. Understand the meaning of the title: Is the heat source process water, and the cold source comes from circulating water, and the two types of water are heat exchanged in a plate heat exchanger? 2. If it is confirmed that the above situation is the case, the following points are for reference: 2.1. Both media are water. Although the enthalpy values are different at different temperatures, most estimates of the cold source flow rate are reliable. 2.2. To reduce the flow difference and increase the temperature difference of circulating water, the total heat load remains unchanged. As long as the cooling water tower has no limit on the inlet water temperature, it is not a problem. Of course, the owner should also know if there are other specific restrictions. 2.3. The flow difference between the two media of the plate heat exchanger is 6 times. The distance between the cold side plates can also be adjusted to appropriately reduce the resistance drop on the cold side. 3. If you choose a structural parameter, as long as the parameters are appropriate, it can be applied to the two working conditions desired by the poster. The area margin of the same structural heat exchanger under different working conditions is slightly different, as shown in the figure.
The big difference between hot and cold flow is not a problem. But if the circulating water outlet temperature increases to 42 degrees, it may be a problem - scaling. So first make sure that the circulating water quality allows you to increase the temperature to 42 degrees.
The big difference between hot and cold flow is not a problem. But if the circulating water outlet temperature increases to 42 degrees, it may be a problem - scaling. So first make sure that the circulating water quality allows you to increase the temperature to 42 degrees.
Yes, if the outlet temperature is increased, the flow difference will be smaller.