What is the typical pressure drop of circulating water through a heat exchanger?

Should this problem be approached by considering temperature differences and flow rates? For reference. It’s best to post the problems you want to solve. Because the application scenarios and functions of heat exchangers vary. In terms of the resistance of the heat exchanger alone, it must be determined through field test data or calculations. The flow cross-section of the heat exchanger is also set according to actual requirements. It would be best to clarify the problem to facilitate discussion; this is provided for reference.

As for the pressure difference, of course, the smaller it is, the better. But if it’s too small, careful consideration needs to be given to the structural design of the heat exchanger. Typically, the pressure difference is specified by the process based on the operating conditions.

For circulating water heat exchangers, the main consideration is the pressure drop on the process side; this pressure drop should be as low as possible. There are no strict requirements regarding the pressure drop on the circulating water side; as long as it meets the specified requirements, that’s sufficient. If reducing the pressure drop on the circulating water side is a concern, then the circulating water heat exchanger does not need to have as many tube passes (in the case of heat exchangers where the circulating water flows through the tube passes).

See what pressure drop range the system allows for the heat exchanger.

This post was last edited by wanlirn on 2021-8-16 at 11:10. The circulating water pressure is generally kept below 50 KPa. In fact, this isn’t the fundamental issue; for a heat exchanger, the main factor affecting pressure loss is flow velocity. However, those who have studied heat transfer calculations know that once the flow velocity is increased to a certain level, the heat transfer coefficient increases only slightly. For example, when the fluid outside the tube flows at 1.5 m/s, turbulence occurs, and the convective heat transfer coefficient outside the tube is 2500 W. If the flow velocity is increased to 2.5 m/s, the convective heat transfer coefficient becomes 2600 W. Since there is a quadratic relationship between flow resistance and flow velocity, the pressure loss increases significantly in such cases. Under these circumstances, it becomes impractical to increase the flow velocity; therefore, a value of 1.5 m/s is more reasonable. . . Actually, that’s just one aspect; there are other factors as well. For example, in the case of upgrading an old system, if the pressure drop across the heat exchanger is 30 KPa, then you’ll need to reduce the flow rate or adjust things such as the flow path, the direction of the pipes, and the diameter of the heat exchange tubes, among others

Let’s ignore the pressure drop; it is generally assumed that the pressure remains constant, and energy recovery is achieved through a generator installed in the recovery main pipe

Professional, with a very comprehensive approach to issues!

For general clients, it’s fine to assume a value of 50. More knowledgeable clients will specify the maximum allowable pressure drop

The original poster’s question about pressure drop is one-sided; a higher pressure drop allows for an increase in the head of the circulation pump. Generally, design institutes, after comprehensive consideration, require that the pressure drop be less than 50 kPa; in some cases, it can be up to 100 kPa. The original poster is asking about the pressure drop range when circulating water passes through a plate heat exchanger. There’s no such notion; plate heat exchangers can increase the pressure drop and improve heat transfer efficiency through measures such as baffling. The pressure drop should definitely be as low as possible, but the heat exchange efficiency also needs to be taken into account.