Questions about parameter selection

Are you the owner party that needs to purchase the plate exchanger, or are you the manufacturer that needs to design it? The parameters they focus on are different

There is a problem with your operating parameters; the flow rate of the cooling-side circulating water is too low. To achieve thermal balance between the cold and hot sides, it is impossible for the outlet temperature on the cold side to be much higher than the inlet temperature on the hot side.

I just used Huahai Chuanliu, which is the production method; these are the parameters provided by the customer. I think there’s something wrong with these parameters, and I’m not sure how to determine the correct values

I understand that water is used on both the hot and cold sides; one type of water serves as the medium, while the other is chilled water. However, the temperature difference at the hot side is 60 – 30 = 30°C, with a flow rate of 25 m3/h. The flow rate at the cold side is only 0.3 m3/h, and the inlet water temperature is 8°C. To achieve an energy balance between the hot and cold sides, the temperature difference at the cold side would need to be 30 * 25 / 0.3 = 2500°C, which is impossible. Please have the client reconfirm the technical parameters, mainly the flow rate of the chilled water. At least a flow rate of 20–30 m3/h is required to theoretically meet the heat exchange needs, but in such cases the heat exchange area will also be very large. In typical practical designs, it is reasonable to estimate that the cold-side flow rate should be twice the hot-side flow rate.

I just used the Huahai Chuanliu method – how should I set the parameters to choose the appropriate option?

Thank you very much. I have one more question: can the temperature difference of the chilled water be made quite large? What is the appropriate temperature difference for chilled water?

This post was last edited by wanlirn on 2022-12-15 at 10:10. In such cases, you don’t need to worry about whether the cold-side flow rate is sufficient; just use the standard values of 7–8 degrees for the chilled water and around 15 degrees for the return water. Make sure to clearly indicate the cold-side flow requirements in the parameters table included in your quote, so that the customer can make their own judgment. Because the supply and return water temperatures of the chiller are fixed. If you can’t report this task, it will suggest that your company has very poor technical capabilities. In our project work, we encounter all sorts of strange operating conditions from users every day; if you can’t describe them, then it’s better not to do this job

I selected one based on a temperature difference of 5 degrees for the chilled water. The client said that their cold-side flow rate wasn’t that high, and they wanted it changed to around 25 tons per hour; as a result, the temperature difference would no longer be correct. What do you think would be the consequences of operating in such conditions?