Seeking advice on heat transfer coefficient
Thread Content
Question: For oil-water heat exchange using plate exchangers, what is an appropriate value for the heat transfer coefficient? The chemical process design manual specifies 400–600 W/(m²·K); when actual heat exchanger manufacturers perform calculations, do they use a higher value for K?
It is sufficient to choose values that are on the conservative side, as scale formation on the inner walls over time can affect heat transfer efficiency. Even if you take into account the K value and h value based on computational estimates, the final result will still be fairly similar to that given in the design manuals
Thank you for your reply~ However, for some heat exchanger manufacturers, the K value obtained through reverse calculation can reach around 1000, which is much higher than the range specified in the manuals.
This post was last edited by qdxf on 2025-11-25 11:05. The plates used for plate replacement have uneven channels, so we increase the K value in our actual calculations. In other words, for a 10-square-meter heat exchanger, the actual heat exchange area increases due to the uneven channels, and it can reach 120 square meters or so; that’s why this phenomenon occurs when going backward.
It makes sense that the actual area of the plate heat exchanger is greater than the calculated area; thank you!
Generally, it is the same as the values specified in the manual; the specific value depends on the operating conditions. I am from a plate heat exchanger manufacturer, and for better performance, we usually increase the margin to reduce the coefficient.
Looking at the specific operating conditions is indeed very important. The key issue is to identify the core of the problem
Generally, a relatively conservative value is chosen; we usually select a value that is slightly lower than the lower limit, and after calculating the heat exchange area, we round it off