Effects of high return water temperature in heat exchanger circulation water
Thread Content
Coolers are the most common type of equipment in chemical plants. Heat exchangers that use circulating water as a cooling medium generally have the return water temperature as their key control parameter. In order to save energy and reduce consumption, the plant will, as much as possible, raise the return water temperature of the circulating water while still meeting the requirements of the production process, thereby reducing the amount of circulating water needed. What impact will excessively high return water temperatures, for example above 60°C, have on heat exchange equipment? Is it possible for the heat exchanger tube bundle to be damaged structurally? I hope everyone will discuss it and learn from each other*.
It’s not what you think; it has nothing to do with the heat exchanger. The temperature difference of the circulating water is kept between 6 and 10 degrees, and this is due to the weather conditions in summer and winter. If the temperature of the returning circulating water is too high, the cooling tower may not be able to cool down properly; therefore, it is necessary to conduct a thorough analysis of the entire system. This task is quite complex, as there are many factors to consider.
The return water temperature is high, causing severe scaling in the heat exchanger, which ultimately affects the heat exchange efficiency.
Hello, friend. Your question is a bit unclear to me, and I’d like to ask: how should we understand the idea that the higher the return water temperature, the better?
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I don’t think this is a good approach. You want to reduce the amount of circulating water, but with a high temperature and low flow rate, scaling will definitely be more severe.
We currently have scaling in one of the heat exchangers; the management suspects that it is caused by an excessively high return water temperature, though the exact mechanism behind this is not clear.
What is the mechanism behind scaling? Chemicals are added to circulating water, so scaling shouldn’t occur even at high temperatures
The higher the return water temperature, the more flow of circulating water can be saved, thereby reducing the load on the circulating water system. This is my opinion; please correct me if I’m wrong. Thank you.
A high outlet temperature of the circulating water can lead to 1) scaling of the heat exchanger, which affects its heat exchange efficiency; 2) additionally, conventional cooling towers typically achieve a temperature reduction of around 10°C, resulting in a higher temperature of the circulating water entering the heat exchanger and thus impacting its heat exchange performance.
I remember that the circulating water temperature exceeds 50–75°C, leading to severe scaling; it is not recommended to keep the return water temperature high. The end of the month would be better, as the growth rate of algae also decreases.