Which of the following two methods provides better heat transfer efficiency?
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There are two types of media, hot and cold; to cool them down to a certain temperature, should they be cooled separately before being mixed together, or should they be mixed first and then cooled? Which method is relatively more water-efficient? For example: when using water at 30 degrees and 70 degrees to cool something down to 28 degrees, is it better to mix them first and then cool, or to cool them first and then mix? Or should we first cool the 70 to a certain temperature before mixing and cooling it properly? How is such a problem calculated? (Without considering equipment investment)
If the amounts of water are not very different from each other, it is possible to lower the temperature of the 70-degree water to below 28 degrees and then mix them directly; therefore, I think it’s better to cool them first before mixing； If there is a significant difference between the amounts of water, it can be divided into cases with more hot water or more cold water; in the case of more hot water, the method is the same as before ； There is plenty of cold water; it cools down after mixing. Method---thermal equilibrium calculation.
Use plenty of hot water; mix after it cools down； There is plenty of cold water; it cools down after mixing.
Use plenty of hot water; mix after it cools down； There is plenty of cold water; it cools down after mixing. Give it a boost!
The hot and cold media are heat-exchanged using a plate heat exchanger and then mixed, after which the mixture is cooled with water. It also depends on the boiling points of the hot and cold fluids.
I would like to add that when designing, it is essential to ensure that the temperature difference is not too large, otherwise water is prone to scaling, which affects the heat transfer coefficient.
I would like to add that when designing, it is essential to ensure that the temperature difference is not too large, otherwise water is prone to scaling, which affects the heat transfer coefficient.