Why is heat transfer efficiency not considered when calculating the area of a heat exchanger?
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Why is heat transfer efficiency not considered when calculating the area of a heat exchanger?
The heat transfer efficiency must certainly be taken into account; it needs to be considered when calculating the overall heat transfer coefficient. Additionally, there is also the issue of a margin for the heat transfer area, and all these factors need to be considered in heat transfer calculations
Is the poster referring to the issue of heat loss? 1. A 10% margin is usually added to the heat exchange area during design ； 2. The process takes into account on-site heat retention and heat dissipation losses.
http://bbs.hcbbs.com/viewthread.php?tid=64197 Check out this post; it has the information there.
According to the law of conservation of energy, the heat released by the hot fluid is always equal to the heat absorbed by the cold fluid; therefore, there is no need to consider the heat transfer efficiency when performing heat transfer calculations. Terms such as scaling and fin efficiency are merely components of thermal resistance when calculating the heat transfer area.
So, under normal circumstances, what is the heat exchange efficiency?
Heat exchangers cannot be generalized; in chemical engineering calculations, tubular heat exchangers are considered to have a efficiency of 95%.
It definitely needs to be taken into consideration – the issue of heat loss
But generally, heat exchanger manufacturers don’t mention anything about the heat exchange efficiency.
Although heat exchanger manufacturers do not mention the heat transfer efficiency, they always leave a certain margin when calculating the heat transfer area. The heat exchangers produced by our factory have never shown any problems with regard to heat transfer performance, hehe:victory:
When designing heat exchangers, heat loss is considered first; therefore, the heat transfer amount used in calculations should be multiplied by a coefficient such as 0.95. A certain margin, such as 10%, should also be reserved when calculating the heat exchange area.