What is the heat transfer efficiency of typical heat exchangers?
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For example, in the case of shell-and-tube exchangers, what is the average efficiency, assuming other design factors and operating conditions are not taken into account?
This concept isn’t very clear; does it refer to the utilization of heat?
Yes, think of it as the energy utilization rate when other conditions are the same~!
This post was last edited by wiseboy on 2011-4-12 at 12:50. As long as the concept is clear, anything can be “calculated”. I derived specific quantitative relationships: for tubular heat exchangers, the average temperature difference is generally >5°C, while for plate heat exchangers it is generally >2°C, when trying to cool the fluid as much as possible. The heat utilization improvement achieved by the plate type = {(T1-T2)/1-T2-(5-2)]-1}X100%. Example 1: T1=50°C; T2=30°C: Heat utilization improvement = {(50-30)/-1}X100% = 17.64%. Clearly, in this first scenario, the plate-type heat exchanger offers a significant advantage. Example 2: T1=90°C; T2=30°C: The heat utilization improvement provided by the plate heat exchanger = {(90–30)/-1} × 100% = 5.26%. Clearly, in the second scenario, the advantages of the plate heat exchanger are much smaller. If T1 is increased further, the advantages of plate heat exchangers in this regard almost disappear, and defects such as low pressure resistance become the main issues. So, analyze each specific situation on its own. The above only analyzes one aspect, intended to serve as a starting point for further discussion. Other aspects, such as equipment investment comparisons, can also be quantitatively calculated.