What impact will reducing the gas flow rate have on the heat exchange efficiency of a shell-and-tube heat exchanger when the pressure remains constant?
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This post was last edited by Desert Fish on 2016-4-9 21:05. For shell-and-tube heat exchangers, where the fluids in both the tube side and the shell side are high-pressure gases (H2, N2, CH4, CO, CO2), does pressure (such as 3 Mpa and 5 Mpa) have a significant impact on the heat exchange efficiency? What impact will reducing the gas flow rate have on the heat exchange efficiency when the pressure remains constant?
If flow velocity is not considered, pressure has no effect on heat transfer. Actually, sometimes it is said that pressure has an effect because pressure affects the flow rate, which in turn causes that effect. The flow rate has a significant impact on heat transfer, especially when the α value of the gas itself is relatively low.
Reducing the gas volume means less heat is carried, so the impact on the heat exchange efficiency of the entire system will not be significant.
Q=KA* deltaTm; some way needs to be found to change the value of K
If the flow rate is low, how can it have little impact on the heat exchange efficiency? The heat release rate and K value are greatly affected by the flow rate!