What is the K value of a tube and tube heat exchanger?
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This post was last edited by guoshanyao on 2011-12-23 11:03 What is the K value of the tube heat exchanger? The known material is SUS316L, the heat exchange medium is an organic solvent, and the tube wall thickness is 2mm... Use an 8-degree liquid solvent to cool a 25-degree gas solvent
This post was last written by li* ch1968 on 2011-12-24 18:17 The editor is an empirical value, and the calculated results are very different from the actual application.
According to your heat exchanger form and fluid type, you can find it in any heat exchanger manual or chemical process manual, but the error is relatively large.
Generally check it first and then adjust it. It has something to do with the type of heat exchange medium, the state of the heat exchanger structure, etc.
Special programs are usually used for calculations in engineering, but for some special media due to the limitations of the program database (the medium is special and not available in the library), the existing device can be used to measure and back-calculate the K value, and then use the approximate flow rate to calculate the new heat exchanger in a similar form. For the poster's question In this case, K values of similar substances may be found in many books for coolers. Generally, the range is large and the error is large (due to the physical properties of the heat exchanger, the structural form of the heat exchanger, (number of passes, baffle form, spacing, etc.), and many influencing factors). The author can only give a rough estimate. The above opinions are for discussion.
Liquid-gas heat exchange takes 20W/m2* ℃Almost the same, liquid-liquid heat exchange takes 120W/m2 * ℃
Liquid-gas heat exchange is 50W/m2* ℃. The old K is an empirical value, and it must be multiplied by the insurance coefficient when calculating the heat exchanger.
According to your heat exchanger form and fluid type, you can find 5 j w2 in any heat exchanger manual or chemical process manual. ] 1 ] ' w' [" X/ X0 U But the error is relatively large