Total heat transfer coefficient K
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A mixture of propylene (58.8%), hydrogen chloride (19.6%), chloropropene (19.6%), and dichloropropene (2%) with an inlet temperature of 180 degrees and an outlet temperature of 40 degrees is condensed by water with an inlet temperature of 33 degrees and an outlet temperature of 40 degrees. I don’t know how to calculate the overall heat transfer coefficient; could you tell me what value to use based on empirical data? I am extremely grateful
http://bbs.hcbbs.com/viewthread.php?tid=251702&highlight=%D7%DC%B4%AB%C8%C8%CF%B5%CA%FDK Empirical values of the overall heat transfer coefficient K in some shell-and-tube heat exchangers; the original poster might want to take a look!
The overall heat transfer coefficient K = Q/Ft. It can be seen that, for the same heat transfer area F and average temperature difference Δt, the larger the overall heat transfer coefficient K, the greater the amount of heat transferred Q. In other words, for the same amount of heat to be transferred and the same average temperature difference, the larger the overall heat transfer coefficient K, the smaller the heat transfer area required. Pressure drop: The pressure drop in a heat exchanger is caused by two types of losses, namely frictional losses due to flow and losses associated with changes in flow direction. Increasing the fluid velocity can raise the heat transfer coefficient K and reduce the heat transfer area F. Generally, it is appropriate for the pressure drop in the tube side and shell side to be between 0.034 MPa and 0.17 MPa.
Calculate using the range of 200-400; for complex operating conditions, one should not rely too much on empirical values. Such values are generally obtained under conditions where the structure is relatively well-developed and under single operating conditions, and can only be used as a reference.