Heat exchanger piping issues
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If there is a requirement to arrange the tubes according to the layout of the heat exchange tubes, 109 tubes can be installed; however, the actual number of heat exchange tubes together with the tie rods is 104. What should be done with the space left for those five additional heat exchange tubes? Of course, we can’t reduce DL any further; otherwise it won’t be enough. How should it be handled? Empty? Weld five blind tubes? Should we just add 5 more heat exchange tubes?
The process calculations for the heat exchanger are not very accurate; having a few more tubes might be better (it’s better not to have too few). If the number of heat exchange tubes must not be increased, the following options are available: 1. Change the arrangement of the tubes, from a straight arrangement to an angled one, which may reduce the number of tubes needed. 2. Change the pipe center distance. 3. Reduce the number of tubes at the edges by a few, as long as k＜1.
:Lol, why do you have to fill the heat exchange tubes completely? If there are 5 empty ones, just leave them empty.
Well, it depends on how much margin you have in terms of the heat exchange area calculated; if it’s permissible, then reduce it. Five fewer root canals should not be a big problem.
It’s not necessary to have it completely covered; some of the elements on top can be removed, as long as the side flow isn’t too severe. Sometimes it’s necessary to remove some of the pipes; having a few more pipes shouldn’t be a problem either. The heat exchange area increases as well, so it won’t have a significant impact on the overall system.
It’s normal to have a few extra heat exchange tubes; moreover, the heat exchange area usually tends to be on the higher side.
Among the pipe layout options, uniform distribution across the span and uniform distribution along the centerline can be adjusted. From the perspective of heat transfer flow, the heat exchange tubes should be distributed as evenly as possible, within a range of 5/109 to less than 5%; however, in practical engineering applications, it’s not necessary to be too strict about this
An asymmetric arrangement can be used to increase the number of exhaust pipes.
The heat exchange area is generally a bit larger than what is normally required, so having a few extra ones isn’t a problem at all! Moreover, since there are other reasons that could cause blockages in the heat exchange tubes, having a few extra tubes can help compensate for the lost heat exchange area!
The poster said that the piping method cannot be changed. Generally, when conducting process calculations, a certain margin is taken into account for the heat exchange area; a difference of 5 tubes should not have any impact on the heat exchange area. In some of our company’s heat exchangers, when the heat exchange tubes corrode or there is cross-contamination between the tubes and the shell, the tubes are simply welded in place (of course, this occurs in very rare cases), and it does not affect normal operation.
Agree, 10. Generally, the heat exchange area is calculated as 10-20%; it doesn’t matter if there are a few fewer tubes
The piping is arranged according to a design of 104 tubes; any extra space can be ignored, as there is usually some margin in the tube sheet.