Single-pass heat exchangers do not have expansion joints; how can expansion and deformation in the tube and shell sides be eliminated?
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For a single-pass heat exchanger, the calculation shows that no expansion joint should be used; otherwise, the calculation cannot be completed successfully. Besides installing expansion joints, what other methods are there to eliminate expansion stresses in the tube and shell sides? Thank you
The absence of expansion joints indicates that the pulling stress between the shell and the tube bundle is not high, and no expansion joints are required to accommodate its expansion.
By standardizing the materials for the shell side and the tube side, the discrepancy in thermal expansion coefficients is reduced, and the calculations may pass. It’s very hot, and when there is a large temperature difference, it’s not very useful. However, standardizing materials also involves cost issues. It is recommended to use a U-tube heat exchanger or a stuffing box; in that case, this problem does not arise, although the cost is slightly higher than that of a fixed-type design.
Could the length of the heat exchanger be appropriately reduced and the diameter of the cylinder increased, in order to decrease the amount of expansion and thus reduce the pulling stress?
The owner needs to check which stress value in the calculations does not meet the requirements, before deciding on which solution to adopt.
Change the thickness of the shell side casing or the thickness of the tube sheet.
There are some methods for this, but it’s difficult to say which one is suitable without referring to the calculation sheets. It can be considered to change the material of the shell-side cylinder, thicken the tube sheet, and thicken the cylinder; different combinations of these measures may lead to improved calculation results.