Questions for help! Discussion on the segmentation of the shell-side cylindrical structure of SW6 heat exchanger

1. Under what circumstances does the shell side cylinder need to be designed in sections? For example, if the temperature difference between the shell side cylinder is too large, an expansion joint is required. When the cylinder materials at both ends of the expansion joint are different, segmented design is required? Carry out segmented design if necessary: ​​lol, it is difficult to say. For example, some heat exchangers require stainless steel at the shell entrance, but the shell is made of carbon steel. In this case, part of the shell needs to be made of stainless steel. Another example is that some heat exchangers that cannot use expansion joints but can use carbon steel need to improve the support of the tube plate and thicken the tube plate connection (this situation is more common when analyzing and designing the tube plate). At this time, from the perspective of economy and feasibility, the thickened shell does not need to be made of stainless steel, and the thickened parts are made of carbon steel. There are also heat exchangers that change the corrosion characteristics of the internal heat exchange medium on the shell side. Special materials may be partially used to obtain better corrosion resistance and economy. Wait, it is difficult to say completely. In short, it is where necessary. The installation of expansion joints does not need to be considered in this case, because the rigidity and thermal expansion have been specially treated when calculating the expansion joints and do not need to be considered in this calculation. 2. Are there any advantages and disadvantages to this segmented structure design? For example, can it effectively reduce temperature difference stress? The advantage is to obtain better economy under the premise of meeting strength and stiffness, or to make the design more feasible. If it were not for economic considerations it would rarely be designed in this way. The disadvantage is that the calculation is not accurate, and the design and manufacturing are still a bit cumbersome, so try not to use them if possible. 3. Is there a more detailed explanation on the segmented design of the shell side cylinder in GB/T 151-2014? You can look at the standard explanation for this, but it seems that the content is limited, but the calculation idea does not seem to be complicated. My ability is limited and I can only say so much.

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