Heat exchanger tube sheet design

Strictly speaking, this issue does not apply to GB/T150-2014; it applies only to GB151-1999. GB/T151-2014 stipulates that for fixed-tube-sheet heat exchangers, in certain cases it is necessary to consider six different hazardous combination conditions for calculation. This is because, as analyzed, in cases where the shell side cylinder is equipped with expansion joints, if the pressure on the shell side is high and the expansion joints are wide but have low stiffness, local self-balancing pressures within the expansion joint rings cause significant deformation. As a result, the absolute value of the final negative term in the expressions used to calculate the effective combined pressure Pa and Σs becomes large. Even when both the shell side pressure and the tube side pressure are positive, a hazardous condition may still occur under circumstances where both pressures act simultaneously.

When the pressure on one side of the tube/shell is high and the calculated thickness of the tube sheet is too large, the pressure difference method can be used to design the tube sheet. Taking the pressure values on each side into account, it is sufficient to ensure that the pressure difference between the two sides does not exceed a certain specific value during operation and design.