NUMERICAL INVESTIGATION OF STRESS GENERATED IN HIGH PRESSURE HEAT EXCHANGER

Heat Exchangers are used to transfer heat effectively from one medium to another medium. There are several aspects to study the performance of heat exchanger. This paper is concerned with thermo - mechanical issues i.e. thermal expansion due to high temperature and high pressure conditions of U - tube heat exchanger. Tubesheet is very complex part of heat exchanger which expands at high temperature. Due to high temperature difference between shell side and channel side fluids thermal stress are generated in the tubesheet which effects on the performance of the heat exchanger. 3 D FEA model wa s modeled in ANSYS ® to study the thermo - mechanical effect on heat exchanger. Mesh sensitivity analysis was performed to obtain precise results and optimum mesh size. Static structural stress analysis was performed under for two conditions , at first only mechanical loading was studied and secondly mechanical and thermal loading effects were studied. In steady state condition, tubesheet thickness was optimized using 3D parametric model in FEA. The results o f the elastic stress analysis were eval uated as per ASME Section VII DIV - 2 code limits. It is found that with the optimization design, the tube shee t thickness could be reduced by 20 - 25 % without affecting the safety of the heat exchanger within the allowable limits.