Frequently Overlooked Heat Exchanger Design Conditions

This paper explores the current design methodology for heat exchanger channel pass partition plates using ASME and TEMA design rules. Unanticipated elevated stress levels above allowable stress may exist at the channel pressure boundary due to differential pressure. In performing finite element analysis on two-pass heat exchanger channel geometry, elevated bending stress magnitudes were identified on the channel pressure boundary in the vicinity of the pass partition plate. These elevated stresses are induced by the pressure drop across channel passes, which load the pass partition plate and subject the channel pressure boundary to a bending stress which is frequently not evaluated. The combined membrane and bending stress may exceed allowable limits. This paper is intended to highlight this potentially overlooked loading condition in the design of heat exchanger channels.