Effect of geometric conditions on residual stress of brazed stainless steel plate-fin structure

Abstract

Plate-fin heat exchanger (PFHE) is the delegate of the miniaturization of heat exchanging equipment. As the core of PFHE, plate-fin structure is fabricated by vacuum brazing. Owing to the material mismatching between filler metal and base metal, residual stresses can arise during the brazing process and decrease the structure strength greatly. Therefore, estimating the magnitude and distribution of residual stress and discussing its influence factors for the early design and fabrication of plate-fin structure are deemed necessary. This paper presented a finite element analysis (FEA) of brazed residual stresses for a counter-flow stainless steel plate-fin structure. The effects of geometric conditions including brazing gap, plate thickness, fin thickness, fin pitch, fin height and fin layers on residual stress were investigated. This work provides a reference for design and decreasing residual stress for stainless steel plate-fin structure.