Application of the Progressive Forming Method in Simulation and Experimental Study of Rectangular Fins in a Heat Exchanger

Abstract

A progressive forming method is applied where stamping is continuously executed to produce the rectangular fins of the plate fin heat exchanger. This process produced the fins one-by-one instead of by bundles. In order to produce a fin having a depth of more than 6.0 mm, the forming load and effective stress according to the size of the edge radii of punch and die are predicted by forming simulation. Furthermore, the process of forming the second, as well as the third, fins is predicted. As the edge radii of the die and those of the punch became smaller, the effective stresses generated during deformation became smaller. The forming load during deformation also became smaller. The sizes of the edge radii of die and punch were set to 0.5 mm and 0.2 mm, respectively. When the second fin was formed, overforming occurred at the ribs. The punch was therefore modified so that the rib could be compressed at the same time the fin was formed. With the designed process, the inner fins close to the target size could be manufactured. The resulting fins had right-angled ribs, although the fin width was a slightly opened isosceles trapezoid due to the spring-back.