Investigations on Regenerative Heat Exchangers

Abstract

A comparison of the thermal attributes of different heat transfer surfaces shows a large potential to improve regenerators with respect to the ratio between pressure drop and heat transfer. The lower limit of this ratio is given by a single plate. With the use of computational fluid dynamics (CFD), shapes and arrangements of matrix elements were investigated systematically. As the most influential parameter, we determined the velocity changes within the matrix due to changes in the free flow areas and the aspect ratio of the single elements. The optimum geometry consists of slim elements in the flow direction, arranged in a staggered overlapping pattern. Such regenerators could provide thermal performance equal to stacked screens, but with up to five times lower pressure drop.