Experimental investigation of additively manufactured high-temperature heat exchangers

Abstract

This article examines various additively manufactured heat exchangers for high-temperature applications. The heat exchangers differ in terms of their internal fin structure as well as optimizations in terms of manufacturing quality. Starting from a reference fin type, optimizations with focus on low pressure drop and high heat transfer are performed. The heat exchangers are investigated experimentally, focusing on the laminar flow regime between 60<Re<600. By means of a presented evaluation algorithm, the Nusselt numbers for the different fin types and designs are determined. The investigations show that even the smallest manufacturing deviations result in up to 70–120% higher f-factors and up to 30% higher Nu numbers. Taking these manufacturing deviations into account in the design process leads to very good agreement with the numerically determined values and the influence of surface roughness is comparatively small. Furthermore, the influence of internal heat radiation is of minor importance for the heat exchangers considered here.