Comparison of Several Heat Transfer Enhancement Technologies for Gas Heat Exchangers

Abstract

A comparative study about the performance of several enhanced heat transfer technologies for gas heat exchangers is presented. A Reynolds number range from 100 to 50,000 is considered for plate heat exchangers and the tube side of shell-and-tube heat exchangers. A volumetric performance measure has been adopted to evaluate the comparative performance of widely different technologies. The performance parameter, based on the heat transfer rate per unit pumping power, is suitable for different geometries, Reynolds numbers, and fluid properties. Modern technologies can achieve significant heat transfer enhancement, but comparison reveals that recent advances offer only marginal improvements that are often associated with more complex technology. Care must be exercised in choosing a technology because the best performing one is not necessarily the preferred choice since construction, retrofit, and maintenance costs may significantly alter the economic viability. However, there is an intrinsic interest in the comparative performance of very different technologies. Our performance evaluation indicates an upper limit may exist for single-mode convective heat transfer enhancement and compound enhancement may exceed this limit.