Effects of Prandtl number on heat transfer and pressure drop in a cross-corrugated polyment film compact heat exchanger (PFCHE)

摘要

This paper investigates the effects of Pr number on the performance of a cross-corrugated polymer film compact heat exchanger (PFCHE) by using different fluid systems. The working fluids for the experiments are air, water and glycerol water mixtures. The tests conducted covered a Re number range of 2-2540 depending on the fluid system used. Heat transfer and pressure drop results in the laminar flow for the 0.7 to 192 Pr number range are included in this study. The PFCHE was developed using thin (100μm) poly ether ether ketone (PEEK) films which have an excellent thermal, chemical and mechanical stability. The Pr number was found to have a significant effect on the PFCHE performance and therefore it proved necessary to develop a correlation for the heat transfer and friction factor characteristics that covers a wide range of Prandtl numbers (wide spectrum of fluids). Using regression analysis, Nu and f plots are used to develop a design model (unique PFCHE design correlations) as a function of both Re and Pr numbers. Once the correlations are established, the paper concludes with a PFCHE performance comparison; involving the Pr number, with data from literature.