Numerical study on indirect evaporative cooling performance comparison between counterflow and crossflow heat exchangers

Abstract

This paper aimed to numerically investigate the performance comparison between counterflow and crossflow heat exchangers for indirect evaporative air cooler. Simulation results indicate that cooling performance difference between the two configurations considerably depends on the configuration structure of heat exchangers, the inlet air status and the mass flow rates of primary and secondary. Among types of the cross-sectional shape considered in this paper, the counter configuration with rectangle channels which has a length-to-width ratio of 16:1 can provide the best cooling performance. The wet bulb effectiveness of counterflow configuration is about 7% greater than that of crossflow configuration with increasing inlet air temperature on average. The higher the inlet air temperature, the bigger the EER, cooling capacity and supply air temperature difference between the two configurations. With increasing relative humidity, the two configurations keep an average wet bulb effectiveness difference of 7.1%. The wet bulb effectiveness difference between the two configurations narrows down from 8.3 to 5.3% with increasing air velocity. © The Author 2010. Published by Oxford University Press. All rights reserved.