Comparative performance analysis of different novel regenerative evaporative cooling device topologies

Abstract

Indirect evaporative cooling may be the eco-friendly substitute of the conventional high energy-consuming vapor compression cooling technology, and regenerative evaporative cooling is an advancement of this to achieve below-wet bulb temperature cooling. Based on the primary air, secondary air and water flow directions, various design configurations of this device are possible, which may affect the performance significantly; however, the extensive comparison has not been done yet. Hence, this work analyzes the performance of regenerative evaporative cooler with all the possible configurations (four configurations of parallel/counter-flow and four configurations of cross-flow) of the air-flow direction by keeping the water flow in natural (gravity-driven) downward direction. All the configurations are numerically simulated using one set of generalized governing equations and configuration-specific boundary conditions. Configurations are compared based on the cooling capacity, effectiveness and coefficient of performance. Effects of geometrical (gap of the wet or dry channel) and operational (inlet temperature, humidity, extraction ratio, volume flow rate) parameters on the performances of all the configurations are investigated. The study reveals that the crossing temperature depends on the configuration of parallel/counter and cross flows, and two configurations (parallel/cross-flow in the wet channel) are better choices for most of the studied operating conditions. © 2020 Elsevier Ltd