The energy and exergy analysis of counter-flow regenerative evaporative cooler

Abstract

Recently the regenerative evaporative cooler (REC) has drawn great attention from researchers because it can cool the intake air below the wet-bulb temperature and approaching its dew point temperature. For further understanding of the heat and mass transfer occurred in a counter-flow REC, a novel mathematical model is developed based on the law of energy conservation and the principle of the thermodynamic theory. The proposed mathematical model is validated against experimental data from literature. The parametric study is performed to investigate the performance of the REC under different operating and geometrical conditions. It is found that the exergy destruction and exergy efficiency ratio of the REC are strongly influenced by the intake air velocity, the working to intake air ratio and channel gap, followed by the channel length. The working to intake air ratio choosing from 0.3 to 0.4 is appropriate in order to achieve better thermal performance with permissible level of thermodynamic cost. Moreover, the results obtained in this paper reveal that the best thermal performance does not correspond to the best thermodynamic performance. Thus, both the first and second law of thermodynamics should be considered for a comprehensive analysis.