Experimental investigation on airside thermal-hydraulic performance of vertical-fin microchannel heat exchangers

Abstract

The vertical-fin microchannel heat exchanger (MHX) demonstrates significant potential as an evaporator for heat pump systems. This study provides an experimental comparison of three typical vertical-fin configurations: MHXs with fin leading (MHX-L), trailing (MHX-T), and both edges extended (MHX-LT). The airside thermal-hydraulic performance is comprehensively evaluated under dry, wet, and frosting operating conditions. The results indicate that, for dry and wet conditions, the MHX-L outperforms the MHX-T. Under frosting conditions, the MHX-T exhibits the poorest performance in frosting and drainage. Consequently, the MHX-L is recommended for practical applications over the MHX-T. The MHX-LT exhibits the highest heat transfer capacity across all conditions due to its larger heat transfer area, albeit with an increased air pressure drop. When assessing the drainage performance in terms of drainage rate and residual ratio, the MHX-L surpasses the MHX-LT. Although the MHX-LT has a higher capacity in the initial cycle than the MHX-L, its inferior drainage performance may lead to a more significant reduction in cyclic capacity.