Experimental investigation of the flow and heat transfer performance in micro-channel heat exchangers with cavities

Micro-channel heat exchangers are widely applied in many industrial fields. Compared with conventional scale channels, micro-channels are of larger surface-to-volume ratio and higher heat transfer rate with more miniaturized scale and lower weight. In this study, micro-channel heat exchangers with cavities in two different shapes were designed and fabricated, and experiment research were conducted to analyze the influence of the shape, expansion and contraction cross-sectional lengths of cavities on flow and heat transfer characteristics. The results indicate that compared with straight channel, adding cavities in micro-channels could achieve heat transfer enhancement and pressure drop reduction simultaneously. The detailed effects of the shape as well as the expansion and contraction cross-sectional lengths of cavities on the heat transfer and the pressure drop are also revealed. (C) 2020 Elsevier Ltd. All rights reserved.