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

• Published in: International journal of heat and mass transfer Vol. 159; p. 120075
• Main Authors: Huang, Binghuan, Li, Haiwang, Xia, Shuangzhi, Xu, Tiantong
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.2020; Elsevier BV
• Subjects: Cavity; Cross-sections; Heat exchangers; Heat transfer; Heat transfer performance; Micro-channel heat exchanger; Microchannels; Pressure drop; Shape effects; Straight channels; Heat transfer performance; Micro-channel heat exchanger; Cavity; Pressure drop
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2020.120075

•Cavities could enhance the heat transfer in micro-channels.•The Nu numbers obtained in this investigation are lower than theoretical value for conventional scale channels.•The pressure drop in micro-channels with cavities is reduced comparing with that in straight micro-channels. 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.