Research on mitigation strategies for axial heat conduction in cryogenic microchannel heat exchangers

The compact design of microchannel heat exchangers (MCHX) offers significant advantages for their utilization in cryogenic systems, but it is accompanied by serious axial heat conduction problems. To address this issue, various strategies for mitigating axial heat conduction in MCHXs are proposed in...

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Bibliographic Details
Main Authors: Tao Zhu, Xiaoli Duan, Bingcheng Wang, Cheng Shao, Zheng Cui
Format: Article
Language:English
Published: Elsevier 2025-10-01
Series:Case Studies in Thermal Engineering
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Online Access:http://www.sciencedirect.com/science/article/pii/S2214157X25010676
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Summary:The compact design of microchannel heat exchangers (MCHX) offers significant advantages for their utilization in cryogenic systems, but it is accompanied by serious axial heat conduction problems. To address this issue, various strategies for mitigating axial heat conduction in MCHXs are proposed in this study. The results reveal that the heat exchanger efficiency loss (Δε) due to the axial heat conduction can reach 0.193 at a thermal conductivity of 100 W m−1 k−1. The substantial quantity of ribs and the reduced length of the separating wall create favorable conditions for axial heat conduction in MCHXs. The incorporation of slotted ribs in the MCHXs serves as an effective method to directly disrupt heat flux transferred axially in the ribs due to its non-continuous configuration. Furthermore, optimizing the separating wall materials and enhancing localized heat transfer capacity methods can increase the absolute and relative values of axial conductive thermal resistance of separating wall, respectively, thereby reducing the proportion of axial heat flux within it. The optimized thermal conductivity of separating wall is 10 W m−1 K−1. Ultimately, by incorporating all the enhancement strategies in MCHXs, 80.8 % of Δε can be effectively mitigated at a thermal conductivity of 100 W m−1 k−1.
ISSN:2214-157X