Performance evaluation of cryogenic counter-flow heat exchangers with longitudinal conduction, heat in-leak and property variations

[摘要] Counter-flow plate-fin heat exchangers are commonly utilized in cryogenic applications due to their high effectiveness and compact size. For cryogenic heat exchangers in helium liquefaction/refrigeration systems, conventional design theory is no longer applicable and they are usually sensitive to longitudinal heat conduction, heat in-leak from surroundings and variable fluid properties. Governing equations based on distributed parameter method are developed to evaluate performance deterioration caused by these effects. The numerical model could also be applied in many other recuperators with different structures and, hence, available experimental data are used to validate it. For a specific case of the multi-stream heat exchanger in the EAST helium refrigerator, quantitative effects of these heat losses are further discussed, in comparison with design results obtained by the common commercial software. The numerical model could be useful to evaluate and rate the heat exchanger performance under the actual cryogenic environment.

[发布机构] Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui; 230031, China^1;University of Science and Technology of China, Hefei, Anhui; 230026, China^2

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Counter flow heat exchangers;Cryogenic applications;Distributed parameter;Heat exchanger performance;Longitudinal heat conduction;Performance deterioration;Performance evaluations;Variable fluid properties