A mathematical model is developed to investigate the effects of working media, operating conditions and fin structural parameters on the flow and heat transfer performance of sub-atmospheric and low-temperature helium in serrated fin. For helium, nitrogen and air, when the Reynolds number (Re) is less than 2500, the Colburn heat transfer factor (j factor) of helium is in the middle, while that is the lowest when Re is higher than 2500. The Fanning friction factor (f factor) of helium under the working condition is much higher than those of air and nitrogen under corresponding working conditions. The results show that short fin height is selected for high Re and high fin height is selected for low Re. The overall performance can be improved by increasing the fin spacing and decreasing the fin thickness. Small fin length can improve the overall performance, but the effect is poor at high Re. The Kriging response surface is used to fit the flow and heat transfer correlations of serrated fin. The fitting degrees of j and f factors are 0.963 and 0.978 respectively, and the average relative errors are 4.31% and 8.79% respectively. The two correlations have good prediction performance, which can provide a theoretical reference for the design of sub-atmospheric and low-temperature plate-fin heat exchanger.

建立了数学模型，研究了工作介质、工况和翅片结构参数对锯齿翅片中亚大气压和低温氦气流动和传热性能的影响。对于氦气、氮气和空气，当雷诺数( Re )小于2500时，氦气的科尔本传热系数( j因子)居中，而当Re大于2500时最低。 范宁摩擦氦气在工况下的因子（f因子）远高于相应工况下的空气和氮气。结果表明，高Re选择短鳍片高度，低Re选择高鳍片高度。关于。可以通过增加翅片间距和减小翅片厚度来提高整体性能。较小的鳍片长度可以提高整体性能，但在高Re 时效果较差。克里金响应面用于拟合锯齿翅片的流动和传热关系。j和f因子的拟合度分别为0.963和0.978，平均相对误差分别为4.31%和8.79%。两者相关性具有良好的预测性能，可为亚大气压低温板翅式换热器的设计提供理论参考。