Numerical Simulation of Serrated Fin Performance of Plate Fin Heat Exchanger under Negative Pressure and Low Temperature Condition

The flow and heat transfer performance of heat exchanger under low temperature condition is obviously different from that under normal temperature condition.In order to analyze the influence of key structural parameters of plate fin heat exchanger on its flow and heat transfer performance under negative pressure and low temperature condition,the numerical model of flow and heat transfer performance in serrated fin channel is constructed and improved.Using the central composite design method to obtain the experimental points and combining with the Kriging response surface method,the flow and heat transfer correlation equation of the negative pressure cryogenic helium in the serrated fin channel is obtained by fitting.The results show that:j factor has positive correlation with spacing and thickness,negative correlation with pitch,positive correlation with height at low Reynolds number,and negative correlation with height at high Reynolds number;f factor has negative correlation with spacing and pitch,positive correlation with thickness,positive correlation with fin height at low Reynolds number,and negative correlation with fin height at high Reynolds number;the average absolute deviation of j factor and f factor is 4.31% and 8.79%,respectively.The two correlations have good prediction performance.The research results can provide theoretical guidance for the design of negative pressure low temperature plate fin heat exchanger.