变截面耦合通道PCHE内超临界CO_(2)热工水力性能研究

Study on Thermal and Hydraulic Performance of Supercritical CO_(2) in Coupled Channel PCHE With Variable Cross-section

本文采用数值模拟方法,以超临界CO_(2)(S-CO_(2))作为印刷电路板式换热器(Printed Circuit Heat Exchanger,PCHE)冷、热两侧耦合换热的流体,对圆形等截面耦合通道、圆形渐扩截面耦合通道以及圆形渐缩截面耦合通道的热工水力性能进行了对比研究。研究结果表明,在相同换热面积下,相较于传统等截面通道PCHE,S-CO_(2)在冷热两侧均为渐缩通道的PEC均大于1,最大达到了2.16,最小则为1.38,其综合性能最优。然而,S-CO_(2)在两侧均为渐扩通道的PEC均小于,综合性能较差。降低冷侧运行压力有利于提高渐缩通道的综合性能。研究结果为PCHE的设计提供了新的思路和理论指导。

In this paper,using S-CO_(2) as the heat transfer fluid on the cold and hot sides of the Printed Circuit Heat Exchanger(PCHE),the thermal and hydraulic performance of the circular constant cross section coupling channel,the circular diverging channel and the circular converging channel were compared by numerical simulation method.The results show that,under the same heat transfer area,compared with the traditional constant cross section channel PCHE,the PEC of S-CO_(2) in the converging channel on both hot and cold sides is greater than 1,the maximum reaches 2.16,and the minimum is 1.38,which shows the best comprehensive performance.However,the PEC of S-CO_(2) in both sides of the diverging channel is less than 1,and the overall performance is poor.Decreasing the cold side operating pressure is beneficial to improve the comprehensive performance of the converging channel.The results provide new ideas and theoretical guidance for the design of PCHE.