超临界CO_(2)板式扩散焊矩形微通道换热器扰流格栅结构优化研究  

Optimization of Grid Structure for Supercritical CO_(2) Plate Diffusion Welded Rectangular Micro-channel Heat Exchanger

作　　者：任燕 王沛东 李洪 刘婧楠[1] 武卫东[1] 章立新[1] 杨其国 REN Yan;WANG Peidong;LI Hong;LIU Jingnan;WU Weidong;ZHANG Lixin;YANG Qiguo(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Yangpu District,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海市杨浦区200093

出　　处：《中国电机工程学报》2024年第12期4850-4858,I0020,共10页Proceedings of the CSEE

基　　金：国家自然科学基金项目(52176016);上海市科技计划项目(20060502000,20YF1431300)。

摘　　要：为提升超临界二氧化碳(supercritical carbon dioxide,S-CO_(2))布雷顿循环系统中印刷电路板式换热器(printed circuit heat exchanger,PCHE)的流动传热综合性能,该文通过数值模拟的方法,基于一种全蚀刻工艺的新型矩形截面PCHE,建立以冷热通道换热单元为研究对象的数学物理模型。研究不同运行工况下,通道内扰流格栅间距对S-CO_(2)流动传热特性的影响机理和影响规律。结果表明:不同格栅间距的热通道内S-CO_(2)的流速均沿程逐渐减小,而冷通道内S-CO_(2)的流速反而沿程逐渐增大。冷热通道内的流动摩擦阻力系数(f)和努塞尔数(Nu)均随着格栅间距的增大而逐渐增大,但不同格栅间距的冷通道内的f和Nu均大于其对应的热通道内的f和Nu。当格栅间距为5.97 mm时,矩形截面通道具有相对最优的综合性能,可以在阻力损失较小的情况下实现强化换热。研究结果可为全蚀刻工艺矩形截面PCHE的性能提升和结构优化提供理论依据和数据支撑。In order to improve the comprehensive flow and heat transfer performance of the printed circuit heat exchanger(PCHE)in the supercritical carbon dioxide(S-CO_(2))Brayton cycle system,a mathematic-physical model of the heat exchange unit with hot and cold channels is established,based on a new-type rectangular section PCHE manufactured by full etching technology in this paper.The influence mechanism and law of the grid spacing in the channels on the flow and heat transfer characteristics of S-CO_(2) under different operation conditions are numerically investigated.The results show that the flow velocity of S-CO_(2) in hot channels with different grid spacings decreases gradually along the channel,while that in cold channels increases gradually along the channel.At the same time,the flow frictional resistance coefficient(f)and Nusselt number(Nu)in hot and cold channels are both increased with the increasing grid spacing.Besides,f and Nu in cold channel are always larger than those in hot channel.When the grid spacing is 5.97 mm,the rectangular section channel has relatively optimal comprehensive performance,which can achieve enhanced heat transfer with small resistance loss.The research results can provide theoretical and data support for the performance improvement and structure optimization of rectangular section PCHE manufactured by full etching technology.

关 键 词：超临界二氧化碳(S-CO_(2)) 印刷电路板式换热器 矩形截面 格栅间距 综合传热增强因子 

分 类 号：TK172[动力工程及工程热物理—热能工程]