超临界二氧化碳用印刷电路板式换热器性能分析  

Performance analysis of printed circuit heat exchanger for supercritical carbon dioxide

作　　者：张义飞 刘舫辰 张双星 杜文静[1] ZHANG Yifei;LIU Fangchen;ZHANG Shuangxing;DU Wenjing(School of Energy and Power Engineering,Shandong University,Jinan 250061,Shandong,China)

机构地区：[1]山东大学能源与动力工程学院,山东济南250061

出　　处：《化工学报》2023年第S01期183-190,共8页CIESC Journal

摘　　要：印刷电路板式换热器(PCHE)作为一种高效紧凑的新型微通道换热器,在超临界二氧化碳(SCO_(2))布雷顿循环中具有广阔应用前景。通过数值模拟分析了SCO_(2)在变径PCHE中的热工水力性能,结果表明:随着宽径的减小,表面传热系数增大,其相对于等径PCHE的提升效果更加显著;较大宽径PCHE的变径形式有着较小的CO_(2)压降增长率,宽径较小时变径结构会使综合性能有更显著的提高;表面传热系数随着渐变比的增加而增加,将变径段置于PCHE后端具有更优的传热特性,其表面传热系数峰值较其他形式提高了23%。不同结构的变径PCHE性能分析可为SCO_(2)冷却理论研究和PCHE典型工程应用提供参考和借鉴。Printed circuit heat exchanger(PCHE),as a new micro-channel heat exchanger with high efficiency and compactness,has very high potential to be applied to supercritical CO_(2) Brayton cycle.Based on the principle of heat transfer enhancement,the straight channel of PCHE is improved and the PCHE with variable diameter is proposed.This kind of channel can adapt to the change of fluid physical properties and obtain better comprehensive performance.The thermal-hydraulic performance of supercritical CO_(2) in PCHE channel with variable diameter is analyzed by numerical simulation.The results show that with the decrease of width,convective heat transfer coefficient increases,and the more it increases than corresponding PCHE with constant diameter.The structure of variable diameter has little influence on the pressure drop of cold fluid,and the application of structure of variable diameter to PCHE with larger width can reduce the increase of CO_(2) pressure drop.The structure of variable diameter will improve the comprehensive performance more obviously for PCHE with smaller width.For PCHE whose width is 1.6 mm,the comprehensive performance of PCHE with variable diameter is 1.81 times that of PCHE with constant diameter at 1.2 g/s.Convective heat transfer coefficient increases with the augment of changing ratio of width.When the changing ratio of width changes from 2 mm/m to 2.75 mm/m,the peak value of convective heat transfer coefficient increases by 2.9%.Arranging the variable diameter section at the back end of PCHE has better heat transfer characteristics,and its peak of convective heat transfer coefficient is increased by 23%compared with other forms.Analysis of thermal-hydraulic performance of PCHE with different structures can provide reference for theoretical research of supercritical CO_(2) cooling and typical engineering application of PCHE.

关 键 词：超临界二氧化碳 印刷电路板式换热器 预冷器 数值模拟 流动 传热 

分 类 号：TK124[动力工程及工程热物理—工程热物理]