水平流向不同小流道加热管内超临界CO_(2)的传热特性  

Heat transfer characteristics of supercritical CO_(2) in different heated mini-channels under horizontal flow condition

作　　者：王磊[1] 王艳[1] 甘玉凤 罗凯[1] 费华[1] 栾俨丁 WANG Lei;WANG Yan;GAN Yufeng;LUO Kai;FEI Hua;LUAN Yanding(School of Architectural and Surveying&Mapping Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China;School of Mechanical and Electrical Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China)

机构地区：[1]江西理工大学土木与测绘工程学院,江西赣州341000 [2]江西理工大学机电工程学院,江西赣州341000

出　　处：《化工进展》2025年第4期1945-1956,共12页Chemical Industry and Engineering Progress

基　　金：江西省自然科学基金(20242BAB25281,20242BAB20217);赣鄱俊才支持计划-急需紧缺海外人才引进项目(20242BCE50075);江西省教育厅科学技术研究项目(GJJ2200817);江西理工大学高层次人才资助项目(205200100620)。

摘　　要：针对水平流动方向上超临界CO_(2)在不同小流道加热管内的对流换热特性进行了详细实验研究。结果表明,当加热管的管径尺寸保持恒定时,超临界CO_(2)的对流换热系数均随着质量流量的增大而显著增大,但随着加热功率的增大以及进口温度的升高而明显减小。然而,超临界CO_(2)的对流换热系数随着压力的变化趋势却有所不同。当流体温度低于假临界温度时,超临界CO_(2)的对流换热系数随着压力的降低而显著增大;当流体温度高于假临界温度时,超临界CO_(2)的对流换热系数随着压力的升高而显著增大。不同实验参数(压力、质量流量、加热功率以及进口温度)独自保持恒定时,超临界CO_(2)的对流换热系数均随着管径尺寸的减小而显著增大。相较于管径尺寸为1mm时的对流换热系数而言,不同实验参数的独立变化对超临界CO_(2)在管径尺寸分别为0.75mm以及0.5mm时的最小和最大相对传热增强率并无显著影响。若忽略不同小流道加热管内浮升力效应的影响,对流换热系数的变化规律可通过超临界CO_(2)的热物理性质在其假临界区域发生剧烈变化的现象进行合理解释。The convective heat transfer characteristics of supercritical CO_(2) were investigated experimentally in different heated mini-channels under horizontal flow condition.The results showed that the convective heat transfer coefficients of supercritical CO_(2) increased significantly with the increase of mass flow rate.But the convective heat transfer coefficients decreased obviously with the increase of heating power and inlet temperature.However,the trends of convective heat transfer coefficient under the pressure condition were totally different.When the fluid temperature was below the pseudo-critical temperature,the convective heat transfer coefficient of supercritical CO_(2) increased significantly with the loss of pressure.If the fluid temperature was higher than the pseudo-critical temperature,the convective heat transfer coefficient of supercritical CO_(2) increased significantly with the increase of pressure.The convection heat transfer coefficient of supercritical CO_(2) significantly rose with the reduction of diameter of mini-channel when the different experimental parameters (pressure, mass flow rate, heating power, and inlet temperature) held constant, respectively. Compared with the convective heat transfer coefficient when the diameter of mini-channel was 1mm, the variation of different experimental parameters had no significant influence on the minimum and maximum of relative heat transfer enhancement rates of supercritical CO_(2) when the diameters of heated tube were 0.75mm and 0.5mm, respectively. If the buoyancy effect would be ignored in different heated mini-channels. The variation trend of convective heat transfer coefficient could be explained reasonably by the drastic change of thermal physical properties of supercritical CO_(2) near the pseudo-critical region.

关 键 词：超临界 水平流动 不同管径 对流传热 浮升力 

分 类 号：O359[理学—流体力学]