入口温度对倾斜圆管内超临界CO_(2)的流动传热影响研究  

Numerical Research on the Effect of Inlet Temperature on Flow and Heat Transfer of Supercritical CO_(2)in Inclined Tube

作　　者：董文志 韦武 周亭羽 巴金 DONG Wenzhi;WEI Wu;ZHOU Tingyu;BA Jin(School of Mechanical Engineering,Guizhou University,Guiyang 550000)

机构地区：[1]贵州大学机械工程学院,贵阳550000

出　　处：《计算机与数字工程》2023年第9期2165-2170,共6页Computer & Digital Engineering

基　　金：国家自然科学基金项目(编号:52066004);贵州省科技计划项目课题(编号:[2020]1Y237)资助。

摘　　要：为探究不同入口温度下倾斜圆管内超临界CO_(2)的流动与传热规律,论文采用SST k-ω低雷诺数湍流模型,对超临界CO_(2)在倾斜角α=30°,管长3660mm,内径22.14mm的倾斜圆管内进行了数值模拟。首先,通过超临界CO_(2)在水平圆管内流动传热的实验数据验证了数值模型的合理性和正确性。其次,通过对温度场和速度场等参数揭示了CO_(2)在倾斜管内的流动传热规律。最后,重点研究了入口温度对倾斜圆管内超临界CO_(2)对流换热的影响,结果表明:入口温度升高会造成加热段顶母线与底母线壁面温差减小,换热系数增大,增强了超临界CO_(2)吸收来自管壁热量的效果。此外,入口温度升高,造成相对二次流动能总体水平提高,进而导致了横截面内更多的密度低且传热性能差的流体沿着管壁两侧流向顶母线区域,增加了底母线附近传热效果,降低传热恶化现象的发生。研究结果可以为新型换热装置的设计和安全运行提供一定的理论依据。In order to investigate flow and heat transfer of S-CO_(2)(supercritical CO_(2))in inclined tubes under different inlet temperature,the SST k−ωlow Reynolds number turbulence model is used to simulate the supercritical CO_(2) in inclined tube with length of 3660 mm and inner diameter of 22.14 mm at an inclination angle of 30°.Firstly,accuracy of the calculation model is verified by the experimental data of S-CO_(2) in a horizontal circular tube.Secondly,the law of flow and heat transfer of S-CO_(2) in inclined tube is revealed through the flow parameters such as temperature field and velocity field.Finally,the effect of inlet temperature on the convective heat transfer of S-CO_(2) in inclined circular tube is studied,the results show that with the increase of inlet temperature,the wall temperature difference between top generatrix and bottom generatrix in the heating section decreases,the heat transfer coefficient increases,and the effect of absorbing heat from the pipe wall by S-CO_(2) is enhanced.In addition,the increase of the inlet temperature results in an increase in the overall level of relative secondary flow energy,which leads to the flow of more fluids with low density and poor heat transfer performance along both sides of the tube wall to the top generatrix area,which increases the heat transfer effect near the bottom generatrix and reduces the heat transfer deterioration.The research results can provide a theoretical basis for the design and safe operation of the new heat exchanger.

关 键 词：超临界CO_(2) 倾斜圆管 数值模拟 二次流动能 换热系数 

分 类 号：TK124[动力工程及工程热物理—工程热物理]