浮升力效应和流动加速效应对超临界二氧化碳传热影响理论分析  

Theoretical Analysis of Effect of Buoyancy and Flow Acceleration on Heat Transfer of Supercritical Carbon Dioxide

作　　者：刘光旭[1] 黄彦平[1] 王俊峰[1] 刘生晖 昝元锋 郎雪梅[1] Liu Guangxu;Huang Yanping;Wang Junfeng;Liu Shenghui;Zan Yuanfeng;Lang Xuemei(CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology,Nuclear Power Institute of China,Chengdu,610213,China)

机构地区：[1]中国核动力研究设计院中核核反应堆热工水力技术重点实验室

出　　处：《核动力工程》2018年第6期34-38,共5页Nuclear Power Engineering

基　　金：国家杰出青年科学基金(11325526);国家自然科学基金资助(11605193)

摘　　要：从边界层基本特性出发,分析了拟临界区强变物性导致的浮升力效应和流动加速效应对近壁面区域超临界二氧化碳传热特性的影响机理,基于受力分析推导得到了2种效应作用下的超临界流体传热弱化起始点理论判据。研究结果表明,对于加热工况竖直向上流动,浮升力效应和流动加速效应均会导致近壁面区域切应力减弱,进而影响近壁面区湍流的生成与扩散,最终导致传热弱化;2种效应作用下传热弱化起始点判据分别为浮升力因子Bu=1.16×10^-5和流动加速因子Ac=2.91×10^-6,上述阈值与实验结果吻合良好。Based on the basic behaviors of the boundary layer,this paper analyzed the effects of buoyancy and flow acceleration resulted from the significant changes of thermal properties near the pseudo-critical region on the heat transfer of supercritical fluids near the wall.The theoretical thresholds of heat transfer deterioration,which resulted from buoyancy force and flow acceleration, were developed.Results showed that,for the heat transfer in the vertical flow,both buoyancy and flow acceleration would decrease the shear stress near the wall,and finally retrain the production and diffusion of turbulence.The thresholds of heat transfer deterioration resulted from buoyancy force and flow acceleration were Bu=1.16×10^-5and Ac=2.91×10^-6,respectively.These thresholds agreed well with experimental data.

关 键 词：超临界流体 拟临界区 传热 理论分析 

分 类 号：TL334[核科学技术—核技术及应用]