超临界二氧化碳流体中纳米颗粒热泳沉积计算研究  

Computing Research on Nanoparticle Thermophoresis Deposition in Supercritical Carbon Dioxide Fluid

作　　者：周涛 唐剑宇 张帆[1,2] 刘文斌 ZHOU Tao;TANG Jianyu;ZHANG Fan;LIU Wenbin(Department of Nuclear Science and Technology,School of Energy and Environment,Southeast University,Nanjing 210096,China;Institute of Nuclear Thermal-hydraulic Standardization,China)

机构地区：[1]东南大学能源与环境学院核科学与技术系,江苏南京210096 [2]核热工安全与标准化团队

出　　处：《原子能科学技术》2022年第12期2717-2724,共8页Atomic Energy Science and Technology

基　　金：国家重点研发计划重点专项(2020YFB1901700);江苏省双创人才经费(1103000297)。

摘　　要：超临界二氧化碳中纳米颗粒的运动沉积问题是目前的国际前沿课题。纳米颗粒由于其粒径小、具有更高的相对表面能,其穿透性更强,对超临界系统装置可能有较大破坏性。选择不锈钢纳米颗粒、超临界二氧化碳作为具体对象,以1 m长的水平直管作为流动几何通道,运用Fluent软件采取控制单一变量法,对影响纳米颗粒热泳沉积的因素进行了计算分析。对于热泳沉积而言,流体与壁面温差是影响沉积率的最主要因素,呈正相关关系;来流速度、粒径、管径与沉积率呈负相关关系。The movement and deposition of nanoparticles in supercritical carbon dioxide is a current international frontier subject. In the development of new nuclear reactors, using supercritical carbon dioxide Brayton cycle instead of traditional steam Rankine cycle can greatly improve the cycle efficiency, reduce equipment size and improve safety. In this new cycle, the movement and deposition of nanoparticles play a significant role under normal and abnormal operating conditions in nuclear power plants. Nanoparticles, due to their small particle size and higher relative surface energy, are more penetrable. When it under the thermophoresis force will emerge the thermophoresis deposition, causing collision and erosion to the pipeline. And it may be more destructive to supercritical devices or systems. To study the movement and deposition characteristics of nanoparticles in supercritical media, then further explore the factors affecting nanoparticles deposition, and find their qualitative and even quantitative relationship. This paper studies this problem from the aspects of particle size, wall temperature difference, incoming flow velocity, and so on to try to clarify the motion mechanism of nanoparticle deposition. In specific studies, stainless steel nanoparticles and supercritical carbon dioxide were selected as the objects, a 1 meter long horizontal straight pipe was taken as the flow geometric channel, based on the control single variable method, the factors affecting the thermophoresis deposition of nanoparticles were calculated and analyzed by Fluent software. According to the calculation to obtain the curve picture, the results show that the higher the fluid temperature, the greater the temperature gradient, and the greater the thermophoresis force on nanoparticles, which increases the dimensionless thermophoresis deposition velocity and the thermophoresis deposition rate. In addition, the increase of fluid temperature leads to the decrease of fluid viscosity and viscous resistance of particle movement, which also

关 键 词：超临界二氧化碳 纳米颗粒 热泳沉积 温差 

分 类 号：TL334[核科学技术—核技术及应用]