液态包层复杂几何构件下的MHD流动、传热和氚输运研究

发布时间：2018-01-10 02:03

本文关键词：液态包层复杂几何构件下的MHD流动、传热和氚输运研究　出处：《中国科学技术大学》2017年博士论文　论文类型：学位论文

【摘要】：聚变堆包层因其适应等离子体形状而结构设计相对复杂,对于液态金属包层普遍存在几种共性的几何构件,如突扩突缩管道、弯管、分配收集箱等,磁流体在这些复杂形状管道内流动会出现显著不同特征的三维磁流体效应,是包层内最为严重的磁流体现象,同时影响到包层传热效果和氚的输运,也是液态金属包层共有的热工水力学问题。为支持聚变液态包层的研究与发展,本文对聚变液态锂铅包层中存在的复杂几何构件开展了磁流体动力学液态金属流动、传热和氚输运的数值模拟分析,从程序开发、程序性能分析和加速方法、复杂几何管道的MHD流动传热特性分析、氚输运关键参数敏感性分析四个方面展开分析,具体工作总结如下:(1)聚变环境下液态锂铅的流动过程是非常复杂的,受到诸如磁流体动力学(MHD)流的多种物理环境的耦合影响。围绕聚变液态锂铅增殖包层内存在着MHD流动、浮升力及氚输运耦合问题,基于OpenFOAM平台根据不同的边界耦合方法发展了多网格单矩阵和双边界耦合两种求解技术。开发了 MHD流动-热-电势-l#输运多物理场耦合程序,并分别开展Shercliff和Hunt算例理论验证、KIT突扩和MHD自然对流实验验证以及氚输运实验等相关验证。验证结果表明,所开发的程序适用于聚变环境下流体高Ha数和高Gr数特点,计算结果具有很好的准确性和可靠性,可用于液态包层流动、传热和氚输运分析。(2)基于所开发的耦合求解程序开展并行性能分析,开发GPU异构和全GPU加速求解器。针对CPU并行,分析并行加速性能影响因素,发现求解算法为求解快慢的主要因素,并行分块对并行效率影响明显。CPU和GPU求解器基于相同算例分别分析其在普通流体、MHD流体、不同求解算法和网格尺寸上的计算效率。结果显示,GPU适合于MHD问题求解,在大网格问题上加速明显。(3)开展液态锂铅包层中存在的复杂的几何构件内MHD流动和传热分析,针对于现有的液态锂铅包层结构进行了描述,归类出共同存在的复杂几何构件的特征。对聚变液态包层复杂几何流道,如弯管、分配联箱和带有氦气流道的管道壁面的MHD流动展开了数值模拟分析,基于管道MHD流动,展开传热耦合特性对比分析。结果显示,氦气流道使内部MHD流出现波动,壁面耦合效应使得壁面附近射流偏小或反向(传热)等。(4)氚输运数值模拟首先针对分配联箱管道进行氚浓度分析,随后针对管道流开展l#输运关键参数敏感性分析,包括流动速度、磁场大小、壁面导电性能、传热效应和氚扩散系数等因素对l#浓度和l#在壁面上的渗透率的影响。结果显示流动速度分布,特别是靠近壁面的速度分布对氚在壁面的渗透率的影响显著,MHD效应可减少壁面氚渗透率,随着磁场强度增加,氚在壁面上的渗透率近似于指数下降,氚的扩散系数在一定范围内影响的效果较为显著,且氚溶解度不确定性影响显著等。本文工作完成了聚变包层复杂几何构件下的MHD流动、传热和氚输运研究,在同一个平台开发了 MHD流动和传热两种边界耦合处理分析程序、氚输运分析程序和双扩散MHD流动分析程序,初步建立了液态锂铅增殖包层热工水力分析和氚输运分析研究工具,掌握了复杂几何流道对MHD流动和传热的影响特点,以及氚输运过程中的敏感参数特点。
[Abstract]:Fusion reactor blanket because of its adaptability to the plasma shape and structure design is relatively complex, the geometric component of liquid metal cladding exists several common, such as sudden expansion / contraction pipe, pipe, distribution collection box, magnetic fluid flow in these complicated pipeline will appear three-dimensional magnetohydrodynamic effect significantly different characteristics, is the package the most inner layer of magnetic fluid phenomenon is serious, also affect the heat transfer effect of cladding and tritium transport, and liquid metal clad common thermal hydraulics problem. To support the research and development of fusion liquid blanket, this paper carried out the magnetic fluid dynamics of liquid metal flow on the complex geometric components of liquid lithium lead blanket fusion in the layer, heat transfer and tritium transport numerical simulation analysis, from program development, analysis and accelerating method of program performance analysis of MHD flow and heat transfer characteristics of complex geometry pipeline, tritium transport key parameter sensitivity The perceptual analysis of four aspects of analysis, specific work are summarized as follows: (1) the flow process of the liquid lithium lead the fusion of environment is very complex, such as magnetohydrodynamic (MHD) coupling effects of various physical environment. The flow around the fusion liquid LiPb breeder blanket existed in the MHD flow and the buoyancy tritium transport coupling problem, OpenFOAM platform for the development of multi grid single and double coupling matrix for solving the two technology according to the boundary coupling method based on different development. MHD flow heat transport potential -l# multiphysics coupling procedure, and carry out Shercliff and Hunt examples of theoretical verification, KIT expansion and MHD convection experiment and tritium transport experiment were verified. The verification results show that the developed program for fusion environment fluid with high Ha number and Gr number, the calculation results with good accuracy and reliability, availability In the liquid cladding flow, heat transfer and transport of tritium analysis. (2) coupling program developed by carry out parallel analysis based on the development of GPU and GPU heterogeneous accelerated solver. For CPU parallel, parallel analysis influence factors of acceleration performance, found the main factors for solving algorithm speed, parallel to the block.CPU and GPU significantly influence the efficiency of parallel solver based on the same example respectively in the analysis of ordinary fluid, MHD fluid, the calculation efficiency of different algorithms and grid size. The results showed that GPU is suitable for solving MHD problems, the grid problem plus speed is obviously. (3) to carry out the analysis of flow and heat transfer in complex geometry the component liquid lithium lead blanket in MHD, according to the existing liquid lithium lead blanket structure are described, classified the characteristics of complex geometry are common. The fusion liquid blanket complex geometric flow, such as pipe, branch The wall of the MHD pipe flow distribution header with helium channel launched the numerical simulation analysis of pipeline MHD flow based on analysis of heat transfer coupling characteristics of contrast. The results showed that the internal flow of helium MHD flow fluctuations, the coupling effect of the wall surface near the wall jet is small or reverse (heat transfer) (4). Tritium transport numerical simulation firstly according to the analysis of tritium concentration distribution header pipe, then the pipeline flow transport to carry out l# analysis of key parameters, including flow velocity, magnetic field, surface conductivity, heat transfer effect and influencing factors of tritium diffusion coefficient on the permeability of the concentration of l# and l# on the wall of the results. Flow velocity distribution, especially the velocity near the wall on the distribution of tritium significant influence in wall permeability, the MHD effect can reduce the wall tritium permeability increases with increasing magnetic field strength, on the wall of the tritium permeability near Similar to the index decline, diffusion coefficient of tritium effect in a certain range of remarkable effect, and the effect of uncertainty of tritium solubility. This work is done in the fusion package MHD flow layer under complex geometry components, study heat transfer and tritium transport, MHD flow and heat transfer of two kinds of boundary coupling analysis program is developed in the the same platform, analysis procedures and double diffusion MHD flow analysis program of tritium lose, initially established a liquid LiPb breeder Blanket Thermal Hydraulic Analysis and tritium transport analysis as research tools, grasp the complicated geometric flow effect on MHD flow and heat transfer characteristics of the sensitive parameters and characteristics of tritium transport process.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TL64

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