水冷包层增殖球床热机械性能研究

发布时间：2018-01-20 17:58

本文关键词： 聚变水冷包层两元混合球床热机械性能离散元方法　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】：作为中国聚变工程实验堆(CFETR)候选包层概念之一的水冷固态陶瓷增殖剂包层(WCCB)正在开展设计工作。WCCB采用新型的混合增殖球床(Li2TiO3Be12Ti)作为产氚载体,同时也布置少量Be球床倍增中子。包层球床的传热性能和力学性能直接影响包层热工水力与结构设计的可靠性和安全裕度,因此本论文旨在针对WCCB包层球床构建球床热机械分析模型,为WCCB包层设计与研发提供基础数据支持。首先,本论文基于离散元方法(DEM),开发了典型随机球床填充程序,研究了一元球床和WCCB混合增殖球床的填充结构,获得了满足WCCB设计要求的混合球床填充方案。其次,由于目前缺少混合材料球床有效热导率理论模型,论文基于一元球床的SZB模型,经过理论推导,提出了两元混合球床有效热导率唯象理论模型(M-SZB),并经过了初步验证。基于M-SZB模型获得的WCCB混合增殖球床有效热导率约为2.0 W/(m·K)到4.0 W/(m ·K),导热能力较一元锂陶瓷球床提高约2～4倍。此外,本论文提出基于DEM-CFD耦合方法分析球床传热,建立了对一元/两元球床普遍适用的有效热导率计算模型。该模型计算结果与一元球床(Li2TiO3球床、Li4SiO4球床和Be球床)有效热导率文献实验数据吻合较好,也与一元球床的SZB理论模型计算结果一致。此外,本论文应用该方法分析了WCCB两元混合增殖球床传热,结果表明其有效热导率也为2.0 W/(m·K)到4.0 W/(m · K),与M-SZB理论模型计算结果基本一致。最后,本论文基于DEM方法,开发了球床热场和力场双向全耦合分析模型。基于该方法初步分析了不同载荷模式(加载、卸载、循环载荷)下的球床热机械响应。
[Abstract]:WCCB, one of the candidate cladding concepts for CFETR, is being designed. WCCB uses a new hybrid proliferating ball bed (WCCB). Li2TiO3Be12Ti) is used as carrier for tritium production. At the same time, a small number of be spherical beds are arranged to multiply neutrons. The heat transfer and mechanical properties of the blanket directly affect the reliability and safety margin of the thermal hydraulic and structural design of the cladding. Therefore, the purpose of this paper is to build a thermal mechanical analysis model for the WCCB cladding ball bed to provide basic data support for the design and development of WCCB cladding. Firstly, this paper is based on discrete element method (DEM). A typical random ball bed filling program was developed, and the filling structure of monolithic ball bed and WCCB mixed multiplication ball bed was studied, and the mixed ball bed filling scheme satisfying the requirements of WCCB design was obtained. Secondly. Due to the lack of theoretical model of effective thermal conductivity of ball bed with mixed materials, this paper is based on the SZB model of monolithic ball bed. A phenomenological model of effective thermal conductivity of two-element mixed spherical bed is presented. The effective thermal conductivity of WCCB mixed multiplication spherical bed based on M-SZB model is about 2.0 W / m 路K) to 4.0 W / L m 路K). The thermal conductivity is about 2 ~ 4 times higher than that of the monolithic lithium ceramic ball bed. In addition, the DEM-CFD coupling method is proposed to analyze the heat transfer in the spherical bed. An effective thermal conductivity calculation model for monolithic / two-element spherical bed is established, and the calculated results are compared with that of single-element spherical bed Li _ 2TiO _ 3 spherical bed. The experimental data of effective thermal conductivity of Li4SiO4 and be are in good agreement with the results of SZB model. In this paper, the heat transfer of WCCB two-element mixed multiplication spherical bed is analyzed by using this method. The results show that the effective thermal conductivity is also from 2.0 W / m 路K to 4.0 W / M 路K). The results are in good agreement with M-SZB theoretical model. Finally, this paper is based on DEM method. A bidirectional fully coupled analysis model of the thermal field and the force field of the spherical bed is developed. Based on this method, the thermo-mechanical response of the spherical bed under different load modes (loading, unloading, cyclic load) is preliminarily analyzed.
【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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