球床堆芯石墨多孔介质氧化过程及数值模拟研究  

Numerical Simulation of the Oxidation Process of Graphite Porous Media in the Reactor Core of Pebble Bed HTGR

作　　者：鲁伟 李晓伟[1] 吴莘馨[1] LU Wei;LI Xiao-Wei;WU Xin-Xin(Institute of Nuclear and New Energy Technology,Tsinghim University,Beijing 100084,China)

机构地区：[1]清华大学核能与新能源技术研究院反应堆结构研究室,北京100084

出　　处：《工程热物理学报》2019年第4期888-893,共6页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.51576103)

摘　　要：本文基于多孔介质模型采用数值模拟方法研究了IG110石墨球与石墨粉在氧气气氛下的扩散传质耦合氧化反应过程。根据已有实验结果拟合出石墨在氧气气氛下的四步总包反应动力学参数,四步总包反应机理比一步总包反应可以更好地描述石墨氧化反应过程.多孔介质模型能有效模拟气体在石墨内外表面的扩散传质过程以及表面化学反应,活性比表面积是分析不同尺度下石墨氧化过程的重要参数,较低温度下石墨氧化腐蚀主要分布在石墨孔隙结构内部。The oxidation coupled with diffusion and mass transfer process of IG110 graphite sphere and graphite powder in oxygen atmosphere is numerically simulated with the porous medium model.According to the existing experimental results, the four step overall reaction kinetic parameters of graphite in oxygen atmosphere are fitted. The four step overall reaction mechanism can better describe the process of graphite oxidation than one-step overall reaction. The porous media model can effectively simulate the gas diffusion and mass transfer inside and outside the graphite and surface chemical reaction. The active surface area is an important parameter in analyzing the graphite oxidation process under different scales. Graphite oxidation corrosion at lower temperature is mainly distributed in the internal pore structure.

关 键 词：球床堆芯 石墨 多孔介质 反应动力学 

分 类 号：TK124[动力工程及工程热物理—工程热物理]