化学链燃烧载氧体中反应与扩散的竞争与协调  

The Competition and Coordination Between Reaction and Diffusion for Oxygen Carrier Particle in Chemical Looping Combustion

作　　者：王会[1] 李振山[1] 范晓旭[2] 蔡宁生[1] WANG Hui;LI Zhen-Shan;FAN Xiao-Xu;CAI Ning-Sheng(Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China;Energy Research Institute of Shandong Academy Science,Jinan 250014,China)

机构地区：[1]清华大学能源与动力工程系热科学与动力工程教育部重点实验室,北京100084 [2]山东省科学院能源研究所,济南250014

出　　处：《工程热物理学报》2019年第1期204-212,共9页Journal of Engineering Thermophysics

基　　金：国家重点研发计划(No.2016YFB0600801);山东省自然科学基金(No.ZR2015YL001)

摘　　要：为了从原理上解释反应与扩散对化学链燃烧中载氧体颗粒还原反应的控制机制,本文以载氧体和还原性气体的反应为研究对象建立了晶粒-颗粒模型,并通过实验数据验证了模型的正确性。本文从颗粒尺度和晶粒尺度两个层面分析了颗粒行为和晶粒行为的对应关系,结果表明,在反应与扩散控制机制的竞争与协调下,颗粒内被还原晶粒的结构呈现三种典型分布。此外还讨论了气体产物层扩散系数和化学反应速度常数对晶粒转化率的影响。The competition and coordination between reaction and diffusion occur during the reaction process of reducing gas and oxygen carrier particle in chemical looping combustion.In this work,a multi-scale model was developed to describe the control mechanisms of reaction and diffusion fundamentally.The overall particle conversion obtained with the developed model showed good agreement with the experimental data.The reduction reaction characteristics of oxygen carrier at both particle scale and grain scale were analyzed.The model results showed three typical kinds of grain structure distribution under different control mechanisms.Moreover,the effects of gas diffusion coefficient in product layer and chemical reaction rate constant on grain conversion were discussed.

关 键 词：载氧体颗粒 晶粒 反应控制 扩散控制 

分 类 号：TK16[动力工程及工程热物理—热能工程]