双流化床反应器间气体泄漏规律的数值模拟  

Numerical Simulation of Gas Leakage in a Dual Fluidized Bed

作　　者：关彦军[1] 常剑[1] 张锴[1] 王宝冬 孙琦 

机构地区：[1]华北电力大学热电生产过程污染物监测与控制北京市重点实验室,北京102206 [2]北京低碳清洁能源研究所,北京102209

出　　处：《化学反应工程与工艺》2014年第1期48-56,共9页Chemical Reaction Engineering and Technology

基　　金：国家高技术研究发展计划(2012AA06115);国家自然科学基金项目(51076043)

摘　　要：建立了描述双流化床化学链燃烧反应器内气固两相流动的数学模型,采用计算流体动力学方法,模拟考察了提升管和鼓泡床相耦合的双流化床内不同单元之间气体泄漏产生原因和影响因素。化学链燃烧系统压力平衡的分析结果表明,反应器间的气体泄漏主要发生在溢流装置和鼓泡床之间;增大溢流装置表观气速,气体泄漏增大,而增大提升管或鼓泡床表观气速时,气体泄漏会随之减小;化学链燃烧系统内颗粒总藏量增加时,气体泄漏会减小;颗粒粒径减小后反应器之间气体泄漏降低。其研究结果对其他循环流化床反应器的设计与工程放大也有一定的借鉴作用。Based on the Eulerian-Eulerian model with the kinetic theory of granular flow, a gas-solid two-phase flow model is established to investigate the gas leakage in a dual fluidized bed for chemical looping combustion （CLC） using computation fluid dynamics （CFD）. This CLC system mainly consists of a riser as air reactor and a bubbling bed as fuel reactor, which are connected by a cyclone and a fluidized pot-seal. Particles and gas from the riser are separated by the cyclone. The particles fall down into a bubbling bed, and then are transported back into the riser via the pot-seal. Simulation results show that the pressure balance of the system is a key issue for the gas leakage. The pressure difference between the bubbling bed and cyclone or pot-seal should be as small as possible. The gas leakage is mainly from the pot-seal into the bubbling bed at normal operating conditions. With increasing the gas velocity in the riser or the bubbling bed, the gas leakage decreases from the pot-seal into the bubbling bed, whilst the increase in the gas velocity of the pot-seal results in more gas leakage. In addition, the gas leakage decreases with a decrease in the particle size or an increase in the solid inventory.

关 键 词：双流化床 化学链燃烧 气体泄漏 数值模拟 计算流体力学 

分 类 号：TK05[动力工程及工程热物理]