四级过热器管束壁面颗粒沉积的数值模拟  

Numerical Simulation of Ash Deposition on Wall of Fourth-Stage Superheater Pipes

作　　者：王毅斌[1] 谭厚章[1] 刘鹤欣 许伟刚[1] 曹锐杰 WANG Yi-bin;TAN Hou-zhang;LIU He-xin;XU Wei-gang;CAO Rui-jie(MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China;Linfen Thermal Power Limited Company of Shanxi Province, Linfen 041000, China)

机构地区：[1]西安交通大学,能源与动力工程学院,热流科学与工程教育部重点实验室,西安710049 [2]山西临汾热电有限公司,山西临汾041000

出　　处：《新能源进展》2017年第3期163-169,共7页Advances in New and Renewable Energy

基　　金：国家自然科学基金项目(91544108,51376147)

摘　　要：以某12 MW生物质锅炉炉膛出口四级过热器为研究对象,建立了考虑惯性、布朗力和热泳力作用下灰颗粒的沉积模型,同时耦合碱金属盐蒸气的凝结效应以及颗粒反弹、粘附机制。基于数学模型考察了管排截距与灰中KCl含量对过热器管束壁面颗粒沉积质量的影响。结果表明,灰颗粒中碱金属盐KCl含量由15%增至25%后,各排管壁灰颗粒沉积质量显著增加,首排单管迎风面沉积质量由4.82×10^(-7) kg/m^2增大为4.03×10^(-6) kg/m^2。当管束的纵向节距由1.5D增大至2.5D时,各排管壁迎风面与背风面颗粒沉积质量显著增加。首排管束下游壁面形成不规则初始沉积形貌,其主要源于含尘气流进入下游管排,烟气冲刷位置、涡生成与脱落位置发生变化所导致。For the fourth stage superheater at the outlet of a12MW biomass-fired power plant,an ash particle depositionmodel considering the condensation of gaseous alkali metal salts and rebound/stick of ash particles was developed byconsidering of the inertial force,Brownian force and thermophoretic force.The effects of tube arrangement and KClcontent in ash particles on ash deposition characteristics were investigated based on a mathematical model.Resultsshowed that the ash deposited mass on tube surface for each row was sharply increased with the KCl content increased;as the KCl content increased from15%to25%,and the deposited mass on the windward side of the first row increasedfrom4.82×10?7kg/m2to4.03×10?6kg/m2.The deposits on tube wall of each row were increased when the longitudinalpitch varied from1.5D to2.5D.The formation of irregular depositing characteristic around the tube was mainly attributedto the scouring position variation for upstream flue gas to downstream of the tube bundle,and the generation and sheddingposition of vortex.

关 键 词：过热器 颗粒 沉积 凝结 盐蒸气 

分 类 号：TK6[动力工程及工程热物理—生物能]