410t/h循环流化床锅炉防磨梁对边壁气固流场影响的数值研究  

Numerical Study of Gas-Solid Hydrodynamics in 410t/h CFB Boiler with Anti-wear Beams

作　　者：邹阳军 程乐鸣[2] 许霖杰 何胜 郑文广 

机构地区：[1]华电电力科学研究院 [2]浙江大学能源清洁利用国家重点实验室

出　　处：《电站系统工程》2017年第2期9-12,16,共5页Power System Engineering

基　　金：国家"十二五"科技支撑计划(NO:2012BAA02B01-03)资助

摘　　要：对410 t/h循环流化床(CFB)锅炉加设多阶防磨梁前、后炉内气固流场分布规律进行数值模拟,研究了加设防磨梁后对炉膛内固相平均浓度、边壁区域固相浓度和轴向速度分布的影响。结果表明:炉内加设防磨梁后,炉膛密相区颗粒平均质量浓度有所下降,而稀相区略有增大;无防磨梁时,四周边壁颗粒浓度分布较为均匀;加设防磨梁明显破坏了边壁颗粒下降流的连续性,且四周边壁颗粒浓度分布规律存在较大差异;2层防磨梁之间边壁下降流颗粒浓度的增加速度远远大于无防磨梁时此区间的增加速度,且最下层防磨梁区间与其他防磨梁区间颗粒浓度分布存在较大差异;无防磨梁时,炉膛后墙颗粒浓度分布与其他边壁存在较大差异;加设防磨梁后,只在后墙出口区域存在明显差异;加设防磨梁后,边壁区域颗粒下降流总体速度随床高降低而减小,与无防磨梁时趋势相反,能明显减轻炉膛中下部磨损较为严重区域的壁面磨损。Numerical simulations were carried out to study the effect of anti-wear beams on the distribution of solids concentration and axial velocity both in the furnace and in the region close to the furnace wall in a 410t/h circulating fluidized bed（CFB） boiler. Results show that the average solids concentration decreases slightly in the lower dense phase region but increases slightly in the upper dilute phase region. Anti-wear beams block the falling down of dense particles close to the wall, and distributions of solids concentration close to different furnace wall have greater difference. Within the area between two anti-wear beams, the increase degree of solids concentration and falling velocity of particles adhering to wall is higher than that with no anti-wear beams, and distribution of solids concentration in lowest anti-wear beam region differs from that in other anti-wear beam regions. Distribution of solids concentration adhering furnace back wall differs from that adhering other three walls with no anti-wear beam, and with installing anti-wear beams, there is different only at outlet areas. For water walls protected with anti-wear beams, the solids overall axial velocity in region close to the furnace wall decreases with decreasing the bed height. This trend is different from that with no anti-wear beams, and can improve the water walls resistance at middle and lower furnace region.

关 键 词：CFB锅炉 防磨梁 气固流场 数值模拟 

分 类 号：TK229.6[动力工程及工程热物理—动力机械及工程]