水泥窑SCR脱硝反应器入口烟气均流扩散的数值模拟研究  

Numerical simulation of uniform flow diffusion of flue gas at inlet of SCR denitrification reactor in cement kiln

作　　者：崔一尘[1] 钟隆春 吴立纲 汪澜[2] CUI Yichen(Beijing Boqi Electric Power Technology Co.LTD.,Beijing 100022,China)

机构地区：[1]北京博奇电力科技有限公司,北京100022 [2]中国建筑材料科学研究总院,北京100024

出　　处：《水泥》2023年第2期16-22,共7页Cement

摘　　要：为解决上进下出布置形式的SCR反应器入口烟道内流场分布不均匀、催化剂层中心区域磨损以及靠近烟道壁面区域积灰等问题,本研究以天津振兴产能为2000 t/d二线水泥窑的中温中尘SCR脱硝装置为研究对象进行了流场模拟及流场优化。通过Ansys fluent软件对全尺寸SCR反应器烟道内的流场分布特性进行了模拟,提出了在反应器扩张段烟道进口位置设置一组导流格栅、在扩张段烟道中间位置设置一层均布板及第二组导流格栅的流场优化方案,优化方案中导流格栅起到引导烟气扩散流动的辅助作用,均布板起到了主要的均流作用,本研究通过仿真试验的方式选取50%开孔率、60°错排圆孔、孔径60 mm作为均布板的最优参数,优化方案通过工程案例进行了可行性验证。计算结果显示优化方案对系统压损的负担较小,能有效提高烟气分布均匀性,实现催化剂入口速度分布Cv<15%的技术要求。优化改造后现场实测结果显示,催化剂入口速度分布均匀性由C_(v)=48.5%,优化到C_(v)=14.5%,系统阻力仅增加91.5 Pa,脱硝效率提高了11.2%达到86.4%。In order to solve the problems of uneven flow field distribution in the inlet flue of SCR reactor in the form of upper inlet and lower outlet,abrasion in the center area of catalyst layer and ash deposition near the flue wall,etc.In this study,the flow field simulation and flow field optimization were conducted for a medium temperature medium dust SCR denitration device with a design capacity of 2000 t/d for a second line cement kiln in Tianjin Zhenxing cement company.The flow field distribution characteristics in the flue of a fullsize SCR reactor were simulated by the Ansys fluent software.A flow field optimization scheme was proposed to set a group of guide grids at the inlet of the flue in the expansion section of the reactor,a layer of uniform distribution plate and a second group of guide grids at the middle of the flue in the expansion section.In the optimization scheme,the guide grid plays an auxiliary role in guiding the diffusion and flow of flue gas,and the uniform distribution plate plays a major role in current sharing.In this study,50%opening rate,60°staggered round holes and 60 mm hole aperture were selected as the optimal parameters of the uniform distribution plate through simulation test.The feasibility of the optimization scheme was verified through engineering cases.The calculation results show that the optimized scheme has less burden on the system pressure loss,can effectively improve the uniformity of flue gas distribution,and achieve the technical requirements of catalyst inlet velocity distribution Cv<15%.The field measurement results after optimization and reconstruction show that the uniformity of catalyst inlet velocity distribution is optimized from C_(v)=48.5%to C_(v)=14.5%,the system resistance is increased by 91.5 Pa,and the denitrification efficiency is improved by 11.2%to 86.4%.

关 键 词：水泥窑 SCR脱硝 中温布置 流场优化 数值模拟 

分 类 号：TQ172.625.3[化学工程—水泥工业]