【作者】 蒲林茂； 高宇； 钟圣俊； 张勇； 吉利娟； 柳鑫雨； 严中浩；

【Author】 PU Linmao;GAO Yu;ZHONG Shenjun;ZHANG Yong;JI Lijuan;LIU Xinyu;YAN Zhonghao;School of Environment and Chemical Engineering, Shenyang University of Technology;School of metallurgy, Northeastern University;Shenyang Ecological Environment Monitoring Center of Liaoning Province;

【机构】 沈阳工业大学环境与化学工程学院； 东北大学冶金学院； 辽宁省沈阳生态环境监测中心；

【摘要】 为控制火电厂氮氧化物排放,满足国家超低排放标准,基于计算流体力学（CFD）的方法,数值模拟仿真某热电厂168MW机组循环流化床锅炉（CFB）掺烧生物质的烟气脱硝过程,研究了还原剂喷射量的影响,喷射源数量、分布及喷射方向的优化。以目标电厂锅炉实体为模板,1:1建立简化几何模型,结合实际情况入口边界条件设置的各烟气组分质量分数分别为:O₂2%、H₂O11.6%、CO₂16.2%、NO0.1%,使用ANSYS Fluent 2021 R1中的SNCR模型对不同优化条件下的还原反应进行数值模拟,分析各条件下的模拟结果。结果表明:最佳的氨氮比应取NSR=1.25,此时三个出口处有较高的脱硝效率89.61%、90.00%、91.56%,13.86 mg/s、24.64 mg/s、56.91 mg/s的氨逃逸量也在合理范围内;增加喷射源数量,能显著减小还原剂喷射对烟气流场的扰动;喷射方向平行于烟气流动方向,正交喷射源连线于烟气流动方向,均有利于还原剂与烟气的混合。更多还原

【Abstract】 In order to control the nitrogen oxide emissions of thermal power plants and meet the national ultra-low emission standards, based on the computational fluid dynamics（ CFD） method, the flue gas denitrification process of a 300 MW unit circulating fluidized bed boiler（ CFB） in a thermal power plant was simulated. The process of determining the amount of reducing agent injection, the number and distribution of injection sources and the optimization of injection direction were studied.Taking the boiler entity of the target power plant as a template, a simplified geometric model was established at 1 : 1. The mass fractions of each flue gas component set by the actual inlet boundary conditions were: O₂2%, H₂O11.6%, CO₂16.2%, NO0.1%. The SNCR model in ANSYS Fluent 2021 R1 was used to simulate the reduction reaction under different optimization conditions, and the simulation results under various conditions were analyzed. The results show that the best ammonia nitrogen ratio should be NSR =1.25, at this time, the three outlets have higher denitrification efficiency of 89.61 %,90.00 %, 91.56 %, and 13.86 mg/s, 24.64 mg/s, 56.91 mg/s of ammonia escape is also within a reasonable range. Increasing the number of injection sources can significantly reduce the disturbance of reducing agent injection on the flue gas flow field. Injection direction parallel to the direction of flue gas flow, injection source line orthogonal to the direction of flue gas flow, will be conducive to the mixing of reducing agent and flue gas.更多还原