塔式炉膛内烟气流动及对其SNCR法脱硝  

Flue gas flow in tower furnace and its SNCR denitration

作　　者：丁弘毅 赵敬帅 王治云[1] 杨茉[1,2] DING Hongyi;ZHAO Jingshuai;WANG Zhiyun;YANG Mo(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Academic Affairs Office,Shanghai Jianqiao University,Shanghai 201306,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]上海建桥学院教务处,上海201306

出　　处：《化学工程》2023年第11期55-60,共6页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(51736003)。

摘　　要：为研究某1000 MW塔式锅炉在炉墙上对称添加两尿素喷口时炉膛内的燃烧特性及非线性特性,以对称四角切圆超(超)临界塔式锅炉为基础,在左右墙上对称添加两尿素喷口,建立一个几何结构和边界条件完全对称的三维简化锅炉模型。运用FLUENT软件模拟锅炉在满负荷时炉膛内的流场、温度场及NO组分规律,并分析他们的非线性情况,由此研究出一种提高SNCR(选择性非催化还原)法脱硝效率的方法。结果表明:即使对称添加两尿素喷口,完全对称的炉膛内烟气流动速度、温度和组分分布仍存在非线性现象;两尿素喷口对称向炉膛喷射尿素时,炉膛出口NO摩尔分数显著降低,脱硝效率为24.52%;增大尿素液滴粒径能减小计算域出口NO的摩尔分数偏差,且脱硝效率随着液滴粒径的增大先升高后降低,在300μm时脱硝效率最高。In order to study the combustion characteristics and nonlinear characteristics of a 1000 MW tower boiler with two urea nozzles added symmetrically on the furnace wall,a three-dimensional simplified boiler model with completely symmetrical geometric structure and boundary conditions was established based on a symmetrical quad-circular super(super)critical tower boiler with two urea nozzles added symmetrically on the left and right walls.Using FLUENT software to simulate the flow field,temperature field and NO composition law in the furnace of the boiler at full load and analyzed their nonlinear conditions,and thus developing a method to improve the denitrification efficiency of the SNCR(selective non-catalytic reduction).The results show that even if two urea vents are added symmetrically,the flow velocity,temperature and component distribution of flue gas in the completely symmetrical furnace still have nonlinear phenomena.When the two urea nozzles spray urea symmetrically to the furnace,NO molar fraction in the furnace outlet is significantly reduced,and the denitration efficiency is 24.52%.The molar fraction deviation of NO at the exit of calculation domain can be reduced by increasing the particle size of urea droplet,the denitration efficiency increases first and then decreases with the increase of the particle size of urea droplet,and the denitration efficiency is the highest at 300μm.

关 键 词：不同负荷 切圆燃烧 非线性 脱硝 数值模拟 

分 类 号：TK123[动力工程及工程热物理—工程热物理]