流场模拟在脱硝系统超低排放中的应用

Application of Flow Field Simulation in Ultra-low Emissions of Denitration System

燃煤电厂烟气脱硝目前以选择性催化还原脱硝(SCR)技术为主。在超低排放的要求下,脱硝系统普遍采用的提效措施是改善流场、加强混合效果,并加装第三层催化剂(原设计2层)。其中,通过CFD技术对流场进行优化设计是一项关键技术,通过合理的导流板、整流格栅、喷氨格栅、混合器的设计,提高催化剂入口烟气流速均匀性、氨气分布均匀性、降低整体系统阻力。文章对CFD技术做了简要介绍,并结合实际工程案例,对CFD在SCR脱硝系统优化中的应用做出分析。

At present,the flue gas denitration gives priority to selective catalytic reduction(SCR)technology in the coal-fired power plants.Under the requirement of the ultra low emissions,the existing denitration system widely adopts the efficiency-raising measures to improve the flow field,strengthen the mixing effect,and add the catalyst of the third layer(original designed as two layers).The optimization design of the flow field is a key technology through the CFD technology.Based on the reasonable designs of guide plates,rectifier gratings,spraying ammonia gratings and mixer,the paper increases the uniformity of flue gas’s velocity of catalyst inlet and ammonia gas distribution and decreases the resistance of the whole system.The paper briefly introduces CFD technology and combines the practical engineering cases,and analyzes the application of CFD in the optimization of SCR DeNOx system.