SCR防堵灰型流场优化技术及工程应用  

Anti-blocking type SCR flow field optimization technology and its application

作　　者：张祥翼 罗志[2] 尚桐[2] 王晓冰[2] 常磊[2] 潘栋[2] 牛国平[2] ZHANG Xiangyi;LUO Zhi;SHANG Tong;WANG Xiaobing;CHANG Lei;PAN Dong;NIU Guoping(SPIC Guizhou Jinyuan Co.,Ltd.,Guiyang 550081,China;Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710054,China)

机构地区：[1]国家电投集团贵州金元股份有限公司,贵州贵阳550081 [2]西安热工研究院有限公司,陕西西安710054

出　　处：《热力发电》2020年第2期110-114,共5页Thermal Power Generation

摘　　要：贵州地区燃煤机组普遍燃用高硫、高灰分及高沾污性煤质,选择性催化还原(SCR)脱硝系统普遍存在喷氨格栅、水平烟道、导流板、整流格栅和催化剂等位置严重积灰,及氨逃逸量高和空气预热器等后续设备堵塞的问题。为此,本文提出SCR防堵灰型流场优化技术,并应用于贵州某电厂660MW机组W型炉SCR脱硝系统。该技术改造方案是将原喷氨格栅更换为防积灰型花瓣式喷氨格栅,优化导流板形式和布置,加大导流板和烟道底部壁面流速以减轻积灰,优化入射整流格栅角度。改造后运行5个月停炉检查,喷氨格栅、烟道壁面和导流板严重堵灰问题得到了根本解决,为SCR脱硝系统发挥正常性能,降低氨逃逸量,保证后续设备安全可靠运行提供了有利条件。The coal-fired power units in Guizhou Province generally use high-sulfur,high-ash and high-contamination coal,which causes serious ash accumulation in the selective catalytic reduction(SCR)flue gas denitration system,like in the ammonia spray grid,horizontal flue,deflector,rectifier grid,catalyst and other places.Moreover,the ammonia escape is obviously exceeding the standard value,resulting in high differential pressure of air preheater.For this reason,this paper proposes an SCR anti-blocking ash flow field optimization technology and applies it to the SCR flue gas denitration system of a 660 MW unit W-type boiler.The main transformation plan is to replace the original ammonia-spraying grid with petal-type ammonia-spraying grid which has strong anti-ashing ability,optimize the baffle arrangement,and increase the flow velocity at the deflector and flue bottom to reduce the ash accumulation and optimize the angle of the incident rectifying grid.After 5 months operation since the transformation,the boiler shutdown inspection shows that the abnormal ash blocking of the ammonia spray grid,flue and deflector was solved fundamentally.It provides favorable conditions to achieve good performance of the SCR denitration system and to reduce ammonia escape concentration.

关 键 词：脱硝系统 SCR 积灰 防堵灰 氨逃逸 流场优化 

分 类 号：X511[环境科学与工程—环境工程]