燃用高沾污性煤质锅炉SCR脱硝流场优化  

Optimization of flow field in SCR denitration system for boiler burning highly contaminated coal

作　　者：罗志[1] 许剑[2] 李斌 常磊[1] 尚桐[1] 牛国平[1] 谭增强[1] 王晓冰[1] LUO Zhi;XU Jian;LI Bin;CHANG Lei;SHANG Tong;NIU Guoping;TAN Zengqiang;WANG Xiaobing(Xi’an Thermal Power Research Institute Co., Ltd., Xi’an 710054, China;CR Power, Shenzhen 518001, China;North United Electric Power Co., Ltd., Baotou Third Thermal Power Plant, Baotou 014040, China)

机构地区：[1]西安热工研究院有限公司,陕西西安710054 [2]华润电力控股有限公司,广东深圳518001 [3]北方联合电力有限责任公司包头第三热电厂,内蒙古包头014040

出　　处：《热力发电》2018年第12期111-117,共7页Thermal Power Generation

基　　金：中国华能集团有限公司总部科技项目(HNKJ14-H10)~~

摘　　要：某2×300 MW机组选择性催化还原(SCR)烟气脱硝装置,自2013年运行以来,一直存在喷氨格栅、水平烟道和导流板等位置积灰严重,氨逃逸量明显超标,空气预热器差压高等问题。通过计算流体动力学(CFD)流场校核分析产生问题的原因,最终确定优化方案为:更换防积灰能力强、混合特性好的花瓣型喷氨格栅,优化导流板布置,并加大导流板和烟道壁面处流速以减轻积灰。优化后,喷氨格栅分区可调性能明显好转,SCR脱硝装置出口NOx质量浓度分布更为均匀,氨逃逸量显著降低,运行8个月后停炉检修时发现喷氨格栅、烟道和导流板异常堵灰的情况得到了根本解决。Since the SCR device of a2×300MW unit was put into service in2013,there has been serious problems such as ash deposition in the location of ammonia injection grid,horizontal flue gas duct and deflector.Meanwhile,the ammonia slip concentration obviously exceeded the standard value,resulting in a high differential pressure of the air preheater.To solve these problems,the flow field was checked through computational fluid dynamics(CFD)to find out the reason.The final optimization scheme is:replacing the original ammonia injection grid(AIG)by the petal type one better anti-fouling ability and mixing characteristics,optimizing the deflectors,and increasing the velocity near the guide plate and flue duct wall to alleviate ash accumulation.After the modification,the adjustable performance of the ammonia-spraying grille zoning was improved obviously,the distribution of nitrogen oxide concentration at outlet of the SCR denitrification system was more uniform,and the ammonia escape amount was significantly reduced.The abnormal ash blockage in the ammonia-spraying grille,flue and guide plate was solve when the furnace was shut down after8months’operation.

关 键 词：高沾污性煤质 超低排放 SCR 脱硝装置 流场优化 喷氨格栅 导流板 堵灰 

分 类 号：TK16[动力工程及工程热物理—热能工程]