循环流化床锅炉烟道型SCR催化剂堵灰原因分析和预防措施

Cause Analysis and Preventive Measures of SCR Catalyst Plugging in CFB Boiler

为解决某公司循环流化床锅炉的烟道型SCR催化剂大颗粒异物沉积和堵灰的问题,分析了其成因并总结了其带来的危害,提出了防止SCR催化剂堵灰的措施,包括加强炉内脱硫,以及在尾部烟道各层受热面布置金属防护网,并在该公司的75 t/h CFB锅炉实施所提措施。经过8个月的运行后,停炉检查时未见明显大颗粒异物沉积和堵灰情况,且运行期间的氨水消耗量、氨逃逸浓度、NO_(x)排放浓度和催化剂阻力都保持稳定,得到了良好的收效。所提方案可为采用烟道型SCR催化剂的CFB锅炉提供参考。

In order to solve the problem of large particle foreign matter deposition and ash blocking of SCR catalyst in the flue of a circulating fluidized bed boiler of a company,the causes are analyzed and the harm brought by it is summarized.The measures to prevent ash blocking of SCR catalyst are proposed,including strengthening desulfurization in the furnace,arranging metal protective nets on the heating surfaces of each layer of the tail flue,and implementing the measures in the 75 t/h CFB boiler of the company.After 8 months of operation,no obvious large particle foreign matter deposition and ash blockage were found during shutdown inspection,and the ammonia consumption,ammonia escape concentration,NO_(x)emission concentration and catalyst resistance remained stable during operation,and good results were obtained.The proposed scheme can be used for reference in CFB boiler with flue type SCR catalyst.