摘要
随着新能源高比例接入电网,燃煤电厂深度调峰低负荷运行成为常态。燃煤电厂深度调峰时烟气温度为260~300℃,低于传统脱硝催化剂320~400℃的温度窗口。为了确保低负荷下脱硝系统的高效运行,以某330 MW机组为研究对象,采用前两层宽温催化剂加下层常规催化剂的组合模式对脱硝系统催化剂布置方式进行了优化。结果表明,机组在低负荷运行时,烟气温度高于263℃的最低喷氨温度即可投氨运行;结合实际运行工况,烟温达到270℃以上机组可连续喷氨稳定运行,由硫酸氢氨结露引起催化剂失效的风险较低;机组在304 MW、150 MW及75 MW负荷下,前两层宽温催化剂脱硝效率分别为84.5%、84.1%、90.1%;整个脱硝系统的效率分别为89.8%、90.1%、95.3%;氨逃逸浓度分别为1.9、2.2、2.7μL/L,节省喷氨量为2.0 kg/h;NO_(x)排放质量浓度分别为27、34、29 mg/m^(3),满足机组超低排放的要求。
The high proportion of new energy connected to the power grid makes peak shaving low load operation of coal-fired power plants become regular.The flue gas temperature during low-load operation of coal-fired power plants is 260℃~300℃,which is lower than 320℃~400℃temperature window of conventional denitrification catalysts.Taking a 330 MW unit as the research object,the layout of catalysts in the denitrification system was optimized by using the combination mode of the middle and upper layers of wide temperature catalysts and the lower layer of conventional catalysts to ensure the efficient operation of denitrification system under low load.The results show that under low load operation,ammonia can be injected to the unit when the smoke temperature is higher than 263℃minimum injection temperature.Combined with the actual operation conditions,ammonia can be continuously injected to the unit when the smoke temperature is higher than 270℃,and the risk of catalyst failure caused by ammonium bisulfate(ABS)condensation is low.Under the load of 304 MW,150 MW and 75 MW,the denitrification efficiency of the first two layers of wide temperature catalyst is 84.5%,84.1%and 90.1%,respectively;the efficiency of the whole denitration system was 89.8%,90.1%and 95.3%,respectively;ammonia escape concentrations were 1.9μL/L,2.2μL/L and 2.7μL/L,respectively,saving ammonia injection amount was 2.0 kg/h;NO_(x) emission concentrations are 27 mg/m^(3),34 mg/m^(3) and 29 mg/m^(3),respectively,which meet the requirements of ultra-low emission.
出处
《电力科技与环保》
2021年第6期51-56,共6页
Electric Power Technology and Environmental Protection
基金
国家能源集团科技创新项目“宽温运行窗口脱硝催化剂关键技术与应用研究”(GJNY-19-95)。
关键词
催化剂设计
低负荷运行
宽温脱硝催化剂
超低排放
catalyst design
low load operation
wide temperature denitration catalyst
ultra-low emissions
