循环流化床锅炉炉内低氮燃烧无法满足排放要求时，需要对排烟进行进一步净化。烟气净化工艺主要有SNCR脱硝和SCR脱硝。为了比较2种工艺的经济性，建立了技术经济分析模型，对比分析了满负荷时的经济技术指标。结果表明：脱硝剂价格、催化剂价格和年运行时间是影响脱硝成本的主要因素，尿素价格对SNCR脱硝成本的敏感度最大，液氨对SCR脱硝成本的敏感度大于催化剂价格。SNCR脱硝的运行成本和总成本相对较低时要求NOx浓度分别低于140和228 mg/m3。基于入口NOx浓度200 mg/m3，对SCR工艺和SNCR工艺的经济性比较表明，当尿素价格低于3 402元/t时，SNCR总成本较低；当液氨单价高于3 300元/t时，SNCR工艺总成本更经济；在催化剂和年运行时间研究波动范围内，SNCR总成本始终最低、最经济。SNCR-SCR联合脱硝工艺不具备经济优势，且入口NOx浓度为151～273 mg/m3时总成本最高。超低排放循环流化床锅炉技术可以改善SCR工艺和SNCR工艺的经济性，并使SNCR工艺的优势更为突出。

The exhaust flue gas from a circulating fluidized bed boiler with low nitrogen combustion should be cleaned once again when NOx concentration exceeds the emission limit. Flue gas purification process mainly includes SNCR denitrification and SCR denitrification.In order to identify the most economical and suitable denitrification technology for circulating fluidized bed combustion conditions，the techno-economic analysis model was suggested and the techno-economic index for two cases was predicted under the condition of full load. The results indicate that reductant price，catalyst price and annual operating time are the main factors affecting the denitrification cost. The price of urea is the most sensitive to the cost of SNCR denitrification，and the sensitivity of liquid ammonia to the cost of SCR denitrification is greater than that of the catalyst. When operating cost and total cost of SNCR denitrification technology are relatively low，NOx concentration can be required below 140 mg/m3 and 228 mg/m3. Based on the inlet NOx concentration of 200 mg/m3，the economic comparison between two cases shows that when the price of urea is lower than 3 402 yuan/ton，the total cost of SNCR denitrification technology is lower. When the unit price of liquid ammonia is higher than 3 300 yuan/ton，the total cost of the SNCR denitrification technology is more economical. Within the research fluctuation range of catalyst and annual operating time，the total cost of SNCR denitrification technology is always the lowest and the most economical. SNCR-SCR combined denitration technology has no economic advantage，and the total cost is the highest when the inlet NOx concentration is 151-273 mg/m3. Ultra-low emission circulating fluidized bed boiler technology can improve the economy of SCR denitrification technology and SNCR denitrification technology，and make the advantages of SNCR denitrification technology more prominent.

0 引言

1 CFB常用脱硝技术

   1.1 炉内低氮燃烧技术

   1.2 SNCR技术

   1.3 SCR技术

2 技术经济性分析模型

   2.1 成本计算方法

   2.2 关键因素敏感性分析

   2.3 超低排放循环流化床锅炉技术对SCR、SNCR经济性的影响

3 结论