摘要
混合法脱硝工艺是结合了SCR技术高效、SNCR技术投资省的特点而发展起来的一种新型的、成熟的工艺。通过伊敏电厂三期2×600MW机组SNCR+SCR混合法脱硝工艺方案的论述。首先对SNCR系统的供氨能力进行了摸底测试,结果发现SNCR系统能够产生足够的氨逃逸满足SCR系统的使用,但氨逃逸分布的均匀性较差。然后根据测试的结果对SCR系统烟道进行了优化设计并安装了烟气混合器,改善了进入SCR反应器的氨逃逸分布均匀性。通过改造,成功的将NO_x从260mg/m~3降至90mg/m~3以下;并且通过进一步增加SNCR系统四区喷枪喷入的尿素溶液流量能够将SCR出口的NO_x降低至50mg/m~3以下。
Mixed denitrification process is a new and mature process, which combines the characteristics of high efficiency of SCR technology and low investment of SNCR technology. The denitrification process scheme of SNCR +SCR mixed method for 2 ×600 MW units in Yimin Power Plant is discussed in this paper. First of all, the ammonia supply capacity of SNCR system is tested.The results show that SNCR system can produce enough ammonia escape to meet the use of SCR system, but the uniformity of ammonia escape distribution is poor. Then, according to the test results, the flue of SCR system is optimized and the flue gas mixer is installed to improve the uniformity of ammonia escape distribution into SCR reactor. Through the transformation, the NO_xis successfully reduced from 260 mg/m~3 to below 90 mg/m~3, and the NO_xat the exit of SCR can be reduced to below 50 mg/m~3 by further increasing the flow rate of urea solution sprayed into the fourth zone gun of SNCR system.
引文
[1]Lyon R K, Method for the Reduction of the Cocentration of NO in Combustion Effluents Using Ammonia, U.S. Patent 3900554,1975.
[2]祝百东.SNCR烟气脱硝技术的实验研究[D].哈尔滨工业大学,2006.