气态氨作还原剂的SNCR脱硝工艺的试验研究与模拟

在自行研制的试验台上对氨气作还原剂的SNCR脱硝工艺进行了实验研究,并利用化学反应动力学软件Chemkin 4.1进行了模拟.通过试验发现,采用自制改进型槽缝式TB系列喷嘴内部喷入的方式明显优于侧喷,提高了NO_x的去除率.以NO_x去除率高于50%为标准,试验所得温度窗口为863～937 ℃.随着氨氮比的增大,NO_x的去除率和氨的泄漏量增大,当氨氮比大于1.0后,NO_x去除率的随氨氮比增大的幅度减小,而氨的泄漏量增大幅度增大.利用Chemkin 4.1的模拟所得的温度窗口和NO_x去除率与实验基本相符,通过对详细机理中重要基元的分析,得出了各温度下的主要反应途径.

Experimental Study and Simulation of SNCR (selective non-catalytic reduction) Denitrification Process with Gas-state Ammonia Serving as a Reducing Agent

Experimentally studied was the SNCR (selective non-catalytic reduction) denitrification process on a self-developed test rig with ammonia serving as a reducing agent.Its simulation was performed by using chemical reaction dynamics software Chemkin 4.1.It has been found through tests that the inner spray-in mode by use of self-developed and improved type slot TB series nozzles is conspicuously superior to the lateral spray-in mode with NO_x removal rate being enhanced.With the NO_x removal rate of above 50% serving as a standard,the temperature window obtained by the test ranges from 863 to 937 ℃.With an increase of the ammonia/nitrogen ratio,the NO_x removal and ammonia leakage rate will increase.When the ammonia/nitrogen ratio is bigger than 1.0,the growth margin of the NO_x removal rate will decrease with an increase of the above ratio,but the growth margin of the ammonia leakage rate will increase.The temperature window and the NO_x removal rate obtained from the simulation by using software Chemkin 4.1 are basically in agreement with the test results.Through a detailed analysis of the important elements of the mechanism,the main reaction routes at various temperatures were identified.