气态氨作还原剂的SNCR脱硝工艺的试验研究与模拟

Experimental Study and Simulation of SNCR(Selective Non-catalytic Reduction) Denitrification Process with Gas-state Ammonia Serving as a Reducing Agent

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NOx的去除率。以NOx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,NOx的去除率和氨的泄漏量增大,当氨氮比大于1.0后,NOx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NOx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。

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 NOx removal rate being enhanced.With the NOx 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 NOx removal and ammonia leakage rate will increase.When the ammonia/nitrogen ratio is bigger than 1.0,the growth margin of the NOx 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 NOx 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.