摘要
传统SNCR脱硝的温度窗口为850 ℃~1100 ℃;在没有氧(或痕迹氧)条件下,可扩展至更高温度。针对火焰喷氨工艺研发了还原剂喷枪,使用保护气形成隔离气膜,创造喷氨区的较低氧浓度。实验与CFD模拟的研究结果表明:旋流保护气比直流保护气隔氧效果更好;弱旋流喷射(叶片角度小于30°)不会形成中心回流区,不会影响中心喷氨的效果;模拟结果与实测数据基本一致,气流速度衰减的区域也是氧气扩散的区域,弱旋流隔离气膜对于实现痕迹氧区域有一定作用。
The traditional SNCR temperature window is 850~1100 ℃. However, it can be extended to higher temperature atmosphere in the absence of oxygen or lower oxygen. A new type of denitration process, ammonia spraying in high temperature flame, has been verified through a serious of research studies. In this article, a new spraying nozzle was developed for reduction agent feeding. The protective gas was set at the outside of nozzle to form a barrier gas film to lower the local oxygen concentration in the ammonia spraying area. Results from both of experiments and CFD simulations show that the swirl geometry of shielding gas is better to the barrier film controlling rather than direct introducing. The relatively weak swirl intensity of jetting does not form the central recirculation zone with the blade angle less than 30°, which retrofit the central injection of ammonia reagent. Simulation results are basically consistent with measured data. The airflow velocity decays in boundary area, where the oxygen diffuses. The trace/lower oxygen area is formed upon the use of weakly-swirling gas film pattern.
作者
刘毅成
张健
刘薇
马倩慧
LIU Yi-cheng;ZHANG Jian;LIU Wei;MA Qian-hui(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China)
出处
《能源工程》
2021年第1期48-53,共6页
Energy Engineering
基金
国家重点研发计划项目(2018YFB0604202)。
关键词
喷枪
保护气
CFD模拟
中心回流区
spraying nozzle
shielding gas
CFD simulation
central recirculation zone
