SCR脱硝反应区域运行温度影响因素研究

摘要

The lower operating temperature of SCR denitration reactor directly caused catalyst deactivation. In order to resolve this problem, taking the typical SCR denitration system of 600 MW coal-fired unit as research object,the influence of reaction temperature,NH3 HSO4 formation temperature in catalytic reaction region,sprayed ammonia diluted wind and permissible error of temperature measurement compo-nents on the temperature of denitration area was analyzed. The minimum safe operating temperature of SCR denitration reactor was deter-mined. The results showed that,the activation temperature of vanadium-tungsten-titanium catalyst ranged from 320 ℃ to 420 ℃. When the temperature was between 340 ℃ and 380 ℃,the reaction had the best performance and the denitration efficiency reached about 90%. The condensation temperature of NH3 HSO4 which was the major component in gas phase was between 270 ℃and 320 ℃. The sprayed am-monia diluted wind reduced the denitration temperature by 2. 6 ℃ to 2. 9 ℃. The permissible error of temperature measurement compo-nents had relatively fixed influence on SCR denitration reactor,the maximum reduction was about 4 ℃. At last,the inlet temperature was determined in the range of 350 ℃ and 390 ℃.%针对降低SCR脱硝反应区域运行温度后造成催化剂失活的问题，以600 MW燃煤机组典型SCR脱硝反应系统为研究对象，分析了脱硝SCR催化反应温度、催化剂区域硫酸氢铵生成温度、还原剂稀释风、测温元件允许误差等对机组脱硝反应区域温度的影响，确定SCR反应器区域最低运行温度安全值。结果表明，钒钨钛系催化剂的活性温度窗口为320~420℃，最佳反应温度窗口主要集中在340~380℃，SCR脱硝反应效率达到最高约90%；SCR反应器入口的气相主体硫酸氢铵的凝结温度为270~320℃；喷氨稀释风会降低SCR反应器运行温度，温度降低2.6~2.9℃；温度测量元件的允许误差对SCR反应器系统测量温度造成相对固定的影响，造成温度最大偏低约4℃。提出SCR脱硝反应器进口温度应集中在350~390℃。