提高SCR反应器入口烟气温度的技术方法

SCR催化剂的活性受烟气温度影响，当反应器进口烟气温度降低到催化剂最低投运温度时，脱硝系统须退出运行。按照火电厂燃煤锅炉SCR脱硝装置的常规设计，在低负荷运行时经常出现SCR反应器进口烟气温度低于催化剂最低投运温度的情况，导致氮氧化物排放浓度超标。为了保证锅炉日常运行时SCR反应器进口的烟气温度满足催化剂投运条件，介绍了采用高温烟气加热、省煤器分段布置、旁路部分省煤器给水、提高锅炉给水温度等技术方法，并就其特点进行了对比分析。

Technical Measures to Raise the Inlet Flue Gas Temperature of SCR Reactor

The flue gas temperature may have significant impact on the activity of SCR catalyst. The denitrification system will have to be turned off from service when the flue gas temperature falls down below the allowed minimum commissioning temperature of the catalyst. As it is designed in the conventional denitrification systems, it is not uncommon that the SCR inlet flue gas temperature is lower than the minimum catalyst commissioning temperature at low loads, which will cause the NOx emissions higher than the standard limit. In this paper, in order to make the inlet flue gas temperature of SCR reactor meet the catalyst commissioning conditions in boiler routine operation, the technical measures to raise the inlet flue gas temperature are proposed such as heating by high temperature flue gas, economizer partition arrangement, bypassing the economizer on the waterside and raising the feedwater temperature. In addition, the comparative analysis on the characteristics of these measures is also conducted.