垃圾焚烧烟气再循环技术的应用研究--以某垃圾焚烧厂为例  

Application Research of Exhaust Gas Recirculation Technology in Waste Incineration Industry--Take a WtE as an Example

作　　者：龙吉生 刘露 袁旗斌 冯淋淋 王加俊 LONG Ji-sheng;LIU Lu;YUAN Qi-bin;FENG Lin-lin;WANG Jia-jun(Shanghai SUS Environment Co,Ltd,,Shanghai 201703,China)

机构地区：[1]上海康恒环境股份有限公司,上海201703

出　　处：《四川环境》2022年第5期63-70,共8页Sichuan Environment

摘　　要：为了探索适用于国内垃圾焚烧的烟气再循环(exhaust gas recirculation,EGR)技术路线,适应日益提高的NO_(X)排放要求,本文以国内某垃圾焚烧厂为例,采用CFD模拟等方法,研究了EGR系统再循环比例、取风口位置等工艺设计要点,并通过工程试验评估了EGR系统的脱硝效果及其对锅炉效率和燃烧稳定性的影响。结果表明,“SNCR+EGR”工艺能够将NO_(X)值降低至100 mg/Nm^(3)(11%O_(2)、干基)以下,且相比传统工艺焚烧线,采用EGR工艺的焚烧线吨垃圾产汽量提高3.29%。另外,EGR系统运行时,焚烧炉燃烧充分,CO浓度稳定达标。同时,炉膛温度可降低约50℃,有利于减少炉内结焦,延长耐火材料使用寿命。但是,系统运行控制要求较高且存在设备腐蚀风险。本研究为垃圾焚烧脱硝工艺的选择提供了新的方向,对于NO_(X)<100mg/Nm^(3)的地区,可采用“SNCR+EGR”工艺,对于NO_(X)<50mg/Nm^(3)等要求更加严格的地区,仍需配合SCR工艺,达到排放要求。In order to explore the exhaust gas recirculation(EGR)technology route suitable for waste incineration in China and meet the increasing NO_(X)emission requirements,.this paper took a waste incineration plant in China as an example,the key design points of EGR process such as the recirculation ratio and the extraction position were researched using CFD simulation and other methods.Meanwhile,the engineering test was applied to evaluate the denitrification of ERG system and the impact of which on the boiler efficiency and incineration stability.The results showed that the concentration of NO_(X)can be reduced to below 100mg/Nm^(3)(11%O_(2)、dry)by“SNCR+EGR”process,and the steam production per ton of waste of the incineration line using EGR process is increased by 3.29%compared to the conventional process incineration line.In addition,when the EGR system is running,the combustion of incinerator was complete and the release of CO was stable and up to standard.At the same time,the temperature of boiler was reduced by~50℃,which was beneficial to limit the formation of coke and prolong the service life of refractory materials.However,this system requires high control capability,and exists equipment erosion risk.This research provides a new denitrification process for waste incineration.For areas with NO_(X)<100mg/Nm^(3),"SNCR+EGR"process can be adopted.For areas with more stringent requirements such as NO_(X)<50mg/Nm^(3),SCR process is still needed to meet the emission requirements.

关 键 词：烟气再循环 低氧燃烧 氮氧化物 锅炉效率 

分 类 号：X799.3[环境科学与工程—环境工程]