烟气再循环对液雾旋流火焰的影响

Influences of exhaust gas recirculation on spray swirl-flame

在柱状燃烧室内利用C anon数码相机跟踪研究了气泡雾化喷嘴出口下游的旋流液雾火焰,发现再循环烟气对油雾颗粒的预热作用使火焰缩短、并有效削弱了高温区存在;利用T esto350烟气分析仪对液雾旋流火焰所产生的烟气成分进行了测定,探讨了烟气再循环措施对不完全燃烧产物以及燃烧污染物生成量的影响,发现热烟气的再循环可以有效降低不完全燃烧产物的排放量,同时可以抑制NOx的生成。

In a cylindrical combustion chamber, Canon A70 was used to take pictures and thermocouples were used to measure the temperature of kerosene spray flame produced by an effervescent atomizer. Based on those experimental data, it can be found that exhaust gas recirculation will strengthen the process of evaporation of droplets, so shorten the length of flame. At the same time, the exhaust gas dilute the oxygen in high temperature zone, thus the color of flame is no longer white and shiny. Using TESTO350 Fuel Gas Analyzer, the composition and concentration of the exhaust gas were obtained. It can be found that the gas recirculation will decrease the fraction of CmHn drastically, so the combustion efficiency can be improved. The reason could be that high temperature exhaust gas heating the fuel spray. Additionally, exhaust gas recirculation reduces the NOx emission level about 30%. Experimental data indicate that the exhaust gas recirculation can control NOx emission effectively.