中文摘要：

采用Rijke型自激式脉动燃烧器,结合纹影摄像,对不同脉动频率、脉动振幅和燃烧功率下的NOx排放量进行了比较和机理分析.结果表明：在试验工况范围内,甲烷自激励脉动燃烧与非脉动燃烧相比可降低NOx的生成,NOx最高降低了99%,对应的CO降低了13.8%;当燃烧功率增大时,会出现燃烧不完全和燃烧效率降低的现象;脉动火焰符合分形特征,其分形维数大于非脉动燃烧,火焰内流场褶皱、卷曲的程度更高;脉动燃烧下NOx降低的原因是掺混程度更好、传热率更高;随着脉动频率的增加,NOx的排放量降低,说明频率增加促进了气体掺混,减少了气体在高温区的停留时间;脉动燃烧下NOx的排放随燃烧功率的增大而升高.

英文摘要：

Experimental tests on NO_x emission from methane combustion were carried out in a Rijke self-excited pulsating combustor under varying conditions of pulsating frequency,pulsating amplitude and combustion power with Schlieren photography system,after which the test results were compared and the reaction mechanisms analyzed.Results show that compared with non-pulsating combustion,methane self-excited pulsating combustion produces less NO_x emission,with a maximum 99% reduction of NO_x emission,and a 13.8% reduction of CO emission.Incomplete combustion may occur when the combustion power rises to a certain degree,which will result in lower combustion efficiency.The pulsating flame is subject to higher fractal dimensions and its inner flow field is highly wrinkled and irregular.Low NO_x emission of pulsating combustion is found to be caused by better mixing and heat transfer in the combustion chamber.With the rise of pulsating frequency,NO_x emission of pulsating combustion reduces,indicating that the frequency rise can promote gas mixing and reduce the lingering time of gas in high-temperature areas.NO_x emission of pulsating combustion increases with growing combustion power.