Mitigation of Combustion Instability and NO_(x)Emissions by Microjets in Lean Premixed Flames with Different Swirl Numbers  

作　　者：ZHOU Hao HU Liubin 

机构地区：[1]Zhejiang University,Institute for Thermal Power Engineering,State Key Laboratory of Clean Energy Utilization,Hangzhou,310027,China

出　　处：《Journal of Thermal Science》2023年第4期1697-1709,共13页热科学学报（英文版）

基　　金：This work was supported by the National Science Fund for Distinguished Young Scholars(Grant 51825605).

摘　　要：Swirl combustion serves as a helpful flame stabilization method,which also affects the combustion and emission characteristics.This article experimentally investigated the effects of CO_(2)microjets on combustion instability and NO_(x)emissions in lean premixed flames with different swirl numbers.The microjets’control feasibility was examined from three variables of CO_(2)jet flow rate,thermal power,and swirl angles.Results indicate that microjets can mitigate the combustion instability and NO_(x)emissions in lean premixed burners with different swirl numbers and thermal power.Still,the damping effect of microjets in low swirl intensity is better than that in high swirl intensity.The damping ratio of pressure amplitude can reach the maximum of 98%,and NO_(x)emissions can realize the maximum reduction of 10.1×10^(−6)at the swirl angle of 30°.Besides,the flame macrostructure switches from an inverted cone shape to a petal shape,and the flame length reduction at low swirl intensity is higher than that of high swirl intensity.This research clarified the control differences of mitigation of combustion instability and NO_(x)emissions by microjets in lean premixed flames with different swirl numbers,contributing to the optimization of microjets control and the construction of high-performance burners.

关 键 词：combustion instability swirl numbers thermal power CO_(2)microjets NO_(x)emissions lean premixed flame 

分 类 号：TK16[动力工程及工程热物理—热能工程] X701[环境科学与工程—环境工程]