Experimental and Numerical Study of Non-Premixed Dimethyl Ether/Methane-Air Hot Flame at Elevated Pressures  

作　　者：CAO Jin ZHOU Xun ZHANG Rui YANG Shenghua LIU Dong 

机构地区：[1]MIIT Key Laboratory of Thermal Control of Electronic Equipment,School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,China [2]Advanced Combustion Laboratory,School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing210094,China

出　　处：《Journal of Thermal Science》2023年第1期401-413,共13页热科学学报（英文版）

基　　金：the support from the Fundamental Research Funds for the Central Universities(30919012104);the National Key R&D Program of China(2016YFB0600100)。

摘　　要：Methane has a narrow range of flammable limits,low flame speed and poor ignition characteristics,which limit its utilization in internal combustion engines.However,this issue can be remedied through the use of CH_(4)/DME blends,because DME has better ignition and combustion characteristics.In this study,the effects of pressure and blending ratio on the combustion characteristics of CH_(4)/DME blended fuels were investigated by using a high-pressure diffusion counterflow system,a constant volume combustion bomb,and CHEMKIN software.The reaction pressures are 0.1 MPa,0.2 MPa,0.3 MPa,and the blending ratios are 100%DME,75%DME+25%CH_(4),50%DME+50%CH_(4)and 25%DME+75%CH_(4)(mol%).The results show that the laminar flame speed,flame temperature,and extinction limit of CH_(4)/DME blended fuel decrease as the CH_(4)blending ratio or pressure increases.CH_(4)addition and increasing pressure both lead to the competition for OH and H radicals between CH_(4)and DME.However,the increase of CH_(4)mole fraction can also increase the path flux of CH_(4)+H=CH_(3)+H_(2),while the increase of pressure can decrease this path flux.Moreover,increasing pressure can promote all reaction processes and reaction rates.

关 键 词：COUNTERFLOW high-pressure DME CH4 extinction limit 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]