Studies On One-dimensional Counterflow Flame Structure And Characteristics Of Pollutant Emission Under ODPP/OESC

The thesis based on one-dimensional linear counterflow flames system and cosilab simulator analyse the combustion characteristic of ODPP/OESC one-dimensional counter-flow flames,and compared with PPC.By adjust partlly of the premixed equivalent ratio,oxygen concentration,The ratio of fuel,flow velocity,and distance of nozzles and so on,the process of combustion,extinguish characteristics and emission rules are analysed.So the following aspects was emphasized studied:First,by adjusting species concentration and flow velocity of both side,the major fac-tors which influence counterflow flames structure was studied.The oxidant side have less influence than Premixed side,in the point of strain rate,the distance of nozzles have less influence for flame structure,and flow velocity have the decisive effect.Second,by using experiment system and cosilab software flame temperature,flame propagation velocity,and other combustion feature in different conditions were studied.The resuit show with?_p reduce or oxygen concentration of premixed side increase flame temperature and flame propagation velocity both gradually increase,and in the condition of PPC reach the maximum.Compared with _p?,oxygen concentration has bigger influence to combustion.By contrast distribution of temperature and heat flux of linear counterflow flames and cylinder counterflow flames,the basic reason of tensile deformation of cylinder premixed flame is teat accumulation of the flame center.Next,different extinguish was studied.Extinguish limit?⁰_extis controlled by thermal convection.With the increase of oxygen concentration and dimethyl ether in the fuel,flame propagation velocity become faster,flame surface become more thick,and the flame in small equivalence ratio is more stability.Extinguish limit low strain rateK_ext is controlled by thermal radiation,and is inversely proportional to _p?and the concentration of oxygen.Last,when generation mechanism of NOx under different conditions were studied.Prompt NOx is major NOx under different conditions which are produce on the premixed flame surface.with the increase of?_p the production increased first and then decreased,and there is the peak at?_p=1.2.However in the reaction zone thermal NOx is major,with he increase of_p?the production decreased.with the decrease of concentration of oxy-gen,two types of NOx both decreased,and the production of NOx reach the maximum at PPC.From the above,by reasonable distribution C/O,ODPP/OESC is better than Partlly air premixed on flame stability,NOx emission and other side,which prove ODPP/OESC is a clean and efficient combustion craft.