Study On The Diffusion Flame Of Ethanol Gasoline Based On The Technology Of The Optical Diagnosis And Image Processing

While consuming energy,mankind has caused serious damage to the natural environment of the earth.Therefore,how to coordinate their relations to achieve sustainable development has become the important topic of world development.Consumption of petroleum resources plays a leading role in energy consumption.To Coordinate the contradiction between the shortage of petroleum resources and the huge domestic demand in China,solve the most prominent air pollution problem in China's environmental pollution and achieve harmonious coexistence between man and nature,developing alternative fuels to partially replace petroleum fuels and reduce vehicle emission is a feasible way.And ethanol gasoline,as one of the alternative fuels,can reduce the emission of soot in combustion.In order to study the volume fraction distribution of soot in the laminar diffusion flame,firstly,laser-induced incandescence method was used to measure the distribution of soot volume fraction in paraffin diffusion flame.And then the light extinction method was used to measure the soot volume fraction distribution in ethanol gasoline diffusion flame containing 20%ethanol.After comparing two soot optical diagnostic methods,the light extinction method was chosen to study laminar diffusion flame of ethanol gasoline.Ethanol volume fractions of 0%,20%,80%and 100%of Ethanol gasoline were selected as the research object while the laminar diffusion combustion was chosen as a combustion mode.And experiments were carried out in a liquid fuel atomization and evaporation combustion system.Furthermore,the structure of laminar diffusion flame is redefined in combination with flame image.It was difficult and complex to deal with data,so a set of three-point Abel inversion algorithm flow was selected to solve this problem.And the MATLAB was creatively used to quantitatively analyze the flame structure of ethanol gasoline due to its stronger ability of the image processing and data computing.Related algorithms were written to accurately calculate the flame height in order to avoid the effect on the visible flame height whose differences result from different observers and the periodic pulsation of the flame.The delay of incandescence signal with energy density of 0.2 J/cm~2 is optimum at the laser wavelength of 532 nm and pulse energy of 30 mJ,and its time is 158?s.Under these circumstances,the flame images are most clear.In the laminar diffusion flame of ethanol gasoline,the larger the volume fraction of ethanol is,the smaller the area of soot forming area is and the larger the area of the blue flame region is.While the transition area accounts for about 21%of the total flame area and does not change significantly with the increase of ethanol volume fraction.