Experimental Investigation On The Ignition And Combustion Characteristics Of Dieseline

Dieseline is attracting more and more attention because of its great potential in the clean combustion of internal combustion engines.Based on the physical and chemical characteristics of volatile gasoline,diesel fuel mixed with part of the gasoline,can effectively reduce the diesel engine spray combustion mixture of local over-concentrated situation,thereby reducing soot emissions.In this paper,the direct firing method and the chemiluminescence method are used to study the ignition and combustion characteristics of the gasoline and diesel blends,which provide important experimental data for the application and popularization of the gasoline and diesel blended fuels,and has important theoretical and practical value.A mobile constant volume combustion bomb device,and the high-pressure common rail fuel injection system,getting combustion flame images by high-speed camera and ICCD.According to the different types of images,the processing program based on Matlab software is extracted and analyzed.The ignition location,flame area and lift off length are extracted from the image,and the ignition delay and air entrainment are calculated.The effects of mixing ratio of gasoline and diesel fuel,ambient temperature,ambient density and injection pressure on the ignition and combustion characteristics of dieseline were studied.The range of the gasoline rate is from 0%to 60%,the ambient temperature ranges from 750K to 850K,the ambient density ranges from 15.2kg/m~3 to 22.8kg/m~3,and the injection pressure ranges from 60MPa to 175MPa.The results show that the higher proportion of gasoline,the longer the ignition delay and the farther the ignition position.At the quasi-steady state,the lift off length and its brightness value are larger,which leads to the strong air entrainment rate.When the gasoline proportion exceeds 40%,the flame area and the air entrainment rate are greatly changed.This is determined by the physical properties of gasoline.When the ambient temperature increased,the ignition delay is decrease while the ignition position is far away from the nozzle.At the quasi-steady state,the lift off length,its brightness value is greatly reduced,and the lift off length and entrainment rate can be improved by blending the gasoline at low ambient temperature.When the density of ambient increases,the ignition delay,ignition position,lift off length and the brightness value of the flame are reduced.The air entrainment rate is obviously reduced even though the air content per unit space increases.Increasing the injection pressure can reduce the ignition delay,but because of the impact of fuel penetration speed is very large,resulting in fire location and lift off length increases,while the brightness and air entrainment rate has been improve.