Ethanol/Diesel Dual Fuel Combustion Visualization Test And Image Processing

In the context of the global energy crisis and environmental pollution in the 21 st century,various countries and regions have formulated more stringent emission regulations to limit the emissions of fuel-burning vehicles.The application of clean and renewable fuels is one of the solutions to this dilemma.Because of the ignition mode of diesel engine and the characteristics of ethanol fuel,the application of ethanol in diesel engine is difficult to start cold,combustion lag and combustion phase control.Based on the above background,the main purpose of this paper is to explore the effective means of regulating ethanol/diesel dual fuel combustion and the influence of ethanol premix on the combustion process.Based on the optical engine test platform,this paper conducted ethanol injection in the inlet and diesel injection in the cylinder twice,changed the premix ratio of ethanol,the injection time of ignition diesel,the amount of ignition diesel injection,and combined with the image processing technology,analyzed the combustion characteristics and flame image.Through the test,it is found that the starting point of combustion in this test is mainly controlled by the injection time of the ignition diesel,and the overall combustion process is the diffusion combustion of the ignition diesel.As the premix ratio of ethanol increases,the cylinder pressure and soot concentration will gradually decrease,and the combustion duration will decrease first and then increase.Ignition diesel injection time can effectively change the combustion phase,the appropriate injection time can make the heat release concentration,so as to increase the burst pressure.The increase of the amount of igniter diesel injection will lead to the advance of combustion phase and the increase of soot concentration and cylinder pressure.To study the temperature parameters in the combustion process.Based on the calibration system of visible light radiation,the blackbody furnace image of each temperature point was shot in turn,and the color value of the image was collected under the same temperature and different exposure time,and the function curve of the radiation intensity on the color value of the image was obtained.The combustion phase of ethanol/diesel dual fuel combustion was calculated by temperature measurement and pseudo-color treatment.The temperature range of the combustion process in this test is mainly 1200k-2000 k.Increasing the premix ratio of ethanol can effectively reduce the temperature in the cylinder.The delay of ignition diesel injection time and the increase of oil injection amount will increase the high temperature area.From the above research,it can be obtained that the proper premix ratio of ethanol can improve the combustion process and reduce the temperature,cylinder pressure and soot generation in the cylinder.The ignition of diesel can effectively change the local equivalent ratio and activity,and the injection time and amount can regulate the ethanol/diesel dual fuel combustion process.