The Preparation Of Micro Emulsified Diesel And The Study Of Engine Characteristics

Energy and environmental protection are the two main problems that we human face now.Micro-emulsified diesel fuel,used as an alternative fuel,not only does it can decrease the fossil fuel consumption,but also it can improve engine exhaust emissions.So it is necessary to explore characteristics of the emulsified diesel.However,till now the domestic research on the emulsified diesel is not very mature,it is just on the theory of experimental research stage.This paper studied the stability characteristic,the evaporation characteristic and the engine load characteristic of micro-emulsified diesel.The stability test is to seek for the optimal formula of micro-emulsified diesel and the stability time is used to evaluate the formula.The factors are screened through the micro mechanism of the stability of emulsifying diesel.Through the design of experiments,analysis of variance,the interactive effect between factors and model optimization,the optimal formula is figured out,finally we should validate the optimal formula.The optimal formula for the compound emulsifier volume fraction was 2.13%,the latent solvent volume fraction was 1.02%,diesel volume fraction was 80.85%,HLB value was 6.56,glucose solution volume fraction was 16%,and the stable time was 292.6 h.Compared with the theoretical stability time,the theoretical error was 4.7%.In this study,different formula of micro-emulsified diesel were prepared and the study on the evaporation characteristics is based on the thermogravimetric analyzer.Test control variables are mass fraction of glucose solution,oil film thickness,the heating rate,nitrogen gas flow rate.The results were analysed by the Origin 8.6 software.The results showed that the evaporation speed increased fast,then slow down after 100℃;When glucose solution of emulsified diesel keeps constant,the proper glucose concentration can accelerate the evaporation rate,reduce the end of the evaporation temperature;When the glucose concentration of emulsified diesel is constant,increasing moisture content can accelerate the evaporation rate,and decrease the end of the evaporation temperature;Increasing heating rate and nitrogen rate will accelerate the evaporation of emulsified diesel,reduce evaporation time and lower the end temperature of evaporation.The engine bench test is to research the economy characteristic and emissions fueled the micro-emulsified diesel of the engine and compare that with the pure diesel,which provide theoretical basis for the micro emulsified diesel promotion.The results showed that the brake thermal efficiency of the micro-emulsified diesel is higher than diesel at rated speed and different loads.In high load,the exhaust emissions of diesel is higher than micro-emulsified diesel,however in lower load,the HC and CO emissions of micro-emulsified diesel is higher.