Performance Study Of Electronic Controlled High Pressure CRDI Diesel Engine Fuelled With Tung Oil-diesel-ethanol Micro-emulsion

Due to vegetable oil's characteristics of its renewable,environmental protection,source widely,it has been used by many countries at home and abroad,and was considered to be one of the most potential alternative fuels.For vegetable oil with the issues of high kinematic viscosity,diesel engine burning vegetable oil of simple and economic method is the micro emulsion.Based on micro emulsification mechanism,different blending ratio of plant oil-base micro emulsion fuels was made from 0~# diesel,tung oil and ethanol,and measured the main fuel properties.Then it conducted bench test on CRDI diesel engine to analyze the similarities and differences of engine performance and emission characteristics and its combustion characteristic of 0~# diesel oil and emulsified fuel.Finally it is concluded that the combustion and emission laws of plant oil-base micro emulsion fuel.In this paper,the main works and conclusions were as follows:(1)Based on micro emulsification mechanism,experiment used the mix of tung oil / 0~# diesel fuel as oil phase(O),low carbon alcohol(ethanol)as water phase(W),under the action of the mixed emulsifier(oleic acid/n-butyl alcohol)made plant oil-base micro emulsion fuels of the water-in-oil(W/O)type.The micro emulsion fuels was clear and transparent,it can be storage at room temperature and in the airtight environment over six months.(2)Considering the power performance and fuel economy of micro emulsion fuels,the tests made four kinds of different blending proportion of micro emulsion fuels named TD30E20,TD30E40,TD50E20 and TD50E40 respectively.According to national standard,t measured the main physical and chemical index of fuels,its viscosity,density,low calorific value etc.(3)In medium and small load used two stage injection,namely the combination of pre injection and main injection,under the heavy load used a single injection,then researched the fuel economy and emission characteristics of CRDI diesel engine burned different fuels.The results showed that burning micro emulsion fuel reduced energy consumption and increased effective fuel consumption compared with 0~# diesel oil.In small load,the NO_X emissions was lower,HC and CO emissions was higher.In medium and heavy load,the NO_X emissions increased,HC and CO emissions was no obvious difference.In heavy load,its soot emission was decreased obviously.(4)Under the two stage injection strategy researched the combustion characteristic of CRDI diesel engine burned different fuel,including the combustion pressure and the law of heat release.Research results showed that burned the micro emulsion fuel making maximum pressure and heat release rate curve corresponding crank angle were relatively delayed.With the increase of load,the micro emulsion fuel's pressure and heat release rate increased,and its peak were greater than 0~# diesel oil,and the fuel's ignition delay period was shortened.Due to the micro emulsion fuel's combustion and heat release was relatively concentrated.The combustion duration was less than 0~# diesel oil.