Deperimental Study Of Direct Injection Diesel Engine Operated On High Proportion Biodiesel-DME Blends

The conflict of Human energy demand and energy using caused environmental pollution has been to haunt the world.With the continuous development of the automotive industry,the environmental issue has become increasingly serious.In the densely populated city and traffic developed mining areas,a large number of distributed everywhere emissions are a serious threat to the physical and mental health of residents and undermined the ecological balance.At the same time,automobile fuel consumption as a source of the world's petroleum resources exacerbate the shortage.Therefore,looking for clean alternative fuel vehicles has a great significance for development of the whole world.Biodiesel as a clean alternative fuel has been favored by the States.It has high cetane number,cold start performance,and it is an ideal alternative fuel oil. However,the high viscosity of biodiesel is not conducive to evaporation in the cylinder,which directs simpact on the bio-diesel in the compression-ignition engine power and exhaust emissions.And DME has low viscosity,low boiling point.The biodiesel blended with low proportion of the DME is conducive to reducing the viscosity of biodiesel,and it is conducive to biodiesel mixed with air in the cylinder,and the engine is conducive to reducing emissions of harmful substances.So a high proportion ofbiodiesel blended with low of DME fuel was made experiment in ZS 1110TD diesel engine.Viscosity is to determine the nature of the primary fuel atomization factors. The first issue is testing the biodiesel and 0# diesel in different temperatures, and contrast tests,concluded:When the temperature of 20℃,the viscosity of biodiesel is the viscosity of diesel 1.80 times.when the temperature is 80℃,the viscosity of biodiesel is the viscosity of diesel 1.73 times.Generally speaking, biodiesel viscosity changes with the temperature lower rate than the rate of decrease viscosity of diesel.The blended fuel BD70,BD80,BD90 have been experimented in the engine which without adujusting the ZS1110TD engine's parameters.The power performance,economic performance and emissions performance are testing in the engine,and choosing better blended fuel DB70.The blended fuel BD70,biodiesel and diesel fuel,are burned in In ZS1110TD diesel engine.On the basis of comparative test,the power,economy and emissions are analysis and draw the corresponding conclusions:Because of the calorific value of fuel,bio-diesel's caloricity has only 90%of diesel's.The DB70 fuel's caloricity has only 72.8%of diesel's.Bio-diesel fuels and BD70 calorific value are lower than diesel's,the maximum power of bio-diesel Diesel is 5.2%lower than the diesel engine's,the maximum power of BD70-diesel is 19.6%lower than diesel engine's.The maximum torque is 54.9 N·m which is13.3%lower than the bio-diesel engine's,and it is 15.6%lower than the diesel engine's.The minimum fuel consumpation is 1%higher than the biodiesle's,and it is 6.4%higher than diesel's.Emissions:in the same conditions,the CO,HC,and NO_x emissions have greatly reduced than diesel and bio-diese.The BD70's smoke emissions are near zero.And it is almost smoke-free emissions.