| This is for the factory and school cooperative research topic, selecting soybean biodiesel product by a company in Guangxi province as the research object, in a constant volume bomb, high pressure common rail electronic control fuel injection test-bed,there carried on a test of fuel spray, the bench test is carried out for the ZS195 Diesel engine, and using No.0 diesel oil, biological diesel oil mixed fuel ethanol to do the same test, then the results we obtained were used for qualitative comparison and analysis. Through on the different fuel spray penetration distance and spray cone angle measurement and analysis, comparison of different fuel spray development patterns between the differences and part of the fuel physicochemical properties of difference to study the combustion characteristics of different fuels and combustion cyclic variations of differences provide the basis for the analysis.In the spray test, under different injection pressure, spray penetration of D100 is larger than that of B100 of 0.79%-3.52%; spray cone angle of D100 is larger than the spray cone angle of B100D of 1°～4°. Mixed fuel spray penetration increases with the increase of ethanol proportion, when the injection pressure is 18MPa, E20B80 and E30B70 spray penetration is larger than E10B903.96%,3.96% respectively; the spray angle decreases with the increasing of proportion of ethanol, the spray cone angle of E20B80 and E30B70 is smaller than the spray cone angle of E10B90 of 3°～6°nder the same injection pressure.E10B90 has a short spray penetration, large spray cone angle, E10B90 solution drop can be fully mixed with cylinder gas, resulted an ideal mixture formation, the diesel engine has a stable combustion function, in the 1.5kW/2000rpm condition, the cycle fluctuation rate compared with other fuel were smaller,which COVpmax is 1.667%, COVPi is 6.395%.Under low power conditions, the mixed fuel combustion, due to the increasing spray penetration of E10B90, E30B70 and E20B80 in turn, spray cone angle decrease successively, and spray cone angle decreases the amplitude of 6 degrees.E20B80 and E30B70 spray effect will be worse, combustion instability, mixed fuel combustion in cylinder peak pressure is lower than D100 combustion in cylinder peak pressure 2.5%～13.5%, in cylinder pressure corresponding to the peak phase is lag than D100 combustion about 1℃A-5℃A. COVpi of combustion E30B90 and E20B80 are great, respectively 14.058% 12.238%.In high power condition, the difference of different fuel spray has small influence on diesel engine combustion and cycle fluctuations. With the increase of power, the amount of fuel increase, burning more fuel for the combustion temperature increase, the effect of the viscosity of the fuel on the atomization of the fuel injector weaken, fuel atomization effect on combustion influence greatly weakened. Different fuel’s cycle fluctuation decreases.COVpi, COV(dP/de)max and COVPmax of D100, B100 and mixed fuel combustion are less than 5%, the diesel engine work in the normal range smoothly.The results showed that the application of biological fuel mix, throughout its spray distance, spray cone Angle and the change of the parameters such as injection pressure on the engine combustion and operation cycle has distinct effect on the volatility. Under 18 MPa injection pressure, E10B90 spray through the short distance (68.22 mm), spray cone Angle is big (18.4°), which will have achieve better combustion stability and the cycle of low volatility. |
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