| In recent years,the development of new energy vehicles has changed rapidly,but there are still many problems that need to be optimized.In this period of transition from traditional fuel vehicles to new energy vehicles,the development and application of biological alternative fuels is of great significance.And from the long-term perspective of energy and the environment,biological alternative fuels will become the mainstream direction of automobiles in the future together with pure electric and fuel cells.ABE is an intermediate product of the fermentation process for producing butanol.It is a mixture of acetone,butanol and ethanol close to 3: 6: 1.The nature performance also takes into account the cost issue,and has great potential as a biological alternative fuel.This article intends to conduct experimental research on ABE fuel as a new type of bio-replacement fuel.In this paper,a combined injection gasoline engine test bench with two sets of fuel injection systems is used.ABE and gasoline are mixed at different volume ratios as fuel.In the test,different direct injection ratios are used as the main variables.At the same time,the variable and excess air coefficient are taken into account.,Rotation speed,load and direct injection time,the effects of mixing ratio and direct injection ratio on the combustion and emission laws under different operating conditions were studied.In order to analyze the related problems more concisely and accurately,the blending ratio and direct injection ratio of the main study were investigated with the torque and the peak pressure of the cylinder as reference indicators.The experimental results show that the ABE ratio is 75% and the direct injection ratio is 25 The best torque and cylinder pressure peak performance at%.Therefore,the data under these two working conditions are selected for detailed analysis,and the following conclusions are drawn:(a)The effect on combustion characteristics and emission characteristics when the direct injection ratio is 25%:(1)The principle of controlling variables in the test.Under different excess air coefficients,speed loads,and injection timings,similar characteristics appeared in the combustion characteristics parameters.That is,as the mixing ratio increased,the peak pressure and torque of the cylinders increased first and then There is also a downward trend.When the ABE blending ratio is 75%,there is a maximum value.Among them,the maximum increase in torque was13.7%,and the peak cylinder pressure increased by 9.9%.(2)With the increase of the blending ratio,NOx emissions gradually increase,but the change is relatively insignificant during the process from G100 to G50.CO and HC emissions have been continuously reduced,with a decline of more than 40%,and the maximum reduction rate of HC emissions has reached 69%.Both the nuclear membrane state particles and the accumulated state particles are continuously reduced,and finally both show a unimodal distribution of the nuclear membrane state.The total number of particles also showed a decreasing trend,and the final reduction was more than 95%.(b)When the ABE blending ratio is 75%,the influence on combustion characteristics and emission characteristics:(1)The control variables in the test,under different excess air coefficients,speeds,loads,and injection timings,with the continuous increase of the direct injection ratio,the torque and the peak pressure of the cylinder both increased and then decreased.There is a maximum at 25%.The maximum torque increase was 6.8%,and the peak pressure of cylinder pressure increased by8.9%.(2)With the increase of the direct injection ratio,the HC emission decreases first and then increases.It is the lowest near 25% of the ABE direct injection ratio,and the maximum reduction rate is 45% compared to the pure direct injection method with the highest HC emission.NOX emissions have been continuously reduced by about 30%.CO emissions continue to increase,with both nuclear membrane and accumulated particles increasing,and the total number and concentration of particles increasing.(c)In this test,under the set conditions,the best direct injection time in the compression stroke was investigated.With the continuous advancement of the direct injection timing,the peak pressure and torque of the cylinder both increased and then decreased,and reached the highest value at 105 ° CA BTDC.Among them,when the ABE blending ratio was 75%,the peak cylinder pressure at 105 ° CA BTDC increased by 3.6% compared with 75 ° CA BTDC,and the peak cylinder pressure increased by 2.7% compared with 150 ° CA BTDC. |
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