| The fuel ethanol is clean and reproducible resource. It is meaningful to implement our country's "energy-saving and ejection-decreasing" policy to explore its application on the diesel engine as substituted fuel.An investigation of 1-butanol's feasibility analyze as solvent of ethanol-diesel fuel blends is conducted in this paper, then we used the blends to study the influence to the engine's overall performances on the YC6J170-21 diesel engine, the other running performances such as starting performance, idling performance,mapping characteristics is also discussed which used blend. Then we discuss the combustion characteristics.The solvent test result shows that, 1-butanol can be used as the solvent of ethanol-diesel fuel blends. When 1-butanol is used 5% as additive, the blend fuels could remain good stability. It is satisfy the practicality require of engine.On the YC6J170-21 diesel engine, the effects to the overall performance of diesel engine which used the blended fuel with different proportional component of ethanol were studied. The results show that, the torque of diesel engine output slightly reduce when used the ethanol-diesel blends fuel ,the oil consumption rate rised. But the power and torque output can be restored by increasing the fuel-feed, and the equivalent oil consumption rate was lower compared to diesel oil at the low speed, but it was almost the same with the diesel oil at high speed, even reduced slightly which proved that the diesel engine had good efficiency when itis used with the ethanol-diesel blended fuel. The emission of NO_x and soot could beimproved obviously. The emission of CO is almost the same as diesel, the HC emission is worsening. The tendency of the change relation above would be larger with the content of ethanol increasing. Take blends Z5E20D75 and Z5E30D65 for example, undering the external characteristic mode, the biggest reduce range of soot is 77.4% and 83.9%, and NO_x is 18.6% and 31.0%, the CO emmision is closed to diesel's, but the increase range of HC is 225% and 350%; undering the load characteristic mode of 2600r/min, the biggest reducerange of soot is 73.7% and 79.6%, and NO_x is 11.5% and 25.5%, the CO emmision isclosed to diesel's, but the increase range of HC is 80% and 80%; undering the load characteristic mode of 1500r/min, the biggest reduce range of soot is 71.2% and 71.2%, andthe NO_x is closed to diesel's, but the increase rangeof the CO emmision at the low load is100% and 1100%, the increase range of HC is133.3% and 200%.According to economy, blend Z5E20D75 is better than others. Z5E25D70 takes the second place, then is Z5E10D85 and Z5E30D65. The change trends of emissions are belonged to the proportion of ethanol. So give a compositive advisement, Z5E20D75 is the most suitable blend fuel for diesel engine.The starting performance of the engine which used the blended fuel with ethanol proportion of 20% is well; and the idling performance is stabilization. While the fuel deliveryadvanced angle reduced, the emission of NO_x dropped suddenly, but the soot increasedquickly, also with the rise of the oil consumption rate; mapping characteristics compare on blend Z5E20D75 and diesel, blend Z5E20D75 has higher torque output at low speed, and nearly the same the middle-high speed. It is proved that the power characteristic of blend Z5E20D75 is well; the most economic area of blend Z5E20D75 is longer at portrait when compared to diesel, it is showed that the change of oil consumption rate is lesser. The lowest oil consumption rate is lesser than diesel. It is proved that the economic characteristic of blend Z5E20D75 is well.As for the combustion characteristics, with the increasing of the engine load ,it gives a increase in the in-cylinder pressure and heat release, and results in longer ignition ahead period and longer combustion duration when fueled with the same blends. The in-cylinder pressure is double-peak.At high load, compare to diesel, the maximum of in-cylinder pressure of blends is larger than diesel, its appearance delayed. The tendency of the change relation above would be larger with the increasing of ethanol proportion. At middle-high speed, low load, the double-peak value of in-cylinder pressure is obvious, in the first peak, the maximum in-cylinder pressure and its appearance are almost the same when burned with different fuels, but in the second peak, with the increasing of ethanol proportion, the maximum in-cylinder pressure is lower, and its appearance delayed. At low speed, low load, the in-cylinder pressure is signal peak value curve, with the increasing of ethanol proportion, the maximum of in-cylinder pressure reduces, and its appearance delayed.At high speed, high load, as to diesel, the heat release rate curve of blend fuels is the typical double-peak value curve. In the first peak, the peak heat release rate of blends is higher than diesel, and their appearance are late.The heat release rate curve move back whole.In the second peak, the peak heat release rate and its appearance are almost the same when burned with different fuels. At low load, the heat release rate curve is signal peak value curve, the heat release rate is increase, the peak value of the heat release rate is delayed,combustion delayed worsely with the increasing of ethanol proportion.In summary, ethanol-diesel fuel blends showed great advantages on the diesel engine. Thus promoting ethanol-diesel fuel blends on the diesel engine is practical. |
PDF Full Text Request