Study On The Effect Of Methanol Shutdown On The Performance Of A Multi-point Injection Methanol/diesel Dual-fuel Engine

With the increase in car ownership,the demand for oil has increased year by year,but oil resources are increasingly scarce.Therefore,it is an irresistible trend to develop alternative fuels to make the car develop in the direction of energy saving and cleanliness.Because of its good combustion performance,wide range of sources and low prices,methanol gradually enters people's field of vision.In order to analyze the influence of methanol cylinder deactivation on the performance of a multi-point injection methanol-diesel dual-fuel engine,the engine rig is designed and built.The specific operation is on an electronically controlled common rail,supercharged intercooled,six-cylinder four-stroke diesel engine.A methanol supply system is installed to achieve the combustion of methanol on the diesel engine;by comparing the effective specific fuel consumption rate,cylinder pressure,heat release rate,cyclic variation and HC,CO ratio before and after cylinder deactivation under different working conditions,the parameters are used to analyze the effect of methanol deactivation on the performance of multi-point injection methanol-diesel dual-fuel engine.The test results at 1800 r/min,30% load,and four blending ratios(17.82%,25.53%,33.28%,37.26%)show that comparing with the non-stop cylinder dual-fuel mode,the engine's economy became better under the mode stopping methanol injection,the pressure in the cylinder,the rate of pressure rise and the instantaneous heat release rate increase,and the coefficient of variation of the peak pressure cycle increase;the emissions of HC and CO decrease significantly.At 1400 r/min,moderate blending ratio,the test results under three loads(20%,30%,40%)show that the economy after methanol deactivation is better than that of the non-stop cylinder dual fuel mode.The pressure in the cylinder,the rate of pressure rise and the instantaneous heat release rate increase,the peak pressure cycle coefficient increases;the HC and CO emissions are significantly reduced.Under the condition of speed of 1400 r/min and load rate of 20% and 30% respectively,gradually increase the blending ratio,and the fuel of different cylinder deactivation modes(stop four cylinder mode,stop three cylinder mode,stop two cylinder mode)specific fuel consumption rate,cylinder pressure,heat release rate,peak pressure cycle coefficient and HC,CO ratio emissions are compared and analyzed.The test results show that the effective specific fuel consumption rate of the four-cylinder mode is the smallest,the cylinder pressure,heat release rate and peak pressure cycle coefficient are the highest,and the ratio of HC and CO is the lowest.The effective specific fuel consumption rate of the two-cylinder mode is the largest.The heat release rate and peak pressure cycle coefficient are the lowest,and the ratio of HC and CO is the highest;the parameters of the stop three-cylinder mode are somewhere in between.