Fundamental Research On The Hot Area In The Compression Stroke Of Hydrogen Fueled Internal Combustion Engine

Hydrogen-fueled internal combustion engines have huge advantages in alleviating the two problems of energy crisis and environmental pollution,and require low hydrogen concentration during the combustion process,simple modification,and high thermal efficiency.As a fuel,hydrogen has the advantages of low ignition energy,wide ignition limit,and fast combustion speed.Therefore,scholars from various countries are studying hydrogen internal combustion engines in the ascendant.However,there are abnormal combustion phenomena during the operation of hydrogen internal combustion engines,that is,pre-ignition,backfire,and knocking.These phenomena are related to each other,promote each other,and transform each other,which poses a huge obstacle to the promotion of hydrogen internal combustion engines.There is a close relationship between the hot area in the cylinder of a hydrogen-hydrogen fuel internal combustion engine and pre-ignition.In order to explore the changing law of the hot area under different working conditions,the appearance time and duration of the hot area,the highest temperature of the hot area(or the instantaneous temperature before the fire,that is,the critical temperature),the maximum area(or the area immediately before the fire)are proposed.(I.e.critical area)four variables are used as the characteristic parameters to describe the hot zone;the equivalent ratio,ignition timing and initial intake pressure under different speed conditions(1000r/min,3500r/min,6000r/min)are used as research variables,Study their four characteristic parameters in the hot zone and the change law of the peak temperature during the combustion process.On this basis,five variables including the characteristic parameters of the hot zone and the peak temperature during the combustion process are constructed to characterize the intensity of the hot zone,and the equivalence ratio,ignition timing,and the change law of the initial intake pressure and the intensity of the hot zone are studied.Reveal their relationship with the occurrence of pre-ignition.The research results show that:(1)Equivalence ratio and initial intake pressure at different speeds have significant effects on the time of occurrence,duration,maximum temperature,maximum area and peak temperature in the combustion process of the hot zone;ignition is positive Time has a greater impact on the duration,maximum temperature,maximum area,and peak temperature of the hot zone,but has a small effect on the time when the hot zone appears.(2)Under different speed conditions,the mixture concentration decreases and Advance the ignition timing can effectively alleviate the intensity of the hot area.Appropriately increasing the initial intake pressure can still reduce the intensity of the hot area at low and medium speeds,but under high speed conditions,the intensity of the hot area can still be reduced under the conditions of appropriate mixture concentration,and at high mixture concentration conditions The following will be counterproductive;(3)In the selected variable range,under different speed conditions,the above research variables have different effects on the duration,temperature,area of the hot zone and the peak temperature in the cylinder during the combustion process;...