在柴油引燃氢气/柴油发动机中,通过柴油引燃氢气/空气的预混合气,故有希望实现准均质和低温燃烧。氢气/空气混合气氛围中的柴油雾化特性将直接影响到柴油在气缸内的分布,影响内燃机的燃烧过程,从而决定发动机准均质燃烧的程度,是发动机能否实现低温燃烧的关键。利用KIVA-3V程序对柴油在氢气/空气混合气氛围中的雾化特性进行研究,研究结果表明,氢气的存在能够在一定程度上促进柴油液滴的雾化,增大柴油喷射终了时的缸内柴油蒸气质量;氢气的存在对喷雾油束的偏转和喷雾的贯穿距离具有明显的影响,能够在一定程度上降低液滴碰壁强度,从而有助于气缸内形成较均匀的柴油蒸气分布;但氢气浓度超过一定值后则会增大柴油液滴碰壁的概率。
In hydrogen/diesel engine,pre-mixture of hydrogen and air is ignited by diesel oil for the purpose of quasi-homogeneous and low-temperature combustion.The spray atomization of diesel oil in the hydrogen/air environment will influence the distribution of diesel vapor in the cylinder and the combustion progress of the internal combustion engine,and determine the degree of quasi-homogeneous combustion.The spray atomization is the key point to the low-temperature combustion of engine.The spray atomization characteristics of diesel oil in the hydrogen/air environment are studied by using the KIVA-3V code.The research results show that hydrogen in the air can promote the atomization of the diesel oil spray,increase the mass of diesel vapor at the end of oil injection,influence the deflection and the penetration distance of the spray,can reduce the collision intension of the spray particles against the cylinder wall to some extent and facilitate the well-proportioned oil vapor distribution in the cylinder.But the collision probability of the spray particle against the cylinder wall will increase when the hydrogen concentration in the air exceeds a certain limit.