燃油碰撞形成混合气在直喷式柴油机上的应用

介绍一种新型直喷式柴油机燃烧系统。在普通轴针式喷油嘴头部加装一挡块，燃油束经其撞击后，部分燃油向垂直于轴针方向四周扩展，增大燃油与空气的接触面积，加快燃油与空气的混合速率，实现了在较低涡流比条件下用单孔轴针式喷油嘴进行直喷式燃烧。实验在一台卧式单缸柴油机上进行。结果表明，该燃烧系统可行，对燃油品质要求不高、工作可靠、起动性好。

Application of Air/Fuel Mixture Formed by Impingement to a DI Diesel Engine

This paper describes a new direct injection combustion system,which uses a pintle nozzle as its injector instead of a multiple hole one.The unique characteristic of the system is that the pintle nozzle has a special head with an impinging tip.The fuel spray injected from the nozzle impinges onto the tip and then most of the fuel spreads in all directions perpendicular to the axis of the nozzle off the tip.In this way the mixing process of fuel and air is speeded up and the quality of the mixture is improved.It realized that the combustion could proceed in a direct injection way by the pintle nozzle only at a low intake swirl ratio.Experiments were conducted on a single cylinder diesel engine with a small size bore.The results show that the combustion system is feasible and has many advantages such as not sensitive to fuel quality,high working reliability and easy starting up.Compared with the direct injection combustion system with a multiple hole nozzle,the new system has some disadvantages at the present time,for instance,high fuel consumption and exhaust temperature as well as soot emission.All these disadvantages need to be overcome in future.