喷油提前角对非道路移动机械用柴油机性能的影响

以一台四缸非道路移动机械用柴油机为试验发动机,在喷油提前角为3℃A、1℃A和-1℃A条件下,对发动机的外特性、经济特性以及排放特性进行了研究。研究表明:喷油提前角的推迟,对发动机动力性影响不大;但对柴油机的经济性影响比较大,尤其是发动机运行在中高转速时;喷油提前角对排放也有较大影响,随着喷油提前角的推迟,CO和HC排放增加,NOx排放得到一定程度的改善;喷油提前角3℃A下的八工况点比排放得到大幅改善。因此,通过调整喷油提前角可使该非道路用柴油机达到拟国3排放法规的要求。

Effect of Fuel Injection Timing on the Performance of Diesel Engines Used by Off-Road Mobile Machinery

Based on one experimental diesel engine with four cylinders used by non-road mobile machinery,the external characteristics,economic performance and engine emission were studied deeply with different fuel injection timing of 3℃A,1℃A and-1℃A.The results indicated： the delaying of fuel injection timing has not much effect on dynamic characteristic of diesel engine,while economic characteristic of engine closely relates to fuel injection timing,especially when running at medium and high speed.The emission characteristic of engine is also Influenced by fuel injection timing.CO and HC emission of engine increases with delaying of fuel injection timing,while the tendency of NOx emission is different to that of CO and HC emission,improved to a certain extent.Emission quantity under eight operating modes with fuel injection timing 3℃A drops greatly.Moreover,diesel engine with poor emission performance used by off-road mobile machinery can meet requirement of emission regulation by technical means of changing fuel injection timing.