柴油/天然气双燃料发动机控制系统设计

Research on a Control System for Diesel/Gas Dual Fuel Engines

利用自主设计的双燃料发动机的控制系统,将高压共轨柴油机改装成双燃料发动机。该系统包括天然气供给系统、控制单元(ECU)及其配套传感器等。发动机起动和怠速时在纯柴油模式下运行,当负荷达到某一设定值时,柴油ECU减少引燃柴油的喷射,同时天然气ECU增加天然气量的喷射,发动机在双燃料模式下运行。台架试验结果表明:在不同工况下,天然气平均替代率达到75%,最高替代率达到90%。

A electronically controlled system is developed so that to convert a high pressure common rail engine into a diesel/natural gas dual fuel engine. The system includes a natural gas fuel supply system, a control unit （ECU） and matching sensors etc. When the engine is starting and operating at idle load, it runs in diesel fuel mode alone. When the speed and load reaches a certain setpoint, the diesel ECU reduces the supply of the pilot diesel, meanwhile, the natural gas ECU increases natural gas injection. In such case, the engine runs in dual fuel mode. The bench experiment of the engine shows that the average substitution rate is 75 % and the highest substitution rate is 90% in different operating condition.