Electronic Injection System for Natural Gas in a Diesel Engine-Development and Testing

A new electronically controlled fuel system is proposed for direct injection of natural gas in diesel engine. It consists of the solenoid controlled injectors interfaced with a metering valve under stepper motor control. This system proved to operate well in different configurations with metering valve being located at various distances from the injector; two injectors interfaced by one metering valve were also tested. In all cases, the required maximum and minimum gas doses were obtained, either by the change of the metering valve flow area or the injector opening time. The gas dose was measured using a special closed chamber. The conclusions drawn from these tests were used for the proposal of improvement of the injector design in order to reduce its size and weight and obtain more reliable operational characteristics.