The common rail fuel injection system was only officially put into practical use in the mid-to-late 1990s. This type of electronic control system can be divided into: Accumulator type electronically controlled fuel injection system, hydraulic booster type electronically controlled fuel injection system and high pressure common rail type electronically controlled fuel injection system. The high pressure common rail system can achieve functions that cannot be achieved in conventional fuel injection systems. The advantages are:
1. The fuel injection pressure in the common rail system can be adjusted flexibly. The optimum injection pressure can be determined for different working conditions to optimize the overall performance of the diesel engine.
2. The fuel injection timing can be independently controlled flexibly, and with high injection pressure (120MPa~200MPa), NOx and PM can be controlled at the same time to meet emission requirements.
3.Flexible control of fuel injection rate changes to achieve the ideal fuel injection law, easy to achieve pre-injection and multi-injection, can reduce diesel engine NOx, while ensuring excellent power and economy.
4. The injection valve is controlled by the solenoid valve, its control accuracy is high, there is no phenomenon of air bubbles and residual pressure in the high-pressure oil circuit. Therefore, in the diesel engine operating range, the cyclic fuel injection quantity change is small, and the oil supply of each cylinder is not Uniformity can be improved, thereby reducing diesel engine vibration and reducing emissions.