Working principle of high pressure common rail electronically controlled fuel injection system

 

The high pressure common rail system is a new concept fuel injection system, which gives people a fresh feeling. It can improve the performance of diesel engines in an all-round way, making it a hot topic in the research field of diesel engines. Its composition mainly includes a high-pressure pump, a common rail pipe with a pressure regulating valve, an injector with a battery valve, an electronic control unit and various sensors.

 

The low-pressure fuel pump feeds fuel into the high-pressure fuel pump. The high-pressure fuel pump pressurizes the fuel and sends it to the high-pressure fuel rail. The fuel passes through the high-pressure fuel pipe. According to the operating state of the machine, the electronic control unit determines the appropriate injection timing and injection duration from the preset map, and the fuel is injected into the cylinder by the injector.

 

特点 Characteristics of high pressure common rail system:

 

1. The fuel injection pressure in the common rail system is flexible and adjustable. The optimal injection pressure can be determined for different working conditions, thereby optimizing the overall performance of the diesel engine.

 

2. The fuel injection timing can be controlled independently and flexibly. With high injection pressure (120Mpa ～ 200MPa), the nitrogen oxides and particulates can be controlled to a smaller value at the same time to meet the emission requirements.

 

3. Flexible control of the fuel injection rate change, to achieve the ideal fuel injection rule, easy to achieve pre-injection and multiple injections, which can reduce the nitrogen oxides of the diesel engine, and ensure excellent power and economic efficiency.

 

4. The fuel injection is controlled by a solenoid valve, and its control accuracy is high. There will be no bubbles and residual pressure in the high-pressure oil circuit. Therefore, within the diesel engine operating range, the cycle fuel injection volume changes little, and the fuel supply of each cylinder is not Uniformity can be improved, thereby reducing diesel engine vibration and reducing emissions.

 

前景 Development prospects of high pressure common rail system:

 

The high pressure common rail system is considered to be one of the three major breakthroughs in the 20th century internal combustion engine technology. At present, there are:

 

1. Constant high pressure sealing problem of high pressure common rail system.

 

2. Uneven injection volume caused by small fluctuation of common rail pressure in high pressure common rail system.

 

3. Optimization of 3D control data of high pressure common rail system.

 

4. Key technical problems in the manufacturing process of the micro-structure, high-frequency response electromagnetic switch valve.

 

In summary, the high-pressure common rail electronically controlled fuel injection technology helps reduce harmful exhaust emissions from diesel engines, and has comprehensive performance in reducing noise, reducing fuel consumption, and improving power output. The application of high-pressure common rail electronically controlled fuel injection technology is beneficial to the environmental protection of the earth, and accelerates the development of the diesel engine industry, the automobile industry, especially the construction machinery related industries.