Introduction to Fuel Injectors for Diesel Generator Sets

The fuel injector is an important component of the fuel system of the diesel generator set. Its main function is to atomize the diesel oil into fine particles and spray them into the combustion chamber, so that the shape and distribution of the fuel spray can adapt to the combustion chamber. At the same time, it can also distribute the fuel to the entire combustion chamber, so that the fuel particles and air can be well mixed to form a uniform combustible mixture. Therefore, the diesel generator sets should ensure that the fuel injector can meet the following technical requirements.

1. Must meet certain injection pressure and range, as well as appropriate spray cone angle and spray quality.

2. Fuel injection and fuel supply shall be stopped quickly, and no fuel leakage is allowed, so as not to deteriorate the combustion process.

3. In each cycle of fuel injection, there are less fuel injection at the beginning, more fuel injection at the middle stage and less fuel injection at the later stage to reduce the fuel accumulation in the purging period and improve the adverse conditions in the later combustion period.

Modern diesel generators widely use hydraulic valve opening (also known as closed) fuel injectors. There are many types of fuel injectors, but the main difference between them is in the fuel injector. The structure of the fuel injector is related to the shape of the combustion chamber. There are many forms of closed fuel injectors, and their basic types are single hole, multi hole, pintle and cooling fuel injectors. Common classifications are as follows:

(1) According to the number of orifices, the fuel injectors can be divided into porous type and single hole type.

(2) According to different cooling methods, it can be divided into coolant cooling injector and fuel cooling injector.

(3) It can be divided into mechanical control and electronic control according to different control modes.

(4) It can be divided into cooling type and non cooling type according to whether it is forced cooling.

(5) According to the position of the adjusting spring, it can be divided into upper spring type and lower spring type.

(6) According to the resistance value of the internal solenoid coil of the injector, there are two types: low resistance injector and high resistance injector.

(7) It can be divided into MPI and SPI according to the purpose; The fuel injector is actually a solenoid valve, its nozzle is facing the intake valve (multi-point cylinder injection), and its tail is connected with the fuel distribution pipe.

The fuel injector is the most critical and complex component in the fuel system of the diesel generator set, and it is also the most difficult component in the design and manufacturing process. The quality of the fuel injector directly affects the performance and working stability of the diesel generator. Therefore, users should also pay attention to the regular maintenance of the fuel injector when using the diesel generator set.