Causes and preventive measures of fuel injection nozzle burning of excavator
The main function of the diesel injector is to spray the high pressure diesel supplied by the fuel pump into the combustor evenly in a mist shape with a certain pressure, speed and injection taper, so as to facilitate the formation and combustion of the mixture. At present, most diesel engines use hole and shaft injector, among which hole injector is the most widely used.
Once the fuel Injector nozzle at the end of the fuel injector is burned and melted, the diesel engine will not operate smoothly. In serious cases, it may cause obvious vibration, black smoke from the exhaust pipe, overheating of the engine body and fuel consumption increase, etc., and even cause the diesel engine to flameout. Therefore, keeping the injector in good working state is of vital importance for the normal operation of the diesel engine.
1. Cause of fuel Injector nozzle burning
Idle for a long time
When the diesel engine is idling for a long time, due to the low temperature in the cylinder and insufficient fuel combustion, carbon deposition is easy to form on the combustion chamber and Injector nozzle, resulting in deterioration of the Injector nozzle working conditions. This is especially true in cold winter climates. Due to the carbon accumulation in the combustion chamber, the heat dissipation is slow. In serious cases, the orifices of the Injector nozzle are blocked or dripping oil occurs. The fuel oil sticks to the Injector nozzle head for a long time to burn. The local high temperature will cause the Injector nozzle and the heat insulation jacket to melt.
The injection time is too late
If the injection Angle is too small, the injection time will be too late and the fuel combustion will deteriorate. If the adjustment is not made for a long time, the local high temperature will cause the burner and the heat insulation jacket to melt.
Clean fuel oil
There are small particles in the fuel oil, which will cause the needle valve and needle valve body at the Injector nozzle wear, serious clockwise valve stuck in the needle valve body. Needle valve lag, the fuel can not time, quantitative and rapid injection into the combustion chamber, will appear dripping oil or injection phenomenon. At this point, the fuel is not atomized well, the combustion speed is reduced, and the combustion time at the Injector nozzle is prolonged, which eventually leads to the burner and heat insulation sheath melting. At the same time, the black smoke and jitter of the diesel engine will occur.
If the Injector nozzle heat shield is not cleaned when installed, there is a gap between the Injector nozzle head and the heat shield, which will allow gas to enter the gap, resulting in reduced heat insulation and heat dissipation effect, and burning of the Injector nozzle and heat shield. If the heat shield is installed too tight, the Injector nozzle will generate additional stress, and more oil information oil information regulation technology please pay attention to WeChat public number oil ring ypq0910 under the combined action of thermal alternating load and fuel injection high-pressure load, the Injector nozzle head will break and the needle valve will stick and drip oil. In addition, if the heat shield is not installed during maintenance, the Injector nozzle can be extended to the combustion chamber more than 4 mm below the cylinder cover, which will increase the heat absorbed by the Injector nozzle and cause the Injector nozzle to melt.
Improper use of diesel engines
The lack of cooling fluid in the operation of diesel engine, the high temperature of the combustion chamber due to lack of good cooling, is also an important cause of jet Injector nozzle melting.
2. Prevention of burn-in measures of Injector nozzle
In order to prevent the burner from melting, the following should be done:
Clean and replace the fuel filter in time. Check and calibrate the injection advance Angle frequently, and timely adjust the injection pressure and atomization of the injector; Correct installation of Injector nozzle jacket to eliminate potential trouble; Ensure the normal operating temperature of the diesel engine and prevent long time high temperature operation.