The reason for fuel nozzle melting

Nowadays, the application fields of diesel generators are increasing and their importance is also increasing. We all know that the fuel injector is one of the main equipment of diesel generators, and after using it for a period of time, sometimes there may be melting faults. Below is a brief analysis of the reasons for the melting of the fuel injectors in diesel generators, in order to help everyone quickly solve the problem and ensure the normal operation of diesel generators.

1. Long term idle operation

When a diesel engine is idling for a long time, due to the low temperature inside the cylinder, fuel combustion is not sufficient, and carbon deposits are easily formed on the combustion chamber and fuel injectors, which can worsen the working conditions of the fuel injectors. Especially in cold winter weather conditions, it is more severe. Due to carbon accumulation in the combustion chamber, heat dissipation is slow, and in severe cases, it can cause blockage or dripping of fuel in the nozzle. If fuel stays at the head of the fuel injector for a long time and burns, the local high temperature generated will cause the fuel injector and insulation sheath to melt.

2. Fuel injection time too late

If the fuel injection advance angle is too small, it will cause the fuel injection time to be too late, and the fuel combustion situation will deteriorate. If it is not adjusted for a long time, local high temperatures will cause the fuel injector and insulation sheath to melt.

3. Unclean fuel

The presence of small particulate impurities in fuel can cause wear on the needle valve and needle valve body at the fuel injector, resulting in severe blockage of the clockwise valve in the needle valve body. The needle valve is stuck and the fuel cannot be injected into the combustion chamber in a timely, quantitative, and rapid manner, resulting in dripping or jetting of fuel. Causing poor fuel atomization, reduced combustion speed, prolonged combustion time at the fuel injector, ultimately leading to melting of the fuel injector and insulation sheath. At the same time as such malfunctions occur, there will be black smoke and shaking from the diesel engine.

4. Improper assembly

If the insulation sleeve of the fuel injector is not cleaned before installation, there is a gap between the fuel injector head and the insulation sleeve, which allows gas to enter the gap and reduces the insulation and heat dissipation effect, causing the fuel injector and insulation sleeve to melt. If the insulation sheath is installed too tightly, the fuel injector will generate additional stress. Under the combined action of thermal alternating load and fuel injection high-pressure load, the head of the fuel injector will break, the needle valve will jam and drip oil. In addition, if insulation sheaths are not installed during maintenance, and the fuel injector extends more than 4 mm into the combustion chamber below the cylinder head, it will also increase the heat absorbed by the fuel injector, causing it to melt.

5. Improper use of diesel generators

If the diesel generator lacks coolant during operation, the combustion chamber will not receive good cooling, resulting in high temperatures, which is also an important reason for fuel nozzle melting.

The above is an analysis of the reasons why diesel generator fuel injectors are prone to melting, hoping to be helpful to customers.