Main Components of Diesel Engine Fuel System

by Starlight Generator dieselgeneratortech

This post mainly introduces the major components of diesel generator fuel system. Moreover, each part is described in details. If you are interested, take a few time to read it.

In most generating unit diesel engines, the fuel system loop consists of the following major parts:

1. Day Fuel Tank

2. Fuel Water Separator

3. Fuel Strainer

4. Fuel Supply Pump

5. Fuel Filter

6. Fuel Injection Pump

7. Injectors

8. Return line to the day tank

About Day Fuel Tank

The day fuel tank is designed and fabricated with sufficient capacity to supply the diesel generator for at least 6 to 8 hours, and some times up to 12 hours at its full rated load. For small genset below 250 KW the day fuel tank is usually an integral part of the genset skid base. It becomes a separate free-standing rectangular or cylindrical tank for bigger genset.

About Fuel Water Separator

Fuel Water Separator is a primary filtration unit used to remove the water from the diesel fuel before it reaches to the sensitive parts of the engine. Water and contaminants have a direct impact on the service life and performance of diesel engines.

About Fuel Strainer

the fuel strainer if the first stage of filtering the solid particles from the diesel. Usually any sensitive instrumentation is fitted after this point so it is to prevent the harmful solid particles to reach these parts and also block the relatively big particles from reaching the fuel filters. The strainer delivers the fuel to the lifting pump.

About Fuel Pump

Fuel injection pumps must be supplied with fuel under pressure because they have insufficient suction ability. All diesel injection systems require a supply pump transfer fuel from the supply tank through the filters and lines to the injection pump.

About Fuel Filters

The purpose of any diesel fuel filter is to remove foreign particles as well as water. If the filter is installed on the pressure side of the boost pump it must have sufficient strength to handle pump pressure without bursting or leaking. As with all fuel system components, the filter must be located well away from sources of heat, preferably outside of the engine compartment.

About Fuel Injection Piping

These pipes should have the same volume so that that the injection pump delivers exact equal amount to the cylinder injectors.

About Fuel Injector

The injector atomizes the diesel fuel and spray it into the combustion chamber. The injector consists mainly of the nozzle and the nozzle holder. The opening pressure of the nozzle is adjusted by means of shims at the compression springs.

The fuel injector is typically consists of the following main parts:

1) Rod type filter

2) Cap nut

3) Compressing spring

4) Compression pin

5) Cap nut for fixed nozzle

6) Nozzle needles

7) Connect hole for fuel delivery

8) Nozzle holder

9) Connect tube for overflow

10) Shim

11) Pin