Fuel supply, function

W47.00-1011-79

Shown on engine 541

1 Fuel tank

2 Manual fuel feed pump

2.1 Fuel prefilter

4 Fuel heat exchanger

5 Fuel pump

6 Fuel filter

7 Nozzle holder combination

9 Overflow valve

A Suction or vacuum side fuel feed line

B Pressure side fuel feed line

C Fuel high pressure line

D Fuel return line

A6 MR/PLD control unit

Y6 Cylinder 1 unit pump

Y7 Cylinder 2 unit pump

Y8 Cylinder 3 unit pump

Y9 Cylinder 4 unit pump

Y10 Cylinder 5 unit pump

Y11 Cylinder 6 unit pump

General information

Fuel supply ensures that the fuel required for combustion is available under all operating conditions in the adequate quantity at the correct time and has the required pressure.

The fuel to individual cylinders is supplied by the pump-line-nozzle system (PLD system) that receives fuel from the fuel low pressure circuit.

Fuel low pressure circuit

The fuel low pressure circuit ensures that the fuel is cleaned and is supplied to the unit pumps of the pump-line-nozzle system in the required quantity and with the required pressure.

It basically consists of the following parts:

 Fuel tank(1)

 Manual fuel feed pump (2)

 Fuel prefilter (2.1)

 Fuel heat exchanger (4)

 Fuel pump (5)

 Fuel filter (6)

 Suction or vacuum side fuel feed line (A)

 Pressure side fuel feed line (B)

 Fuel return lines (D)

Pump-line-nozzle system (PLD system)

The fuel supplied by the fuel low pressure circuit is injected into the cylinder via the pump-line-nozzle system at the correct time, in the adequate quantity and with the required pressure.

The pump-line-nozzle system consists of individual unit pumps

(Engine 541: Y6 to Y11, engine 542: Y6 to Y13), the injection nozzles in the nozzle holder combinations (7) and the fuel high pressure lines (C), over which the individual unit pumps are connected to the respective injection nozzles.

The excess fuel delivered during the fuel high pressure delivery goes back to the fuel low pressure circuit via the fuel return lines (D).