11 - Fuel Systems Flashcards
What two sections can the fuel system be split into
Fuel distribution subsystem
Fuel control subsystem
What are the three tasks of the distribution system
Safely supply fuel combustion chamber
Pressurise fuel so it can be vaporised
Heat fuel to prevent ice build-up
What does the low-pressure fuel pump raise the pressure to and where does it go
175 psi to be transported through oil cooler and fuel filter to high pressure stage
At max engine speed, what psi is the fuel
900 psi
What prevents damage to the system components
Pressure relief valve
What does the metering section control
Amount of fuel passed to the nozzles
What happens to excess fuel
It is retuned to the pump via the bypass return line
What are the two types of EDPs
- Constant displacement
- Non-constant displacement
When is a non-constant fuel pump used
At the inlet of the EDP to provide positive flow to the second stage of the pump
What are the three categories of engine fuel control
Hydromechanical
Hydromechanical/electronic
Full Authority Digital Engine Control (FADEC)
