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Connection diagram for model tank systems
A) Refueling of a "normal" tank system with flowback line
Flow
Sensor
Pump
Fuel detector
Fuel detector
Fuelstation
Fuel container
/Kraftstoffreservoir
Flowback line / Rücklauf
Fuel supply line
Kraftstoffversorgung
Fueltank(s)
Header tank
to engine
/zur Turbine
Model
Fuel overflow
/Kraftstoff-Überlauf
Fueling
connector
/Kraftstoff-
befüllanschluß
Fill-line
/Befüll-Leitung
Flowback-line
/Rücklauf-Leitung
This is the ideal variant for normal or even complex tank systems, consisting of one or more "normal"
fuel tanks connected in series (not for bag tanks!).
"Tank full" detection occurs with fuel flowback on the overflow pipe:
The tank overflow line, which is normally led out of the bottom of the model, must be connected to the
flowback line of the fuel station!
Once all the fuel tanks have been filled, fuel flows back to the fuel station via the flowback line at the
end of refueling. Typically, first, a mixture of fuel and air bubbles will flow back/escape from the tank
overflow (
Tanks are almost, but not quite full).
At that moment, the system is already reducing pump performance to counteract the excessive pressure
rise in the model fuel system.
When the tanks are finally full, bubble-free fuel will eventually flow back to the fuel station. This
circumstance is recognized by the system and evaluated as a "tank full" signal.
Now, the fuel pump is automatically reversed, and fuel is reverse pumped from the model tank until
"air" is detected again on the flowback line instead of "fuel".
This causes overpressure possibly built-up during the refueling in the model tanks to be reduced. This
pressure reduction is terminated precisely when no more fuel leaks out via the flowback line and instead
air is sucked back from the fuel container into the flowback line. The refueling process is basically
complete. In addition, an optional programmable volume (
Drawback Volume parameter p.27) can be
reverse pumped to possibly further drain the return hose or additionally decompress the system.
