GE-CF6-80E1-63

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SERVO FUEL HEATER
IDG FUEL/OIL
FUEL FLOW TRANSMITTER
INLET
PORT
OUTLET PORT
FWD TUBE
BRACKET
SUPPORT
CLAMP
DRAIN VALVE
COMBUSTOR
AFT TUBE
AIR MANIFOLD
7TH STAGE LPT COOLING
BOTTEM VIEW
A
A
OIL BYPASS
VALVE
HEAT EXCHANGER
THERMAL BYPASS
VALVE
5:30
7
A330 - ENGINE ATA 71 up 80
GE CF6-80E1 125 of 394
 
 
 
 
 
 
 
 
 
 
 
FUEL OIL HEAT EXCHANGER
The Fuel Oil Heat Exchanger
� uses scavenge oil to heat the fuel to provide better atomization and
decrease the possibility of icing. The heated fuel is returned to the pump.
A cored gallery carries the fuel to the opposite side of the pump where the
fuel filter is mounted.
� is located between high pressure gear pump and fuel filter.
� contains a differential pressure valve, which opens with contaminated or 
very cold oil (bypass relief at approx. 85 120 PSI ).
Since the oil is cooled down by unregulated high pressure fuel (max. 1500 psi),
an internal leakage is hazardous, because the engine oil system inevitable be
comes contaminated with fuel.
System Description
Total output fuel flow from the fuel pump flows into the fuel/oil heat exchanger.
The heat exchanger uses this fuel supply to cool the engines oil. Under
extreme cold operating conditions (cold ambient and cold aircraft fuel tank
temperatures), the oil heats the fuel to help avoid fuel icing conditions in the
HMU.
The fuel/oil heat exchanger is a shell and tube type heat exchanger with fuel
flowing through the tubes and oil flowing around the tubes. The fuel side of the
heat exchanger is two pass using straight tubes and two end domes. One end
dome is divided by an internal baffle to form the fuel entrance and exit.
Fuel enters the first end dome, flows to the opposite end through one half of its
tube, turns 180 Deg. in the second end dome and returns to the fuel exit
through the remaining half of the tubes. The oil side of the heat exchanger is 6
pass which is controlled by baffles within the heat exchanger tube bundle.
The fuel/oil heat exchanger includes an oil bypass valve which cracks open
when oil delta P exceeds 85 psi (5.86 bar) and is full open at 120 psi (8.27 bar).
This valve is needed for cold startups when the heat exchanger’s pressure
drop is high due to high oil viscosity.
A330 - ENGINE ATA 71 up 80
GE CF6-80E1 126 of 394