BOMBARDIER BD-100-1A10, Руководство по эксплуатации

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POWERPLANT
Volume 2 Flight Crew Operating Manual May 06/2005
18-01-04
CSP 100-6
REV 2
ENGINE FUEL SYSTEM
DESCRIPTION
Fuel is delivered to the fuel injectors at the pressures and flow rates necessary to maintain the desired engine thrust. The
engine fuel system also performs the following functions:
- Compressor variable geometry actuator.
- Cool the engine oil (heat transfer).
- Actuate and lubricate fuel system components.
- Provide motive flow for the scavenge and main ejector pumps.
Combustion fuel can be interrupted by moving the L (R) ENGINE run switches to STOP or by selecting the L (R) ENGINE
FIRE switches. The STOP position shuts off the fuel at the fuel metering unit. The L (R) ENGINE FIRE switch closes the
fuel shutoff valve and the fuel metering valve shutoff valve.
COMPONENTS AND OPERATION
FUEL PUMP
The fuel pump mounted on the accessory gearbox is comprised of three separate pumps contained within a single housing.
The fuel pump provides fuel under high pressure and at flow rate that exceeds the requirements of the engine at any power
setting. Excess fuel is bypassed back through the fuel filter system for re-circulation.
Fuel pump pressure is also used to generate motive flow for the scavenge and main ejectors of the aircraft fuel system.
FUEL/OIL HEAT EXCHANGER AND FUEL FILTER
A fuel/oil heat exchanger warms engine fuel and cools engine oil. The engine fuel temperature is indicated on the FUEL
synoptic page.
A 10 micron fuel filter is used to remove solid contaminants from the fuel. The filter is depicted on the FUEL synoptic
page. An impending fuel filter bypass condition on either engine is reported by an advisory CAS message L(R) ENGINE
FUEL BYPASS. A dual impending fuel filter bypass condition on both engines is reported by a caution CAS
message (ENGINES FUEL BYPASS).
FUEL METERING UNIT
The fuel metering unit (FMU) is an electrohydraulic device that meters and distributes the fuel needed for combustion
based upon control signals from the FADEC system. The FMU’s primary components are the fuel metering valve and pres-
surizing and shutoff valve. The metering valve supplies fuel in response to commands from the FADEC to maintain com-
bustion under all operating conditions. The pressurizing and shutoff valve controls the supply of fuel for combustion.
The FMU also supplies the high-pressure fuel to actuate the VG inlet guide vanes and compressor stator vanes.
FUEL SYSTEM OPERATION
The main fuel ejectors or DC powered boost pumps deliver fuel from the collector tanks via fuel feed manifolds to the en-
gines. Engine fuel shutoff valves (SOVs) are installed in the manifold to interrupt the supply of fuel to the engines during
a fire. The L (R) ENGINE FIRE switches control the SOVs.
At the engine, the fuel is pressurized, heated, filtered, metered, and distributed to the combustion chamber. All fuel sched-
uling is controlled by the FADEC.