aerospace propulsion study for shenyang aerospace university by lale420 (final_eaxm_3 )
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Powerplant Fire
Protection System
1 Devinder K Yadav
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System Overview
2
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Fire Detection Methods
Rate of Temperature Rise Detector
Smoke Detector
Overheat Detector
Observation of Crew or Passenger
3
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Fire Detection Systems
Thermal switch system
Thermocouple system
Continuous loop detector system (Used in turbine engines of
large transport aircraft)
4
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Fire Detection Systems
Thermal switch system:
It uses a bimetallic
thermostat switch or spot
detector.
5
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Fire Detection Systems
Thermocouple system: Works on rate of temperature rise.
Does not give warning when an engine slowly overheats.
6
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Continuous - loop detector system
In case of fire, the core resistance drops and
current flows between the signal wires and the
ground, energising the alarm system
Fire Detection Systems
7
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Continuous - loop detector system
Fire Detection Systems
8
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Fire Protection Systems
9
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A Typical Fire Detection Systems
10
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Fire System Warnings
11
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Fire Warning
12
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Loop Warning
13
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Fire Warning Schematic
14
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Fire Warning Schematic
15
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Fire Extinguishing Systems
Types of fires
16
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Fire Extinguishing Systems
Types of extinguishing systems
High Rate of Discharge (HRD) System: Provide high discharge rate through high pressurisation, short feed
lines, large discharge valves and outlets. Extinguishing agent is
released into the zone in one second or less.
Conventional System System is designed around a cylinder that stores the CO2 under
pressure and a remote control valve assembly in the cockpit to
distribute the extinguishing agent to the engine.
17
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Conventional System
CO2 cylinder
Fire Extinguishing Systems
18
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Fire Extinguishing Systems
19
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Typical Fire Extinguishing Systems
20
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Typical Fire Extinguishing Systems
21
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Typical Fire Extinguishing Systems
22
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Typical Fire Extinguishing Systems Schematic
23
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Gas Turbine
Ignition & Starting
Devinder K Yadav 1
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Engine Ignition System
The Ignition system initiate combustion of the air/fuel mixture in the combustion chamber. Each System is composed of: A high energy ignition exciter An exciter-to-igniter plug lead An igniter plug
2
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Engine Ignition System
3
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Engine Ignition System Ignition Exciter
4
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Ignition Systems
Spark systems are the most common
ignition system used with gas turbine
engines
Once the flame is started and stabilised
the ignition system is switched off
If potential flame-out conditions exist the
ignition system may be activated 5
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Typical Ignition System
Large transport aircraft are fitted with two independent ignition systems. System A System B
6
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Ignition Systems
Whenever there is a flame-out risk
such as flying in rain or turbulence
ignition systems are generally switched
on and operate continuously
This gives an immediate re-light in the
event of a flame out
7
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Typical Ignition System Operation
8
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Typical Ignition System Operation
Continuous relight is recommended for turbulent weather operation, flameout, and inflight relight situations
9
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Typical Ignition System Operation
10
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Engine Starting System
11
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Turbine Engine Starting
For double and triple spool engines only
the high(est) pressure spool is rotated
The most common types of
starting systems used in civil
aircraft are
electric
pneumatic
12
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Gas Turbine Engine Starting
The starter motor must accelerate the
compressor to provide sufficient air
under pressure to support combustion
Once fuel has been introduced and
ignited the starter motor must continue
to assist the engine to a self sustaining
speed
13
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Turbine Engine Starting Systems
Both electric and pneumatic starters have
very high power to weight ratios
Operating times are very limited
Overheating will result from exceeding
limits
Turbine starters have defined duty cycles
for both times on and cool down times
14
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Electric Starters
Used on small turbofans turboprop and
turboshaft engines
Aircraft battery or Ground Power Unit
(GPU)
GPU power supply must be carefully
monitored
15
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Pneumatic Starters
Mainly used on large turbojet and
turbofan engines
Air impingement is supplied by either a
ground power unit, typically an Auxiliary
Power Unit (APU) or bleed air supply
from an operating engine
16
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Pneumatic Starters
17
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Pneumatic Starters
18
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Pneumatic Starters
19
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Pneumatic Starters
20
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Pneumatic Starters
21
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Engine Starting Sequence
Ref: www.faa.gov 22
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Engine Starting Sequence
Ref: www.smartcockpit.com 23
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Typical Starting System (A310)
Ref: www.smartcockpit.com 24
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Typical Starting Procedure
Ref: www.smartcockpit.com 25
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Typical
Starting
Procedure
Ref: www.smartcockpit.com 26
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27
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Being 747-400 Overhead Panel
www.avsim.com 28
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Being 747-400 pedestal Panel
www.avsim.com 29
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Being 747-400 pedestal Panel
www.avsim.com 30
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Starting Procedure B747-400
Select Ignition as desired (ignition 1). Pull the Engine Start Selector for Engine 4 . Watch the N2% RPM increase in the EICAS display. Bleed air from the APU is being supplied to starter and it begins to turn the compressor (N2). Check for visual N1 rotation. When the N2% RPM indicator on the EICAS reaches max motoring speed around 15%), switch the Fuel Control Switch for Engine 4. Watch for Max EGT, oil pressure and other parameters
www.avsim.com 31
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Hot Starts
Premature cut out of the starter motor
will cause the fuel control unit to
automatically supply extra fuel to
maintain a programmed acceleration rate
If light-up occurs too early the airflow is
insufficient to accommodate the light-up
fuel flow resulting in an over rich
mixture and high turbine temperature
32
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Hot starts
If there is insufficient torque from the
starter motor the fuel control unit will
automatically supply extra fuel to maintain
a programmed acceleration rate
Defective compressors or turbines
wastes energy available for acceleration
Abnormally high propeller or accessory
loads also waste energy 33
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Hot Starts
An engine start must be abandoned if it
is apparent that starting turbine
temperatures will be exceeded
A hot start is abandoned by cutting the
fuel supply then motoring the engine for
a short period to reduce turbine
temperature
34
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Hung Starts
A hung start is a potentially dangerous
situation where the engine fails to
accelerate past a certain RPM during
starting
Causes are as for a hot start
The engine start must be abandoned if
the RPM hangs or the duty cycle of the
starter motor is exceeded 35
BGT 7 Fire Protection Systems.pdfBGT 8 Ignition & Starting System.pdf