GAS TURBINE 15
Transcript of GAS TURBINE 15
Protection SystemsProtection Systems Turbine protection system consists of number of sub-
systems which operate during each normal start-up and shutdown Few operate strictly during emergency and abnormal
operating conditions.
Protection systems are set up to Detect and alarm the failure. If the failure is of serious nature, protection system will trip
the turbine.
Protection system responds to: Simple trip signals like
– low lube oil pressure
– high gas compressor discharge pressure etc….
Protection SystemsProtection Systems
More Complex parameters like
– Over speed
– Over temperature
– High Vibration,
– Combustion monitor
– Loss of flame etc…..
To ensure the safety and safe operation of turbine
Speedtronic system is equipped with master control and
protection circuit
Protection SystemsProtection Systems Turbine Protection systems includes:
Trip Oil – Inlet orifice, Check Valves & Orifice network– Pressure switches– Dump valves
Over speed Protection Electronic Over speed trip Over temperature Protection
Over Temperature Protection Over temperature alarm (L30TXA) Over temperature Trip (L86TXT)
Flame Detection and Protection System
Protection SystemsProtection Systems
Vibration Protection High Vibration Alarm & Trip Vibration transducer fault Alarm
Combustion monitoring Spread calculations Exhaust Thermocouple Trouble
Alarm Combustion Trouble Alarm High Exhaust Temperature
Spread Trip Spread monitor enable
MasterProt.
Circuit<RST>
GCV
SRV
RelayVoting
Module
20FG
FUELPUMP
PrimaryOS
Overtemp
Vibration
CombMonitor
SecOS
LossOf
Flame
MasterProt.
Circuit<XYZ>
BypassValveServovalve
RelayVotingModule
20FL
Gas FuelGas FuelControlControl ValveValve
Gas FuelGas FuelSpeed Ratio/Speed Ratio/Stop ValveStop Valve
LiquidLiquidFuel StopFuel StopValveValve
Trip FunctionsTrip Functions
OR
Primary Over speed Detected
Emergency Over speed Detected
Loss Of Speed Signal
Vibration Trip
High Lube Oil Temp Trip
Low Lube Oil Pressure Trip
Low Servo Pressure Trip
Generator Differential Trip
Manual Trip
Customer Trip
Exhaust Over temp Trip
TRIP TURBINE
Compt. Fire Detection Trip
Loss of Flame Trip
Trip Oil protectionTrip Oil protection It is a primary protection interface between the turbine control and
protection system and the components of the turbine which admit or shut-off, fuel.
System devices are electrically operated by Speedtronic control system as well as some totally mechanical devices.
MasterProtection
L4Circuits
20FG
20FL
63HL
Gas FuelSpeed Ratio/Stop Value
OH
Gas Fuel Dump Relay
Valve
63HG
Orifice AndCheck Valve
Network
Protective Signals
RESETManual
Trip
OVERSPEEDTRIP
INLET ORIFICE
Manual Trip(When Provided)
12HA
Liquid Fuel Stop Valve
Gas fuel
LiquidFuel
Over Speed ProtectionOver Speed Protection Electronic Over speed function is
performed in <RST> and <XYZ>. TNH is compared with TNKHOS. When TNH>TNKHOS, turbine is
tripped and latched till Reset. “ELECTRICAL OVERSPEED TRIP”
is displayed in CRT.
TNKHOST
TNHHigh Pressure Over Speed Trip
<RST> <XYZ><RST> <XYZ>
HP Speed
Trip Setpoint
Test
Test Premissive
TNKHOS
LK3HOST
L86MR1 Master ResetReset
SetAnd
Latch
L12H To Master
ProtAnd
AlarmMsg
A A>BB
ManualReset
ManualTrip
12HP
OD
Overspeed Bolt
OLT Mechanical Over speed system
Consists of Over speed bolt assembly in accessory
gear box. Over speed trip mechanism in the
accessory gear. Position limit switch 12 HA. Acts as a back-up control Trip setting > Electronic Setting
Over Temperature ProtectionOver Temperature Protection
Protects GT against possible damages against Over firing.
TTXOT3TTXOT3
TTXOT1TTXOT1
TTXOT2TTXOT2
TTXMTTXMOVER-TEMP. TRIP & ALARM.OVER-TEMP. TRIP & ALARM.
TTRXBTTRXB
L86MR1L86MR1
L30TXAL30TXAALARMALARM
To AlarmTo AlarmMessageMessage
And And SpeedSpeed
SetpointSetpointLowerLower
To To Master Master
Prot.Prot.And And
AlarmAlarmMsgMsg
TRIPTRIP IsothermalIsothermal
ALARMALARMA A A>BA>BBB
AA A>BA>BBB
A A A>BA>BBB
SetSetAndAnd
LatchLatch
ResetReset
OORR
TTREF
CPD
CONTROL
25ºF25ºF
40ºF40ºF
ALARM
TRIP
ISO TRIP1090º F
1030ºF
It is a backup protection system, operates only after the failure of temperature control system.
Flame Detection & ProtectionFlame Detection & Protection Speedtronic Mark-V flame detectors perform two functions
One in the Sequencing system other in Protective system
Flame detected by UV radiation. Speedtronic control furnish +350VDC to drive the UV detector
tube. In the presence of UV radiation, the gas in the detector tube ionizes and conducts current.
Speedtronic counts the no.of current pulses/sec through UV sensor.
Typically 300 pulses/sec when strong UV signal is present.
Flame Detection & ProtectionFlame Detection & Protection
TUEBINEPROTECTION
LOGIC
TURBINECONTROL
LOGIC
FLAMEDETECTION
LOGIC
ANALOGI/O
(FlameDetectionChannels)
28FDUV SCANNER
28FDUV SCANNER
28FDUV SCANNER
28FDUV SCANNER
CRTDISPLAY
Speedtronic MK-V Flame Detection
NOTE: Excitation for the sensor and signal processing is performed by SPEEDTRONIC Mk V circuits
<P>
Vibration ProtectionVibration Protection Gas Turbine unit comprises
Several independent vibration channels
Each channel detects excessive vibration by a seismic pickup
Each channel includes one vibration pickup (velocity type) and a Speedtronic Mark-V amplifier circuit.
Vibration detectors generate a relatively low voltage by the relative motion of a permanent magnet suspended in a coil and therefore no excitation is required.
Vibration protection system trips the turbine when vibration level exceeds predetermined level.
A A>BB
A A<BB
L30TEST
A A>BB
OR
AND
RESET
SETAND
LATCH
30V
FAULT
ALARM
TRIP
<RST>
VF
VA
VT
Auto Or Manual Reset
TRIPL39VT
ALARML39VA
FAULTL39VF
Speedtronic control generatesHigh Vibration Trip
Vibration Transducer Fault
Combustion MonitoringCombustion Monitoring Primary function
to reduce the likelihood of extensive damage to the gas turbine if the combustion system deteriorates.
Continuously examines the exhaust temperature and compressor discharge temperature thermocouples
Reliability of combustion monitor depends on condition of exhaust thermocouples.
Several software programs are written to achieve this
<RST><RST>
MedianSelect
CalculateAllowable
Spread
CalculateActual
Spreads
A A>BB
A A>BB
A A>BB
A A>BB
TTXSPL
L60SP2
L60SP3
L60SP4
CTDA
MedianSelect
TTKSPL1
TTKSPL2
TTKSPL5
TTKSPL7
Constants
TTXC
TTXD2
Combustion Monitor Algorithm
L60SP1