Presentation
on
Turbine Protection System
TURBINE PROTECTION
The turbine protection system can be actuated
by any of the following trip systems :
-- Hydraulic trip system
-- Electrical trip system
Both the trip systems, when initiated, act on
the hydraulic control system and cause trip oil
pressure to collapse which in turn closes the
Emergency stop valves, Interceptor valves
and control valves.
HYDRAULIC TRIP SYSTEM
Overspeed trip device 1
Overspeed trip device 2
Vacuum trip device
Thrust Bearing trip device
Hand trip lever 1 (local)
Hand trip lever 2 (local)
TURBINE PROTECTIONS
LUB OIL PRESSURE LOW
HIGH AXIAL SHIFT
LOW VACUUM
HP EXHAUST TEMP HIGH
HPC TOP-BOTTOM DIFF TEMP HIGH
IPC FRONT TOP-BOTTOM DIFF TEMP HIGH
IPC REAR TOP-BOTTOM DIFF TEMP HIGH
FIRE PROTECTION
MFT
ATRS TRIP
GENERATOR TRIP LEADING TO TURBINE TRIP
TURBINE PROTECTIONS
LIQUID MAIN LEADS TOP HIGH
COLD GAS COOLERS TEMP A&B HIGH
COLD GAS COOLERS TEMP C&D HIGH
SEAL OIL TEMP AFTER COOLER AIR SIDE HIGH
HOT AIR MAIN EXCITER TEMP HIGH
PRIMARY WATER TEMP AFTER COOLER HIGH
STATOR WINDING FLOW LOW
MAIN BUSHING R FLOW LOW
MAIN BUSHING S FLOW LOW
MAIN BUSHING T FLOW LOW
TURBINE PROTECTIONS
TURBINE TRIP (COMPULSARY)
LOW VACUUM
HIGH AXIAL SHIFT
OVERSPEEDING OF TURBINE
MAIN OIL TANK LEVEL LOW
LOW LUBE / CONTROL OIL PRESSURE
MAIN STEAM TEMPERATURE LOW
DRUM LEVEL HIGH TURBINE HAND TRIP FROM
GOVERNING RACK
TURBINE REMOTE PUSH BUTTON TRIP
TURBINE HAND TRIP FROM MOT ROOM / TG FLOOR
(FIRE PROTECTION)
BOILER TRIP LEADING TO TURBINE TRIP
GENERATOR TRIP LEADING TO TURBINE TRIP
TURBINE PROTECTIONS
TURBINE ADVISORY TRIP
HIGH SHAFT VIBRATION / ECCENTRICITY
HIGH BEARING VIBRATION
HIGH BEARING METAL TEMPERATURE
HIGH DIFFERENTIAL EXPANSION
HIGH HP/LP EXHAUST TEMPERATURE
TOP BOTTOM DIFFERENTIAL TEMPERATURE
HIGH MAIN STEAM TEMPERATURE
LOW / HIGH FREQUENCY
GOVERNING RACK
GOVERNING RACK
ELECTRICAL
TRIP
CONDITIONS
ELECTRICAL
TRIP
CONDITIONS
TRIP
RELAY 1
TRIP
RELAY 1
TRIP
SOLENOID 1
HYDRAULIC
TRIP
DEVICES
TURBINE
TRIP VALVE
STOP
VALVE
TRIP
SOLENOID 2
TURBINE PROTECTIONS
Two trip solenoids are provided in the hydraulic
circuit, which get trip signals from the electrical
system. Actuation of any one solenoid is sufficient
to trip the turbine.
The electrical system is configured as a 2-channel
system. Each channel is realized in a Processing
Unit
Both the processor units are completely
independent of each other and input modules,
processor module and output modules reside on
each.
TURBINE PROTECTIONS
Each channel having two processors Unit with
one processor in hot standby mode .
Realisation of 2 out of 3 trip logic is carried
out in the processor.
Both the channels are tested periodically even
while the turbine is running. Cyclic testing is
done automatically at preset intervals
FIRE PROTECTION:
Fire protection switch either in control room or
in machine hall operated.
Level in main oil tank falls to a very low value
indicating substantial leakage of oil from the
system.
HP EXHAUST TEMP HIGH
During startup/shutdown or load rejections,
steam turbines are operated at very low
volumetric flows. Energy transmitted by the
turbine shaft is
converted to thermal energy, which in turn result
in an increase in the temp.of both the exhaust
AXIAL SHIFT VERY HIGH
A too high axial displacement of the turbine
shaft may cause damage to the turbine blades.
The axial shift is measured in both directions ()
using three proximity probes.
HPT/IPT TOP BOTTOM TEMP HIGH
Excessive large temp. differentials within
turbine components cause heat stresses. The
temp. differential between upper & lower parts
of the turbine casing (HP and IP sections) is a
measure of casing distortion.
ISOLATION OF GENERATOR FROM GRID
Turbine has tripped and reverse power relay
has operated. The command signal shall be
initiated with a delay of 3 Seconds
Reverse power relay has operated. The
command signal shall be initiated with a time
delay of 10 seconds.
OVERSPEED TRIP BOLTS IN BEARING NO. 1 PEDESTAL
BEARING / SHAFT VIBRATION PICK UP
MOUNTED ON BEARING NO. 4 PEDESTAL
IP DIFFERENTIAL EXPANSION PICK UP
MOUNTED ON BEARING NO. 3 PEDESTAL
HALL PROBE IN BEARING NO. 1 PEDESTAL
IP DIFFERENTIAL EXPANSION PICK UP
MOUNTED ON BEARING NO. 3 PEDESTAL
LP DIFFERENTIAL EXPANSION PICK UP
MOUNTED ON BEARING NO. 4 PEDESTAL
AXIAL SHIFT MEASUREMENT AT IP COLLAR
THANK YOU
