Turbine trouble shooting
S.N Trouble Possible cause
i). Bending of rotor due to supply of sealing
steam pressure with out rotation of the rotor
ii). In sufficiancy of warming-up period(Time)
iii). In sufficiancy of turning period.
iv). Remained drains in turbine
v). Rubbing of the laybrinth fin with the turbine
rotor
vi). Foreign material in the inlet steam.
vii). Scale deposit on the balde and nozzles.
viii). The damage or rubbing of the journal
bearings.
1 High vibrations ix). Less clearance between the journal bearing
and rotor.
x). Unbalance of the rotor.
xi). Losen the probe holder for shaft vibration.
xii). Water hammering in the steam piping
i). Rubbing of labrinth packing with rotor.
ii). Steam leakage.
iii). Remained drain in the turbine.
iv). Loosen the lock nut on the linkage of
governor valve.
2 Abnormal noise and or sound
v). Foreign material in the inlet steam.
vi). The damage or rubbing of the journal
bearing.
vi). Water hammering in steam and/or water
piping.
i). The scale diposit on blade & nozzle
ii). Drain in the steam
3 Excessive axial displacement
iii). Loosen the probe holder for axial
displacement.
i). Lack of quantity of lube oil supply to the
journal bearings.
ii). High supply of lube oil temperature
iii). The foreign material in the oil
Excessive journal bearing
4
temperature iv). Choke of the oil supply piping and / or hole
in the bearing housing for oil supply.
Excessive journal bearing
4
temperature
v). Less clearance between the rotor and the
journal bearings.
vi). Wrong alignment.
i). Lack of quantity of lube oil supply to the
thrust bearings.
ii). High supply of lube oil temperature
Excessive thrust bearing
5 iii). The foreign material in the oil
temperature.
iv). Choke of the oil supply piping and / or hole
in the bearing housing for oil supply.
v). Less clearance between the rotor and the
thrust bearings.
vi). Sensor installation
i). Stick of the mechanism of the governor
valve.
ii). Scale deposit on the shaft of the governor.
iii). Unstable movement of output shaft of
actuator.
Malfunction of the governor iv). Foreign material through the emergency
6
valve & actuator. stop valve.
v). High frequency vibration of the actuator or
control oil supply pipe due to air in the control
oil.
vi). Speed up automatically just after opening
the emergency stop valve due to the steam
leakage through the governor valve seat.
1. Scale deposit on the shaft of the emergency
stop valve
2. Stick of the mechanism of the emergency
Can not close and/or open the stop valve
7
emergency stop valve
3. Low pressure of control oil
1. lack of performance of the oil vapour
extractor. (Excessive pressure in bearing
Oil leakage from the bearing housing)
8
housing
2. Choke of the oil return hole in the bearing
housing.
1. Increase the gland leakage steam quality
Steam leakge from the turbine
9
front/rear turbine gland
2. High gland sealing steam pressure.
Steam leakge from the turbine
9
front/rear turbine gland
3. Lack of performance of the gland steam
condensor.
1. Increase the gland leakage steam quality
2. High gland sealing steam pressure.
10 Water in the lube oil 3. Lack of performance of the gland steam
condensor.
4. No operation of the oil purifier unit.
5. Damaged the cooling tube of oil cooler.
1. High deifferential pressure of lube oil filter
11 Low lube oil pressure 2. Oil control valve not working properly.
3. Oil leakage
1. High deifferential pressure of lube oil filter
12 Low control oil pressure 2. Oil control valve not working properly.
3. Oil leakage
1. High deifferential pressure of lube oil filter
13 Jack oil pressure 2. Oil control valve not working properly.
3. Oil leakage
1. The scale deposit on the blade and the
turbine nozzle.
2. high extracion steam pressure
14 High extraction steam pressure 3. Mul-function of extraction steam pressure
control valve.
4. Stick the disc of check valve for extraction
check valve
1. Governor trouble
15 Unstable inlet steam pressure 2. Stick of governor valve
3. Error of the pressure transmitters.
1. The scale deposit on the blade and the
turbine nozzle.
16 Low generator output
2. High frequency of national grid
3. Low vaccum
uble shooting
Countermesures
i). Operate the bent rotor in slow speed for long period up to
recovery by iteself.
ii). Operate the turbine for long time
iii). Operate the turning gear for long time
iv). Purge the drains.
v). Inspect the laybrinth packing. If necessary, repair and adjust
the fin.
vi). Inspect the strainer in the EMSV.
vii). Remove the scale deposits and analyse the deposition.
viii). Replace the new journal bearing to new one
ix). Mesure and adjust the clearance.
x). 1) Analysis of the vibration is carried out by the additional
analyser while all signals from SHINKWA monitors are input the
analysers.
2). Rebalance the turbine rotor using field balance weight with
out overhaul of turbine casing.
3). If possible, Re balance the turbine rotor on a balancing
machine after overhaul of turbine casing.
xi). Check the probe holder. If necessary, fasten it.
Xii). Check the point of water leakage and close the isolating
valves. Stop the turbine if necessary.
i). Inspect the labrinth packing and adjust the labyrinth packing.
ii). Check and repair the steam leakage.
iii). Purge the drains.
iv). Fasten the nut.
v). Inspect the strainer in the main steam stop valve and if
necessary replace it.
vi). Replace the new journal bearing pads.
vii). Check the point of water hammer and close the isolating
valve. Stop the turbine unit if necessary.
i). Remove the scale diposit and analyse the diposit.
ii). Check the thrust bearing.
iii). Check the probe holder if necessary fasten it.
i). Check the pressre & temp of the lube oil.
iia). Check the oil temperature control valve on oil control unit.
iib). Check the cooling water supply temperature.
iii). Operate the oil purifier unit and if necessary change the oil
completely.
iv). Check and clean the choke point in the piping and or hole.
v). Adjust the bearing clearance.
vi). Recheck and adjust the alignment between the turbine &
reduction gear box.
i). Check the pressure and temprature of the supply oil.
iia). Check the oil temperature control valve on oil control unit.
iib). Check the cooling water supply temperature.
iii). Operate the oil purifier unit and if necessary change the oil
completely.
iv). Check and clean the choke point in the piping and or hole.
v). Adjust the bearing clearance.
vi). Adjust the temp. sensor depth in thrust bearings.
ia). Check the greese cup & if necessary add the greese on the
cup.
ib). Overhaul and inspect the linkage of the governor valve.
ii). Remove the scale deposit after complete over haul of the
governor valve.
iiia). Re-adjust the dynamics of the speed governor.
iiib). Check the tie rod on lever linkage of governor valve.
iiic). Overhaul inspection of the actuator.
iv). Check and inspect the internal parts of the governor valve.
va). Air in the actuator will be removed during the start up of the
turbine.
vb). Chcek the oil level in the oil reservoir.
vc). Air vent valves on the oil filter and the oil cooler are opened
to the purge air.
vi). Reduce the vaccum pressure.
1. Remove the scale formation after complete overhaul of the
emergency stop valve.
2. Overhaul and inspect the emergency saftey valve.
3a. Check the control oil pressure. If necessary, adjust the
control oil pressure control valve on the oil unit.
3b. Check the orifice plate in the supply piping for oil relay of
the emergency stop valve.
1). Check and adjust the orifice plate on suction of extractor on
the oil reservior.
2). Clean the oil shelter and the hole in bearing housing.
1. Replace the labyrinth packing to the new one.
2 Check and adjust the set pressure of the gland sealing steam
pressure controller
3a. Check the cooling water flow on the sight glass.
3b. Adjust the bypass valve on the cooling water piping.
3c. Check the cooling water inlet temp (Check the water temp).
1a. Check the steam leakage around the turbine gland.
1b. Replace the labrynth packing to new one.
2 Check and adjust the set pressure of the gland sealing steam
pressure controller
3a. Check the cooling water flow on the sight glass.
3b. Adjust the bypass valve on the cooling water piping.
3c. Check the cooling water inlet temp (Check the water temp).
4. Operate the oil purifier unit.
5. Check and inspect the cooling tube one by one after change
over oil cooler to stand by oil cooler.
1. Clean the oil filter by replacing stand by one.
2. Adjust the oil control valve.
3. Check and arrest the oil leakge on oil piping.
1. Clean the oil filter by replacing stand by one.
2. Adjust the oil control valve.
3. Check and arrest the oil leakge on oil piping.
1. Clean the oil filter by replacing stand by one.
2. Adjust the oil control valve.
3. Check and arrest the oil leakge on oil piping.
1. Remove the scale deposits and analyze the deposits.
2. Check the vaccum system.
3. Check the extraction steam control system.
4. overhaul and inspect the disc.
1. Check the alarm list on the governor display.
2a). Check the greese cup necessary. Add the grease.
2b). Overhaul and inspect the linkage of governor valve.
3. Check the transmitters.
1.Remove the depositions of scales and analysing the deposits.
2. wait unit the grid frequency is lower.
3. Check the vaccum system.
