Post on 13-Mar-2021
TRIP OF BOILER FEED WATER PUMP 10-P-8001A
This is boiler feed waterpump is driven by ST through reduced gearbox. Operating speed of turbine is
4990rpm and pump is about 2900rpm.
This pump is operated occassionally depending on the process requirement and steam.
From 25/05 until 18/06/15 we make a major overhaul for all plant but do nothing for this pump.
Before this starting on 18/06/15, this pump is operated normally with all parameter in acceptance.
18/06/15 we restart the plant and the pump is runned as required but it is tripped.
- 1st trip : we start the ST normally up to near 5000rpm, the pump is tripped due to high vibration
at NDE ST, vibration at pump and gearbox is normal. As my opinion, it is by carbon seal make
their seat and lead to high vibration. By this, we restart up again.
- 2nd run: speed just up to over 700rpm. Vibration at ST in acceptance but trip by high vibration at
DE of LSS of gearbox and at NDE of pump. But I think that the high vibation of pump is effected
by high vibration of LSS of GB.
- 3nd, 4th and 5th run: Speed up to the same 2nd run. The pump tripped by high vibration at LSS of
gearbox, all other positions is in acceptance.
I wonder that why the oil whirl happens at starting up when gear load but not at shutdown time when
gear unload as normal (this ussually happened in the past)?
Why the restarting at previous time the oil whirl do not happen but it is so much now.
Speed trend.
Vibration at both side of steam turbine.
1
2
3
4
5 6
Vibration at bearing positions of LSS of gearbox.
Vibration at both side of pump.
1. First trip
Vibration of steam turbine.
Cascade at NDE side of ST
Cascade at DE side of ST
Shaft centerline at both side of ST.
SCL at both side of HSS of gearbox.
Orbit at NDE side of ST
Polar at both side of ST.
Vibration of gearbox.
Vibration at both side of pump
2. Second & 3rd trip
Vibration at DE of LSS of Gearbox
Vibration at both side of pump
Orbits at bearing of LSS of gearbox and both side of pump at trip.
3. Trip 4th and 5th
4. 5. Trend viration up to trip value.
6. 7. Oil whirl seems tobe noted with frequency of 0.343X.
8. 9. Orbit at the time of high vibration.