TRIP OF BOILER FEED WATER PUMP 10-P-8001A - · PDF fileTRIP OF BOILER FEED WATER PUMP 10-P-8001A This is boiler feed waterpump is driven by ST through reduced gearbox. Operating speed

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.