“A” bank HP turbocharger bearing failure. J624 Engine 15,380 Operating Hours

Attached below is a file pertaining to a HP turbocharger bearing failure. The trip reports included are from the IMG Energy Solutions Beaver Dam LLC plant in Canton, PA.

Event Summary

Beaver Dam Unit 4 was issued a start at 09:49. At 12:17:48 Unit 4 tripped with indications of 1092 Scavenging Flap Failure. Technician on site was contacted for visual report when a back-fire event was witnessed when Unit #4 tripped. The back-fire relief T lifted and portions of the graphite gasket for the back-fire relief were scattered throughout the engine hall. No other trip indications were present in the alarm summary of the DIANE XT3. Closer review of operator messages and information messages on My Plant indicated a 3227 Deflagration Protection message recorded at 12:16:20, a little more than one second prior to the trip.

The technician reported burnt oil odor near the “A” bank HP turbo. Trending also indicated that the “A” bank HP turbo speed was slightly lower than the “B” bank HP turbo. This variance was not enough to trigger a warning but this prompted the technician to investigate the “A” bank HP turbo closer. A borescope inspection revealed oil puddled in the “A” bank HP turbo and in the exhaust manifold leading to the HP turbo.

Preparations were made to remove the “A” bank HP turbo for closer inspection.

BD #4 A Bank HP Turbo Trip Report.pdf

Download PDF • 3.78MB

Summary of Findings per ABB Report

1. Problem seems to be with bearings &/or oil supply

2. Damage to Compressor Wheel and Turbine appears consequential

3. The condition of the components on the turbine side, like the nozzle ring and turbine wheel, indicates that the turbocharger was suffering from foreign objects entering at the turbine stage. Turbine blades tips found bent.

4. Turbine Radial Bearing found without Locating Screws. Marks indicate they were originally fitted and its not clear how they extracted themselves from the Bearing Bush.

5. Turbine Bearing has been rotating in the Bearing Flange……likely after bolts either broke or came loose.

6. Compressor Radial Bearing journal running surface is relatively lightly damaged but the Axial Auxiliary Bearing face is badly worn down.

7. There are several components with coked / laquered oil coating. Possibility that post-lubrication time is too short. This needs to be checked.

Power2 340-H44

Possible scenarios:

1. Short post-lub time leads to Turbine Bearing sticking to the hot shaft after shutdown

2. Many start-ups (peaking application) with Bearing stuck to shaft leads to forces on the Bearing securing bolts

3. Consequential damage to other Bearing and Rotor components.