Controlling a rabbet load and air/oil seal temperatures in a turbine

Patent · Tue Jan 01 04:00:00 EST 2002

OSTI ID:874379

Schmidt, Mark Christopher ^[1]

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1. Niskayuna, NY

During a standard fired shutdown of a turbine, a loaded rabbet joint between the fourth stage wheel and the aft shaft of the machine can become unloaded causing a gap to occur due to a thermal mismatch at the rabbet joint with the bearing blower turned on. An open or unloaded rabbet could cause the parts to move relative to each other and therefore cause the rotor to lose balance. If the bearing blower is turned off during a shutdown, the forward air/oil seal temperature may exceed maximum design practice criterion due to "soak-back." An air/oil seal temperature above the established maximum design limits could cause a bearing fire to occur, with catastrophic consequences to the machine. By controlling the bearing blower according to an optimized blower profile, the rabbet load can be maintained, and the air/oil seal temperature can be maintained below the established limits. A blower profile is determined according to a thermodynamic model of the system.

• Research Organization: General Electric Company (Schenectady, NY)
• DOE Contract Number: FC21-95MC31176
• Assignee: General Electric Company (Schenectady, NY)
• Patent Number(s): US 6379108
• OSTI ID: 874379
• Country of Publication: United States
• Language: English

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