Performance envelope extension method for a gas turbine engine
AssigneeCEF Industries, Inc.
InventorsNeil M. Nelson, William A. Sponzilli, Quitman W. Lott
Life of this patent
Estimating the term…
Abstract
The present invention relates to a device for extending the performance life of a gas turbine engine by rotating the turbine after shutdown to achieve uniform cooling. The apparatus includes a motor, a high ratio gearset engaged with the motor, an overridable coupling means engaging the gearset with an accessory shaft of the turbine, and a logic circuit. The circuit determines when the engine has been shut down and continues to rotate the turbine for a predetermined period of time. If an external force interferes with the post-shutdown turning, the circuit will sense that force and compensate for it.
Claims13
A method of uniformly cooling a gas turbine engine having a spool, comprising the steps of:
- determining when the engine is shutdown;
- turning on an auxiliary motor to rotate the spool after the engine is shutdown;
- determining if an external force in preventing the auxiliary motor form rotating the spool;
- turning off the auxiliary motor if such an external force is detected and allowing the external force to rotate the spool;
- determining when a predetermining time period after turbine shutdown has elapsed;
- and turning the auxiliary motor off after the time period has elapsed if the auxiliary motor is on at that time.
A method of uniformly cooling a gas turbine engine having a spool, comprising the steps of:
- determining when the engine is shutdown;
- rotating the spool after the engine is shutdown by means of an auxiliary motor;
- determining when a predetermined time period after turbine shutdown has elapsed;
- ceasing rotation of the spool after the predetermined time period has elapsed;
- monitoring the engine to determine of an external force is preventing the auxiliary motor from rotating the spool during the predetermined time period;
- and
- turning off the auxiliary motor if such an external force is detected and allowing the external force to rotate the spool.
A method of uniformly cooling a gas turbine engine, comprising the steps of:
- monitoring the speed of the engine to determine if the engine speed has exceeded a first predetermined speed and then subsequently slowed below a second predetermined speed;
- activating an auxiliary motor to continue rotating the engine when the engine speed has slowed below the second predetermined speed after previously exceeding the first predetermined speed;
- and
- deactivating the auxiliary motor after a predetermined period of time after the activation of the auxiliary motor.
Dependencies are inferred from the claim text.