System and method to manage transients for rapid power demand changes

Patent metadata

Field	Value
Publication number	US-9765640-B2
Application number	US-201514722339-A
Country	US
Kind code	B2
Filing date	May 27, 2015
Priority date	May 29, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

An exemplary system may include a gas turbine engine configured to operate at an engine power level to satisfy an engine power demand. The system may also include at least one generator operatively coupled to the engine and configured to generate electrical power based at least in part on the engine power demand. The system further may include at least one heating element in communication with the at least one generator, and at least one control unit coupled to the at least one heating element. The at least one heating element may be configured to receive electrical power from the at least one generator to generate thermal energy. The at least one control unit may be configured to energize the heating element when the engine power demand is below the engine power level and/or there is an anticipated increase in the engine power demand.

First claim

What is claimed is:

1. A system comprising:
a gas turbine engine having at least one compressor section and at least one turbine section mounted on at least one spool, the at least one compressor section being configured to receive an inlet air stream, the gas turbine engine being configured to operate at an engine power level to satisfy an engine power demand;
at least one generator operatively coupled to the gas turbine engine, the at least one generator being configured to generate electrical power based at least in part on the engine power demand;
at least one heating element in communication with the at least one generator, the at least one heating element being configured to receive electrical power from the at least one generator and generate thermal energy; and
at least one control unit coupled to the at least one heating element, the at least one control unit being configured to energize the at least one heating element during at least one condition of an anticipated increase in the engine power demand;
wherein energizing the at least one heating element occurs a predetermined time frame prior to an actual increase in the engine power demand when the at least one condition exists.

2. The system of claim 1 , wherein the gas turbine engine is one of a turboshaft, a turboprop, and a turbofan.

3. The system of claim 2 , wherein the gas turbine engine is a turboprop having a propeller, and the at least one heating element is located at the propeller.

4. The system of claim 1 , wherein the at least one heating element is located upstream of the at least one compressor section such that the at least one heating element transfers the thermal energy to the inlet air stream.

5. The system of claim 4 , wherein the gas turbine engine has an inlet duct through which the inlet air stream is drawn into the gas turbine engine, the at least one heating element being located within the inlet duct.

6. The system of claim 5 , wherein at least a portion of the inlet duct is made of a material having a heat capacity above a predetermined threshold.

7. The system of claim 1 , wherein the at least one heating element has a steady state power limit and a transient power limit, and the at least one control unit is configured to energize the at least one heating element to a steady state power limit when the transient heater limit is exceeded, and to energize the at least one heating element to the transient power limit when the transient power limit is not exceeded.

8. The system of claim 1 , wherein the at least one heating element is an electrical heating pad.

9. The system of claim 1 , wherein the at least one heating element is a de-icing circuit.

10. The system of claim 1 , wherein the electrical generator is hydraulically powered by a hydraulic pump that is mechanically driven by the gas turbine engine.

11. A method comprising:
commanding a gas turbine engine and a generator operatively coupled to the gas turbine engine to operate at an optimum speed for a current power setpoint, the gas turbine engine operating at an engine power level to satisfy an engine power demand, and the generator generating electrical power based at least in part on the engine power demand;
determining if one of a first condition and a second condition exists, wherein the first condition includes the engine power demand dropping below the engine power level, and the second condition includes an anticipated increase in the engine power demand;
if one of the first condition and the second condition exists, then energizing at least one heating element to convert at least a portion of the electrical power into thermal energy to exchange heat with an inlet air stream into the gas turbine engine;
wherein energizing the at least one heating element occurs a predetermined time frame prior to an actual increase in the engine power demand when the second condition exists.

12. The method of claim 11 , wherein the anticipated increase in the engine power demand actually occurs when the gas turbine engine accelerates from an idle speed within a predetermined time frame.

13. The method of claim 11 , wherein energizing the at least one heating element does not exceed a transient limit of the at least one heating element when the second condition exists and a time frame until the anticipated increase in engine power demand is to occur is unknown.

14. The method of claim 11 , further comprising, when the first condition exists, turning off the at least one heating element when one of the engine power is less than the engine power demand and the engine power speed is decreasing below an engine speed limit occurs.

15. The method of claim 11 , further comprising, when the second condition exists, turning off the at least one heating element when the anticipated increase in the engine power demand actually occurs.

16. The method of claim 11 , further comprising increasing speed of the generator and the gas turbine engine to a maximum speed limit at a low power operation.

17. A system comprising:
a gas turbine engine having an inlet duct through which an inlet air stream enters the gas turbine engine, the gas turbine engine being configured to operate at an engine power level to satisfy an engine power demand;
at least one generator operatively coupled to the gas turbine engine via a shaft, the at least one generator being configured to generate electrical power based at least in part on the engine power demand;
at least one heating element located within the inlet duct of the gas turbine engine and in communication with the at least one generator, the at least one heating element being configured to receive electrical power from the at least one generator and generate thermal energy; and
at least one control unit coupled to the at least one heating element, the at least one control unit being configured to energize the at least one heating element when there exists an anticipated increase in the engine power demand;
wherein energizing the at least one heating element occurs a predetermined period prior to an actual increase in the engine power demand.

18. The system of claim 17 , wherein at least a portion of the inlet duct is made of a material having a heat capacity above a predetermined threshold.

19. The system of claim 17 , wherein the at least one heating element is a de-icing circuit.

Assignees

• Rolls Royce Corp

Inventors

• Smith Alan W

Classifications

• F01D25/02 Primary

  De-icing means for engines having icing phenomena · CPC title

• H02P9/008

  wherein the generator is controlled by the requirements of the prime mover · CPC title

• F05D2220/76

  an electrical generator · CPC title

• F05D2220/32

  in gas turbines · CPC title

• F02C7/047

  Heating to prevent icing · CPC title