Non-intrusive measurement of hot gas temperature in a gas turbine engine

• US 9,453,784 B2
• Filed: 09/04/2013
• Issued: 09/27/2016
• Est. Priority Date: 09/04/2013
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Energy Incorporated (Siemens AG)
• Inventors: DeSilva, Upul P., Claussen, Heiko, Yan, Michelle Xiaohong, Rosca, Justinian, Ulerich, Nancy H.
• Primary Examiner(s): Phan, Minh
• Assistant Examiner(s): Rhodes, Jr., Leon W
• Application Number:
  US14/017,386
• Publication Number:
  US 20150063411A1
• Time in Patent Office: 1,119 Days
• Field of Search: 374/119
• US Class Current: 1/1
• CPC Class Codes: F02C 7/32 Arrangement, mounting, or driving, of auxiliaries
• CPC Class Codes: F05D 2260/83 Testing, e.g. methods, components or tools therefor
• CPC Class Codes: G01H 3/00 Measuring characteristics of vibrations by using a detector in a fluid G01H7/00, G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G01K 11/24 of the velocity of propagation of sound
• CPC Class Codes: G01K 13/02 for measuring temperature of moving fluids or granular materials capable of flow
• CPC Class Codes: G01K 13/024 of moving gases
• CPC Class Codes: G01M 15/14 Testing gas-turbine engines or jet-propulsion engines

Abstract

A method and apparatus for operating a gas turbine engine including determining a temperature of a working gas at a predetermined axial location within the engine. An acoustic signal is encoded with a distinct signature defined by a set of predetermined frequencies transmitted as a non-broadband signal. Acoustic signals are transmitted from an acoustic transmitter located at a predetermined axial location along the flow path of the gas turbine engine. A received signal is compared to one or more transmitted signals to identify a similarity of the received signal to a transmitted signal to identify a transmission time for the received signal. A time-of-flight is determined for the signal and the time-of-flight for the signal is processed to determine a temperature in a region of the predetermined axial location.

Claims

1. A method of operating a gas turbine engine, including determining a temperature of a working gas passing through a flow path within the gas turbine engine, the method comprising the steps of:

transmitting an acoustic signal from an acoustic transmitter located at a predetermined axial location along the flow path of the gas turbine engine;

receiving the acoustic signal from the acoustic transmitter at an acoustic receiver located at the predetermined axial location;

the acoustic signal being encoded with a distinct signature defined by a set of predetermined frequencies transmitted as a non-broadband acoustic signal;

wherein receiving the acoustic signal includes comparing a received signal to one or more transmitted signals to identify a similarity of the received signal to a transmitted signal to identify a transmission time for the received signal;

determining a time-of-flight for the signal from the acoustic transmitter to the acoustic receiver; and

processing the time-of-flight for the signal to determine a temperature in a region of the predetermined axial location.

2. The method of claim 1, wherein comparing the received signal to one or more transmitted signals includes correlating frequencies of the received signal to a distinct signature of a transmitted signal to identify a transmission time for the signal.

3. The method of claim 1, wherein the set of predetermined frequencies transmitted as a distinct signature comprises a set of frequencies transmitted simultaneously for a predetermined time duration.

4. The method of claim 3, wherein each of the frequencies of the distinct signature has an associated preset amplitude, and receiving the signal includes verifying a predetermined amplitude level for a plurality of the frequencies in the distinct signature received at the receiver to identify the corresponding distinct signature and an associated transmission time for the signal.

5. The method of claim 1, including a plurality of distinct signatures, where each of the distinct signatures have a different set of predetermined frequencies than at least one other of the distinct signatures.

6. The method of claim 5, wherein the plurality of distinct signatures are transmitted simultaneously from a plurality of respective transmitters located around the flow path at the predetermined axial location.

7. The method of claim 6, wherein the plurality of distinct signatures are uncorrelated to each other.

8. The method of claim 1, including transmitting a series of the distinct signatures sequentially in time, each of the distinct signatures having the same set of predetermined frequencies.

9. The method of claim 1, wherein transmission of each acoustic signal includes continuously generating the acoustic signal at a signal generator and operating an audio switch between the signal generator and the transmitter to selectively transmit portions of the continuously generated signal from the transmitter.

10. The method of claim 1, including monitoring a current background noise within the gas path on-line and adjusting the set of predetermined frequencies forming one or more distinct signatures to have a low correlation to the current background noise.

11. A gas turbine engine including an apparatus for controlling operation of the gas turbine engine, and the engine having a boundary structure defining a flow path passing through the engine, the apparatus for controlling operation of the engine comprising:

at least one acoustic transmitter located on the boundary structure at a predetermined axial location along the flow path;

at least one acoustic receiver located on the boundary structure at the predetermined axial location;

a signal generator producing at least one signal having a distinct signature defined by a set of predetermined frequencies forming a non-broadband signal;

a signal processor configured to compare signals received at the receiver to one or more transmitted signals to identify a similarity of a received signal to a transmitted signal to identify a transmission time for the received signal, and the processor configured to determine a time-of-flight for the received signal and to process the time-of-flight to determine a temperature in a region of the predetermined axial location.

12. The apparatus of claim 11, including a signal generator for connection to the transmitter that continuously produces the at least one signal for a plurality of time-of-flight measurements.

13. The apparatus of claim 12, including an audio switch between the signal generator and the transmitter to provide a signal to the transmitter from the generator for predetermined durations at predetermined spaced time intervals.

14. The apparatus of claim 11, including a plurality of acoustic transmitters and receivers located around a circumference of the boundary structure.

15. The apparatus of claim 11, including a plurality of signal generators connected to respective ones of the signal generators to provide a unique signal, having a distinct signature, to each of the transmitters.

16. The apparatus of claim 15, wherein the signal generators continuously produce the signals provided to the transmitters, and including an audio switch between each of the signal generators and the transmitters to provide a signal to each transmitter from a respective generator for predetermined durations at predetermined spaced time intervals.