Systems and Methods for Measuring Temperature in a Gas Turbine Using Acoustic Interference

Patent metadata

Field	Value
Publication number	US-2016341606-A1
Application number	US-201615229613-A
Country	US
Kind code	A1
Filing date	Aug 5, 2016
Priority date	Feb 2, 2015
Publication date	Nov 24, 2016
Grant date	—

Abstract

Systems and methods for measuring temperature in a gas turbine are disclosed. The method can include directing a first acoustic signal and a second acoustic signal towards a gas path in a turbine; receiving the first acoustic signal and the second acoustic signal at a downstream gas path location; combining the first acoustic signal and the second acoustic signal to create a combined acoustic signal, wherein the combined acoustic signal forms at least one of either a signal maxima or a signal minima; and based at least in part on the combined acoustic signal, determining a temperature of the gas path.

First claim

The claimed disclosure is:

1 . A method for measuring temperature in a turbine, the method comprising:
directing a first acoustic signal and a second acoustic signal towards a gas path in a turbine; receiving the first acoustic signal and the second acoustic signal at a downstream gas path location; combining the first acoustic signal and the second acoustic signal to create a combined acoustic signal, wherein the combined acoustic signal forms at least one of either a signal maxima or a signal minima; and based at least in part on the combined acoustic signal, determining a temperature of the gas path.

2 . The method of claim 1 , wherein determining a temperature of the gas path comprises:
identifying a first frequency of the first acoustic signal; identifying a second frequency of the second acoustic signal; and based at least on the first frequency of the first acoustic signal and the second frequency of the second acoustic signal, determining a temperature of the gas path.

3 . The method of claim 1 , wherein directing a first acoustic signal and a second acoustic signal towards a gas path in a turbine comprises:
generating, via at least one sound source, an input signal; directing the input signal to at least one input microphone; transferring the input signal to a wave splitter via an input waveguide; splitting, via the wave splitter, the input signal into the first acoustic signal and the second acoustic signal; directing the first acoustic signal to the gas path via a carrier waveguide; and directing the second acoustic signal to the gas path via an interference waveguide, wherein the interference waveguide is longer than the carrier waveguide.

4 . The method of claim 1 , wherein directing a first acoustic signal and a second acoustic signal towards a gas path in a turbine comprises:
generating, via at least one sound source, an input signal; directing the input signal to at least two input microphones; transferring via a first input microphone the first acoustic signal to a first waveguide; and transferring via a second input microphone the second acoustic signal a second waveguide, wherein the second waveguide is longer than the first waveguide.

5 . The method of claim 1 , further comprising:
directing the first acoustic signal to a first output microphone; directing the second acoustic signal to a second output microphone; and attenuating the first acoustic signal at a first damping coil and attenuating the second acoustic signal at a second damping coil.

6 . The method of claim 1 , wherein when the combined acoustic signal forms a signal maxima, a portion of the first acoustic signal adds with a portion of the second acoustic signal to form the signal maxima.

7 . The method of claim 1 , wherein when the combined acoustic signal forms a signal minima, a portion of the first acoustic signal cancels out a portion of the second acoustic signal to form the signal minima.

8 . The method of claim 1 , wherein a frequency of the first acoustic signal and a frequency of the second acoustic signal cover a frequency spectrum encompassing the signal maxima or the signal minima.

9 . The method of claim 1 , wherein when the combined acoustic signal forms a signal maxima, determining the temperature of the gas path comprises gathering a set of signal maxima at a set of higher frequencies of the first acoustic signal and the second acoustic signal, or when the combined acoustic signal forms a signal minima, determining the temperature of the gas path comprises gathering a set of signal minima at a set of higher frequencies of the first acoustic signal and the second acoustic signal.

10 . The method of claim 1 , wherein combining the first acoustic signal and the second acoustic signal to create a combined acoustic signal comprises one of:
combining the first acoustic signal and the second acoustic signal via a wave adder; and mathematically recombining the first acoustic signal and the second acoustic signal.

11 . The method of claim 1 , wherein combining the first acoustic signal and the second acoustic signal to create a combined acoustic signal further comprises:
combining, via a wave adder, the first acoustic signal and the second acoustic signal; directing, via at least one output waveguide, the combined acoustic signal to at least one output microphone, wherein the at least one output microphone is coupled to a digital-to-analog converter; generating, via the at least one output microphone, at least one electrical wave based on the combined acoustic signal; generating, via the at least one output microphone, at least one analog signal based on the at least one electrical wave; and converting, via the digital-to-analog converter, the at least one analog signal into at least one digital signal.

12 . The method of claim 3 , wherein a length of the carrier waveguide and a length of the interference waveguide are selected based at least in part on thermal expansion properties of respective materials of the carrier waveguide and interference waveguide.

13 . A system comprising:
a measurement device comprising:
at least one sound source configured to generate an input signal;
at least one input microphone configured to receive the input signal;
a wave splitter configured to split the input signal into a first acoustic signal and a second acoustic signal;
a carrier waveguide configured to direct the first acoustic signal towards a gas path in a gas turbine;
an interference waveguide configured to direct the second acoustic signal towards the gas path in the gas turbine, wherein the interference waveguide is longer than the carrier waveguide;
a wave adder configured to combine the first acoustic signal and the second acoustic signal to create a combined acoustic signal, wherein the combined acoustic signal forms at least one of a signal maxima or a signal minima;
at least one output microphone configured to receive the combined acoustic signal;
a damping coil configured to dampen the combined acoustic signal; and
at least one controller configured to:
based at least in part on the combined acoustic signal, determine a temperature of the gas path.

14 . The system of claim 13 , wherein the at least one controller is further configured to:
identify a first frequency of the first acoustic signal; identify a second frequency of the second acoustic signal; and based at least on the first frequency of the first acoustic signal and the second frequency of the second acoustic signal, determine a temperature of the gas path.

15 . The system of claim 13 , wherein the at least one controller is coupled to the at least one sound source and further configured to generate the input signal from the at least one sound source.

16 . The system of claim 13 , wherein a length of the carrier waveguide and a length of the interference waveguide are selected based at least in part on thermal expansion properties of respective materials of the carrier waveguide and interference waveguide.

17 . The system of claim 13 , wherein the at least one controller is further configured to:
identify the signal maxima in the combined acoustic signal, wherein the signal maxima corresponds to the portion of the first acoustic signal added to the second acoustic signal identify the signal minima in the combined acoustic signal, wherein the signal minima corresponds to the portion of the first acoustic signal canceled out by a portion of the second acoustic signal; select a first frequency associated with the signal maxima, wh

Assignees

• Gen Electric

Inventors

• Gleeson Eamon P
• Han Fei

Classifications

• G01K11/22 Primary

  using measurement of acoustic effects · CPC title

• G01M15/14

  Testing gas-turbine engines or jet-propulsion engines · CPC title

• G01K13/02

  for measuring temperature of moving fluids or granular materials capable of flow · CPC title

• G01K13/024

  of moving gases · CPC title