ACOUSTIC WAVEGUIDE SENSING THE CONDITION OF COMPONENTS WITHIN GAS TURBINES

• US 20020157471A1
• Filed: 02/05/2001
• Published: 10/31/2002
• Est. Priority Date: 02/05/2001
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Westinghouse Power Corporation
• Inventors: Harrold, Ronald Thomas, Sanjana, Zal N.
• Granted Patent: US 6,487,909 B2
• Time in Patent Office: Days
• US Class Current: 73/593
• CPC Class Codes: G01N 2291/015 Attenuation, scattering
• CPC Class Codes: G01N 2291/0237 Thin materials, e.g. paper, membranes, thin films
• CPC Class Codes: G01N 2291/0258 Structural degradation, e.g. fatigue of composites, ageing of oils
• CPC Class Codes: G01N 2291/2693 Rotor or turbine parts
• CPC Class Codes: G01N 29/228 related to high temperature conditions
• CPC Class Codes: G01N 29/2462 Probes with waveguides, e.g. SAW devices
• CPC Class Codes: G01N 29/28 providing acoustic coupling , e.g. water impedance matching G10K11/02
• CPC Class Codes: G01N 29/42 by frequency filtering or by tuning to resonant frequency

Abstract

A system for online monitoring the condition of a thermal barrier coating on the vanes and/or blades of a combustion turbine, or other forms of component deterioration affecting the acoustic properties of the vanes and/or blades. The system begins with a signal generator for transmitting a signal to an acoustic transmitter, and then to an acoustic waveguide secured within the turbine, adjacent to a vane. Acoustic waves passing through the vane'"'"'s coating will have a certain magnitude and velocity when passing through an intact coating, which will change as the coating deteriorates. Additional variation of the acoustic wave will occur due to pressure pulses from passing blades, with the magnitude of the pressure pulses increasing as the blade'"'"'s coating deteriorates. The acoustic waves are then received by a second acoustic waveguide. The resulting signal will be converted from an acoustic signal to an electrical signal by an acoustic receiver, and will pass through a filter to remove the lower frequency signals of the turbine from the higher frequency signals to be analyzed. The remaining higher frequency signals are sent to a computer, permitting the variations in the acoustic waves to be analyzed. A second embodiment relies solely on pressure pulses from passing blades to generate acoustic signals within the vanes.

Claims

1. An apparatus for monitoring the condition of a thermal barrier coating, said apparatus comprising:

means for generating an acoustic signal within the thermal barrier coating;

means for receiving said acoustic signal;

means for analyzing said acoustic signal to determine the existence and location of a defect within the coating.

2. The apparatus according to claim 1, wherein said means for generating an acoustic signal within the thermal barrier coating include at least one acoustic waveguide proximate to the coating.

3. The apparatus according to claim 2, wherein said means for generating an acoustic signal within the thermal barrier coating include an acoustic waveguide proximate to each component for which monitoring is desired.

4. The apparatus according to claim 1, wherein said means for receiving said acoustic signal include at least one acoustic waveguide proximate to the coating.

5. The apparatus according to claim 4, wherein said means for receiving said acoustic signal include an acoustic waveguide proximate to each component for which monitoring is desired.

6. The apparatus according to claim 1, wherein said means for analyzing said acoustic signal include a filter for filtering out acoustic signals having a frequency below 30 kHz.

7. The apparatus according to claim 1, wherein said means for generating said acoustic signal include a pressure pulse generated by a turbine blade passing a turbine vane.

8. An apparatus for monitoring the condition of components within a combustion turbine, said apparatus comprising:

means for generating an acoustic signal within the turbine component;

means for receiving said acoustic signal;

means for analyzing said acoustic signal to determine the existence and location of a defective component within the turbine.

9. The apparatus according to claim 8, wherein said means for generating an acoustic signal within the turbine component include at least one acoustic waveguide proximate to a vane.

10. The apparatus according to claim 9, wherein said means for generating an acoustic signal within the turbine include an acoustic waveguide proximate to each vane for which monitoring is desired.

11. The apparatus according to claim 8, wherein said means for receiving said acoustic signal include at least one acoustic waveguide proximate to a vane.

12. The apparatus according to claim 11, wherein said means for receiving said acoustic signal include an acoustic waveguide proximate to each vane for which monitoring is desired.

13. The apparatus according to claim 9, wherein said means for analyzing said acoustic signal include a filter for filtering out acoustic signals having a frequency below 30kHz.

14. The apparatus according to claim 8, wherein said means for generating said acoustic signal include a pressure pulse generated by a turbine blade passing a turbine vane.

16. The method according to claim 15, further comprising the step of filtering said acoustic signal to remove a portion of said acoustic signal below 30 kHz.

17. The method according to claim 15, wherein:

a plurality of acoustic signals are generated, received, and analyzed; and

said step of analyzing said acoustic signals for changes indicating the presence and location of deteriorating portions of the thermal barrier coating includes the step of comparing said plurality of acoustic signals to each other for locating deteriorating components.

19. The method according to claim 18, further comprising the step of filtering said acoustic signal to remove a portion of said acoustic signal below 30 kHz.

20. The method according to claim 18, wherein:

a plurality of acoustic signals are generated, received, and analyzed; and

said step of analyzing said acoustic signals for changes indicating the presence and location of deteriorating portions of the thermal barrier coating includes the step of comparing said plurality of acoustic signals to each other for locating deteriorating components.

15. A method of monitoring the deterioration of a thermal barrier coating, said method comprising the steps of:

generating at least one acoustic signal within said thermal barrier coating;

receiving said at least one acoustic signal; and

analyzing said at least one acoustic signal for changes indicating the presence and location of deteriorating portions of the thermal barrier coating.

18. A method of monitoring the deterioration of components within a combustion turbine, said method comprising the steps of:

generating at least one acoustic signal within said components;

receiving said at least one acoustic signal; and

analyzing said at least one acoustic signal for changes indicating the presence and location of defective components within the combustion turbine.