Systems, methods, and apparatus for monitoring a machine

• US 8,884,628 B2
• Filed: 01/05/2012
• Issued: 11/11/2014
• Est. Priority Date: 04/03/2009
• Status: Active Grant

• Current Assignee: Baker Hughes Oilfield Operations LLC (Baker Hughes Company)
• Original Assignee: General Electric Company
• Inventors: Franklin, Wesley Donald
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): BROWN, LAMARR A
• Application Number:
  US13/343,821
• Publication Number:
  US 20120098552A1
• Time in Patent Office: 1,041 Days
• Field of Search: 324/765.01, 324/545, 324/661, 324/662, 324/679, 736/60, 735/97, 731/160.3, 731/160.4, 702/183, 415/118
• US Class Current: 324/522
• CPC Class Codes: G01R 27/26 Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
• CPC Class Codes: G01R 31/08 Locating faults in cables, transmission lines, or networks
• CPC Class Codes: G01R 31/343 in operation

Abstract

Systems, methods and apparatus for monitoring rub detection in a machine are provided. An electrical signal may be provided for transmission to and into a component of the machine. A capacitance associated with the electrical signal in the component may be monitored. Based at least in part upon a determined change in the monitored capacitance, a potential rub condition for the component of the machine.

Claims

1. A method for monitoring a machine, the method comprising:

providing an electrical signal for transmission to and into a component of the machine;

monitoring a capacitance associated with the electrical signal in the component;

determining an increase in the monitored capacitance as the component of the machine moves towards another component of the machine;

determining that the increase in the monitored capacitance exceeds a threshold value;

detecting a potential rub condition for the component of the machine based at least in part on the determination that the increase in the monitored capacitance exceeds the threshold value; and

determining a severity associated with the potential rub condition based at least in part on a length of time for which the increase in the monitored capacitance exceeds the threshold value.

2. The method of claim 1, wherein the machine comprises a turbine.

3. The method of claim 1, wherein the electrical signal comprises an alternating current voltage signal comprising a voltage of approximately one to approximately two volts.

4. The method of claim 1, further comprising:

monitoring an impedance associated with the electrical signal, and detecting a rub condition based at least in part on determining a decrease in the monitored impedance.

5. The method of claim 4, further comprising determining a severity associated with the detected rub condition based at least in part on a length of time for which the monitored impedance falls outside of an expected range of impedance values.

6. The method of claim 1, wherein the electrical signal comprises an electrical signal with a frequency of approximately one kilohertz to approximately 50 kilohertz.

7. The method of claim 1, wherein monitoring the electrical signal in the component of the machine comprises monitoring the component for an electrical signal having a frequency that is within a predetermined frequency range.

8. A system for monitoring a machine, the system comprising:

a signal generator configured to provide an electrical signal that is transmitted to and into at least one component of the machine;

one or more detection devices configured to detect a capacitance associated with the electrical signal in the at least one component; and

at least one processor configured to;

detect an increase in the capacitance as the component of the machine moves toward another component of the machine;

determine that the increase in the capacitance exceeds a threshold value;

detect, based at least in part on the determination that the increase in the capacitance exceeds the threshold value comparison, the occurrence of a potential rub condition for the component; and

determining a severity associated with the potential rub condition based at least in part on a length of time for which the increase in capacitance exceeds the threshold value.

9. The system of claim 8, wherein the machine comprises a turbine.

10. The system of claim 8, wherein the electrical signal comprises an alternating current voltage signal comprising a voltage of approximately one to approximately two volts.

11. The system of claim 8, wherein the at least one processor is further configured to:

monitor an impedance associated with the electrical signal; and

detect the occurrence of a rub condition based at least in part on detecting a decrease in the monitored impedance.

12. The system of claim 8, wherein the at least one processor is further configured to determine a severity associated with the detected rub condition based at least in part on a length of time for which the monitored impedance falls outside of an expected range of impedance values.

13. The system of claim 8, wherein the electrical signal comprises an electrical signal with a frequency of approximately one kilohertz to approximately 50 kilohertz.

14. The system of claim 8, wherein the one or more detection devices are operable to detect electrical signals that fall within a predetermined frequency range.

15. A method for monitoring a machine, the method comprising:

transmitting an alternating current voltage signal to and into at least one component of the machine;

monitoring a capacitance associated with the signal;

detecting an increase in the monitored capacitance as the component of the machine moves towards another component of the machine;

determining that the increase in the monitored capacitance exceeds a threshold value;

detecting, based at least in part on the determination that the increase in the monitored capacitance exceeds the threshold value, the occurrence of a potential rub condition for the component; and

determining a severity associated with the potential rub condition based at least in part on a length of time for which the increase in the capacitance exceeds the threshold value.

16. The method of claim 15, wherein the alternating current voltage signal comprises a voltage of approximately one to approximately two volts.

17. The method of claim 15, further comprising:

monitoring an impedance associated with the signal, and

detecting a rub condition based at least in part on determining a decrease in the monitored impedance.

18. The method of claim 15, further comprising determining a severity associated with the identified rub condition based at least in part on a length of time for which the determined impedance falls outside of an expected range of impedance values.