Pressure diagnostic for rotary equipment

• US 20090019938A1
• Filed: 07/18/2008
• Published: 01/22/2009
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Klosinski, Andrew Juri
• Granted Patent: US 7,765,873 B2
• Time in Patent Office: Days
• US Class Current: 73/700
• CPC Class Codes: F01D 17/08 responsive to condition of working-fluid, e.g. pressure
• CPC Class Codes: F01D 21/003 Arrangements for testing or measuring for measuring vibrations G01H
• CPC Class Codes: F05D 2220/31 in steam turbines
• CPC Class Codes: F05D 2220/32 in gas turbines
• CPC Class Codes: F05D 2260/80 Diagnostics
• CPC Class Codes: F05D 2260/82 Forecasts
• CPC Class Codes: F05D 2270/301 Pressure
• CPC Class Codes: G01F 1/363 with electrical or electro-mechanical indication G01F1/37 and G01F1/38 take precedence
• CPC Class Codes: G01F 1/42 Orifices or nozzles
• CPC Class Codes: G01F 1/72 Devices for measuring pulsing fluid flows
• CPC Class Codes: G01F 25/10 of flowmeters
• CPC Class Codes: G01M 15/09 by monitoring pressure in fluid ducts, e.g. in lubrication or cooling parts
• CPC Class Codes: G01M 15/14 Testing gas-turbine engines or jet-propulsion engines
• CPC Class Codes: G05B 2219/24077 Module detects wear, changes of controlled device, statistical evaluation
• CPC Class Codes: G05B 23/0283 Predictive maintenance, e.g. involving the monitoring of a system and, based on the monitoring results, taking decisions on the maintenance schedule of the monitored system; Estimating remaining useful life [RUL] preventive maintenance, i.e. planning maintenance according to the available resources without monitoring the system G06Q10/06

Abstract

A system comprises a rotary machine, a sensor and a processor. The rotary machine has a component that operates on a fluid. The sensor senses pressure in the fluid. The processor generates a diagnostic indicative of wear on the component, based on process noise on the pressure.

Claims

1. A system comprising:

a rotary machine having a component for operating on a fluid;

a sensor for sensing a process pressure in the fluid; and

a processor for generating a diagnostic indicative of wear on the component, based on variations in the process pressure.

2. The system of claim 1, wherein the sensor has a sampling frequency that is less than twice a rotational frequency of the rotary machine.

3. The system of claim 2, wherein the sampling frequency is less than the rotational frequency.

4. The system of claim 2, wherein the sampling frequency is greater than 20 Hz.

5. The system of claim 1, wherein the component comprises a blade or a vane.

6. The system of claim 5, wherein the rotary machine comprises a turbine.

7. The system of claim 1, wherein the diagnostic comprises a standard deviation of the process pressure.

8. The system of claim 1, wherein the processor further generates a wear indicator based on a change in the diagnostic.

9. The system of claim 1, wherein the processor further generates a process pressure value based on the process pressure in the fluid.

10. The system of claim 1, further comprising an interface for transmitting the process pressure value and the diagnostic over a loop wire, wherein the loop wire has a maximum current of about 20 mA or less.

11. A method comprising:

sensing a pressure associated with operation of a rotary apparatus;

monitoring process noise on the pressure; and

generating a wear diagnostic as a function of the process noise, such that the wear diagnostic is correlated with a physical change in a component of the rotary apparatus.

12. The method of claim 11, wherein sensing the pressure is performed at less than twice a rotational frequency of the rotary equipment.

13. The method of claim 11, wherein monitoring process noise on the pressure comprises monitoring a standard deviation of the pressure.

14. The method of claim 11, further comprising generating a wear indicator when the wear diagnostic exceeds a threshold value.

15. The method of claim 11, further comprising generating a wear indicator when a slope of the wear diagnostic exceeds a threshold value.

16. The method of claim 11, wherein the physical change in the component comprises wear on at least one of a blade or a vane.

17. The method of claim 11, wherein the physical change in the component comprises a discrete loss of at least part of a blade or a vane.

18. The method of claim 16, wherein the wear diagnostic is further correlated with water content in a steam flow.

19. The method of claim 16, wherein the wear diagnostic is further correlated with particulate content in a pulverized coal flow.

20. The method of claim 11, further comprising transmitting the pressure and the wear diagnostic over a loop wire having a maximum current of about 20 mA or less.

22. The transmitter of claim 20, wherein the sensor has a sampling period greater than a rotational period of the rotary equipment.

24. The transmitter of claim 20, wherein the wear diagnostic comprises a standard deviation of the pressure noise.

25. The transmitter of claim 20, wherein the transmitter operates on no more than 50 mW of power.

21. A diagnostic pressure transmitter comprising:

a sensor for sensing pressure noise generated by operation of rotary equipment;

a processor for generating a wear diagnostic as a function of the pressure noise, and for generating a wear indicator as a function of a change in the wear diagnostic; and

an interface for transmitting the wear diagnostic and the wear indicator to a monitoring system.

23. The transmitter of claim 21, wherein the sampling period is greater than 20 Hz.