System and method for operating a flow process

1. A system for operating a flow process, wherein a device disposed in the flow process causes unsteady pressures to be generated in a fluid flowing in a pipe in the flow process, the system comprising:

a meter for measuring at least one parameter of the fluid in the flow process, the meter including a spatial array of at least two strain sensors disposed at different axial locations along a section of the pipe where the unsteady pressures are present in the fluid, each of the at least two strain sensors providing a pressure signal indicative of pressure within the pipe at a corresponding axial location; and

a signal processor configured to output a flow signal and a diagnostic signal in response to the pressure signals, the flow signal indicating the at least one parameter of the fluid and the diagnostic signal indicating a diagnostic condition of the device.

2. The system of claim 1 , further comprising:

selection logic responsive to the diagnostic signal and the flow signal, the selection logic provides a monitor output signal indicative of at least one of the flow signal and the diagnostic signal.

3. The system of claim 1 , wherein the parameter of the fluid includes at least one of:

speed of sound in the fluid, gas volume fraction of the fluid, volumetric flow rate, size of particles suspended in the fluid, mass flow rate of the fluid, enthalpy of the fluid, and velocity of the fluid.

4. The system of claim 3 , wherein the parameter of the fluid is the gas phase fraction of the fluid, and the fluid is one of a liquid having entrained gas, a mixture having entrained gas, and a slurry having entrained gas.

5. The system of claim 4 , wherein the signal processor includes flow logic configured to:

determine a slope of an acoustic ridge in a k-ω plane to determine the speed of sound propagating through the fluid; and

determine the gas phase fraction of the flow in response to the measured speed of sound.

6. The system of claim 5 , wherein the flow logic is further is configured to:

determine a velocity of the fluid in response to the pressure signals;

determine the volumetric flow rate through the pipe using a cross-sectional area of the pipe and the velocity of the fluid, and

correct the volumetric flow rate of the fluid using the gas phase fraction of the fluid.

7. The system of claim 1 wherein the device in the flow process is acoustically coupled to the pipe at least at the location of the spatial array.

8. The system of claim 1 wherein the at least two strain sensors are selected from a group consisting of: piezoelectric, piezoresistive, strain gauge, PVDF, optical sensors, ported ac pressure sensors, accelerometers, velocity, pressure, and displacement sensors.

9. The system of claim 1 , wherein the at least two strain sensors are wrapped around at least a portion of the pipe and do not contact the fluid.

10. A system for operating a flow process, wherein a device causes unsteady pressures to be generated in a fluid flowing in a pipe in the flow process, the system comprising:

a meter for measuring at least one parameter of the fluid in the flow process, the meter including a spatial array of at least two strain sensors disposed at different axial locations along a section of the pipe where the unsteady pressures are present in the fluid each of the at least two strain sensors providing a pressure signal indicative of pressure within the pipe at a corresponding axial location; and

a signal processor configured to output a flow signal and a diagnostic signal in response to the pressure signals, the flow signal indicating the at least one parameter of the fluid and the diagnostic signal indicating a diagnostic condition of the device;

wherein the signal processor is operable to compare an input evaluation signal based on the pressure signals against a diagnostic evaluation criteria to determine the diagnostic condition of the device.

11. The system of claim 10 , wherein the diagnostic evaluation criteria is based on a signature in at least one of the frequency domain, time domain, spatial domain, wave-number, and k-ω domain.

12. A method of operating a flow process, wherein a device disposed within the flow process causes unsteady pressures to be generated in a fluid flowing in a pipe in the flow process, the method comprising:

receiving pressure signals from a meter including a spatial array of at least two strain sensors disposed at different axial locations along a section of the pipe where the unsteady pressures are present in the fluid, each of the at least two strain sensors providing a pressure signal indicative of pressure within the pipe at a corresponding axial location; and

providing a diagnostic signal and a flow signal in response to the pressure signals, the diagnostic signal indicating a diagnostic condition of the device, and the flow signal being indicative of a parameter of a fluid flowing within the flow process.

13. The method of claim 12 , wherein the parameter of the fluid includes at least one of: speed of sound in the fluid, gas volume fraction of the fluid, volumetric flow rate, size of particles suspended in the fluid, mass flow rate of the fluid, enthalpy of the fluid, and velocity of the fluid.

14. The method of claim 13 , wherein the parameter of the fluid is the gas phase fraction of the fluid, and the fluid is one of a liquid having entrained gas, a mixture having entrained gas, and a slurry having entrained gas.

15. The method of claim 14 , wherein processing the pressure signals to provide the parameter of the fluid includes:

determining a slope of an acoustic ridge in a k-ω plane to determine the speed of sound propagating through the fluid; and

determining the gas phase fraction of the flow in response to the measured speed of sound.

16. The method of claim 15 , wherein processing the pressure signals to provide the parameter of a fluid further includes:

determining a velocity of the fluid in response to the pressure signals;

determining the volumetric flow rate of the pipe using a cross-sectional area of the pipe and the velocity of the fluid, and

correcting the volumetric flow rate of the fluid using the gas volume fraction of the fluid.

17. The method of claim 12 wherein the device is acoustically coupled to the pipe at least at the location of the spatial array.

18. The method of claim 12 wherein the at least two strain sensors are selected from a group consisting of: piezoelectric, piezoresistive, strain gauge, PVDF, optical sensors, ported ac pressure sensors, accelerometers, velocity, pressure, and displacement sensors.

19. The method of claim 12 , wherein the at least two strain sensors are wrapped around at least a portion of the pipe and do not contact fluid within the flow process.

20. A method of operating a flow process, wherein a device disposed within the flow process causes unsteady pressures to be generated in a fluid flowing in a pipe in the flow process, the method comprising:

receiving pressure signals from a meter including a spatial array of at least two strain sensors disposed at different axial locations along a section of the pipe where the unsteady pressures are present in the fluid, each of the at least two strain sensors providing a pressure signal indicative of pressure within the pipe at a corresponding axial location; and

providing a diagnostic signal and a flow signal in response to the pressure signals, the diagnostic signal indicating a diagnostic condition of the device, and the flow signal being indicative of a parameter of a fluid flowing within the flow process;

wherein providing the diagnostic condition further includes comparing an input evaluation signal based on the pressure signals against a diagnostic evaluation criteria to determine the diagnostic condition of the device.

21. The method of claim 20 , wherein the evaluation criteria is based on a signature in at least one of the frequency domain, time domain, spatial domain, wave-number, and k-ω domain.

22. A diagnostic monitoring system for monitoring the health of a device that is acoustically coupled to a pipe, wherein the device causes unsteady pressures to be generated in a fluid flowing in the pipe; the system comprising:

at least one sensor disposed to measure pressures within the pipe along a section of the pipe where the unsteady pressures caused by the device are present in the fluid, the at least one sensor providing a sensor output signal; and

diagnostic processing logic, responsive to said sensor output signal, which provides a diagnostic condition indicative of the health of the device, wherein said diagnostic processing logic comprises logic which compares an input evaluation signal based on said sensor output signal against a diagnostic evaluation criteria to determine the health of the device.

23. The system of claim 22 wherein said evaluation criteria is based on a signature in at least one of the frequency domain, time domain, spatial domain, wave-number, and k-ω domain.

24. A diagnostic monitoring system for monitoring the health of a device that is acoustically coupled to a pipe, wherein the device causes unsteady pressures to be generated in a fluid flowing in the pipe; the system comprising:

at least one sensor disposed to measure pressures within the pipe along a section of the pipe where the unsteady pressures caused by the device are present in the fluid, the at least one sensor providing a sensor output signal; and

diagnostic processing logic, responsive to said sensor output signal, which provides a diagnostic condition indicative of the health of the device.

25. The system of claim 24 wherein said device is acoustically coupled to the pipe at least at the location of said at least one sensor.

26. The system of claim 24 wherein said at least one sensor comprises an axial array of at least two sensors.

27. The system of claim 24 wherein said at least one sensor is selected from a group consisting of: piezoelectric, piezoresistive, strain gauge, PVDF, optical sensors, ported ac pressure sensors, accelerometers, velocity, pressure, and displacement sensors.

28. The system of claim 24 wherein the device includes at least one of motors, fans, pumps, generators, engines, gears, belts, drives, pulleys, hangers, clamps, actuators, valves, heat exchangers, and meters.

29. A method of monitoring the health of a device that is acoustically coupled to a pipe, wherein the device causes unsteady pressures to be generated in a fluid flowing in the pipe, the method comprising:

disposing at least one sensor to measure pressures within the pipe along a section of the pipe where the unsteady pressures are present in the fluid, the at least one sensor providing a sensor output signal;

providing a diagnostic condition indicative of the health of the device in response to said sensor output signal.

30. The method of claim 29 wherein said device is acoustically coupled to the pipe at least at the location of said at least one sensor.

31. The method of claim 29 wherein said at least one sensor comprises an axial array of at least two sensors.

32. The method of claim 29 wherein said at least one sensor is selected from a group consisting of: piezoelectric, piezoresistive, strain gauge, PVDF, optical sensors, ported ac pressure sensors, accelerometers, velocity, pressure, and displacement sensors.

33. The method of claim 29 wherein the device includes at least one of motors, fans, pumps, generators, engines, gears, belts, drives, pulleys, hangers, clamps, actuators, valves, heat exchangers, and meters.

34. A method of monitoring the health of a device that is acoustically coupled to a pipe, wherein the device causes unsteady pressures to be generated in a fluid flowing in the pipe, the method comprising:

disposing at least one sensor to measure pressures within the pipe along a section of the pipe where the unsteady pressures are present in the fluid the at least one sensor providing a sensor output signal;

providing a diagnostic condition indicative of the health of the device in response to said sensor output signal; and

comparing an input evaluation signal based on said sensor output signal against a diagnostic evaluation criteria to determine the health of the device.

35. The method of claim 34 wherein said diagnostic evaluation criteria is based on a signature in at least one of the frequency domain, time domain, spatial domain, wave-number, and k-ω domain.