Method and system for detecting cavitation in a pump

• US 20040117132A1
• Filed: 12/12/2002
• Published: 06/17/2004
• Est. Priority Date: 12/12/2002
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Stephenson, Stanley V., Stribling, David M.
• Granted Patent: US 6,859,740 B2
• Time in Patent Office: Days
• US Class Current: 702/35
• CPC Class Codes: F04B 2205/05 Pressure after the pump outlet
• CPC Class Codes: F04B 51/00 Testing machines, pumps, or pumping installations

Abstract

A system receives a signal from a sensor indicative of a condition of a pump, decomposes the signal into a wavelet, and analyzes the wavelet to detect a likelihood of cavitation in the pump.

Claims

1. A method for detecting cavitation in a pump comprising the steps of:

providing a signal indicative of a condition of the pump;

decomposing the signal into a wavelet; and

analyzing the wavelet to detect cavitation in the pump.

2. The method of claim 1 wherein the wavelet is a Daubechies wavelet.

3. The method of claim 2 wherein the step of analyzing comprises the step of analyzing an n^th order wavelet decomposition of the Daubechies wavelet.

4. The method of claim 3 wherein the step of analyzing the n^th order wavelet decomposition of the Daubechies wavelet comprises the step of analyzing a fluctuation of the n^th order wavelet decomposition of the Daubechies wavelet such that cavitation in the pump is detected in response to the fluctuation decreasing below a predetermined threshold level.

5. The method of claim 4 wherein the Daubechies wavelet is a Daubechies 10 wavelet.

6. The method of claim 5 wherein the n^th order wavelet decomposition of the Daubechies 10 wavelet is a 7^th order wavelet decomposition of the Daubechies 10 wavelet.

7. The method of claim 1 wherein the signal is indicative of pressure.

8. The method of claim 1 wherein the signal is indicative of a pressure of a fluid material output from the pump.

9. The method of claim 1 wherein the signal is indicative of a pressure of a fluid material received by the pump.

10. The method of claim 1 wherein the pump is a positive displacement pump.

11. The method of claim 1 wherein the pump is a centrifugal pump.

12. The method of claim 1 further comprising the step of adjusting an operation of a pump system that includes the pump, in response to detection of cavitation in the pump, such that cavitation in the pump is reduced.

13. The method of claim 12 wherein the step of adjusting the operation of the pump system comprises the step of increasing a pressure of fluid material received by the pump.

14. The method of claim 12 wherein the step of adjusting the operation of the pump system comprises the step of reducing a flow rate of the pump.

15. A system for detecting cavitation in a pump having a fluid input and a fluid output, the system comprising:

a sensor for providing a signal indicative of a condition of the pump; and

a first computer, wherein the signal is decomposed into a wavelet, and the wavelet is analyzed to detect cavitation in the pump.

16. The system of claim 15 wherein the sensor is a pressure transducer.

17. The system of claim 16 wherein the wavelet is a Daubechies wavelet, and the first computer analyzes an n^th order wavelet decomposition of the Daubechies wavelet to detect cavitation in the pump.

18. The system of claim 17 wherein the first computer analyzes a fluctuation of the n^th order wavelet decomposition of the Daubechies wavelet such that cavitation in the pump is detected in response to the fluctuation decreasing below a predetermined threshold level.

19. The system of claim 16 wherein the pressure transducer is located adjacent the fluid input of the pump.

20. The system of claim 16 wherein the pressure transducer is located adjacent the fluid output of the pump.

21. The system of claim 15 wherein the sensor is a flowmeter for detecting a flowrate of the pump, the first computer calculates a volumetric efficiency of the pump in response to the flowrate and a speed of the pump, and the first computer detects cavitation in the pump in response to a decrease in the volumetric efficiency.

22. The system of claim 15 further comprising a second computer for reducing a speed of the pump in response to detection of cavitation in the pump.

23. The system of claim 15 further comprising:

a boost pump for providing fluid material to the fluid input of the pump;

a second computer; and

a third computer;

wherein the second computer instructs the third computer to increase a speed of the boost pump in response to detection of cavitation in the pump by the first computer.

24. The system of claim 23 wherein the second computer reduces a speed of the pump in response to detection of cavitation in the pump when the third computer instructs the second computer that the boost pump is operating at a maximum speed.

25. A system for detecting cavitation in a pump comprising:

a pump;

a boost pump for providing fluid material to the pump;

a sensor for providing a signal indicative of a condition of the pump; and

a computer, wherein the signal is decomposed into a wavelet, and the wavelet is analyzed to detect cavitation in the pump.

26. The system of claim 25 wherein a speed of the boost pump is increased when cavitation is detected.

27. The system of claim 26 wherein a speed of the pump is decreased when cavitation is detected and the boost pump is operating at a maximum speed.

28. The system of claim 25 wherein the sensor is a pressure transducer, and the wavelet is a Daubechies wavelet.