System and method for determining health indicators for impellers

• US 8,620,622 B2
• Filed: 04/02/2009
• Issued: 12/31/2013
• Est. Priority Date: 04/02/2009
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Kar, Chinmaya
• Primary Examiner(s): Kundu, Sujoy
• Assistant Examiner(s): BETSCH, REGIS J
• Application Number:
  US12/417,452
• Publication Number:
  US 20100256953A1
• Time in Patent Office: 1,734 Days
• Field of Search: 702/185
• US Class Current: 702/185
• CPC Class Codes: G05B 23/0221 Preprocessing measurements, e.g. data collection rate adjustment; Standardization of measurements; Time series or signal analysis, e.g. frequency analysis or wavelets; Trustworthiness of measurements; Indexes therefor; Measurements using easily measured parameters to estimate parameters difficult to measure; Virtual sensor creation; De-noising; Sensor fusion; Unconventional preprocessing inherently present in specific fault detection methods like PCA-based methods
• CPC Class Codes: G05B 23/0229 knowledge based, e.g. expert systems; genetic algorithms

Abstract

A system includes a plurality of sensors configured to measure one or more characteristics of an impeller. The system also includes an impeller condition indicator device, which includes a plurality of sensor interfaces configured to receive input signals associated with at least one stage of the impeller from the sensors. The impeller condition indicator device also includes a processor configured to identify a fault in the impeller using the input signals and an output interface configured to provide an indicator identifying the fault. The processor is configured to identify the fault by determining a family of frequencies related to at least one failure mode of the impeller, decomposing the input signals using the family of frequencies, reconstructing a impeller signal using the decomposed input signals, and comparing the reconstructed impeller signal to a baseline signal. The family of frequencies includes a vane pass frequency and its harmonics.

Claims

1. An apparatus comprising:

an input interface configured to receive an input signal associated with at least one stage of an impeller and with two or more frequencies associated with operation of the impeller;

a processor configured to identify a specific failure mode in the impeller using the input signal; and

an output interface configured to provide an indicator identifying a health of the impeller;

wherein the processor is configured to identify the specific failure mode by;

determining a family of frequencies related to at least one of the two or more frequencies associated with operation of the impeller, the family of frequencies including a vane pass frequency and its harmonics;

decomposing the input signal by performing a transform of the input signal and isolating components of the transformed input signal into selected frequency bands;

reconstructing an impeller signal using portions of the decomposed input signal within the selected frequency bands associated with the family of frequencies;

comparing the reconstructed impeller signal to a baseline signal; and

categorizing the comparison based on failure mode rules including effects that the specific failure mode has on the two or more frequencies associated with operation of the impeller.

2. The apparatus of claim 1, wherein:

the two or more frequencies associated with operation of the impeller comprise the vane pass frequency, a rotating shaft speed frequency, a shaft sideband frequency, and a background noise frequency; and

the reconstructed impeller signal comprises at least one of;

a signal associated with the vane pass frequency and its harmonics;

a signal associated with the rotating shaft speed frequency;

a signal associated with the shaft sideband frequency; and

a signal associated with the background noise frequency.

3. The apparatus of claim 1, wherein the processor is configured to decompose the input signal through a plurality of band-pass filters.

4. The apparatus of claim 3, wherein the processor is configured to reconstruct the impeller signal by:

determining maximum and minimum amplitudes in the selected frequency bands in outputs of the band-pass filters;

combining the maximum amplitudes to produce a first matrix;

combining the minimum amplitudes to produce a second matrix; and

reconstructing multiple impeller signals using the first and second matrices.

5. The apparatus of claim 1, wherein the processor further is configured to:

normalize the reconstructed signal with the baseline signal; and

apply a feature fusion technique to obtain a value for use by the indicator.

6. The apparatus of claim 1, wherein the processor is further configured to store a portion of the input signal, corresponding to normal operation of the impeller, as the baseline signal.

7. The apparatus of claim 1, wherein the indicator identifying the health of the impeller comprises at least one of:

an impeller wear indicator, an impeller crack indicator, a cavitation indicator, and an impeller health indicator.

8. The apparatus of claim 1, wherein:

the input signal comprises at least one of;

vibration information in a time domain and speed information in the time domain associated with the impeller;

the input interface comprises multiple input interfaces; and

the processor comprises an artificial intelligence portion, and

the reconstructed impeller signal comprises a time domain signal.

9. A system comprising:

a plurality of sensors configured to measure one or more characteristics of an impeller; and

an impeller condition indicator device comprising;

an input interface configured to receive input signals from the sensors, each of the input signals associated with at least one stage of the impeller and with two or more frequencies associated with operation of the impeller;

a processor configured to identify a specific failure mode in the impeller using the input signals; and

an output interface configured to provide an indicator identifying a health of the impeller;

wherein the processor is configured to identify the specific failure mode by, for each of the input signals;

determining a family of frequencies related to at least one of the two or more frequencies associated with operation of the impeller, the family of frequencies including a vane pass frequency and its harmonics;

decomposing the input signal by performing a transform of the input signal and isolating components of the transformed input signal into selected frequency bands;

reconstructing an impeller signal using portions of the decomposed input signal within the selected frequency bands associated with the family of frequencies;

comparing the reconstructed impeller signal to a baseline signal; and

categorizing the comparison based on failure mode rules including effects that the specific failure mode has on the two or more frequencies associated with operation of the impeller.

10. The system of claim 9, wherein:

the two or more frequencies associated with operation of the impeller comprise the vane pass frequency, a rotating shaft speed frequency, a shaft sideband frequency, and a background noise frequency; and

the reconstructed impeller signal comprises at least one of;

a signal associated with the vane pass frequency and its harmonics;

a signal associated with the rotating shaft speed frequency;

a signal associated with the shaft sideband frequency; and

a signal associated with the background noise frequency.

11. The system of claim 9, wherein the processor is configured to, for each of the input signals, decompose the input signal through a plurality of band-pass filters.

12. The system of claim 11, wherein the processor is configured to reconstruct the impeller signal by:

determining maximum and minimum amplitudes in the selected frequency bands in outputs of the band-pass filters;

combining the maximum amplitudes to produce a first matrix;

combining the minimum amplitudes to produce a second matrix; and

reconstructing multiple impeller signals using the first and second matrices.

13. The system of claim 9, wherein the processor is further configured to store a portion of each of the input signals, corresponding to normal operation of the impeller, as the baseline signal.

14. The system of claim 9, wherein the indicator identifying the health of the impeller comprises at least one of:

an impeller wear indicator, an impeller crack indicator, a cavitation indicator, and an impeller health indicator.

15. A method for identifying a health of an impeller corresponding to a specific failure mode of the impeller, the method comprising:

receiving at one or more processing devices an input signal comprising at least one of vibration and speed infonnation corresponding to at least one stage of the impeller, the input signal associated with two or more frequencies associated with operation of the impeller;

determining a family of frequencies corresponding to at least one of the two or more frequencies associated with operation of the impeller, the family of frequencies including a vane pass frequency and its harmonics;

decomposing the input signal by performing a transform of the input signal and isolating components of the transformed input signal into selected frequency bands;

reconstructing an impeller signal using portions of the decomposed input signal within the selected frequency bands associated with the family of frequencies;

comparing the reconstructed impeller signal to a baseline signal;

categorizing the comparison based on failure mode rules including effects that the specific failure mode has on the two or more frequencies associated with operation of the impeller;

outputting an indicator identifying the health of the impeller; and

in response to determining the reconstructed impeller signal differs from the baseline signal by a threshold amount, outputting an indicator identifying a fault.

16. The method of claim 15, wherein:

the two or more frequencies associated with operation of the impeller comprise the vane pass frequency, a rotating shaft speed frequency, a shaft sideband frequency, and a background noise frequency; and

the reconstructed impeller signal comprises at least one of;

a signal associated with the vane pass frequency and its harmonics;

a signal associated with the rotating shaft speed frequency;

a signal associated with the shaft sideband frequency; and

a signal associated with the background noise frequency.

17. The method of claim 15, wherein decomposing the input signal comprises decomposing the input signal through a plurality of band-pass filters;

and

wherein reconstructing the impeller signal comprises;

determining maximum and minimum amplitudes in the selected frequency bands in outputs of the band-pass filters;

combining the maximum amplitudes to produce a first matrix;

combining the minimum amplitudes to produce a second matrix; and

reconstructing multiple impeller signals using the first and second matrices.

18. The method of claim 15, further comprising:

normalizing the reconstructed signal with the baseline signal; and

applying a feature fusion technique to obtain a value for use by the indicator.

19. The method of claim 15, further comprising:

storing a portion of the at least one of vibration and speed information corresponding to normal operation of the impeller as the baseline signal.

20. The method of claim 15, wherein the threshold amount comprises a first amount associated with a warning threshold and a second amount associated with an alarm threshold.

21. The method of claim 16, wherein the failure mode rules identify at least one of:

a high flow cavitation failure mode having an increasing effect on the background noise frequency and a decreasing effect on the vane pass frequency;

an impeller wear failure mode having an increasing effect on the shaft sideband frequency and an increasing effect on the vane pass frequency; and

an impeller crack failure mode having an increasing effect on the shaft sideband frequency and a decreasing effect on the vane pass frequency.