COMMUNICATION METHOD FOR MONITORING PIPELINES

• US 20130043887A1
• Filed: 08/15/2011
• Published: 02/21/2013
• Est. Priority Date: 08/15/2011
• Status: Active Grant

• Current Assignee: Gas Technology Institute
• Original Assignee: Gas Technology Institute
• Inventors: Huebler, James Emerson, Ziolkowski, Christopher John, Mensinger, Michael Christian Jr.
• Granted Patent: US 9,000,778 B2
• Time in Patent Office: Days
• US Class Current: 324/649
• CPC Class Codes: F17D 1/08 for liquids or viscous products water-main or service pipe systems E03B7/04; domestic hot-water supply systems F24D17/00
• CPC Class Codes: F17D 3/01 for controlling, signalling, or supervising the conveyance of a product
• CPC Class Codes: F17D 5/00 Protection or supervision of installations arrangements for protecting foundations E02D31/00; protecting pipes from damage or internal or external wear F16L57/00, against corrosion and scale F16L58/00; investigation of the fluid-tightness of structures G01M3/00
• CPC Class Codes: F17D 5/005 of gas pipelines, e.g. alarm
• CPC Class Codes: F17D 5/06 using electric or acoustic means
• CPC Class Codes: G01V 15/00 Tags attached to, or associated with, an object, in order to enable detection of the object record carriers for use with machines having a detectable tag or marker G06K19/00

Abstract

A method for underground pipeline monitoring in which a continuous alternating electrical current having a current frequency in a range of about 1 kHZ to about 8 kHz is imparted onto a pipeline, producing an alternating magnetic field at the current frequency along the pipeline. Distributed along the pipeline is a network of RFID tag sensors which absorb an amount of energy from the alternating magnetic field. The impedance of the sensors is modulated, producing a modulated sensor impedance which is detected at a location proximate the location at which the continuous alternating electrical current is imparted onto the pipeline.

Claims

1. A method for underground pipeline monitoring comprising the steps of:

superimposing a continuous alternating electrical current having a current frequency in a range of about 1 kHz to about 30 kHz onto a pipeline, producing an alternating magnetic field at said current frequency along said pipeline;

absorbing an amount of energy from said alternating magnetic field using a network of sensors distributed along said pipeline;

modulating an impedance of said sensors, producing a modulated sensor impedance; and

detecting said modulated sensor impedance with detection means at a location proximate a current location from which said continuous alternating electrical current is superimposed onto said pipeline.

2. The method of claim 1, wherein said sensors are battery-assisted radio frequency identification tag sensors.

3. The method of claim 1, wherein said impedance is sequentially modulated between a first said modulated sensor impedance and a second said modulated sensor impedance.

4. The method of claim 3, wherein said impedance modulation is carried out at two different modulation rates, one said modulation rate corresponding to a data logic “

zero” and

another said modulation rate corresponding to a data logic “

one”

.

5. The method of claim 1, wherein said sensors comprise a primary coil and capacitor tuned to a resonant frequency substantially equal to said current frequency and a normally open-circuit secondary coil concentric with said primary coil, said primary coil and said secondary coil connected only by mutual inductance.

6. The method of claim 5, wherein said mutual inductance is activated by electrically shorting said secondary coil.

7. The method of claim 2, wherein a portion of said amount of energy is harvested for powering said sensors.

8. A communication method comprising the steps of:

imparting a continuous alternating electrical current having a current frequency one of less than and equal to about 8 kHz onto an underground pipeline resulting in generation of an alternating magnetic field at said current frequency along said underground pipeline;

absorbing an amount of energy from said alternating magnetic field with a network of sensors distributed along said underground pipeline;

modulating an impedance of said sensors between a first value and a second value, producing a modulated backscatter signal; and

detecting said modulated backscatter signal at a detection location proximate a pipeline location at which said continuous alternating electrical current is imparted onto said underground pipeline.

9. The communication method of claim 8, wherein said sensors comprise a primary coil and capacitor tuned to a resonant frequency substantially equal to said current frequency and a normally open-circuit secondary coil concentric with said primary coil connected only by mutual inductance with said primary coil.

10. The communication method of claim 9, wherein said impedance of said sensors is modulated by electrically shorting said secondary coil.

11. The communication method of claim 8, wherein a portion of said amount of energy absorbed by said sensors is used to power said sensors.

12. The communication method of claim 8, wherein said sensors are battery-assisted radio frequency identification tag sensors.

13. A method for underground pipeline monitoring comprising the steps of:

providing a continuous alternating electrical current at a current frequency in a range of about 1 kHz to about 30 kHz to an underground pipeline;

absorbing a portion of said current with a network of sensors distributed along said pipeline, producing a sensor draw current;

modulating said sensor draw current, producing a modulated sensor current draw; and

detecting said modulated sensor current draw using detection means disposed proximate a current origin location from which said continuous alternating current is provided.

14. The method of claim 13, wherein said sensors are battery-assisted radio frequency identification tag sensors.

15. The method of claim 13, wherein said sensor current draw is modulated between a first said sensor current draw and a second said sensor current draw.

16. The method of claim 13, wherein said sensors comprise a primary coil and capacitor tuned to a resonant frequency substantially equal to said current frequency and a normally open-circuit secondary coil concentric with said primary coil, said primary coil and said secondary coil connected only by mutual inductance.

17. The method of claim 16, wherein said mutual inductance is activated by electrically shorting said secondary coil.

18. The method of claim 16, wherein a portion of said sensor current draw is harvested for powering said sensors.

19. The method of claim 15, wherein said sensor current draw is modulated at two different modulation rates.

20. An underground communication system comprising;

an underground pipeline;

an underground alternating electrical current source in electrical communication with said underground pipeline;

a plurality of underground sensors disposed one of proximate to and in contact with said underground pipeline; and

current draw detection means disposed proximate said current source for detecting current draw by said underground sensors.

21. The system of claim 20, wherein said underground sensors comprise current draw modulation means for modulating said current draw by said underground sensors.

22. The system of claim 21, wherein said underground sensors are radio frequency identification tag sensors.

23. The system of claim 22, wherein said underground sensors are battery-assisted radio frequency identification tag sensors.

24. The system of claim 23, wherein said current draw modulation means comprises a primary coil and capacitor tuned to a resonant frequency substantially equal to an alternating electrical current frequency provided by said underground alternating electrical current source and a normally open-circuit secondary coil concentric with said primary coil, said primary coil and said secondary coil connected only by mutual inductance, and shorting means for electrically shorting said secondary coil.

25. The system of claim 24, wherein said shorting means comprises a MOSFET.

26. The system of claim 20, wherein said underground alternating electrical current source is disposed within an impressed current rectifier station.