Designs for enhanced reliability and calibration of landfill gas measurement and control devices

Patent metadata

Field	Value
Publication number	US-10705063-B2
Application number	US-201715464236-A
Country	US
Kind code	B2
Filing date	Mar 20, 2017
Priority date	Mar 1, 2016
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

An apparatus for sampling landfill gas from a landfill flowing through a pipe. The apparatus may comprise: an enclosure configured to receive a section of the pipe; a gas sampling port in the section of the pipe; at least one sensor device disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the gas sampling port; and thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure. A method of operating a landfill gas recovery system. The method may comprise: flowing gas from a well riser pipe through a sampling subsystem to a collection system; and heating a portion of the sampling subsystem with the gas flowing from the well riser pipe to the collection system.

First claim

What is claimed is:

1. A sensor calibration method performed by an apparatus for sampling landfill gas flowing through a pipe, the apparatus comprising a region comprising a gas sampling port, the gas sampling port configured for coupling to a section of the pipe, at least one sensor, and at least one calibration port, the method comprising:
isolating the at least one sensor from the gas sampling port;
while the at least one sensor is isolated from the gas sampling port,
obtaining at least one sample of a gas having a known composition through the at least one calibration port;
measuring, using the at least one sensor, at least one concentration of at least one constituent gas in the at least one sample of the gas having the known composition; and

automatically calibrating the at least one sensor based on a comparison between the at least one measured concentration of the at least one constituent gas and an expected concentration of the at least one constituent gas in the at least one sample gas having the known composition,
wherein obtaining the at least one sample comprises obtaining a first gas sample of a first mixture of gasses of known composition and obtaining a second gas sample of a second mixture of gasses of known composition, the second mixture of gasses having a composition of gasses different than that of the first mixture.

2. The sensor calibration method of claim 1 , wherein the apparatus further comprises at least one valve connected between the at least one calibration port and the region comprising the gas sampling port, and wherein isolating the at least one sensor from the gas sampling port comprises actuating the at least one valve.

3. The sensor calibration method of claim 2 , wherein actuating the at least one valve is performed in response to a command.

4. The sensor calibration method of claim 2 , wherein actuating the at least one valve is performed in response to detection of a fitting being connected to the at least one calibration port.

5. The sensor calibration method of claim 1 , wherein obtaining the at least one sample comprises obtaining a sample of ambient air outside the apparatus.

6. The sensor calibration method of claim 1 , wherein obtaining the at least one sample comprises obtaining a gas sample from a gas canister coupled to the at least one calibration port.

7. The sensor calibration method of claim 1 , wherein obtaining the at least one sample comprises obtaining a gas sample of a mixture of at least two gasses of known composition.

8. The sensor calibration method of claim 1 , wherein obtaining the at least one sample comprises obtaining a gas sample including at least CO 2 and CH 4 .

9. The sensor calibration method of claim 8 , wherein obtaining the gas sample including at least CO 2 and CH 4 comprises obtaining a gas sample comprising 35% CO 2 , 50% CH 4 , and 15% N 2 .

10. The sensor calibration method of claim 1 , wherein obtaining the at least one sample comprises obtaining a first gas sample of ambient air outside the apparatus and a second gas sample including at least CO 2 and CH 4 .

11. The sensor calibration method of claim 1 , wherein the at least one sensor includes a gas composition sensor configured to sense oxygen, methane, and/or carbon dioxide.

12. The sensor calibration method of claim 1 , wherein measuring the at least one concentration of the at least one constituent gas comprises measuring at least one of oxygen concentration in the at least one sample of the gas, methane concentration in the at least one sample of the gas, or carbon dioxide concentration in the at least one sample of the gas.

13. The sensor calibration method of claim 1 , wherein automatically calibrating the at least one sensor comprises determining at least one parameter for processing measurements obtained by the at least one sensor.

14. The sensor calibration method of claim 13 , wherein determining the at least one parameter for processing measurements obtained by the at least one sensor comprises:
determining at least one parameter for linearly compensating measurements obtained by the at least one sensor.

15. The sensor calibration method of claim 14 , wherein determining the at least one parameter for linearly compensating measurements obtained by the at least one sensor comprises determining at least one of a gain or an offset to apply to measurements obtained by the at least one sensor.

16. The sensor calibration method of claim 13 , wherein determining the at least one parameter for processing measurements obtained by the at least one sensor comprises:
determining at least one parameter for non-linearly compensating measurements obtained by the at least one sensor.

17. The sensor calibration method of claim 1 ,
wherein the at least one sensor comprises an oxygen sensor;
wherein obtaining the at least one sample comprises obtaining a sample of ambient air outside the apparatus;
wherein the measuring comprises using the oxygen sensor to measure concentration of oxygen in the sample of ambient air; and
wherein the automatically calibrating comprises automatically calibrating the oxygen sensor by:
comparing the measured concentration of oxygen in the sample of ambient air to an expected concentration of oxygen in ambient air; and
determining at least one parameter for processing measurements obtained by the oxygen sensor.

18. The sensor calibration method of claim 17 , wherein the automatically calibrating further comprises calibrating a methane sensor and/or a carbon dioxide sensor based on the determined at least one parameter for processing measurements obtained by the oxygen sensor.

19. An apparatus for sampling landfill gas flowing through a pipe, the apparatus comprising:
an enclosure comprising a gas sampling port, the gas sampling port configured for coupling to a section of the pipe;
at least one sensor disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the at least one gas sampling port;
a calibration port configured for connection to at least one source of gas of known composition; and
a valve connected between the calibration port and the at least one sensor so as to enable gas to flow from the calibration port to the at least one sensor while isolating the at least one sensor from the gas sampling port, wherein the apparatus is configured such that the valve is actuated in response to a fitting being connected to the at least one calibration port.

20. An apparatus for sampling landfill gas flowing through a pipe, the apparatus comprising:
a sampling subsystem comprising:
a gas inlet port and a gas outlet port;
a region comprising a gas sampling port, the gas sampling port configured for coupling to a section of the pipe;
at least one sensor coupled to the gas outlet port; and
a gas flow passage from the gas inlet port, over the at least one sensor, and to the gas outlet port;

a gas sample comprising 35% CO 2 , 50% CH 4 , and 15% N 2 ;
at least one calibration port configured for connection to at least one source of gas of known composition, the at least one source of gas comprising the gas sample; and
at least one valve connected between the at least one calibration port and the sampling subsystem so as to enable gas to flow from the at least one calibration port to the at least one sensor while isolating the at least one sensor from the gas sampling port.

21. The apparatus of claim 20 , wherein the gas flow passage further comprises at least one

Assignees

• Loci Controls Inc

Inventors

• Campanella Andrew
• Martin Ian
• Michels Joseph G
• Pallo Nathan
• Quigley Peter

Classifications

• E21B47/07

  Temperature · CPC title

• E21B49/0875

  determining specific fluid parameters · CPC title

• Y02C20/20

  of methane · CPC title

• Y02W30/20

  Waste processing or separation · CPC title

• B09B1/006

  Shafts or wells in waste dumps · CPC title