Method and apparatus for detecting and locating gas leaks

• US 7,430,897 B2
• Filed: 09/19/2003
• Issued: 10/07/2008
• Est. Priority Date: 09/19/2002
• Status: Expired due to Fees

• Current Assignee: National Research Council Canada
• Original Assignee: National Research Council Canada
• Inventors: Hu, Cheng, Stanley, Kevin G., Wu, Jonathan Q. M., Qu, Xidong
• Primary Examiner(s): LARKIN, DANIEL SEAN
• Application Number:
  US10/528,239
• Publication Number:
  US 20060162428A1
• Time in Patent Office: 1,845 Days
• Field of Search: 73/40, 73/407, 73/492, 73/405.R, 73/491, 73/493
• US Class Current: 73/49.2
• CPC Class Codes: G01M 3/20 using special tracer materials, e.g. dye, fluorescent material, radioactive material
• CPC Class Codes: G01M 3/22 for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators

Abstract

The invention provides an apparatus and method for detecting the location of a gas leak within a test region. The invention comprises an array of calibrated sensors for measuring a plurality of gas concentrations, a control system coupled to the sensor array for calculating and optionally displaying a direction of higher gas concentration, and, an actuator for moving the sensor array under control of the control system, wherein the control system causes the array of sensors to measure the gas concentrations and move in the direction of higher concentration until a stopping condition is achieved. The stopping condition may be achieved when the measured gas concentration exceeds a predetermined threshold or when the concentration otherwise likely corresponds to the leak location based on a comparison with previously measured values.

Claims

1. A method of detecting a location of a gas leak within a test region, the method comprising:

(a) providing a sensor array comprising a plurality of sensors configured to measure a plurality of gas concentrations simultaneously;

(b) measuring the plurality of gas concentrations at the same time, while maintaining a position of the sensor array;

(c) determining a local gas concentration profile based on the measured gas concentrations;

(d) moving the sensor array to a new location depending upon the local gas concentration profile determined in step (c); and

,

(e) repeating steps (b) to (d) until a stopping condition is achieved whereby the location of the gas leak is indicated by the location of the sensor array,

wherein determining the local gas concentration profile comprises calculating a gas concentration gradient.

2. The method as defined in claim 1, wherein the local gas concentration profile indicates a direction of higher gas concentration.

3. The method of claim 2, wherein moving the sensor array to a new location comprises moving the sensor array in the direction of the higher gas concentration.

4. The method of claim 1, wherein the stopping condition is achieved when one of the measured gas concentrations exceeds a threshold.

5. The method of claim 4, wherein the threshold is predetermined.

6. The method of claim 1, comprising, before determining the local gas concentration profile, moving the sensor array within the test region according to a scanning model until the measured gas concentrations exceed a minimum threshold.

7. The method of claim 1, wherein the stopping condition is achieved when the sensor array measures a plurality of nearly equal high gas concentrations within a localized subregion of the test region.

8. The method of claim 1, further comprising displaying the local gas concentration profile.

9. A method of detecting a location of a gas leak within a test region, the method comprising:

(a) providing a sensor array comprising a plurality of sensors configured to measure a plurality of gas concentrations simultaneously;

(b) measuring the plurality of gas concentrations at the same time, while maintaining a position of the sensor array;

(c) determining a local gas concentration profile based on the measured gas concentrations;

(d) moving the sensor array to a new location depending upon the local gas concentration profile determined in step (c); and

,

(e) repeating steps (b) to (d) until a stopping condition is achieved whereby the location of the gas leak is indicated by the location of the sensor array,

wherein determining a local gas concentration profile comprises comparing the measured gas concentrations to previously measured gas concentrations at other locations in the test region.

10. A method of detecting a location of a gas leak within a test region, the method comprising:

(a) providing a sensor array comprising a plurality of sensors configured to measure a plurality of gas concentrations;

(b) measuring the plurality of gas concentrations;

(c) determining a local gas concentration profile based on the measured gas concentrations;

(d) moving the sensor array to a new location depending upon the local gas concentration profile determined in step (c); and

,

(e) repeating steps (b) to (d) until a stopping condition is achieved whereby the location of the gas leak is indicated by the location of the sensor array,

wherein the stopping condition is achieved when the sensor array repeatedly returns to the same location within the test region.

11. A method of detecting a location of a gas leak within a test region, the method comprising:

(a) providing a sensor array comprising a plurality of sensors configured to measure a plurality of gas concentrations;

(b) measuring the plurality of gas concentrations;

(c) determining a local gas concentration profile based on the measured gas concentrations;

(d) moving the sensor array to a new location depending upon the local gas concentration profile determined in step (c); and

,

(e) repeating steps (b) to (d) until a stopping condition is achieved whereby the location of the gas leak is indicated by the location of the sensor array,

wherein the test region is a fuel cell.

12. Apparatus for detecting a location of a gas leak within a test region, the apparatus comprising:

(a) a sensor array comprising a plurality of spaced-apart sensors configured to measure a plurality of gas concentrations;

(b) a control system operatively coupled to the sensor array for determining a local gas concentration profile based on the measured gas concentrations; and

,

(c) an actuator controlled by the control system for moving the sensor array toward the highest concentration of the gas within the test region until a stopping condition is achieved whereby the location of the gas leak is indicated by the location of the sensor array,

wherein the control system comprises a microprocessor configured to calculate a gas concentration gradient.

13. The apparatus of claim 12 wherein the sensors comprise calibrated semiconductor sensors.

14. The apparatus of claim 13, wherein the sensors comprise MOS capacitors.

15. The apparatus of claim 12, wherein the actuator comprises a sensor positioning system movable in one, two or three dimensions within the test region.

16. The apparatus of claim 12 wherein the sensor array is configured to measure the plurality of gas concentrations simultaneously.

17. The apparatus of claim 12 wherein the control system is configured to analyze the gas concentration gradient to determine a direction for moving the sensor array with the actuator.

18. Apparatus for detecting a location of a gas leak within a test region, the apparatus comprising:

(a) a sensor array comprising a plurality of spaced-apart sensors configured to measure a plurality of gas concentrations simultaneously;

(b) a control system operatively coupled to the sensor array for determining a local gas concentration profile based on the simultaneously measured gas concentrations; and

,

(c) an actuator controlled by the control system for moving the sensor array toward the highest concentration of the gas within the test region until a stopping condition is achieved whereby the location of the gas leak is indicated by the location of the sensor array,

wherein the control system comprises a microprocessor, and

wherein the microprocessor is configured to calculate a gas concentration gradient.