Continuous infrared thermography monitoring and life management system for heat recovery steam generators

• US 9,509,923 B2
• Filed: 01/10/2012
• Issued: 11/29/2016
• Est. Priority Date: 01/10/2012
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (General Electric Company)
• Original Assignee: General Electric Company
• Inventors: Pandey, Achalesh Kumar, Nirmalan, Nirm Velumylum, Venugopal, Manoharan, Rogers, David Lee, Laflen, John Brandon, Giametta, Lucy Summerville
• Primary Examiner(s): Anderson, II, James M
• Application Number:
  US13/346,755
• Publication Number:
  US 20130176418A1
• Time in Patent Office: 1,785 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01N 25/72 Investigating presence of flaws
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A method for continuously monitoring the working condition of a heat recovery steam generator (“HRSG”) using infrared thermography, comprising the steps of identifying target locations inside the HRSG, positioning one or more infrared cameras to continuously monitor and record the temperature at each target location, generating continuous thermographic images corresponding to selected components and locations at each target locations, comparing the continuous thermographic images to corresponding, stored base line images and generating a set of comparative data reports in real time for each target location in order to predict the life span or potential failure of HRSG components.

Claims

1. A method for continuously monitoring the working condition of a heat recovery steam generator (“

HRSG”

) using infrared thermography, the method comprising;

identifying one or more target locations inside said heat recovery steam generator;

positioning one or more infrared cameras inside said heat recovery steam generator for continuously viewing said target locations;

capturing at least one image of the one or more target locations using the one or more infrared cameras, while the HRSG is in a downtime condition and not heated by a hot gas stream flowing through the HRSG;

calibrating the one or more infrared cameras, wherein the calibration includes estimating an optimum focal length and range for each of said one or more infrared cameras using tube detection algorithms which detect one or more tubes in the captured images of the target locations;

designating at least one image captured while the HRSG is in downtime as a corresponding base line image or images of the one or more target locations;

after calibrating the one or more infrared cameras and while the HRSG is operating to recover heat from a gas stream, capturing at least one image of the one or more target locations using the one or more infrared cameras;

generating a set of continuous thermographic images for each of said target locations using images captured by the one or more infrared cameras, while the HRSG is operating to recover heat from the hot gas stream passing through the HRSG;

comparing said continuous thermographic images to the corresponding base line image or images of the one or more target locations; and

generating a set of comparative data reports and comparative images based on real time data accumulated for each of said one or more target locations and based on the comparisons of the thermographic images to the corresponding base line images.

2. A method according to claim 1, wherein said step of identifying said target locations includes identifying specific tubes or headers inside said heat recovery steam generator.

3. A method according to claim 1, wherein at least one of said infrared cameras is positioned at the front of said heat recovery steam generator to continuously monitor and record tube temperature profiles.

4. A method according to claim 1, wherein said source code predicts the anticipated life before failure of selected components of said heat recovery steam generator.

5. A method according to claim 1, further comprising the step of generating image-to-3D mapping of the surfaces of components within said target locations based on accumulated infrared data.

6. A method according to claim 1, further comprising the step of installing one or more high band pass filters to prevent the absorption of carbon dioxide and water by said infrared cameras.

7. A method according to claim 1, wherein said infrared cameras monitor the cold end temperature of selected tubes and headers at the back of said heat recovery steam generator.

8. A method according to claim 1, wherein said step of generating a set of continuous thermographic images uses thermocouples installed at each of said target locations.

9. A method according to claim 1, wherein said step of generating a continuous set of thermographic images are used to monitor and analyze tube vibrations occurring at different locations within the HRSG.

10. A method according to claim 9, wherein said step of monitoring and analyzing tube vibrations further comprises predicting the expected lifespan and potential failure of selected HRSG tubes.

11. A system for continuously monitoring the working condition of a heat recovery steam generator (“

HRSG”

) using infrared thermography, comprising;

one or more infrared cameras positioned at target locations inside said heat recovery steam generator;

adjustable mounting structures for each of said infrared cameras, said mounting structures being secured inside said heat recovery steam generator near said target locations;

one or more infrared data transmitters for each of said infrared cameras generating continuous infrared data for each of said target locations;

one or more infrared data receivers generating a continuous set of thermographic images based on said infrared data; and

a controller running source code to compare said continuous set of thermographic images to corresponding base line images of the same target locations, wherein the base line images are captured while the HRSG is down and unheated by a hot gas stream, wherein the controller generates an image-to-3D mapping of the surface of components located within said target locations and includes tube detection algorithms for estimating camera focal length and range.

12. A system according to claim 11, wherein said continuous set of thermographic images generated by said data receivers are used to monitor and analyze tube vibrations occurring at different locations within the HRSG.

13. A system according to claim 11, wherein said infrared cameras continuously transmit data at wavelengths near infrared between 0.9 and 1.7 microns.

14. A system according to claim 11, wherein said infrared cameras continuously transmit data at long infrared wavelengths between 7.0 and 14 microns.

15. A method for continuously analyzing infrared thermography data corresponding to target locations inside a heat recovery steam generator (HRSG), comprising the steps of:

positioning one or more infrared cameras inside said heat recovery steam generator for continuously viewing said target locations;

calibrating the one or more infrared cameras by estimating an optimum focal length and range for said infrared cameras using tube detection algorithms to detect tubes in images captured by the one or more infrared cameras of the target locations, while no hot gas stream passes the target locations of the HRSG;

generating base line infrared data on the target locations in the HRSG using images captured by the one or more infrared cameras of the target locations while no hot gas stream passes the target locations of the HRSG;

transforming received infrared data captured by the one or more infrared cameras, while a hot gas stream passes the target locations of the HRSG, into an electrical signal that can be output for data accumulation and analysis;

compensating for background radiation due to the surface temperature at each of said target locations;

performing a linearization of accumulated infrared data;

generating comparative thermographic images based on said accumulated infrared data and the base line infrared data for each of said target locations; and

generating data reports of said comparative thermographic images.

16. A method for analyzing tube vibrations occurring in a heat recovery steam generator (HRSG), comprising the steps of:

installing one or more infrared (IR) cameras, said IR cameras being positioned to selectively image one or more target HRSG tubes;

calibrating the one or more IR cameras by estimating an optimum focal length and range for said IR cameras using tube detection algorithms to detect the one or more target HRSG tubes in images generated by the one or more IR cameras, while no hot gas stream flow through the target locations of the HRSG;

generating base line infrared data on the target locations in the HRSG using images captured by the one or more infrared cameras of the target locations while no hot gas stream passes the target locations of the HRSG;

continuously acquiring thermographic image data of said target HRSG tubes while hot gases flow through the HRSG;

determining the rate of vibrations of said one or more IR cameras based on comparisons of the base line infrared data and the continuously acquired thermographic image data;

acquiring continuous IR image data of said target HRSG tubes; and

analyzing said continuous IR image data and said rate of IR camera vibrations to determine the vibration rate or potential failure of said target HRSG tubes.