CONTINUOUS INFRARED THERMOGRAPHY MONITORING AND LIFE MANAGEMENT SYSTEM FOR HEAT RECOVERY STEAM GENERATORS

• US 20130176418A1
• Filed: 01/10/2012
• Published: 07/11/2013
• Est. Priority Date: 01/10/2012
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (General Electric Company)
• Original Assignee: General Electric Company
• Inventors: Nirmalan, Nirm Velumylum, Venugopal, Manoharan, Rogers, David Lee, Laflen, John Brandon, Pandey, Achalesh Kumar, Glametta, Lucy Summerville
• Granted Patent: US 9,509,923 B2
• Time in Patent Office: Days
• US Class Current: 348/83
• 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, 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;

generating a set of continuous thermographic images for each of said target locations;

comparing said continuous thermographic images to corresponding base line images of the same target locations; and

generating a set of comparative data reports based on real time data accumulated for each of said target locations.

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 step of comparing said continuous thermographic images to base line images uses source code to generate comparative images and data reports.

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

6. 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.

7. 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.

8. 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.

9. 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.

10. A method according to claim 4, further comprising the step of estimating the optimum focal length and range and said infrared cameras based on tube geometry algorithms.

11. 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.

12. A method according to claim 11, wherein said step of monitoring and analyzing tube vibrations further comprises predicting the expected lifespan and potential failure of selected HRSG tubes.

13. 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

source code comparing said continuous set of thermographic images to corresponding base line images of the same target locations.

14. A system according to claim 13, wherein said source code provides an image-to-3D mapping of the surface of components located within said target locations.

15. A system according to claim 13, wherein said source code includes tube detection algorithms for estimating camera focal length and range.

16. A system according to claim 13, 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.

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

18. A system according to claim 13, wherein said infrared cameras continuously transmit data at long infrared wavelengths between 7.0 and 14 microns.

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

(a) transforming received infrared data into an electrical signal that can be output for data accumulation and analysis;

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

(c) performing a linearization of accumulated infrared data;

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

(e) generating data reports of said comparative thermographic images.

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

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

(2) continuously acquiring IR image data of said target HRSG tubes;

(3) determining the rate of vibrations of said one or more IR cameras;

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

(5) 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.