WO2019035807A1

WO2019035807A1 - Embedded imaging unit for high temperature and pressure applications

Info

Publication number: WO2019035807A1
Application number: PCT/US2017/046850
Authority: WO
Inventors: Erwan Baleine
Original assignee: Siemens Energy, Inc.
Priority date: 2017-08-15
Filing date: 2017-08-15
Publication date: 2019-02-21

Abstract

A system for the online internal inspection of a gas turbine engine 10 is provided. The system includes a cooled, pressurized vessel 38 disposed in a location within the outer casing 22 of the gas turbine engine 10, an imaging optical system 40 having a field of view directed th 5 rough a hole in the vessel 38 effective to capture images of internal components of the gas turbine engine 10, an electronic imaging sensor 50 encapsulated within the vessel 38 for capturing an image transmitted by the imaging optical system, and a processor 34 communicatively coupled to the electronic imaging sensor 50 for storing and analyzing the image. The internal inspection is 10 performed during gas turbine operation. An embedded imaging unit 40 and a method for internal inspection of a gas turbine engine 10 are also provided.

Description

EMBEDDED IMAGING UNIT FOR HIGH TEMPERATURE AND PRESSURE

APPLICATIONS

BACKGROUND 1. Field

[0001] The present disclosure relates to optical imaging systems for high temperature and high pressure applications, and more particularly to an online embedded optical imaging system to facilitate the inspection of gas turbine components.

2. Description of the Related Art

[0002] Gas turbine engines are known to include a compressor section, a combustor section, and a turbine section. Many components within the casing of the gas turbine, such as the stationary vanes, rotating blades and surrounding ring segments, are directly exposed to hot combustion gases that can exceed 1000° C and pressures that are at least 25 bars.

[0003] In the past, inspection for damage to turbine components has been performed by partially disassembling (destructive testing) the gas turbine engine and performing visual inspections on individual components. Alternatively, in-situ visual inspections may be performed without engine disassembly (nondestructive testing) by using a borescope inserted into a gas turbine engine, but such procedures are labor intensive, time consuming, costly, and require that the gas turbine engine be shut down.

[0004] It is known to inspect for turbine component damage while the gas turbine is operating. Online imaging systems to monitor gas turbine components and the gas turbine system may be used to provide data for analysis, however, such systems are frequently impaired by the cost of the instrumentation hardware. In current systems, the cost is driven by the bulkiness of the monitoring components as well as the fact that all the electrical components have to stay cool necessitating their placement outside of the engine. Locating the monitoring equipment outside of the engine may require the use of long optical probes to image the inside of the engine and corresponding flanges to seal for the high pressures within the turbine engine. Additionally, online monitoring with instruments embedded within the gas turbine engine has been difficult given the local pressure and temperature conditions.

[0005] US 2006/0088793, Optical Viewing System for Monitoring a Wide Angle Area of Interest Exposed to High Temperature, describes a wide angle lens viewing system for the non-destructive monitoring of gas turbine components. While the wide angle lens is cooled, the electronic imaging sensor must be placed outside of the gas turbine engine. This limits the viewing to objects within a direct line of sight from the outer casing.

[0006] US 8,713,999 describes a method in which internal components of power generation machinery, such as gas and steam turbines, are inspected with an optical camera inspection system that is capable of automatically positioning the camera field of view to an area of interest within the machinery along a pre-designated navigation path and capturing images without human intervention. However, the inspection is performed off-line after the turbine is cooled down to less than 150°C. The system is also not pressurized.

[0007] Accordingly, there continues to be a need for improved methods and apparatus for online monitoring of gas turbine components.

SUMMARY [0008] Briefly described, aspects of the present disclosure relate to a system for online internal inspection of a gas turbine engine, an embedded imaging unit, and a method for internal inspection of a gas turbine engine.

[0009] A system for the online internal inspection of a gas turbine engine 10 is provided. The system includes a cooled, pressurized vessel 38 disposed in a location within the outer casing 22 of the gas turbine engine 10, an imaging optical system 40 having a field of view directed through a hole in the vessel 38 effective to capture images of internal components of the gas turbine engine 10, an electronic imaging sensor 50 encapsulated within the vessel 38 for capturing an image transmitted by the imaging optical system, and a processor 34 communicatively coupled to the electronic imaging sensor 50 for storing and analyzing the image. The internal inspection is performed during gas turbine operation. [0010] An embedded imaging unit for monitoring a component in a high temperature environment is also provided. The embedded imaging unit includes an optical system with a field of view, an electronic imaging sensor for capturing an image transmitted by the optical system, a cooling system adapted to cool the electronic imaging sensor, and a processor for storing and analyzing the image, and a wireless transmitter communicatively couple to the processor for wirelessly relaying the images from the electronic imaging sensor to the processor. The imaging unit is embedded within a high temperature environment to monitor a plurality of components within the high temperature environment.

[0011] A method for internal inspection of a gas turbine engine is also provided. The method includes the steps of providing an internal inspection unit as described above. A cooled, compressed air is supplied to the vessel through a supply line extending from the compressed cooled air source to the vessel. Images are captured by the electronic imaging sensor transmitted by the imaging optical and stored on the processor. The images are then analyzed by the processor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Fig. 1 illustrates a longitudinal view of a gas turbine engine including an embedded imaging unit,

[0013] Fig. 2 illustrates a schematic view of a system for internal inspection of a gas turbine engine,

[0014] Fig. 3 illustrates a zoomed in view of an embodiment of an embedded imaging unit,

[0015] Fig. 4 illustrates a perspective view of an embedded vessel, and [0016] Fig. 5 illustrates a cross sectional view of the embedded imaging unit.

DETAILED DESCRIPTION

[0017] Referring now to the figures, where the showings are for purposes of illustrating embodiments of the subject matter herein only and not for limiting the same, Fig. 1 illustrates an embodiment of a longitudinal view of a gas turbine engine 10 including an embedded imaging unit 30. Those skilled in the art would understand that the disclosed embedded imaging unit 30 may be employed in many other industrial systems as well as the embodiment including a gas turbine engine 10 as discussed, for exemplary purposes, below.

[0018] Referring to Fig. 1, an industrial gas turbine engine 10 is shown. The engine 10 includes a compressor section 12, a combustor section 14, a turbine section 16, and an exhaust section or system 18. The combustor section 14 includes a plurality of combustors 20. A hot working gas is conveyed from the combustor section 14 through to the turbine section 16. An outer casing 22 encloses the gas turbine engine 10 and delimits an internal environment enclosed within the outer casing 22.

[0019] In accordance with an embodiment, a system for online internal inspection of a gas turbine engine includes an embedded imaging unit is provided. Fig. 2 illustrates a schematic view of the system where the embedded imaging unit 30 includes a cooled, pressured vessel 38 disposed in a location within a casing 22 of the gas turbine engine 10. Encapsulated within the vessel 38 is an imaging optical system having a field of view and an electronic imaging sensor for capturing an image transmitted by the imaging optical system. The system may also include a processor 34 communicatively coupled to the embedded imaging unit 30 for storing and analysing the image.

[0020] In an embodiment, the system further comprises a power source 36 which delivers power to the vessel 38. In the illustrated embodiment of Fig. 2, power is delivered to the vessel by a standard high temperature power line 36 routed from the outside of the engine to the vessel 38. A supply line 32 may be provided for supplying cooled, pressurized air to the interior of the vessel 38. Both the supply line 32 and the power line 36 may be inserted into the gas turbine engine 10 by routing the lines through flexible metal conduits disposed in bores within the turbine casing 22. The supply line 32 and power line 36 are then sealed in position into the turbine casing 22.

[0021] Fig. 3 illustrates an embodiment of a zoomed in view of the embedded imaging unit 30. The embedded imaging unit 30 comprises a cooled and pressurized vessel 38 containing the imaging optical system 40 and the electronic imaging sensor. In an embodiment, the vessel 38 may comprise an insulated box having a plurality of nested walls, including an exterior housing 52, and a supply line 32 for supplying cooled, pressurized air to the interior of the vessel 38. The exterior housing 52 of the insulated box may comprise a pressurized metallic container, however, other materials that can withstand the internal environment of the engine may also be used. In an embodiment, the size of the insulated box is approximately 75mm x 50mm x 50 mm (length, width, height).

[0022] Referring now to Fig. 4, a perspective view of an insulated box 38 supplied with cooled pressurized air by a supply line 32 is shown. Cooled air may be circulated within an interior passageway of the vessel 38 delimited by the exterior housing 52 and a side of each of the plurality of interior nested walls 44. The nested wall design provides the insulation. The internal passageway may be seen in Fig. 4. Cooled air is supplied by the supply line 32 which is routed into the insulated box 38 through a cooling hole and flows, as shown by the arrows, into the center of the insulated box and along the periphery of the insulated box through the internal passageway back to the supply line 32. In an embodiment, the supply line 38 may comprise a hollow tube inserted within a return line 42 to carry the returned air outside the vessel 38 in order to minimize the heating of the cooled air. The interior nested walls 44 may be held within the exterior housing 52 by a plurality of holding pins 46 extending between the interior walls 44 and the exterior housing 52.

[0023] In an embodiment, the cooled air may be compressed air. Compressed air is ready available at any power plant, for example, at a pressure of 6 bars and a mass flow of approximately 50 g/s. The compressed air may be cooled by chiller or a series of vortex coolers down to a temperature of 0° C or lower. As an example, utilizing a mass flow of approximately 2g/s at a pressure of 6 bars, the embedded vessel 38 may be cooled to about 40°C.

[0024] The system further includes a processor 34, as shown in Fig. 2, communicatively coupled to the electronic imaging sensor via a wireless transmitter. A cross sectional view of the interior of an embodiment of the embedded imaging unit 30 is illustrated in Fig. 5. The wireless transmitter 48 may be encapsulated within the vessel 40. The wireless transmitter 48 transmits the image data wirelessly from the electronic imaging sensor 50 to a receiver connected to the processor 34. In an embodiment, the processor 34 may be an embedded computer such as a Raspberry Pi.

[0025] The Raspberry Pi computer is an example of a new computing option. New technology advances have developed low cost and low power computing, low cost sensing, and low cost digital data transmission. Most of these devices also have the added advantage of being small, such as in the millimeter (or smaller) range. The Raspberry Pi computer may be as small as a postage stamp allowing it to be placed in the proximity of the gas turbine engine 10. In the illustrated example of Fig. 2, the embedded processor 34 is disposed outside of the outer casing 22 of the gas turbine engine 10, but in the proximity of the gas turbine engine 10. For example, in an embodiment, the processor 34 may be located on or a few meters away from the gas turbine casing 22. The processor 34 may store the images for later retrieval or be remotely accessed to stream the signal to a server. The server may be located offsite.

[0026] Also, in the illustrated cross sectional view of the embedded imaging unit 30 is the imaging optical system 40. The imaging optical system 40 may include a lens disposed in an opening of the vessel 38 such that the lens is exposed to the high temperature environment in which the vessel 38 is embedded. The lens would be sealed within the vessel 38 in order to prevent hot gases from entering the vessel 38. The exposed lens may be uncooled and comprise sapphire, for example. Other lens materials that can withstand the high temperature environment are also possible.

[0027] The lens of the imaging optical system 40 includes a field of view which may include a wide angle field of view. Typically, a wide field of vision or wide viewing angle is larger than 30 degrees. In an embodiment, the field of view is greater than or equal to 120°. Preferably, the imaging unit 30 provides a hemispherical, 180°, field of view from the surface onto which the imaging unit 30 is attached. The field of view is oriented through a hole in the vessel 38 and is enabled to capture images of the internal components of a gas turbine engine 10, for example.

[0028] Fig. 5 also illustrates the electronic imaging sensor 50 encapsulated within the vessel 38. In an embodiment, the electronic imaging sensor 38 selected is a Raspberry Pi camera which has the advantage of having an acquisition board separate from the sensor itself. The size of the Raspberry Pi camera may be less than 12mm x 12mm x 12mm with a minimum image resolution of 5 Mpixels. Conventionally, imaging sensors are attached directly onto a large electronic board and the size may easily reach 100mm x 100mm x 100mm. Because the electronic imaging sensor 38 is small, the lens may also be designed to a very compact size. The proposed design of the embedded imaging unit 30 uses a visible color camera but the same concept may be applied to an ultraviolet camera, an infrared camera, or a hyperspectral camera.

[0029] The imaging unit 30 may be embedded in a high temperature environment such as the internal environment of a gas turbine engine 10. As stated above, the internal environment of a gas turbine engine 10 can reach temperatures upwards of 1000°C. The embedded imaging system is designed to operate in an environment of at least 450°C so that an internal inspection of gas turbine components, for example, may be performed while the gas turbine engine 10 is operational. Being able to operate in the internal environment of the gas turbine engine 10 enables the embedded imaging unit 30 to be disposed in a location within the outer casing 22 of the gas turbine engine 10 such as the exhaust section of the turbine section 18, on an internal inspection port such as on a blade ring, within a combustion chamber of the gas turbine engine, or within a cavity of the turbine casing 22. For example, the embedded imaging unit 30 shown in Fig. 1 is disposed in the exhaust section 18 of the gas turbine engine 10. The vessel 38 may be attached to a surface of its location, for example, by welding and/or fasteners. [0030] The imaging unit 30 may also include an illumination system coupled to the optical system 40 for illuminating the optical system field of view. For example, the illumination may be delivered by an optical fiber bundle. These fibers or fiber bundle would be capable of operating in the high temperature environment.

[0031] Embodiments feature a method for internal inspection of a gas turbine engine. The method comprises providing an internal inspection system as described above. Cooled, compressed air is supplied to the vessel 38 through a supply line extending from the compressed cooled air source to the vessel 38 in order to cool the vessel 38. Images may be captured of the area encompassing the field of view of the optical system 40. These images may be stored on the processor 34 and analysed. The data may be stored locally on the processor, embodied as an embedded computer that may be interrogated wirelessly by a data center. Either the entire amount or a fraction of the data may be processed on an as needed basis. For example, a triggering event, such as an alarm in the control room, could start the streaming of image data.

[0032] This disclosure describes a scheme where a cooled data-wireless imaging unit may be fully place inside a hot environment, for example a gas turbine engine, to provide continuous or as needed monitoring of critical components. This design eliminates the need for some high cost items typically required for online camera systems such as a flange, pressure window, casing custom drilling or a long optical probe. The proposed system includes a common architecture that fits multiple locations in a gas turbine engine, for example, thus lowering the cost of its production. Furthermore, in the proposed system, the optical system is more compact leading to a much higher resolution. For example, the proposed sensor and image quality is 5 Mpixels as opposed to less than 1 Mpixel for a system requiring an optical probe longer than 500mm. If the imaging sensor has to be placed outside of the engine, a long optical probe may be the only solution to image the target correctly.

[0033] To facilitate an understanding of embodiments, principles, and features of the present disclosure, they are explained hereinafter with reference to implementation in illustrative embodiments. Embodiments of the present disclosure, however, are not limited to use in the described systems or methods. [0034] The components and materials described hereinafter as making up the various embodiments are intended to be illustrative and not restrictive. Many suitable components and materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of embodiments of the present disclosure.

[0035] While embodiments of the present disclosure have been disclosed in exemplary forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the invention and its equivalents, as set forth in the following claims.

Claims

What is claimed is:

1. A system for online internal inspection of a gas turbine engine 10, comprising;

a cooled, pressurized vessel 38 disposed in a location within the outer casing 22 of a gas turbine engine 10;

an imaging optical system 40, having a field of view directed through a hole in the vessel 38 effective to capture images of internal components of the gas turbine engine 10;

an electronic imaging sensor 50, encapsulated within the vessel 38, for capturing an image transmitted by the imaging optical system 40; and

a processor 34 communicatively coupled to the electronic imaging sensor 50 for storing and analyzing the image,

wherein the internal inspection is performed during gas turbine operation.

2. The system as claimed in claim 1, wherein the cooled, pressurized vessel 38 comprises an insulated box including an exterior housing 40 and a plurality of interior nested walls 44 and a supply line 32 to supply cooled air into the interior of the vessel 38,

wherein the cooled air is circulated within an interior passageway of the vessel

38, and

wherein the interior passageway is delimited by the exterior housing 40 and a side of each of the plurality of interior nested walls 44.

3. The system as claimed in claim 2, wherein the cooled air is

compressed air.

4. The system as claimed in claim 1, further comprising a wireless transmitter 48 encapsulated within the vessel 38, and

wherein the electronic imaging sensor 50 communicates with the processor 34 by way of wireless communication using the wireless transmitter 48.

5. The system as claimed in claim 1, wherein the processor 34 is disposed outside of the gas turbine casing 22.

6. The system as claimed in claim 1, wherein the electronic imaging sensor 50 is selected from the group consisting of a visible color camera, an ultraviolet camera, an infrared camera, and a hyperspectral camera.

7. The system as claimed in claim 6, wherein the electronic imaging sensor 50 is a Raspberry Pi camera.

8. The system as claimed in claim 1, wherein the location within the outer casing 22 of the gas turbine engine 10 is selected from the group consisting of an exhaust of the turbine section, on an internal inspection port, within a combustion chamber of the gas turbine engine, and within a cavity of the turbine casing 22.

9. The system as claimed in claim 1, further comprising a power source delivering power to the vessel 38, and

wherein the power source is a high temperature power line 36 routed from the outside of the engine 10 to the vessel 38.

10. An embedded imaging unit 30 for monitoring a component in a high temperature environment, comprising:

an optical system 40, with a field of view;

an electronic imaging sensor 50 for capturing an image transmitted by the optical system 40;

a cooling system adapted to cool the electronic imaging sensor 50;

a processor 34 for storing and analyzing the image; and

a wireless transmitter 48 communicatively coupled to the processor 34 for wirelessly relaying the images from the electronic imaging sensor 50 to the processor 34,

wherein the imaging unit 30 is embedded within a high temperature environment to monitor a plurality of components within the high temperature environment.

11. The imaging unit 30 as claimed in claim 10, further comprising a cooled, pressurized vessel 38 such that the imaging unit 30 is encapsulated within the vessel 38, wherein the vessel 38 is embedded within the high temperature environment.

12. The imaging unit 30 as claimed in claim 10, wherein the high temperature environment is at least 450° C.

13. The imaging unit 30 as claimed in claim 10, wherein the field of view is a wide field of view such that the field of view is >120°.

14. The imaging unit 30 as claimed in claim 10, further comprising an illumination system coupled to the optical system 40 for illuminating the optical system field of view.

15. The imaging unit as claimed in claim 11, wherein the cooling system comprises a supply line 32 supplying cooled air to the interior of the vessel 38.

16. The imaging unit as claimed in claim 10, wherein the processor 34 is disposed outside of the turbine engine casing 22.

17. A method for internal inspection of a gas turbine engine, comprising: providing an internal inspection system, comprising:

a cooled, pressurized vessel 38 disposed in a location within an outer casing 22 of a gas turbine engine 10;

an imaging optical system 40, having a field of view directed through a hole in the vessel 38 effective to capture images of internal components of the gas turbine engine 10,

an electronic imaging sensor 50, encapsulated within the vessel 38, for capturing an image transmitted by the imaging optical system 52;

a processor 34 communicatively coupled to the electronic imaging sensor 50 for storing and analyzing the image;

supplying a cooled, compressed air to the vessel 38 through a supply line 32 extending from the compressed cooled air source to the vessel 38;

capturing an image by the electronic imaging sensor transmitted from the imaging optical system 40; and

storing the image on the processor 34; and

analyzing the image by processor 34.

18. The method as claimed in claim 17, further comprising streaming the image data by the processor 34 to a server.

19. The method as claimed in claim 18, wherein the streaming of image data is commenced by a triggering event.

20. The method as claimed in claim 17, further comprising performing the internal inspection during gas turbine operation.