JPH1172390A - Measuring apparatus for temperature distribution in turbine blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring apparatus, for a temperature distribution, whose structure is simple and by which temperatures in many points can be measured simultaneously. SOLUTION: A plurality of optical fibers 1 are arranged side by side in a row. The respective optical fibers 1 are faced with a turbine blade in such a way that the arrangement direction of the optical fibers 1 becomes the radial direction of the turbine blade. The radiant light of the turbine blade which is fetched by the respective optical fibers 1 is received so as to be converted into a temperature, and a temperature distribution in the radial direction of the turbine blade is found. Temperatures in many points (the temperature distribution) can be measured simultaneously by a simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring temperature from radiation light of a turbine blade, and more particularly to a turbine blade temperature distribution measuring apparatus having a simple structure and capable of measuring multiple points simultaneously.

[0002]

2. Description of the Related Art Gas turbines have turbine blades consisting of a number of blades that rotate about an axis. Since turbine blades become hot during operation, it is desirable to use the temperature of the turbine blades as a control element of the gas turbine. For example, it is possible to provide an optical system for taking in the radiated light facing the turbine blade, provide a light receiver for receiving the radiated light, and measure the temperature from the radiated light intensity. In such a radiation temperature sensor, the light receiver has a strong light receiving sensitivity characteristic in a predetermined wavelength region, and the measurement object changes the wavelength of the radiated light according to the temperature, and the amount of radiation in the above wavelength region changes. , The amount of light received by the light receiver changes, and the output signal of the light receiver changes in proportion thereto. Therefore, the temperature of the measurement target can be measured from this output signal.

[0003]

However, the temperature of the turbine blade is not the same at every location on the blade. In the related art, since the optical system is provided so as to face the turbine blade, when the turbine blade rotates, radiation light from the same diameter portion of the turbine blade is sequentially taken in. For this reason, it is not possible to measure the temperature at portions having different diameters.

In order to change the measurement portion, the installation position of the optical system must be changed, and each time the gas turbine must be stopped, it is inconvenient. Providing a mechanism for moving the optical system is not preferable because the structure becomes complicated. Further, when it is desired to compare the measured temperatures at different positions, the temperatures measured by changing or moving the position of the optical system are not simultaneous temperatures, and therefore cannot be exactly compared.

It is an object of the present invention to solve the above-mentioned problems and to provide a turbine blade temperature distribution measuring apparatus having a simple structure and capable of simultaneously measuring multiple points.

[0006]

In order to achieve the above object, the present invention comprises a plurality of optical fibers, and a temperature distribution measuring unit for receiving radiation light of a turbine blade taken by each optical fiber and converting the radiation light into a temperature. And the optical fibers are arranged in a row in the radial direction of the turbine blade and face the turbine blade.

[0007] A lens system may be provided between the optical fibers and the turbine blade so that the distances between the optical fibers are densely formed and the image of each optical fiber is enlarged and mapped on the turbine blade.

The ferrule accommodating the optical fibers may be formed in a cylindrical shape, and the optical fibers may be arranged along the diameter of the ferrule.

[0009]

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIG. 1, a temperature distribution measuring apparatus according to an embodiment of the present invention comprises an optical fiber bundle 2 in which a plurality of optical fibers 1 are arranged in a line at close intervals.
And a lens system 3 for enlarging and mapping the image of the end face of each optical fiber 1 onto the turbine blade, and receiving the radiated light of the turbine blade taken in by each optical fiber 1 and converting it to a temperature to obtain a temperature distribution. And a temperature distribution measuring section 4. The optical fiber bundle 2 is arranged so that the arrangement direction of the optical fibers 1 is in the radial direction of the turbine blade, and each optical fiber 1 faces the turbine blade, and is fixed to the turbine case.

The turbine blade of the gas turbine has a large number of blades arranged in a circumferential direction. In this figure, only one blade 5 is shown. The lower part of the figure corresponds to the center side of the turbine blade, and the upper part of the figure corresponds to the outer peripheral side of the turbine blade.
Arrow R indicates the direction of rotation of the turbine blade. This blade 5
The mapping 6 of the end face of each optical fiber 1 shown above is arranged in the radial direction. In this embodiment, since the lens system 3 is composed of one convex lens, the mapping 6 is an inverted image.
Therefore, if the reference numerals a, b, c, and d are given to the respective optical fibers 1 in order from the center side of the turbine blade, the mapping 6 on the blade 5 corresponding to the end faces of these optical fibers a, b, c, and d
Are designed to form regions A, B, C, and D in order from the outer peripheral side of the turbine blade. In other words, area A,
The mapping of B, C, and D is the end face of each of the optical fibers a, b, c, and d. That is, the areas A, B, C, and D are the sensing areas of the respective optical fibers 1.

The temperature distribution measuring section 4 is provided with terminals 7 for coupling the optical fibers 1, and the terminals 7 are referred to as terminals a, b, c and d corresponding to the signs of the regions. Although not shown, the temperature distribution measuring unit 4 includes a light receiving element that receives light from the optical fiber 1 and a temperature converter that obtains a temperature value from a light receiving output signal. The light receiving element and the temperature converter may be provided for each terminal 7, or one may be used by switching optically or electrically. The temperature distribution measurement unit 4 can output the temperature distribution of the areas A, B, C, and D. Since the regions A, B, C, and D are arranged in the radial direction of the turbine blade, the temperature distribution in the radial direction can be obtained.

FIG. 2 is a view of the turbine blade viewed from the radial direction. The left and right sides of the figure are in the axial direction of the turbine blade. Arrow R indicates the direction of rotation of the turbine blade. The optical fiber bundle 2 is installed at a position where the space S through which the blade 5 passes is removed in the axial direction. Thus, the optical fiber bundle 2 can be made to face the blade 5 from a direction substantially perpendicular to the surface of the blade 5 without causing interference with the blade 5.

Next, the operation will be described.

[0015] The turbine blades emit radiation when they become hot during operation. This emitted light enters the optical fiber 1 through the lens system 3 and is guided to the light receiving element in the temperature distribution measuring unit 4. Since the light receiving element in the temperature distribution measuring section 4 has strong light receiving sensitivity characteristics in the infrared region, it receives the infrared region of the emitted light and outputs a light receiving output signal proportional to the amount of received light. The intensity and peak wavelength of the emitted light change with temperature. Since the amount of radiated light in the infrared region changes with the change in the intensity and peak wavelength of the radiated light, the amount of light received by the light receiving element changes, and the received light output signal changes. The temperature converter obtains a temperature value from the received light output signal.

Here, since the direction in which the optical fibers 1 are arranged is the radial direction of the turbine blade, the temperatures obtained from the optical fibers a, b, c, and d indicate the regions A, B, and Temperatures of C and D. That is, the temperature distribution measuring unit 4 outputs a discrete temperature distribution arranged in the radial direction along the regions A, B, C, and D.

At the same time, since the turbine blade rotates in the rotation direction indicated by the arrow R, the regions A, B, C, and D move in the opposite directions. Therefore, the time distribution of the temperature distribution in the regions A, B, C, and D output by the temperature distribution measuring unit 4 represents a continuous temperature distribution in the circumferential direction of the turbine blade at each diameter. . As a result, a two-dimensional temperature distribution is obtained.

Thus, each of the optical fibers a, b,
The temperatures of the regions A, B, C, and D corresponding to c and d are measured in parallel. That is, multiple points can be measured simultaneously. Further, since an enlarged image is formed using the lens system 3, a wide range can be measured on the blade 5 while the optical fiber bundle 2 is configured compact. Moreover, the number of the lens system 3 may be one irrespective of the number of the optical fibers 1, and the configuration is simple. The lens system 3 is integrated with the optical fiber bundle 2 by, for example, a cylindrical housing and fixed to a turbine case.

Although four optical fibers are used in the above embodiment, it is needless to say that any number of optical fibers may be used. In addition, although the temperature of the turbine blades of the gas turbine is measured, it can be widely applied to the measurement of the temperature distribution of a rotating mechanism such as a supercharger.

Next, another embodiment of the optical fiber bundle will be described.

As shown in FIG. 3, the optical fiber bundle is
The ferrule 31 for collectively housing the optical fibers 1 is formed in a cylindrical shape, and the optical fibers 1 are arranged along the diameter D of the ferrule 31. This facilitates routing and mounting.

[0022]

The present invention exhibits the following excellent effects.

(1) The temperatures at multiple points of a rotating object can be measured simultaneously.

(2) The structure is simple because no moving mechanism is required.

(3) A two-dimensional temperature distribution is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a temperature distribution measuring device according to an embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement of optical fibers of the temperature distribution measuring device of the present invention.

FIG. 3 is a perspective view of an optical fiber bundle showing another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 optical fiber 3 lens system 4 temperature distribution measuring unit 5 blade 6 mapping of end face of optical fiber

Claims (3)

[Claims] A plurality of optical fibers; and a temperature distribution measuring section for receiving radiation light of the turbine blade taken by each optical fiber and converting the radiation light into a temperature, wherein the optical fibers are arranged in a row in a radial direction of the turbine blade. A turbine blade temperature distribution measuring device, which is disposed at a position facing a turbine blade. 2. The method according to claim 1, wherein the optical fibers are closely spaced.
2. The turbine blade temperature distribution measuring device according to claim 1, wherein a lens system for enlarging and mapping an image of each optical fiber onto the turbine blade is provided between the optical fiber and the turbine blade. 3. The ferrule for accommodating the optical fibers collectively is formed in a cylindrical shape, and the optical fibers are arranged along the diameter of the ferrule.
A temperature distribution measuring device for a turbine blade as described in the above.