JP3091053B2 - Steam leak detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam leak detecting device which can be used for inspection of various plants, and more particularly to a steam leak detecting device using light for detecting means.

[0002]

2. Description of the Related Art FIG. 6 shows, for example, JP-A-63-309831.
FIG. 1 is a schematic view showing an optical unit of a conventional steam leak detection device shown in Japanese Patent Application Publication No. JP-A-2006-115, in which reference numeral 1 denotes a steam transfer pipe installed in a plant, 2 denotes steam leaked from the pipe 1, and 3 denotes a steam. The laser 3-1 is a laser beam emitted from the laser 3.

Further, reference numeral 41 denotes scattered light generated by the laser 3 irradiating the vapor 2, and reference numeral 42 denotes the laser beam 3.
Scattered light generated by -1 hitting a wall is a stereo mirror 5 that captures the same scene from two windows and independently forms light from each window on one image sensor surface.

Further, reference numerals 51 and 52 denote first and second windows for taking in respective screens, 61 denotes a first analyzer having a polarization direction parallel to the irradiation laser attached to the first window 51, and 62. Is a second analyzer whose polarization direction is perpendicular to the irradiation laser mounted on the second window 52, 71 and 72 are mirrors mounted in the stereo mirror 5,
8 is a television camera.

FIG. 7 is a side view showing an installation state of the optical unit. In the figure, reference numeral 8-1 denotes a central axis of the light receiving unit, and reference numeral 24 denotes a tilt angle of the optical axis of the central axis 8-1 of the light receiving unit with respect to the laser beam 3-1.

FIG. 8 is a view showing an output image from the television camera 8. In the figure, 26-1 is the left half of the obtained image, 26-2 is the right half of the obtained image, 10-1, 1
0-2 is a bright spot generated by the scattered light 42 from the wall, 3-
1-1 and 3-1-2 are trajectories (not existing as images) indicated by the laser beam 3-1.

[0007] Also, 27-1 and 27-2 are pixel rows corresponding to one horizontal screen element on the image, and 28 is a horizontal scanning line from a bright point of the image to a horizontal scanning point at which a bright point due to vapor leakage occurs. Is the number N ₁ .

FIG. 9 is a block diagram of the signal processing unit. In the figure, reference numeral 15 denotes a comparator, which binarizes a video signal from the television camera 8. Reference numeral 18 denotes a synchronizing signal separating circuit for separating a synchronizing signal from a video signal. 29 denotes a switching circuit which separates a binarized video signal into sections corresponding to left and right half screens of an image. Send each to the video memory.

Reference numeral 30 denotes a control circuit for controlling the operation of each circuit in the signal processing circuit unit, and reference numeral 31 denotes an address counter, which counts the position of a horizontal scanning line where a bright spot has occurred in the vertical direction of the image. The video memories 32-1 and 32-2 store video signals of the left and right screens of the obtained image. The first and second video memories 33 are comparison circuits, and the first and second video memories 32-1 and 32-2.
The contents on the same horizontal scanning line accumulated in -2 are compared.

Reference numeral 34 denotes a determination circuit which detects the presence / absence of steam leakage from the output of the comparison circuit 33 and the output of the address counter 31 and measures the position of a bright spot caused by the steam leakage.

Next, the operation will be described. When a laser beam 3-1 emitted from a laser 3 and having a linear polarization characteristic is applied to steam 2 leaking from a steam transport pipe 1 in a plant, scattered light 41 is generated from the steam 2 and scattered light is also emitted from a wall. 42 occurs.

As shown in FIG. 7, when the center axis 8-1 of the stereo mirror 5 and the irradiated laser beam 3-1 are arranged on the same plane so as to intersect with a tilt angle of 24, the laser beam 3-1 becomes As shown in FIG. 8, a locus 3-1-1 is drawn on the left half surface 26-1 of the imaging device, and a locus 3-1-2 is drawn on the right half surface 26-2.

Here, since the scattered light 42 from the wall does not maintain the linear polarization characteristic of the laser beam 3-1, it passes through both the first analyzer 61 and the second analyzer 62 of the stereo mirror 5, and the screen The bright spot 10-1 on the locus 3-1-1 of the left half screen and the locus 3-1 of the right half screen symmetrically with respect to the center line.
A bright point 10-2 is generated on -2.

On the other hand, the scattered light 41 from the vapor 2 passes only through the first analyzer 61 whose polarization direction is parallel to the laser beam 3-1 to maintain the linear polarization characteristic of the laser beam 3-1. Bright spot 1 only on half screen locus 3-1-1
1 is generated.

Further, based on the principle of triangulation, the scattered light from the TV camera 8 due to the steam 2 is obtained from the vertical distance between the starting point 3-2-1 of the locus 3-1-1 and the bright spot 11 due to the steam 2 in the screen. It is possible to determine the distance to the position where 41 has occurred.

Also, as shown in FIG.
Are binarized by the comparator 15 and input to the switching circuit 29. On the other hand, the control circuit 30 controls each circuit in the signal processing circuit using the synchronization signal and the clock signal obtained from the synchronization signal separation circuit 18.

In this manner, the binary video signal input to the switching circuit 29 is divided according to the left and right half screens by the control signal from the control circuit 30.
The video signal of the left half surface 26-1 is transmitted to the first video memory 32.
-1 and the video signal of the right half screen 26-2 are sent to the second video memory 32-2.

After the video signal of one screen is sent to each of the video memories 32-1 and 32-2 in this manner, the signals on the same horizontal scanning line of each of the video memories 32-1 and 32-2 are output. The comparison is performed sequentially by the comparison circuit 33. If the positions of the bright spots 10-1 and 10-2 at the left and right portions are symmetrical, it is determined that the bright spots are caused by the scattered light from the wall.

On the other hand, the address counter 31 counts the number of horizontal scanning lines compared by the comparison circuit 33,
The counting result is sequentially determined from the output of the determination circuit 34 to determine the presence / absence of steam leakage, and the counting result of the address counter 31 of the horizontal scanning line determined to have steam leakage is extracted,
By detecting the position on the screen where the bright spot 11 due to the steam is generated, the distance to the position where the steam leak occurs is detected.

[0020]

Since the conventional vapor leak detecting device is constructed as described above, the scattered light is received by the two-dimensional image pickup device of the television camera 8, and the vapor leak is detected by comparing the two images. The presence / absence and occurrence position must be measured, and therefore, there is a problem that real-time processing is difficult, and the configuration of the signal processing unit is complicated and the cost is increased.

The first aspect of the present invention has been made in order to solve the above-mentioned problems, and it is possible to detect the presence / absence of a steam leak and the position where the steam leaks by a simple signal processing unit in real time. It is an object of the present invention to obtain a steam leak detector capable of detecting the degree of the steam leak.

It is another object of the present invention to provide a steam leak detecting device which can determine that there is no steam leak when the center of gravity of the scattered light is near the center line of the trajectory of light.

A third object of the present invention is to provide a steam leak detecting device which can obtain a difference between output signals of a light receiving means when a steam leak occurs and a steam leak does not occur to eliminate disturbance.

According to a fourth aspect of the present invention, the position of the steam leak and the degree of the steam leak are detected from the difference between the output signals of the first light position detecting element and the second light position detecting element and the center of gravity of the scattered light image. It is an object of the present invention to obtain a steam leak detection device capable of performing the above-described steps.

A fifth object of the present invention is to provide a vapor leak detecting device capable of removing disturbance by applying intensity modulation to irradiation light at a specific frequency .

It is another object of the present invention to provide a steam leak detecting device capable of detecting the position of a steam leak and the degree of the steam leak using a non-polarized laser.

Another object of the present invention is to provide a steam leak detecting device capable of preventing deterioration of detection accuracy of steam leak due to fluctuation of steam.

[0028]

According to a first aspect of the present invention, there is provided a vapor leak detecting device for detecting a position of a luminescent spot caused by scattered light and the luminance of the luminescent spot, and an optical position detecting element constituting light receiving means; A center-of-gravity detection circuit for detecting a center of gravity of the image of the scattered light based on an output of the light position detection element; and a determination circuit includes a center-of-gravity position detected by the center-of-gravity detection circuit and an output signal of the light position detection element. Based on this, the position where steam is generated and the degree of steam leakage are determined.

According to a second aspect of the present invention, there is provided a steam leak detecting apparatus, wherein a determination circuit detects a steam generation position and a degree of the steam leak based on an output signal of the light position detecting element and a center of gravity position detected by the center of gravity detection circuit. And let
When the center of gravity of the image caused by the scattered light is located near the center line of the trajectory of the light passing through the first analyzer and the trajectory of the light passing through the second analyzer, This is so as not to be judged as a leak.

According to a third aspect of the present invention, there is provided a steam leak detecting device which calculates a difference between a signal of the light receiving means in a state where no steam leak occurs and a signal of the light receiving means at the time of the steam leak detecting operation. It was done.

According to a fourth aspect of the present invention, there is provided a vapor leak detecting device, comprising: a light projecting means for irradiating a light having linear polarization characteristics to an object to be measured; An analyzer; a second analyzer having a polarization direction perpendicular to the irradiation light;
A first light position detection element imaged through an analyzer of
The difference between the signal obtained from the second light position detecting element and the second light position detecting element to which the light scattered by the measurement object is coupled through the second analyzer is obtained. A subtractor, and a center-of-gravity detection circuit that detects a center-of-gravity position of the image of the scattered light from an output signal of the subtractor; a determination circuit includes a center-of-gravity position detected by the center-of-gravity detection circuit and an output signal of the subtractor. Based on this, the position where the steam leak has occurred and the degree of the steam leak are determined.

According to a fifth aspect of the present invention, there is provided a vapor leak detecting apparatus for performing intensity modulation on irradiation light at a specific frequency, and outputting a signal used for the intensity modulation among the output signals of the light position detecting element.
Only the signal of the wave number is taken out.

A vapor leak detecting device according to a sixth aspect of the present invention is a vapor leak detecting device for irradiating an object to be measured with non-polarized light, and only the first light of a specific polarization direction out of the light emitted from the light projecting device.
First modulation means for performing intensity modulation at a specific frequency, and second modulation means for performing intensity modulation only on light whose polarization direction is perpendicular to the first light at a specific frequency different from that of the first modulation means. An analyzer having a polarization direction parallel to the first light, a light receiving means for forming an image of scattered light from the object to be measured on the optical position detecting element through the analyzer, and a signal obtained from the light receiving means. A subtractor for selecting a signal of the frequency used by the first modulating means and the second modulating means, and taking a difference between these signals, and an image of scattered light from an output signal of the subtractor. A center-of-gravity detecting circuit for detecting the position of the center of gravity of the steam leak, and the determination circuit determines the position of the steam leak and the degree of the steam leak based on the center of gravity detected by the center of gravity detecting circuit and the output signal of the subtractor. What was made to be judged A.

According to a seventh aspect of the present invention, there is provided a vapor leak detecting device for extracting only an AC component due to a fluctuation of steam from a signal obtained by an optical position detecting element.

[0035]

According to a first aspect of the present invention, there is provided a steam leak detecting device comprising:
Since the position of the steam leak and the degree of the steam leak correspond to the position of the bright spot on the light position detecting element and the number of the bright points, respectively, the center of gravity position and the brightness of the image on the light position detecting element are calculated by simple four arithmetic operations. Then, the position of the steam leak and its brightness are detected in real time by a simple analog circuit.

The vapor leak detecting device according to the second aspect of the present invention determines the presence or absence of a steam leak by the determination circuit based on the position of the center of gravity of the image due to the scattered light on the light position detecting element.

According to a third aspect of the present invention, there is provided a vapor leak detecting device for removing disturbance from a difference between respective output signals of the optical position detecting device when a steam leak occurs and when no steam leak occurs.

According to a fourth aspect of the present invention, there is provided a vapor leak detecting device which can determine a position and a degree of a steam leak by a determination circuit based on a difference between signals obtained from one light position detecting element through two analyzers. I do.

According to a fifth aspect of the present invention, the steam leak detecting device modulates the intensity of the irradiation light at a specific frequency, thereby obtaining an output signal from the light position detecting element.
And obtains only the signal having

According to a sixth aspect of the present invention, there is provided a vapor leak detecting apparatus, wherein the first light and the second light in the orthogonal deflecting direction of the irradiation light are intensity-modulated at different frequencies from each other, and are received by the light receiving means. Signal used in each of the above modulations
The signals of the respective frequencies are separated and selected and taken out, and the position and the degree of the steam leak are determined by the determination circuit from the difference between these signals.

The steam leak detecting device according to the seventh aspect of the present invention extracts and removes the alternating current component of the scattered light based on the fluctuation of the steam, thereby improving the measurement accuracy of the position and degree of the steam leak.

[0042]

[Embodiment 1] An embodiment of the first aspect of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 80 generally has a rectangular light receiving surface.
On the top, bottom, left and right sides.
Output electrical signals according to the light receiving position and light intensity
Dimensional optical position detection element as a light position detecting element for, 8
Reference numeral 1 denotes a left edge and a right edge of the two-dimensional light position detecting element 80.
Light-receiving surface based on the output signal from the electrode attached to the
Calculate the horizontal coordinate of the center of gravity of the upper bright spot
Together with the upper and lower ends of the two-dimensional light position detecting element 80
Based on the output signal from the electrode attached to the side of
Calculate the vertical coordinate of the center of gravity of the bright spot on the light receiving surface
The outputted center-of-gravity detecting circuit 82 is a determination circuit, which measures the degree of steam leakage and the position of occurrence based on the output signal of the two-dimensional optical position detecting element 80 and the position of the center of gravity detected by the center-of-gravity detecting circuit 81.

FIG. 2 is a diagram showing an image formed on the two-dimensional light position detecting element 80. In the figure, 26-1 is the left half of the obtained image, 26-2 is the right half of the obtained image,
1-1 and 3-1-2 are trajectories (not existing as images) indicated by the laser beam 3-1.

Next, the operation will be described. In the steam leak detection device of this embodiment, the scattered light from the wall is reflected by the optical axis of the central axis 8-1 of the light receiving means including the stereo mirror 5.
By adjusting the tilt angle 24 with respect to the laser 3-1, it is possible to prevent an image from being formed on the two-dimensional light position detection element 80. When steam 2 is generated, steam 2
Scattered light 41 from the trajectory 3-1 of the left half surface 26-1 of the image
The bright spot 11-1 is generated only on the spot No. 1.

Here, the degree of the vapor leakage corresponds to the luminance of the bright point 11-1, and the distance from the light receiving system to the vapor generation point is the vertical direction of the bright point 11-1 on the two-dimensional light position detecting element 80. Therefore, the degree of steam leakage and the position of occurrence can be measured by the determination circuit 82 from the output signal of the two-dimensional optical position detection element 80 and the output signal of the center of gravity detection circuit 81.

Embodiment 2 FIG. When an object other than vapor enters the measurement area, the locus 3-1 of the right half surface 26-2 of the image
Since the bright spot 11-2 is also generated on the bright spot 11-2, two bright spots 1
The center of gravity of 1-1 and 11-2 is near the center line of the image 11-3
, And can be distinguished from a steam leak.

Embodiment 3 FIG. In the first embodiment, by adjusting the tilt angle 24 that the optical axis of the central axis 8-1 of the light receiving means has with respect to the laser beam 3-1, the light scattered by the wall is reflected on the two-dimensional light position detecting element 80. Although it is shown that no image is formed, the output signal of the two-dimensional light position detecting element 80 in a state in which no vapor leakage occurs, and the output signal of the two-dimensional light position detecting element 80 during the detection operation. The same operation can be expected by taking the difference of

Embodiment 4 FIG. FIG. 3 is a block diagram of a light receiving unit and a signal processing unit according to an embodiment of the fourth aspect of the present invention. In the drawing, reference numeral 83 denotes an imaging lens, and 84 branches light passing through the imaging lens 83 in two directions. A half mirror 85-1 is a first analyzer whose polarization direction is parallel to the irradiated laser beam, and a second analyzer 85-2 whose polarization direction is perpendicular to the irradiated laser beam.

Reference numeral 86-1 denotes a first two-dimensional light position detecting element (first light position detecting element) for receiving light passing through the analyzer 85-1, and reference numeral 86-2 denotes a detector 85-2. A second two-dimensional light position detecting element (second light position detecting element) 87 that receives the passed light, 87 is a two-dimensional light position detecting element 86
-1, 86-2.

Further, reference numeral 81 denotes a center-of-gravity detecting circuit for calculating the center of gravity of the image from the output signal of the subtracter 87, and reference numeral 82 denotes a determination circuit, which is the output signal of the subtractor 87 and the center of gravity detected by the center-of-gravity detecting circuit 81. Measure the degree and location of steam leak from

FIGS. 4A and 4B show images formed on the first two-dimensional light position detecting element 86-1 and the second two-dimensional light position detecting element 86-2, respectively. 3, 3-1-1 and 3-1-2 are trajectories (not present as images) indicated by the laser beam 3-1.

Next, the operation will be described. In the vapor leak detection device of this embodiment, the scattered light 42 from the wall passes through both the first analyzer 85-1 and the second analyzer 85-2, and the first two-dimensional light position detecting element 86 Bright spot 10- on the locus 3-1-1 of the laser beam 3-1 on
1. A bright spot 10-2 is generated on a locus 3-1-2 of the laser beam 3-1 on the second two-dimensional light position detecting element 86-2.

On the other hand, the scattered light 41 from the vapor 2 passes only through the first analyzer 85-1 whose polarization direction is parallel to the irradiation laser beam, and the laser light on the first two-dimensional light position detecting element 86-1 A bright point 11-1 is generated on the beam locus 3-1-1.

Here, by subtracting the output signal of the second two-dimensional light position detecting element 86-2 from the output signal of the first two-dimensional light position detecting element 86-1 by the subtracter 87, the scattered light by the wall is obtained. By removing the influence of 42, it is possible to measure the degree and location of the occurrence of steam leakage by the center-of-gravity detection circuit 81 and the determination circuit 82 as in the first embodiment.

Embodiment 5 FIG. Further, in the above Examples 1 to 4, the laser beam 3-1 was used.
To perform intensity modulation at a specific frequency, two-dimensional optical position detecting element 80, a first two-dimensional optical position detector element 86-1 of the second output signal of the two-dimensional optical position detector element 86-2, the By extracting only the signal of the frequency used in the intensity modulator, the influence of disturbance light in another frequency band can be removed, and the measurement accuracy can be improved.

Embodiment 6 FIG. FIG. 5 shows an embodiment of claim 6, in which 88 is a non-polarized laser, 89 is a polarizing beam splitter for separating the laser beam from the non-polarized laser 88 into two lights whose polarization directions are orthogonal to each other, 90. ,
91 is a mirror, and 92-1 and 92-2 are the first light and the second light separated by the polarization beam splitter 89.

Also, 93-1 and 93-2 are the first
Light 92-1, respectively different specific to the second optical 92-2
First modulating means for applying intensity modulation at a frequency of
A light intensity modulator 94 as a modulating means, a polarizing beam splitter 94 for superimposing the separated light again, an analyzer 95 having a polarization direction parallel to that of the first light 92-1, and an imaging lens 96 (light receiving lens). Means) and 97 are light position detecting elements.

Further, amplifiers 98-1 and 98-2 select and amplify only the signals of the frequencies used in the light intensity modulators 93-1 and 93-2 , respectively, and 99 denotes an amplifier 98-98. 1
And a subtractor for subtracting the output signals of the second and 98-2.

Reference numeral 81 denotes a center-of-gravity detection circuit for calculating the position of the center of gravity of the image from the output signal of the subtractor 99, and reference numeral 82 denotes a determination circuit. Measure the extent and location of the vapor leak.

Next, the operation will be described. In the vapor leak detection device of this embodiment, the first light 92- reflected and scattered by a wall or the like of the laser beam from the unpolarized laser 88 that has been subjected to light intensity modulation at a specific frequency.
Since the first and second lights 92-2 are randomly polarized, they both pass through the analyzer 95.

On the other hand, since the direction of polarization of the scattered light 41 scattered by the vapor 2 is preserved, the first light 92-1 passes through the analyzer 95 whose polarization direction is parallel, but the second light 92-2.
Does not pass.

Therefore, the amplifiers 98-1 and 98-2 use
Used in the light intensity modulators 93-1 and 93-2 , respectively .
By selectively amplifying only the signal of the frequency and taking the difference signal by the subtractor 99, the influence of the scattered light 42 due to the wall is removed, and the steam leakage is performed by the gravity center detection circuit 81 and the determination circuit 82 as in the first embodiment. It is possible to measure the degree of occurrence and the position of occurrence.

Embodiment 7 FIG. Further, each of the above embodiments 1, 4, and 6
Since the scattered light 41 due to the steam 2 includes not only a DC component but also an AC component of a specific frequency due to the fluctuation of the steam, the two-dimensional light position detecting element 80, the first two-dimensional light position detecting element 86-1, Second two-dimensional light position detecting element 86
-2: By extracting only the AC component of the specific frequency band from the output signal of the optical position detecting element 97, the influence of disturbance light can be removed, and the measurement accuracy can be improved.

Embodiment 8 FIG. In the fourth to seventh embodiments, a one-dimensional light detecting element is used instead of the first two-dimensional light position detecting element 86-1, the second two-dimensional light position detecting element 86-2, and the light position detecting element 97. The same effect as in the above embodiment can be obtained even if the laser beam is arranged along the trajectory of the laser beam.

[0065]

As described above, according to the first aspect of the present invention, the position of a luminescent spot caused by scattered light and the brightness of the luminescent spot are detected, and the light position detecting element constituting the light receiving means; A center-of-gravity detection circuit that detects the center of gravity of the image of the scattered light based on the output of the detection element; and a determination circuit based on the center-of-gravity position detected by the center-of-gravity detection circuit and an output signal of the light position detection element. Therefore, since the configuration is made so as to determine the steam generation position and the degree of the steam leakage, an effect is obtained in which the degree and the position of the steam leakage can be detected in real time by a simple analog circuit. is there.

According to the second aspect of the present invention, the determination circuit determines the generation position of the steam and the degree of the steam leakage based on the position of the center of gravity detected by the center of gravity detection circuit and the output signal of the light position detection element. At the same time, when the center of gravity of the image due to the scattered light is located near the center line of the trajectory of the light that has passed through the first analyzer and the trajectory of the light that has passed through the second analyzer on the optical position detection element, Since it is configured not to determine that there is a vapor leak, there is an effect that it is possible to easily determine whether or not there is a vapor leak based on the position of the center of gravity of the scattered light.

According to the third aspect of the present invention, the difference between the signal of the light receiving means in a state in which no steam leak occurs and the signal of the light receiving means in the steam leak detecting operation is obtained. There is an effect that the position and the degree of the vertical leakage can be detected without affecting the disturbance.

According to the fourth aspect of the present invention, the light projecting means for irradiating the object to be measured with light having linear polarization characteristics, the first analyzer having a direction of polarization parallel to the light emitted from the light projecting means, A second analyzer whose polarization direction is perpendicular to the irradiation light, a first light position detecting element in which scattered light of the irradiation light by the measurement target is imaged through the first analyzer, A second light position detecting element to which the scattered light is coupled through a second analyzer, a subtracter for calculating a difference between signals obtained from the first light position detecting element and the second light position detecting element;
A center-of-gravity detection circuit for detecting the position of the center of gravity of the image of the scattered light from the output signal of the subtractor, wherein the determination circuit, based on the position of the center of gravity detected by the center-of-gravity detection circuit and the output signal of the subtractor, Since it is configured to determine the location of the steam leak and the degree of the steam leak, the location and the extent of the steam leak can be more accurately detected from the difference between the output signals of the two optical position detecting elements and the center of gravity of the image. There is an effect that what can be obtained is obtained.

According to the fifth aspect of the present invention, a specific
Since the intensity modulation is performed at the frequency and only the signal of the frequency used in the intensity modulation is extracted from the output signals of the optical position detecting element, there is an effect that a signal that can reliably remove the influence of disturbance can be obtained. .

According to the invention of claim 6, the light projecting means for irradiating the object to be measured with non-polarized light, and only the first light in a specific polarization direction among the light emitted from the light projecting means at a specific frequency. A first modulator for performing intensity modulation, a second modulator for performing intensity modulation only on light whose polarization direction is perpendicular to the first light at a frequency different from that of the first modulator, and An analyzer whose polarization direction is parallel to the light; a light receiving means for forming an image of the scattered light from the object to be measured on the optical position detecting element through the analyzer; and a first modulation based on a signal obtained from the light receiving means. Means for selecting the signals of the frequencies used by the means and the second modulating means , respectively, and taking the difference between these signals; and from the output signal of the subtractor, A center-of-gravity detection circuit for detecting a center-of-gravity position; Based on the output signal of the detected gravity center position and said subtractor, since it is configured so as to determine the extent of the generation position and its steam leakage of the steam leakage, 1
There is the effect that the degree of vapor leakage and the position where the vapor leaks can be detected more accurately by the two light position detecting elements without the influence of disturbance light is obtained.

According to the seventh aspect of the present invention, since only the AC component due to the fluctuation of the steam is extracted from the signal obtained by the optical position detecting element, the influence of the disturbance light due to the fluctuation of the steam can be removed. Thus, there is an effect that a device that can accurately detect the position of the steam is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing the vicinity of a light receiving section of a steam leak detection device according to one embodiment of the inventions of claims 1 to 3;

FIG. 2 is an explanatory diagram showing an image formed on a two-dimensional light position detecting element in FIG. 1;

FIG. 3 is a configuration diagram showing a light receiving section and a signal processing section in a steam leak detection device according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing an image formed on a two-dimensional position detecting element according to the invention of claim 5;

FIG. 5 is a configuration diagram showing a leak detection device according to one embodiment of claims 6 and 7;

FIG. 6 is a schematic view showing a conventional steam leak detection device.

FIG. 7 is a side view showing an installation state of an optical unit of a conventional steam leak detection device.

FIG. 8 is an explanatory diagram showing an output image from the television camera in FIG. 6;

FIG. 9 is a block diagram showing a signal processing unit in a conventional steam leak detection device.

[Explanation of symbols]

Reference Signs List 3 laser (light projection means) 61 first analyzer 62 second analyzer 80 optical position detecting element (two-dimensional optical position detecting element) 81 center of gravity detecting circuit 82 determining circuit 85-1 first analyzer 85-2 Second analyzer 86-1 First two-dimensional light position detecting element (first light position detecting element) 86-2 Second two-dimensional light position detecting element (second light position detecting element) 87 Subtractor 88 Non-polarized laser (light projection means) 93-1 Light intensity modulator (first modulation means) 93-2 Light intensity modulator (second modulation means) 95 Analyzer 96 Imaging lens (light receiving means) 97 light Position detection element 99 Subtractor

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-309831 (JP, A) JP-A-4-54411 (JP, A) JP-A-5-75641 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G01M 3/38 G01C 3/06

Claims (7)

(57) [Claims] 1. A light projecting means for irradiating light having linear polarization characteristics to a measurement object, a first analyzer having a direction of polarization parallel to the light emitted from the light projecting means, and a polarized light for the irradiation light. A second analyzer having a perpendicular direction, and light receiving means for separating and independently forming an image of the scattered light of the irradiation light by the object to be measured on the same light receiving surface through the first analyzer and the second analyzer. In the vapor leak detection device comprising: detecting the position of the bright spot by the scattered light and the brightness of the bright spot, the light position detecting element constituting the light receiving means, based on the output of the light position detecting element, A center-of-gravity detection circuit for detecting a center-of-gravity position of the image of the scattered light; and a position where the steam is generated and a degree of the steam leakage are determined based on the center-of-gravity position detected by the center-of-gravity detection circuit and an output signal of the light position detection element. Judgment circuit A steam leak detector characterized by the above-mentioned. 2. A light projecting means for irradiating a light having a linear polarization characteristic to a measurement object, a first analyzer having a direction of polarization parallel to light irradiated from the light projecting means, and a polarized light for the irradiation light. A second analyzer having a perpendicular direction, and light receiving means for separating and independently forming an image of the scattered light of the irradiation light by the object to be measured on the same light receiving surface through the first analyzer and the second analyzer. In the vapor leak detection device comprising: detecting the position of the bright spot by the scattered light and the brightness of the bright spot, the light position detecting element constituting the light receiving means, based on the output of the light position detecting element, A center-of-gravity detection circuit for detecting a center-of-gravity position of the image of the scattered light; and a position where the steam is generated and a degree of the steam leakage are determined based on the center-of-gravity position detected by the center-of-gravity detection circuit and an output signal of the light position detection element. And the above optical position detection If the center of gravity of the image due to the scattered light is located near the center line of the trajectory of the light passing through the first analyzer and the trajectory of the light passing through the second analyzer, A steam leak detection device, comprising: a judgment circuit that does not judge that the steam leaks. 3. The steam leak detecting device according to claim 1, wherein a difference between a signal of the light receiving means in a state where no steam leak occurs and a signal of the light receiving means at the time of the steam leak detecting operation is obtained. 4. A light projecting means for irradiating the object to be measured with light having a linear polarization characteristic, a first analyzer whose polarization direction is parallel to the light emitted from the light projecting means, A second vertical analyzer, a first light position detecting element in which the scattered light of the irradiation light by the object to be measured is imaged through the first analyzer, and a scattered light by the object of measurement in the second analyzer A second light position detecting element imaged through photons, a subtractor for obtaining a difference between signals obtained from the first light position detecting element and the second light position detecting element, and an output signal of the subtractor A center-of-gravity detection circuit for detecting a center-of-gravity position of the image of the scattered light from
A steam leak detection device comprising: a determination circuit for determining a steam leak occurrence position and a degree of the steam leak based on a gravity center position detected by the gravity center detection circuit and an output signal of the subtractor. 5. The method according to claim 1 , wherein the intensity of the irradiation light is modulated at a specific frequency, and only the signal of the frequency is extracted from the output signal of the optical position detecting element. Steam leak detector. 6. A light projecting means for irradiating the object to be measured with unpolarized light, and a first means for applying intensity modulation at a specific frequency to only a first light in a specific polarization direction among the light emitted from the light projecting means. A modulating means, a second modulating means for performing intensity modulation only on the light having a polarization direction perpendicular to the first light at a specific frequency different from that of the first modulating means; A parallel analyzer, light receiving means for forming an image of the scattered light from the object to be measured on the light position detecting element through the analyzer, and the first modulating means and the second modulating means based on signals obtained from the light receiving means. A subtractor that selects each of the signals of the frequencies used by the modulating means, and takes the difference between these signals, and a centroid detection circuit that detects the position of the centroid of the image of the scattered light from the output signal of the subtractor, The position of the center of gravity detected by the center of gravity detection circuit and the output of the subtractor A steam leak detection device comprising: a determination circuit that determines a position where the steam leak occurs and a degree of the steam leak based on a signal. 7. The method according to claim 1, wherein only an AC component due to a fluctuation of the steam is extracted from a signal obtained by the optical position detecting element.
The steam leak detection device according to any one of claims 4 and 6.