JP2996323B2 - Gas leak position detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a gas leak position from a pipe or various devices in a factory or the like.

[0002]

2. Description of the Related Art Conventional methods for detecting gas leakage from pipes and various devices in a wide area in a factory or the like generally include a method of directly detecting a leaked gas and the like. In the case of low-temperature liquefied gas or high-temperature gas, there is a method of indirectly detecting a temperature abnormality due to gas leakage,
These include the following: A method in which a sensor such as a gas detector or a thermometer that detects gas concentration in the atmosphere is installed at each location where there is a possibility of leakage, and detection is performed by these sensors. Laser light or infrared light is emitted from the light transmitting device toward the monitoring area, and the light beam passing through the monitoring area is received by the light receiving device,
A method of detecting leakage by detecting the presence of gas based on changes in the amount of laser light or infrared absorption spectra. A method of detecting a leaked gas by scanning a monitoring area with a laser light reflection type gas detector that measures the concentration of gas by reflection of laser light by the gas instead of the laser light transmission type gas detector shown in (1). A method of scanning and monitoring an object to be monitored by moving an infrared detector along a monitored object along a traveling rail, and detecting a leak of fluid based on a temperature abnormality in an output of the infrared detector. (For example, one in which a plurality of traveling rails are provided around the object to be monitored and the plurality of infrared detectors are moved vertically along the object to be monitored is disclosed in Japanese Utility Model Application No. 59-45803 (Japanese Utility Model Application No. 60-158298). ), And the one that runs with the running rail spirally around the object to be monitored, see the microfilm of Japanese Utility Model Application No. 59-45804 (Japanese Utility Model Application No. 60-158299).

[0003]

In addition to the problem that the method of the present invention requires a large amount of initial cost and also requires a large amount of cost and manpower for the maintenance thereof, low temperatures from unforeseeable places are required. There is a fundamental defect that fluid leakage cannot be accommodated, and such a defect cannot be solved by increasing the number of sensors. In addition to the fact that the method of the above requires the installation of a receiver, receiver or reflector across the monitored area, such a method is essentially
It detects the direction including the leaking part,
In order to specify the position of the leak, a large number of pairs of sending and receiving devices are provided two-dimensionally, and a moving means of the device for scanning is required. In this method, the sensor is predicted to leak as described above. It has the same fundamental flaw as installing it in a location. The method of the method essentially detects the direction including the position of the leak, the method cannot detect the position of the leak, and the leak points are located at a plurality of places in the same direction. Even if they exist, they cannot be distinguished. In the method of (1), when the monitoring target is large or the monitoring target area is wide, the scale becomes large. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a method capable of detecting gas leakage in a monitoring area together with its position by using a directional gas detector rationally. Is what you do.

[0004]

In order to solve the above-mentioned problems, according to the present invention, a directional gas detector is located at at least two points apart from each other, and each gas detector is placed in a lateral direction. By rotating and scanning, the gas concentration distribution in the target area with respect to each scanning angle is measured, and the gas leak position in the target area is detected from each scanning angle corresponding to the concentration increase point in the measured gas concentration distribution. A method is proposed in which the target area is captured as an image by a camera, and the gas leak position detected by the gas detector is displayed in a superimposed manner on the image to detect the gas leak position.

According to the present invention, in the above method, the gas detector is fixedly installed at a distance,
It is proposed to be configured to be movable and to be located at a point separated by movement.

The present invention proposes to use a laser light reflection type gas detector as a gas detector to which the above method is applied.

Further, the present invention proposes that the camera to which the above method is applied is an ITV camera.

[0008]

By rotating and scanning each gas detector in the horizontal direction, the gas concentration distribution in the target area with respect to each scanning angle can be measured. Therefore, the point where the concentration increases in the target area can be regarded as the direction, that is, the scanning angle of the gas detector.

If these measurements are made at least two points apart from each other, a triangulation method can be performed based on this distance and the scanning angle corresponding to the concentration increase point in the gas detector at each point. Can be used to determine the position of the concentration increase point, that is, the gas leakage position.

As described above, the gas leakage position can be obtained by measuring at least two points. However, by measuring at more points, the concentration distribution at the target part can be obtained. .

The gas leakage position obtained by the above procedure is a two-dimensional position, that is, a position on a plane, and the position in the height direction is unknown.

Therefore, in the present invention, the target area is captured as an image by a camera, and a gas leak position detected by the gas detector is displayed in a superimposed manner in the image. Since the display in the image is a projection of the position on the plane onto the plane, the display is one-dimensional, that is, displayed at the horizontal position in the image. Therefore, the observer can detect the gas leakage position in a pseudo three-dimensional manner from the position display and the image in the image.

In applying the above-described method, the gas detector can be fixedly installed at a point separated by a distance or configured to be movable, and can be positioned at a point separated by movement.

As a gas detector to which the above method is applied, a laser light reflection type gas detector can be used.

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing an embodiment to which the detection method of the present invention is applied. In the figure, a portion surrounded by a two-dot chain line shows a monitoring target area 1 for convenience. The gas detectors 2a and 2b are installed at two points within the target area 1 or outside the target area 1 and separated by a distance L. These gas detectors 2a and 2b are configured to perform rotational scanning in the horizontal direction. The gas detectors 2a and 2b have directivity. For example, the gas detectors 2a and 2b are provided with a sensor unit in which light transmitting and receiving units are integrally formed coaxially or slightly apart from each other, and emit a laser beam from the light transmitting unit. A so-called laser light reflection type gas detector which measures the amount of laser light reflected by the target gas and measures the concentration of the target gas can be used.

Reference numeral 3 denotes a camera, which is an ITV (industrial television) camera. Reference numeral 4 denotes a signal processing the signals from the gas detectors 2a and 2b and the signal from the camera 3 to perform a calculation described later, display an image 6 on a display device 5 such as a CRT, and correspond to the gas leak position. This is control means for superimposing the display on the image 6.

In the above configuration, each gas detector 2
a and 2b are rotated in the horizontal direction to measure the gas concentration distribution of the target area 1 with respect to the scanning angle, and the target area 1 is captured as an image 6 on the display device 5 by the camera 3.

As shown in FIG. 1, if it is assumed that there is a gas leak at the positions A and B in the monitoring area 1, the gas detector 2a on the left side in FIG. The gas concentration distribution with respect to the scanning angle and the gas detector 2b on the right side in the drawing can obtain the gas concentration distribution with respect to the scanning angle as shown in FIG. That is, a gas concentration distribution having a peak at the angle θ ₁ in FIG. 2 and a gas concentration distribution having a peak at each of the angles θ ₂ and θ ₂ ′ are obtained in FIG.

Therefore, the position A can be specified by using the distance L and the angles θ ₁ and θ ₂ as data and using a triangulation method, and similarly, the distance L and the angles θ ₁ and θ ₂ ′ can be specified. And the position B can be specified by using a method of triangulation with the data as the data.

As shown in this embodiment, in the present invention, two gas leak positions which cannot be distinguished by the gas detector 2a on one side can be distinguished by the gas detector 2b on the other side. It can be seen that the position can be specified.

The gas leak position obtained in this manner is a two-dimensional position, that is, a position on the plane of the target area, which is a proper position in the image 6 of the target area 1, and in the embodiment of FIG.
It is displayed one-dimensionally in the lower horizontal direction on the RT screen. That is,
a and b are displays corresponding to the positions detected by the gas detector.

Therefore, the observer can confirm the display a,
From b and the image 6, the three-dimensional positions of the gas leak positions A and B can be detected.

As described above, if the above-described measurement by the gas detector is performed at at least two points apart from each other, the distance and the scanning angle corresponding to the concentration increase point in the gas detector at each point are determined. From this, it is possible to determine the position of the concentration increase point by using the triangulation method, but by measuring at more points, it is also possible to obtain the temperature distribution of the target point, Can be three-dimensionally displayed on a CRT or the like by an appropriate method.

In applying the above method, the above-mentioned gas detector is to be fixedly installed at a point separated by a distance or configured to be movable, and to be located at a point separated by movement. Can be.

The position of the camera that captures the target area as an image is arbitrary, and a plurality of cameras can be installed.

[0026]

As described above, the present invention has the effect that, with a simple structure, gas leakage can be detected together with its position, and a measure can be taken promptly.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example to which the method of the present invention is applied.

FIG. 2 is an explanatory diagram showing measurement results by a gas detector on the left side of FIG.

FIG. 3 is an explanatory diagram showing a measurement result by a gas detector on the right side of FIG. 1;

FIG. 4 is an explanatory diagram showing a state in which a display of a detection position by a gas detector is superimposed and displayed on an image of a target area by a camera.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Monitoring area 2a, 2b Gas detector 3 Camera 4 Control means 5 Display device 6 Image A, B Gas leak position

────────────────────────────────────────────────── ─── Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01M 3/00-3/40 JICST file (JOIS)

Claims (5)

(57) [Claims] 1. A gas concentration distribution in a target area with respect to each scanning angle by locating a directional gas detector at at least two points apart from each other and rotatingly scanning each gas detector in a lateral direction. Was measured, the gas leak position in the target area was detected from each scanning angle corresponding to the concentration increase point in the measured gas concentration distribution, and the target area was captured as an image by a camera and detected by the gas detector. Gas leak position detection method characterized by displaying a gas leak position superimposed on an image 2. A method for detecting a gas leakage position, wherein the gas detector according to claim 1 is fixedly installed at a point separated by a distance. 3. A method for detecting a gas leakage position, wherein the gas detector according to claim 1 is configured to be movable and is located at a point separated by movement. 4. A method for detecting a gas leak position, wherein the gas detector according to claim 1 is a laser light reflection type gas detector. 5. A method for detecting a gas leakage position according to claim 1, wherein the camera is an ITV camera.