JPS63221226A - Liquid leakage detecting method - Google Patents

Abstract

PURPOSE:To easily specify the leak place of liquid by monitoring an object monitor area by an infrared camera and making the variation position of its infrared-ray radiation distribution correspond to the position of an object image corresponding to a visible image. CONSTITUTION:The monitor area 2 including piping 1 to be monitored is monitored by the infrared camera 3. The signal of the camera 3 is processed by an infrared-ray radiation temperature processing part 41 and an object image (piping image) processing part 42 respectively. A variation detection part 43 compares temperature distribution images obtained by the temperature processing part 41 at different times and when variation at leak liquid temperature is detected, both images are put one over the other to specify the leak place 5 of liquid by a weight comparing part 44. Thus, the variation position of the infrared-ray radiation distribution is made to correspond to the position of the object image to easily specify the leak place 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting leakage of low-temperature liquefied gas, high-temperature gas, and other fluids from piping and various devices in a factory shade.

[Conventional technology and its problems]

from piping and various equipment in large areas in factories, etc.
Conventional methods for detecting leaks of low temperature liquefied gases, hot gases and other fluids include the following.

First, there is a method of installing sensors such as gas detectors or thermometers at each location where there is a possibility of leakage, and using these sensors to detect the leak, but this method requires a large initial cost and is expensive. In addition to the problem that maintenance requires a large amount of money and manpower, there is a fundamental flaw in that it cannot deal with leaks of low-temperature fluid from unpredictable locations. This is not something that can be solved by adding more. Another method is to emit infrared rays from an infrared transmitting device toward a monitoring area, and then receive the infrared rays after passing through the monitoring area with a receiver, detecting the presence of gas based on the absorption spectrum of the infrared rays and detecting a leak. However, in addition to requiring the installation of an infrared receiver, receiver, or reflector across the monitored area, such methods are inherently leaky. This method detects the direction including the leakage point, and in order to identify the leakage point, it is necessary to provide a large number of two-dimensional pairs of light transmitting and receiving devices, and a means for moving the device for scanning. However, as mentioned above, there are the same board defects when installing sensors in areas where leakage is predicted. Furthermore, a method has been proposed in which the target monitoring area is captured and monitored using an infrared camera and a visible light camera, and detection is performed using these images. There are other problems.

The present invention aims to solve the above problems.

[Means for solving problems]

In order to achieve the above-mentioned purpose, this application monitors the target monitoring area with an infrared camera, captures changes in the infrared radiation distribution within the monitoring area, and monitors information obtained from the infrared radiation distribution. The gist of this method is to detect fluid leakage and its position from an image of an object within the area.

Next, the present invention will be explained based on FIGS. 1 to 5, which correspond to embodiments.

FIG. 1 schematically shows the configuration of an embodiment to which the method of the present invention is applied, in which reference numeral 1 indicates a pipe through which fluid such as liquefied gas flows, and reference numeral 2 indicates a rectangle surrounded by 2 points and 11 lines. The frame virtually indicates the monitoring area targeted for leak detection. Reference numeral 3 is an infrared camera, and 4 is a monitoring device for monitoring leakage based on images ii[j of the area monitored by the infrared camera 3.

[Effect]

Therefore, in monitoring ¥1t4, the infrared radiation distribution within the monitoring area 2 can be obtained as a two-dimensional image by the signal from the infrared camera 3, and the target object 1
An image corresponding to the visible image, an object image, can be obtained as shown in FIG. 2 by the unique infrared radiation based on the temperature and radiation Q4 rate.

Although the resolution of this object image is generally lower than that of an image obtained by a visible light camera, the resolution required for identifying the leak position, which will be described later, can be obtained relatively easily.

In such a configuration, when monitoring the monitoring area 2, high temperature 21 such as low temperature fluid such as liquefied gas or high temperature steam from the pipe 1 etc.
When the fluid leaks, the temperature near the leak point 5 decreases or increases, which can be detected by the monitoring device 4 as a change in the infrared radiation distribution. In this way, leaks can be detected based on changes in the infrared radiation distribution, that is, the temperature distribution, but this alone is not enough to detect leakage points.
is often difficult to identify.

Therefore, the present invention provides an image showing such an infrared radiation distribution,
The leak location 5 can be easily identified by comparing the image corresponding to the visible image described above with the object image and associating the change position of the infrared radiation distribution with the position of the object image. Such an object image can be obtained as described above based on the infrared radiation distribution obtained through the infrared camera 3 before leakage.

〔Example〕

The above-mentioned detection of changes in the infrared radiation distribution, comparison with the object image, and specification of the leakage position can be performed as appropriate by, for example, the following image processing.

For example, FIG. 3(a) functionally represents the configuration of the monitoring device 4. In this embodiment, the signal from the infrared camera 3 is processed by the infrared radiation temperature processing section 41 and the object image processing section 4.
The temperature distribution images obtained by the temperature processing unit 41 at different times are compared by the change detection unit 43, and when a change in the target temperature range (leakage fluid temperature) is detected, both The f-tatami comparison unit 4
The comparison described above in Section 4 is made. Detection and comparison of such changes can be carried out by dividing the image into a large number of pixels 6 as shown in FIG. In addition to detecting changes by comparing the current image and the current image for each pixel 6, and comparing images of people for each pixel 6, it is also possible to use an appropriate method. can.

Furthermore, the above-described monitoring can be performed completely automatically by image processing, and only changes in the infrared radiation distribution mentioned above can be automatically detected, and based on this detection signal, a human can monitor the image on a CRT, etc. It may be possible to use a semi-automatic method in which leakage is finally identified by looking at the information, or in some cases, it may be configured so that the entire system is monitored by a human using images such as a CRT.

Next, the infrared camera 3 can be installed in various ways as follows. First, Figure 4(a), (
b) is an example of a case where the object to be monitored is in one place where the child can pass through, and the infrared camera 3 is installed in a rotatable position at a high place using a support 7, etc., and the entire wide monitoring area can be monitored by scanning and zooming. It is. Also, Figure 5 shows monitoring target 1@
A plurality of sets of infrared cameras 3 are installed around the area, and each set of infrared cameras 3 has a limited monitoring area 2. In addition to this method, infrared camera 3
As mentioned above, by making it mobile or capable of zooming, it usually monitors a wide monitoring area 2.
If any change is detected in this state, the corresponding location can be enlarged and the above-mentioned image processing etc. can be performed, making it possible to perform more accurate leakage detection. Furthermore, Figure 1~
In Figure 3, the monitoring area 2 is a part of the pipe 1, which is a very narrow area, but this is a zoomed state, and this pond water invention is shown in Figures 4 and 5. Of course, the monitoring area 2 can cover a wide area as shown in FIG.

(Effects of the Invention) As described above, the present invention detects leakage from the infrared radiation distribution within the monitoring area and the object image obtained from the infrared radiation distribution when monitoring a target monitoring area with an infrared camera. Therefore, there is an effect that leakage of low-temperature or high-temperature fluid can be detected by specifying its location. The present invention detects changes due to leakage by projecting the three-dimensional space corresponding to the target monitoring area onto a two-dimensional image, so as long as it is visible, one set of The detector can monitor a very wide space, and the location of the leak can be easily identified. For example, workers can check the location and situation of the leak using an image on a CRT, etc. to prevent leakage. This has the effect that processing can be carried out quickly.In particular, since the present invention uses an infrared camera to obtain an image corresponding to a visible image and an object image, when using a visible light camera, it is possible to There is no need for a monitoring light source to ensure the illuminance of the system, ordinary lighting is sufficient, and energy savings can be achieved.Since a visible light camera is not required, the entire system can be configured compactly. Further, there is no need to adjust the optical axis, and thus the present invention can detect leaks in a wide monitoring area at low cost.
It is effective in detecting leakage of low-temperature or high-temperature fluids from piping, equipment, etc. in factories, plants, and other currency locations.

[BRIEF DESCRIPTION OF THE DRAWINGS] The designs correspond to embodiments of the present invention, and FIG. 1 is a schematic explanatory diagram of a rest, FIG. 2 is an explanatory diagram of an object image, and FIG. 3 (a)
, (b) are explanatory diagrams of image processing, Fig. 4 (a), (b)
), FIG. 5 is an explanatory diagram of an infrared camera installation method, FIG. 4(a) is a side view, and FIGS. 4(b) and 5 are plan views. Code 1...Target object (piping), 2...Monitoring area, 3...Infrared camera, 4...Monitoring device, 5...
・Leakage location, 6...pixel, 7...support. Figure 1 Figure 3 (a) Figure 3 (b) Figure 14 (a) 4th ff1 (b)
Figure 6

Claims (1)

[Claims] Monitor the target monitoring area with an infrared camera,
A method for detecting fluid leakage, comprising detecting fluid leakage and its position from an image of an object within the monitoring area obtained from the infrared radiation distribution by capturing changes in the infrared radiation distribution within the monitoring area.