JPS5987332A - Detector for gas leak - Google Patents

Abstract

PURPOSE:To detect accurately and quickly the position where gas is leaking by scanning a sensor unit array in the direction orthogonal to the lengthwise direction of a face to be detected, and displaying two-dimensionally the output with a gradation corresponding to the gas concentration. CONSTITUTION:A microcomputer of a central control part 6 displays the concentration distribution of methane other than naturally generated gaseous methane on a display screen 20 of a display device 8 in accordance with output of non-methane detectors and methane detectors of automatic suction-type sensor units 2. A parameter set button 26 is operated before measurement of the concentration, and parameters of a sampling running distance, the number of gas concentration measuring points, a color of a mark displayed on the screen 20, the gas concentration, etc. are inputted by a ten key 31, and parameters set once are held even after power off. A pattern of concentric circles is displayed on the screen 20 in a position corresponding to the position of gas leak, and the position of gas leak is found quickly and accurately on a basis of the number of the unit 2 in the horizontal direction of the screen 20 and the running distance in the vertical direction.

Description

[Detailed Description of the Invention] This invention provides concentration distribution of underground gas leakage? : This relates to a gas leak detection device that displays on a display screen in several gradations depending on the concentration.

Gas pipes for city gas are laid underground in a complicated manner, and the conventional method of detecting gas leaks while carrying a gas leak detector was extremely difficult to locate.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a gas leak detection device that can accurately detect the location of gas leaks in city gas pipes that are intricately installed underground. shall be. Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 is a boot diagram showing a gas leak detection device which is an embodiment of the present invention. In the figure, 1 is a sensor unit row, and automatic suction type sensor units 2 are arranged in a row. 3 is a suction pump that sucks air from the sensor unit 2; 4 is a sensor scan unit;
5 is a timing control section, 6 is a central control section, 7 is an operation section, 8 is a display such as a CRT, and 9 is a magnetic sensor that sends signals such as moving distance and direction to the timing control section 5. Next, each of the above sections 1 to 9 will be explained in detail.

FIGS. 2(a) and 2(b) are diagrams showing details of the sensor unit row 1. In FIG. 2(a), 11 is the axle extension m s 4PI, which causes the axle 12.13 to extend or contract. A wheel 14.15 with a tire is rotatably attached to the tip of the axle 12.13. A sensor loading platform 16 on which a plurality of automatic suction type sensor units 2 are mounted in one or several rows is provided on the axle expanding mechanism 11, and this sensor loading platform 16 is also connected to the axle expanding mechanism 11.
It has a structure that allows it to expand and contract in conjunction with the operation of. The axle extension/contraction mechanism 11 extends or retracts the axles 12, 13 according to the width of the road, and the sensor loading platform 16 also extends or retracts to provide an automatic suction type sensor unit.

2 can cover the entire road width.

A plurality of magnet pieces 17 and two magnetic sensors 18A as shown in FIG. 2(b) are mounted on one side of the wheels 14 and 15 with tires.
, 18B is provided, and the tire publication wheel 14.15
A pulse is sent to the timing control section 5 according to the rotation speed of the . Furthermore, by providing two magnetic sensors 18A and 18B, it is possible to determine whether the vehicle is moving forward or backward. That is, as shown in FIG. 3(a), in the case of forward movement, the magnetic sensor 18A detects the magnet piece 17, and then the magnetic sensor 18B detects the magnet piece 17, whereas in the case of reverse movement, the magnetic sensor 18A detects the magnet piece 17. As shown in (b), after the magnetic sensor 1BB detects the magnet piece 17, the magnetic sensor 18A detects the magnet piece 1.
Detecting 7 is K. Therefore, it is possible to determine whether the vehicle is moving forward or backward depending on which of the magnetic sensors 18A or 18B detects the magnet piece 17 first.

FIG. 4 is a diagram showing an example of the display on the display 8, in which the horizontal direction shows the automatic suction type sensor unit 20, the vertical direction shows the distance traveled by the car, and the sensor scan unit 401. By sampling twice, marks for one row in the horizontal direction are color-coded according to the gas concentration. The colors are white (W), light blue (B), green (G), and yellow (Y) from lowest to lowest density.

It is displayed in six stages: purple (V) and red (R).

The current sampling point is marked by a cursor K at the right edge of the screen.

FIG. 5 is a diagram showing the operating section 7 and the display 8. As shown in FIG. In the figure, the operation unit γ is provided with an operation panel 19, and the display 8 is provided with a display screen 20 such as a CRT. The operation panel 19 has a power switch 21 with a key. Power indicator lamp 22° Brightness adjustment button 231 of the display screen 20 Time setting button 24. Failure indicator lamp 25. Parameter setting button 26. Gas leak warning lamp 27. Methane-non-methane display switching button 2B, measurement start button 29
, measurement stop button 30. A numeric keypad 31 and the like are provided.

Figures 6(a) and (b) show the automatic suction type sensor unit 2.
FIG. 3A is a front view, and FIG. 1B is a side view. 32 is the main body of the automatic suction type sensor unit 20, 33 is a suction pipe, and 34 is a pipe connected to the suction pump 3. Air on the road is sucked from the suction pipe 33 by the operation of the suction pump 3, and this air is Gas leakage is detected by detecting whether gas is mixed inside.

To detect gas leaks from underground city gas piping,
It is necessary to determine whether the detected gas is city gas or methane gas that naturally occurs underground. For this reason, there are two types of automatic suction type sensor units 2: one that has a methane detection element that is sensitive to methane, and one that has a non-methane detection element that is not sensitive to methane.

Nearly 100% of the components of methane gas naturally produced from underground are pure methane, and city gas (for example, 13A) contains about 90% methane, but also about 10% ethane, pullane, butane, etc. The non-methane sensing element senses and outputs only this non-methane component. Therefore, in the case of city gas, output can be obtained from both sensing elements, but in the case of naturally occurring methane underground, the non-methane sensing element has almost no output.

The above is the configuration of the gas leak detector according to an embodiment of the present invention.Next, its operation will be explained.

First, when the measurement start button 29 is pressed, a detection range corresponding to a preset travel distance, the number of gas concentration measurement points, etc. is displayed on the display screen 20 of the display 8. Magnetic sensor 1
The first pulse sent from 8A or 18B to the timing control section 5 starts the sampling system of the automatic suction type sensor unit 2 via the sensor scan unit 4. That is, the central control unit 6 uses the pulses sent from the magnetic sensor 18A or 18B to
The gas concentration signal sent from the automatic suction type sensor unit 2 is sampled, and a mark of a preset color is displayed on the display screen 20 of the display 8 according to the concentration. The central control unit 6 uses a microcomputer, and by software processing, pulses sent from the magnetic sensors 18A and 18B are spread at regular intervals, and the sampling interval (distance) can also be changed. It is also possible to change the number of automatic suction type sensor units 2 to be installed depending on the width of the road.

The central control unit 60 microcomputer calculates the concentration distribution f! excluding naturally occurring methane gas underground from the outputs of the non-methane detection element and methane detection element built into the automatic suction type sensor unit 2. :Displayed on the display screen 20 of the display device 8.

When sampling of a preset travel distance is completed, or when the measurement stop button 30 is pressed, the sampling ends and the display on the display screen 20 is maintained until an instruction is received from the customer.

The parameter setting button 26 is operated to set various parameters prior to gas concentration measurement. Settings are made by inputting various parameters using the numeric keypad 31 in a conversational manner using messages displayed on the display screen 20 of the display device 8.

Zumbling mileage, gas concentration measurement points 0 display screen 2
Parameters such as the color of the mark displayed at 0 and gas concentration can be set, and once the parameters are set, they are retained even after the power is turned off by the memory stored in the pantry back.

If there is a gas leak, a concentric circle pattern will appear at the corresponding position on the display 120 of the display 8, for example, with a red mark in the center and surrounding it in colors of purple, black, green, and light blue. . Therefore, the location of the gas leak can be quickly determined based on the arrangement number of the automatic suction type sensor unit 2 in the horizontal direction of the display screen 20 and the distance traveled by the vehicle in the vertical direction.

Note that in the above embodiment, various types of display device 8 are possible. For example, a CRT, a liquid crystal, a large number of LEDs or lamps, etc. are used. In addition to the gradation based on color classification according to the gas concentration, the display may also be based on luminance.

As explained above, the gas leak detection device according to the present invention includes a sensor unit row in which a plurality of sensor units are arranged, means for scanning the sensor unit row in a direction perpendicular to the length direction thereof, and a sensor unit row in which a plurality of sensor units are arranged. It is composed of a signal from each sensor unit in the row and a display that displays the concentration in multiple gradations, so the gas leak point and gas leak status can be grasped two-dimensionally and accurately. It has an extremely excellent effect in that it can be carried out quickly.

[Brief explanation of the drawing]

Fig. 1 is a bootstrap diagram showing an outline of a gas leak detection device which is an embodiment of the present invention, Figs. 2(a) and 2(b) are views showing sensor unit arrays and magnetic sensor portions, and Fig. 3
Figures (a) and (b) are time charts showing the output signals of the magnetic sensor, Figure 4 is a diagram showing an example of the display screen, Figure 5 is a diagram showing the operation section and display, and Figure 6 (a) is a diagram showing an example of the display screen. ),
(b) is a diagram showing an automatic suction type sensor unit, where (a) is a front view and (b) is a side view. In the figure, 1 is a sensor unit row, 2 is an automatic suction type sensor unit, 3 is a suction pump, 4 is a sensor scan unit, 5 is a timing control section, 6 is a central control section,
7 is an operation unit, 8 is a display, and 9 is a magnetic sensor. Sho 11K fJ8he-SoR Fig. 4 Fig. 5 20 8 91 riq') ('', 9627 2R) 93
0 7Figure 6 (a) 3 (b)

Claims (1)

[Claims] (1) A sensor unit row in which a plurality of sensor units each having a detection element for detecting a gas leak are arranged, and this sensor unit row is scanned on a detection surface in a direction perpendicular to its length direction. and a display device for two-dimensionally displaying the output ft of each sensor unit in the sensor unit array on a display surface in a gradation according to the concentration and corresponding to the scanning. Leak detection device. (The gas leak detection device according to claim (1), wherein the 21 sensor unit row is an arrangement in which sensor units for methane gas and sensor units for non-methane gas are arranged alternately. (3) Sensor unit The gas leak detection system according to claim 1, wherein the row consists of two sensor unit rows: a sensor unit row consisting of sensor units for methane gas and a sensor unit row consisting of sensor units for non-methane gas. Device.