JPH0875588A - Gas leakage detection device - Google Patents

Abstract

PURPOSE: To achieve a stable detection without any dipping and easily confirm ventilation state by forming a protruding part on the floor surface of a utility tunnel and a recess which is blocked by a member with a plurality of small holes on the protruding part and detecting oxygen concentration inside. CONSTITUTION: A protruding part 17 is formed on a floor surface 15 of a utility tunnel 4, a recessed part 18 as a gas leakage detection room is provided at the detection part 17, and the leakage of SF6 gas 21 from a gas insulation bus is detected by an oxygen concentration measuring instrument 20 inside. Therefore, even if water enters the utility tunnel 4, it does not flow into the recessed part 18, thus preventing the operation delay and failure of the measuring instrument 20. The contact time between the gas 21 and the measuring instrument 20 can be fully secured for a stable detection for a long time. Further, when the gas 21 leaks, is ventilated, and a recovery operation is performed, the dilution of the gas 21 inside the recessed part 18 starts at a small hole of a blocking member 19 after air inside the utility tunnel 4 advances. Therefore, by confirming that the oxygen concentration inside the recessed part 18 by a measuring instrument 20, the recovery operation can be started safely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a gas for detecting insulating gas leaking from an electric device installed in a building in which an electric device filled with an insulating gas such as SF ₆ gas is placed or in a floor of a basement. The present invention relates to a leak detection device.

[0002]

2. Description of the Related Art In recent years, it has become difficult to acquire a land due to a skyrocketing underground due to an increase in population in urban areas and integration of various living functions. On the other hand, with the background of the development of underground utilization technology, the needs for underground utilization of roads are rapidly increasing, and the needs for high voltage and long distance underground transmission are also increasing. And
Since the underground road is also positioned as a component of the city,
It is necessary to consider disaster prevention more than ever.

From such a background, with the expectation that the gas insulated busbar (GIB), which is more excellent in disaster prevention than the oil-impregnated paper-insulated cable and effective in reducing transmission loss, is expected to be used. Controlling the detection of leaking insulating gas has also become an important issue.

FIG. 5 is a sectional view showing the structure of a gas insulated line equipped with a conventional gas monitoring device disclosed in, for example, Japanese Patent Laid-Open No. 5-91636, and FIG. 6 is a partial sectional view showing the structure near the manhole in FIG. Is. In the figure, 1 is a power plant, 2 is a substation, 3 is a GIB connecting these power plants 1 and 2 and is a metal container 5 which is placed in a cave 4 and is filled with SF ₆ gas. Conductor 6 penetrating inside the container 5
And a plurality of insulating spacers 7 for partitioning the inside of the metal container 5 at a predetermined interval and insulatingly supporting the conductor 6.

Reference numeral 8 is a manhole provided at a predetermined interval in the cave 4 and reference numeral 9 is a gas monitoring device provided in one of the gas sections partitioned by the insulating spacer 7, which is composed of a pressure gauge 10 and a density switch 11. ing. Reference numeral 12 is a failure point evaluation device which is set at a predetermined position of the metal container 5, and 13 is a gas leak detection device which is arranged in a recess 14 formed on the floor surface.

[0006]

When the conventional gas leak detection device 13 is arranged at a position higher than the floor surface, the SF
Since ₆ gas can not contact time is sufficiently secured with the SF ₆ gas leaked for high density, by forming a recess 14 on the floor as shown in the floor or 6, so as to place the internal Therefore, when water enters from the cracked portion such as cement used for the wall surface of the cave 4, the gas leak detection device 13 is provided while the water spreads on the floor surface and reaches the drain groove (not shown). However, there is a problem in that the gas leaks into the inside and causes an operation delay or operation failure, and stable gas leak detection cannot be performed for a long period of time.

Further, when a gas leak is found and repair work is performed, not only the worker enters the cave 4, but also welding work or the like creates a high temperature part in the cave 4, If a small amount of SF ₆ gas remains in the road 4, thermal decomposition will occur and toxic gas such as HF and SO ₂ will be generated, which is dangerous.
There has been a problem that the work has to be started after a sufficient time has been taken for the SF ₆ gas to be completely removed in advance.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to detect gas leaks stably for a long period of time without fear of inundation, and also to check the ventilation status at the start of gas leak restoration work. It is an object of the present invention to provide a gas leak detection device that can be easily performed.

[0009]

According to a first aspect of the present invention, there is provided a gas leakage detection device, which is formed on a gas monitoring section in which an electric device filled with an insulating gas is arranged and a floor surface of the gas monitoring section. A protruding portion, a recess portion formed in the protruding portion, a closing member that covers the recess portion and has at least two small holes formed therein, and a gas leak detection unit disposed in the recess portion. is there.

A gas leakage detection device according to a second aspect of the present invention is the gas leakage detection device according to the first aspect, wherein the protrusion is formed with a gentle slope.

Further, a gas leakage detection device according to a third aspect of the present invention is formed in a gas monitoring section in which an electric device filled with an insulating gas is arranged and an inclined portion of a floor surface of the gas monitoring section. It is provided with a hollow portion, a closing member which covers the hollow portion and has at least two small holes formed therein, and a gas leakage detection means arranged in the hollow portion.

Further, the gas leakage detecting device according to a fourth aspect of the present invention is such that, in the third aspect, a weir is provided on the inclined portion on the higher side of the recessed portion.

Further, a gas leakage detecting device according to a fifth aspect of the present invention is the gas leakage detecting device according to the first or third aspect, wherein the gas monitoring section is a cave having a gas insulating busbar arranged therein.

Further, a gas leak detecting device according to a sixth aspect of the present invention is the device according to the first or third aspect, wherein an oxygen concentration measuring device is applied as the gas leak detecting means.

[0015]

The projecting portion of the gas leakage detection device according to claim 1 of the present invention prevents water from flowing into the recess, and the recess allows the insulating gas leaked from the electric device to stay therein for a long time. , Facilitating detection by the gas leak detection means.

Further, the projecting portion of the gas leakage detection device according to claim 2 of the present invention improves its strength by a gentle slope and alleviates an obstacle for an inspector to improve safety. Improve.

Further, the recess formed in the inclined portion of the floor surface of the gas leakage detection device according to claim 3 of the present invention allows the insulating gas leaked from the electric equipment to stay therein for a long time, and the gas leakage detection means is used. Facilitates detection.

Further, the weir provided on the sloped portion on the higher side of the recessed portion of the gas leakage detection device according to claim 4 of the present invention prevents the water flowing through the sloped portion from flowing into the recessed portion.

Further, the gas leak detecting means of the gas leak detecting device according to the fifth aspect of the present invention detects the insulating gas leaking from the gas insulating bus bar into the cave.

Further, the oxygen concentration measuring device of the gas leakage detecting device according to the sixth aspect of the present invention detects the insulating gas leaking from the electric device according to the concentration of oxygen.

[0021]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view showing the structure of a gas leak detection device according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the structure of the essential parts of the gas leak detection device shown in FIG. In the figure,
The same parts as those of the conventional device are designated by the same reference numerals and the description thereof will be omitted.

15 is the floor of the cave 4 and 16 is this floor 15
Drainage groove provided on the floor, 17 is a protrusion formed on the floor surface 15 with a gentle slope, 18 is a recess formed in the protrusion 17 as a gas leak detection chamber, and 19 is this recess. 18 openings and at least two eyelets 19a
A reference numeral 20 denotes an occlusion member formed with the above, an oxygen concentration measuring device 20 as a gas leak detecting means arranged in the hollow portion 18, and a SF ₆ gas as an insulating gas filled in the metal container 5.

In the gas leak detection device constructed as described above, it is assumed that SF ₆ gas 2
If 1 leaks into the cave 4, the SF ₆ gas 21 flows down vertically because of its high density, reaches the floor surface 15 and moves in four directions, and then diffuses in the vertical direction as well. The concentration of SF ₆ gas at each point as shown in FIG. 3 drops in a short time.

On the other hand, when the SF ₆ gas 21 moves in all directions along the floor surface, due to the effect of the density difference, it flows into the recess 18 from one small hole 19a of the closing member 19 and flows out from the other small hole 19a. The air is replaced with the air that is generated, and is trapped and filled in the recess 18. The SF ₆ gas 21 once trapped in the recess 18 has a high concentration in the recess 18, but the outflow to the outside is diffusion-dominant, so that it cannot easily flow out and stay for a long time. To measure the oxygen concentration 2
The contact time with the sensitive unit (not shown) of 0 is sufficiently secured.

As described above, according to the first embodiment, the cave 4
A protrusion portion 17 is formed on the floor surface 15 of the above, and a depression portion 18 serving as a gas leakage detection chamber is provided in this protrusion portion 17.
The oxygen concentration measuring device 20 is installed in the chamber 8 to detect SF ₆ gas leaked from the GIB.
Even if moisture enters the inside and flows on the floor surface 15, the opening surface of the depression portion 18 is located at a position higher than the floor surface 15, and therefore the depression portion 18
Water does not flow into the inside of the oxygen concentration measuring device 20, and the operation delay and malfunction of the oxygen concentration measuring device 20 are prevented, and the SF ₆ gas 21 and the sensitive portion (not shown) of the oxygen concentration measuring device 20 are formed in the hollow portion 18. Since it is possible to secure a sufficient contact time of (3), stable gas leak detection can be performed over a long period of time.

Further, since the protrusion 17 is formed with a gentle slope, the strength of the protrusion 17 itself is improved, and also when an inspector works in the sinus 4, it trips over. This can be prevented, and safety can be improved.

Further, even when the ventilation work is performed after the SF ₆ gas leaks and the recovery work is performed, the SF ₆ gas in the hollow portion 18 is diluted after the air replacement in the sinus 4 is advanced. Since it starts, if it is confirmed by the oxygen concentration measuring device 20 that the oxygen concentration in the depression 18 is sufficient,
As a matter of course, the oxygen concentration in the sinus 4 should be more sufficient than the oxygen concentration in the depression 18, so that the recovery work can be started with peace of mind and the safety is improved.

Embodiment 2 FIG. FIG. 4 is a sectional view showing the structure of the main part of the gas leakage detection device according to the second embodiment of the present invention. In the figure, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 22 is an inclined portion of the floor surface, 23 is a recessed portion formed in the inclined portion 22 as a gas leak detection chamber, 24 is a closing member which covers the recessed portion 23 and has at least two small holes 24a formed therein, 25 Is a weir protruding from the inclined portion on the higher side of the recess 23, and has a width at least larger than the width of the recess 23.

In the first embodiment, the protruding portion 17 of the floor surface 15 is used.
Although the case where the recessed portion 18 is provided in the above is described, the recessed portion 23 may be provided in the inclined portion 22 of the floor surface as in the second embodiment, or the higher side of the recessed portion 23. By providing a weir on the inclined portion 22 of the
Above the first embodiment.
The same effect as can be obtained.

Example 3. Incidentally, in each of the first and second embodiments,
The case of detecting SF ₆ gas leaked from the GIB installed in the cave 4 has been described, but the present invention is not limited to this. For example, the SF ₆ gas is installed in a building with relatively poor air permeability, and an insulating gas is used. The present invention may be applied to the case of detecting a gas leak from an electric device in which the
The same effect as that of 2 can be obtained.

[0031]

As described above, according to the first aspect of the present invention, the gas monitoring section in which the electric device in which the insulating gas is filled is arranged, and the protruding portion formed on the floor surface of the gas monitoring section. And a recess formed in the protrusion, a closing member that covers the recess and has at least two small holes, and a gas leak detection unit arranged in the recess.
It is possible to provide a gas leak detection device that can perform stable gas leak detection for a long period of time and can easily confirm the ventilation status at the start of gas leak restoration work.

According to the second aspect of the present invention, since the projecting portion is formed with a gentle slope in the first aspect, the gas leak can be stably detected for a long period of time, and the gas leak restoration work can be started. It is possible to provide a gas leak detection device that can easily check the ventilation status of the above and can improve safety during inspection work.

According to a third aspect of the present invention, a gas monitoring section in which an electric device filled with an insulating gas is arranged,
The gas monitoring section is provided with a recess formed in an inclined portion of the floor surface, a closing member that covers the recess and has at least two small holes, and a gas leak detection unit arranged in the recess. Therefore, it is possible to provide a gas leak detection device capable of performing stable gas leak detection over a long period of time and also easily confirming the ventilation status at the start of gas leak restoration work.

Further, according to claim 4 of the present invention, since the weir is provided in the inclined portion on the higher side of the depression in claim 3, stable gas leakage detection can be performed for a long period of time, and at the same time, gas leakage can be detected. It is of course possible to provide a gas leak detection device that can easily prevent the inflow of water into the recessed portion, as well as easily confirming the ventilation state when starting the leak recovery work.

Further, according to claim 5 of the present invention, in claim 1 or 3, the gas monitoring section is applied to the sinus passage in which the gas-insulated bus bar is arranged, so that stable gas leak detection can be performed for a long period of time. It is possible to provide a gas leak detection device capable of easily confirming the ventilation status at the start of gas leak restoration work.

According to the sixth aspect of the present invention, since the oxygen concentration measuring device is applied as the gas leak detecting means in the first or third aspect, stable gas leak detection can be performed for a long period of time, and gas leak recovery is possible. It is possible to provide a gas leak detection device that can easily confirm the ventilation status at the start of construction.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a gas leak detection device according to a first embodiment of the present invention.

2 is a cross-sectional view showing a configuration of a main part of the gas leakage detection device in FIG.

FIG. 3 is a characteristic diagram showing a state in which SF ₆ gas on the floor surface diffuses over time.

FIG. 4 is a sectional view showing a configuration of a main part of a gas leakage detection device according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view showing the configuration of a gas insulated line provided with a conventional gas monitoring device.

6 is a partial cross-sectional view showing the configuration near the manhole in FIG.

[Explanation of symbols]

4 cave (gas monitoring section), 5 metal container (electrical equipment), 15 floor surface, 17 protruding part, 18, 23 recessed part, 19, 24 blocking member, 19a, 24a small hole, 2
0 oxygen concentration measuring device (gas leak detection means), 21 SF
₆ gases (insulating gas), 22 slopes, 25 weirs.

Claims (6)

[Claims] 1. A gas monitoring section in which an electric device filled with an insulating gas is arranged, a protrusion formed on a floor surface of the gas monitoring section, a recess formed in the protrusion, and the recess. A gas leak detection device, comprising: a closing member that covers the portion and has at least two small holes formed therein; and a gas leak detection unit that is disposed in the recess. 2. The gas leakage detection device according to claim 1, wherein the protrusion has a gentle slope. 3. A gas monitoring section in which an electric device filled with an insulating gas is arranged, a recess formed in an inclined portion of a floor surface of the gas monitoring section, and at least 2 covering the recess.
A gas leak detection device, comprising: a closing member having individual small holes formed therein; and gas leak detection means arranged in the recess. 4. The gas leakage detection device according to claim 3, wherein a weir is provided in the inclined portion on the higher side of the depression. 5. The gas leak detection device according to claim 1, wherein the gas monitoring section is a cave in which a gas-insulated bus bar is arranged. 6. The gas leak detecting device according to claim 1, wherein an oxygen concentration measuring device is applied as the gas leak detecting means.