JPH0222969Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a fire extinguishing system for oil-filled electrical equipment.

[Conventional technology]

Conventionally, as a fire extinguishing system for oil-filled electrical equipment, one disclosed, for example, in Japanese Patent Publication No. 56-35287 is known. This fire extinguishing system for oil-filled electrical equipment is as shown in FIG. 2, and is for supplying nonflammable gas into the insulating oil of oil-filled electrical equipment.

In FIG. 2, numeral 1 indicates an oil-immersed transformer;
The tank 2 is filled with insulating oil 3. A conservator 4 is provided above the outer periphery of the oil-immersed transformer 1 , and the tank 2 and the conservator 4 are communicated through a pipe 5 . An on-off valve 6 is interposed in the middle of this piping 5. Open/close valve 6
When a fire occurs in the oil-immersed transformer 1 and a heat detector (not shown) detects the fire, the piping 5 is closed to prevent the insulating oil 3 in the conservator 4 from flowing to the tank 2. It is something to do.

On the other hand, an oil drain pipe 8 is connected to the tank 2 so as to communicate with a drain oil tank 7 . A valve 9 is interposed in the middle of this oil drain pipe 8. The valve 9 is connected to an opening/closing mechanism 10 that opens and closes it, and a solenoid valve 11 is connected to the opening/closing mechanism 10. The solenoid valve 11 operates the opening/closing mechanism 10 and opens the valve 9 only when both the opening/closing valve 6 and a heat detector (not shown) are activated. Further, a diaphragm 12 is provided between the tank 2 and the valve 9 in the oil drain pipe 8. Diaphragm 1
A rod 13 is provided at the tip of 2. The diaphragm 12 contracts to the right in FIG. 2 when the valve 9 is opened, and the rod 13 follows the diaphragm 12.

A valve of a high-pressure gas cylinder (nonflammable gas source) 14 filled with nonflammable gas such as nitrogen gas is connected to an opening/closing mechanism 15 that opens and closes the valve. The opening/closing mechanism 15 is engaged with the rod 13 and is operated by the movement of the rod 13 in conjunction with the diaphragm 12. In addition, high pressure gas cylinder 14 and tank 2
and are communicated with each other by a gas supply pipe 16 connected at the bottom of the tank 2. This gas supply pipe 16
A pressure expansion chamber 17 is interposed in the middle.
A space between the tank 2 and the pressure expansion chamber 17 in the gas supply pipe 16 is filled with insulating oil 3. The pressure expansion chamber 17 adjusts the pressure of the gas sent from the high-pressure gas cylinder 14 to a pressure suitable for extinguishing a fire.

In addition, in FIG. 2, reference numerals 18 and 19
is a weight that descends due to gravity and operates the switches 20 and 21 when the opening/closing mechanisms 10 and 15 are operated, respectively.

According to such a conventional fire extinguishing system for oil-filled electrical equipment, when a fire occurs in the oil-filled transformer 1, the on-off valve 6 closes and the solenoid valve 11 operates to open the valve 9. As a result, a predetermined amount of the insulating oil 3 in the tank 2 is discharged into the drain oil tank 7 via the drain pipe 8. When the diaphragm 12 contracts in the right direction in FIG. supplied to

In other words, the nonflammable gas supplied into the insulating oil 3 through the gas supply pipe 16 enters the insulating oil 3 as bubbles.
The oil rises inside and stirs the insulating oil 3 moderately to cause convection. At the same time, the low temperature insulating oil 3 in the lower part of the tank 2 moves upward. Therefore, the oil surface temperature of the insulating oil 3 becomes below the ignition point, and the fire is extinguished.

[Problem that the invention attempts to solve]

By the way, during normal operation of the oil-immersed transformer 1, it is not preferable that nonflammable gas be supplied into the insulating oil 3. This is because the insulating properties of the insulating oil 3 may be impaired, which may cause an accident. However, in conventional oil-filled electrical equipment fire extinguishing systems,
The nonflammable gas sent from the high pressure gas cylinder 14 is
After the pressure is adjusted in the pressure expansion chamber 17, the oil is directly supplied into the insulating oil 3. Therefore, for example, if a leak or malfunction occurs in the valve 9 or the like, the diaphragm 12 contracts and the opening/closing mechanism 1
9 was operated, and nonflammable gas was supplied into the insulating oil 3.

[Means and actions for solving problems]

In order to solve the above-mentioned problems, the present invention aims to supply non-flammable gas such as nitrogen gas into the insulating oil of oil-filled electrical equipment such as oil-filled transformers. A nonflammable gas source such as a gas cylinder is connected via a gas supply pipe. and,
A gas stagnation tank is interposed in the tank side portion of the gas supply pipe filled with insulating oil. This gas stagnation tank is also filled with insulating oil during normal operation of oil-filled electrical equipment. Furthermore, the gas stagnation tank is provided with an alarm device that issues an alarm when nonflammable gas flows in from the nonflammable gas source.

In the fire extinguishing system for oil-filled electrical equipment of the present invention, if nonflammable gas flows into the gas stagnation tank due to a leak or malfunction in a valve or the like during normal operation of the oil-filled electrical equipment, this gas is immediately insulated. It is captured and stagnated in a gas stagnation tank without being supplied into oil. At the same time, an alarm is issued to notify that nonflammable gas is about to be supplied into the insulating oil.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on an embodiment shown in FIG. Incidentally, the same parts as in the prior art are indicated by the same reference numerals as in FIG. 2, and the explanation thereof will be omitted.

As shown in FIG. 1, a protection relay 22 such as a Buchholz relay is interposed in the middle of a pipe 5 that communicates the tank 2 and the conservator 4. This protection relay 22 detects a failure when an accident occurs in the oil-immersed transformer 1 and the internal pressure increases. Further, the protective relay 22 is connected to a disconnector provided between the oil-immersed transformer 1 and an AC power source (not shown), and
As a result of this operation, the shattered breaker becomes shattered. Furthermore, a shutter valve 23 is provided in the middle of the pipe 5. This shutter valve 23 is
When a flow of insulating oil 3 of a specified amount or more occurs in the direction from the conservator 4 to the tank 2, the valve is automatically closed.

On the other hand, an electric valve 24 is interposed in the middle of the oil drain pipe 8. This motor-operated valve 24 operates only when three operations are performed: the operation of the protective relay 22, the operation of the insulation disconnector (not shown), and the operation of the heat detector 25 provided in the tank 2. It is something to do. Here, the heat detector 25 detects a fire in the oil-immersed transformer 1 as described above. Electric valve 2
4 opens, a predetermined amount of the insulating oil 3 in the tank 2 will be discharged to a height indicated by a broken line 26. Further, a pressure switch 27 is interposed in the oil drain pipe 8. The pressure switch 27 issues a no-pressure signal when the insulating oil 3 in the tank 2 is discharged to the position indicated by the broken line 26, since there is no longer any insulating oil 3 in the drain pipe 8.

Incidentally, an assembly manual valve 28 and a test manual valve 29 are interposed in the oil drain pipe 8 on the side closer to the tank 2 than the pressure switch 27. These manual valves 28,
29 is normally open. Therefore,
In the oil drain pipe 8, the insulating oil 3 is normally filled up to the electric valve 24.

The gas supply pipe 16 that communicates the high pressure gas cylinder 14, which is a source of nonflammable gas such as nitrogen gas, and the tank 2 is equipped with a pressure reducing valve 30,
A safety valve 31, a solenoid valve 32, and a gas stagnation tank 33 are interposed. The pressure reducing valve 30 is connected to the high pressure gas cylinder 14
It adjusts the pressure of nonflammable gas sent from the pipe to a pressure suitable for extinguishing fires, and pressure gauges with alarm contacts are installed on the primary side (high pressure side) and secondary side (low pressure side), respectively. Gas leaks from the pressure reducing valve 30 to the outside,
There is no direct effect on the oil-immersed transformer 1. However, due to a gas leak, the high pressure gas cylinder 14
If the gas capacity inside decreases, the gas supply time when extinguishing a fire will become shorter. For this reason, a pressure gauge with an alarm contact on the primary side issues an alarm when the pressure on the primary side falls below a specified value, thereby notifying the user of a gas leak and the need for gas replenishment. In addition, in a pressure gauge with an alarm contact on the secondary side, if the diaphragm of the pressure reducing valve 30 breaks down and gas leaks from the primary side to the secondary side, the contact will work as the pressure on the secondary side increases. This is to issue a warning.

The safety valve 31 operates when the pressure on the secondary side of the pressure reducing valve 30 exceeds a specified pressure, and protects the solenoid valve 32.

The electromagnetic valve 33 is connected to the electric valve 2 in the oil drain pipe 8.
It operates only when two signals are emitted: a signal emitted when the pressure switch 4 is in an open state, and a signal that the pressure switch 27 is not pressurized. Further, near this electromagnetic valve 33, an emergency manual valve 34 is provided in parallel with the electromagnetic valve 33 by branching off the gas supply pipe 16. This emergency manual valve 34 is used when power is not available in the event of a fire or the like, and the electric valve 24 or solenoid valve 3
This is provided so that nonflammable gas can be supplied manually in the event that the automatic control of the second etc. becomes impossible, and is normally closed. On the other hand, the electric valve 24 also has a built-in manual handle (not shown) for emergency operation. In addition, when an emergency operation is performed, it is assumed that the aforesaid insulator breaker is not immediately disconnected, so the insulator is set so that the insulator breaker is immediately disconnected when the motor-operated valve 24 opens. has been done.

Further, a manual assembly valve 35 similar to the manual assembly valve 28 is installed in the gas supply pipe 16 near the tank 2, and a test manual valve 35 is installed between the solenoid valve 32 and the gas stagnation tank 33. A valve 36 is interposed. Each of these manual valves 35, 36 is normally open. Therefore, under normal conditions, the tank-side portion of the gas supply pipe 16, that is, the portion from the tank 2 to the solenoid valve 32 and the emergency manual valve 34, is filled with the insulating oil 3. For this reason, the gas supply pipe 16 is provided with an air vent plug 37.

As is clear from the above, the gas stagnation tank 33 is also normally filled with the insulating oil 3. On the other hand, this gas stagnation tank 33 is provided with an alarm device 38. For example, if the motorized valve 32 malfunctions or malfunctions and gas leaks to the secondary side of the motorized valve 32, nonflammable gas enters the gas stagnation tank 33. It is configured to issue an alarm when an inflow occurs. Of course, even when a fire occurs in the oil-immersed transformer 1 and the fire extinguishing system is activated, an alarm will be issued because nonflammable gas will flow in.

According to the fire extinguishing system for oil-filled electrical equipment having such a configuration, when a fire occurs in the oil-filled transformer 1, the shutter valve 23 closes to prevent the insulating oil 3 from flowing from the conservator 4 to the tank 2. ,
The electric valve 24 opens and a predetermined amount of the insulating oil 3 in the tank 2 is discharged into the drain oil tank 7 via the drain pipe 8. Further, the solenoid valve 32 is opened and nonflammable gas is supplied from the high-pressure gas cylinder 14 into the insulating oil 3 in the tank 2 via the gas supply pipe 16, thereby extinguishing the fire.

On the other hand, if the solenoid valve 32 or the like malfunctions and gas leaks from the secondary side of the solenoid valve 32 during normal operation of the oil-immersed transformer 1, this leaked nonflammable gas will immediately flow into the tank 2. is not supplied into the insulating oil 3. That is, the leaked gas is temporarily captured and stagnated in the gas stagnation tank 33, and at the same time, the alarm device 38 issues an alarm to notify of the gas leak.

[Effect of idea]

As described above, according to the present invention, a gas stagnation tank is interposed in the gas supply pipe, and an alarm device that issues an alarm when nonflammable gas flows into the gas stagnation tank is installed, so that oil-filled electrical equipment can be operated normally. Even if a failure or malfunction occurs in a solenoid valve or the like during operation, it is possible to prevent nonflammable gas from being supplied into the insulating oil in the tank.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing an embodiment of the fire extinguishing system for oil-filled electrical equipment of the present invention, and FIG. 2 is a schematic front view showing a conventional fire extinguishing system for oil-filled electrical equipment. 1... Oil-filled transformer, 2... Tank, 3... Insulating oil, 16... Gas supply pipe, 33... Gas stagnation tank,
38...Alarm device.

Claims (1)

[Scope of utility model registration request] In order to supply a nonflammable gas into the insulating oil of the oil-filled electrical equipment, a tank of the oil-filled electrical equipment and a nonflammable gas source are connected via a gas supply pipe, and the tank side portion of the gas supply pipe is connected to the insulating oil of the oil-filled electrical equipment. In a fire extinguishing system for oil-filled electrical equipment filled with oil, a gas stagnation tank is interposed in the tank side portion of the gas supply pipe, and
A fire extinguishing system for oil-filled electrical equipment characterized by being provided with an alarm device that issues an alarm when nonflammable gas flows into the gas stagnation tank.