JPH0677609B2 - Fire extinguisher in the flammable material handling room in a nuclear power plant - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention has a fire resistant wall structure and is configured to supply carbon dioxide (CO ₂ ) to a combustible material handling chamber, which becomes an airtight structure in the event of a fire, for extinguishing fire. The present invention relates to a fire extinguisher for a combustible material handling room in a nuclear power plant.

[Technical background of the invention]

In a nuclear power plant, a combustible material handling room that handles a large amount of combustible materials such as fuel oil and lubricating oil is subject to two laws. 1
One is the Building Standards Act, and the other is the Fire Service Act. According to the Building Standards Law, the combustible material handling room of a nuclear power plant must form a fireproof compartment as a compartment for different purposes. Therefore, the partitioning wall must be a fireproof wall and a structure without openings. The door installed on the fire wall must be a class A fire door with an automatic closing device. Here, the fire door with an automatic closing device is a door that automatically closes even if the door is pushed and opened to prevent the inflow and outflow of flames and smoke even when the pushing force disappears. The structure without openings means that if a duct for ventilation and air conditioning penetrates a fireproof wall as a fireproof section, install a damper that has a fireproof function that automatically closes in the event of a fire, and ducts and piping are fireproof. When the wall of the compartment is penetrated, the through hole portion is subjected to fire resistance treatment.

According to the standards of the Fire Service Law, it is obligatory to install carbon dioxide fire extinguishing equipment in a combustible material handling room, that is, a hazardous material facility. Carbon dioxide fire extinguishing equipment is a storage container for carbon dioxide that is connected to a pipe filled with compressed and liquefied carbon dioxide, and in the event of a fire, the valve of this storage container is opened to remove CO _{2 in the} pipe. To discharge CO ₂ from the jet head installed at the end of the pipe or in the middle of the pipe to fill and combust flammable substances to extinguish the suffocation. When operating the carbon dioxide fire extinguishing equipment and releasing CO ₂ into the combustible material handling room, it is necessary to stop the ventilation system in that room according to fire regulations.Therefore, a ventilation air conditioner that penetrates the fireproof wall of the combustible material handling room The duct for use is equipped with a damper that closes in conjunction with the operation of the carbon dioxide fire extinguishing equipment, and releases the carbon dioxide after closing the damper. In addition, CO ₂
Since the combustible material handling chamber that discharges the air must have an airtight structure as much as possible, the ducts and the through holes of the pipes that are disposed so as to penetrate the fireproof wall 7 are airtightly treated. The door of the handling room must have an airtight structure.

By implementing the above measures, the atmosphere in the combustible material handling room can be shut off from the outside when CO ₂ is released, and the room can be filled with CO ₂ to extinguish the suffocation.

[Problems of background technology]

The building structure of a conventional nuclear power plant, for increasing the extinguishing effect of the CO _2, also waste of man-made and extinguishing CO ₂ by CO ₂ flows into the combustibles handling chamber other passages and other rooms that releases CO ₂ To prevent this, a fire-resistant wall structure consisting of reinforced concrete walls, floors, and ceilings with a thickness of 30 cm to 250 cm was added, and air-tight seals were added to the parts where piping, conduits, and ventilation / air-conditioning ducts penetrate the fire-resistant wall. ing. In addition, the door of the entrance and exit of the combustible material handling room that emits CO ₂ has a semi-airtight structure, and CO ₂
By providing a damper that automatically closes upon release, the combustible material handling room is airtight with the outside in the event of a fire.

However, when a flammable material handling chamber that releases CO ₂ when a fire occurs is made airtight and CO ₂ is released, the existing air and the released CO ₂ at atmospheric pressure before the release fills the combustible handling room. It will be. In this case, when the combustible material handling chamber that emits CO ₂ is completely airtight and the room pressure after CO _{2 is} released is calculated to be about 1.43 kg / cm ² atm, which exceeds the strength of the fire wall and fittings. . However, since there is some leakage from the airtight seal part, door and damper part, it is considered that the above indoor pressure will not be reached, but even considering the amount of gas for this leak, with respect to the fire resistant wall and fittings, There is a possibility of adverse effects due to high pressure.

[Object of the Invention] The present invention has been made in view of the above circumstances, when the carbon dioxide fire extinguishing equipment operates in a nuclear power plant, the carbon dioxide fire extinguishing equipment protection target room becomes airtight, that is,
An object of the present invention is to provide a fire extinguisher for a combustible material handling room in a nuclear power plant, which prevents excessive pressure from being applied to a fireproof wall and fittings when CO ₂ is released into the combustible material handling room.

[Outline of Invention]

The present invention provides a carbon dioxide fire extinguishing facility for supplying carbon dioxide to a combustible material handling chamber, which has a fireproof wall structure and becomes an airtight structure when a fire occurs, in which a nuclear power is passed through the fireproof wall of the combustible material handling chamber. It is characterized in that a pressure relief duct is provided which leads to the outside of the power plant building and releases the air in the room to the outside when carbon dioxide is supplied into the combustible material handling room in the event of a fire.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings. In the figure, reference numeral 1 is in a nuclear power plant building, and a part of it is buried under the ground surface 2. Nuclear power plant building 1
A combustible material handling chamber 3 for handling a large amount of combustible materials is provided inside the room, and a wall 4, a floor 5, and a ceiling 6 are surrounded by a frame of a reinforced concrete fireproof wall 7. The carbon dioxide extinguishing equipment 8 provided for fire extinguishing activities when a fire occurs in the combustible material handling room 3 includes a carbon dioxide storage container 9 placed outside the combustible material handling room 3 and this carbon dioxide storage. It is composed of a pipe 10 connected to the container 9 and an injection head 11 attached to the end of the pipe in the combustible material handling chamber 3 or in the middle thereof.

The air supply fan 12 provided for ventilation and air conditioning of the nuclear power plant building 1 sucks outdoor air from the air supply suction duct 13 and supplies the air to the inside of the nuclear power plant building 1 through the air supply discharge duct 14. I am worried. Exhaust fan 15
Is configured to suck the air inside the nuclear power plant building 1 from the exhaust suction duct 16 and exhaust the air to the outside of the nuclear power plant building 1 through the exhaust discharge duct 17. Among the ducts installed for ventilation and air conditioning of the nuclear power plant building 1, penetrate the fireproof wall 7 of the combustible substance handling room 3 and both inside the combustible substance handling chamber 3 and other rooms inside the nuclear power plant building 1. For the duct 18 that supplies and exhausts air to and from, a damper 19 having a fireproof property and having a function of automatically closing in the event of a fire is installed. This is because if there is a combustible material handling room 3 inside the nuclear power plant building 1, it is necessary to form a fireproof compartment as a different-purpose compartment according to the provisions of the Building Standards Act, and therefore, a combustible material surrounding a large amount of combustible material. Wall 4, floor 5, of the handling room 3
As described above, the ceiling 6 has a frame made of the structure of the fireproof wall 7, and the duct 8 passing through the fireproof wall 7 is provided with a damper 19 having a fireproof function and a function of automatically closing in the event of a fire. It is based on what is obliged to do. Further, the protection target room of the carbon dioxide fire extinguishing equipment 8, that is, the duct 18 penetrating the wall 4, the floor 5 and the ceiling 6 surrounding the combustible material handling room 3 is operated by the carbon dioxide fire extinguishing equipment 18 in accordance with the provisions of the fire regulations. This is because it is necessary to provide a damper 19 having a function of automatically closing when CO ₂ is released into the combustible material handling chamber 3. In this embodiment, from the viewpoint of economy and simplification of installation, this damper is used.
19 is a CO ₂ fire damper.

Furthermore, carbon dioxide extinguishing equipment 8
Wall 4, floor 5, ceiling 6 of combustible material handling room 3 which is the room to be protected
As a general rule, no clearance should be provided, so a through hole 20 that is airtightly treated with boot rubber is used for the opening for the pipe 10 and duct 18 to penetrate the fireproof wall 7. ing.

The wall 4 of the combustible material handling chamber 3 is provided with a pressure relief duct 21 that penetrates the refractory wall 7 and leads to the outside of the nuclear power plant building 1. This pressure relief duct 21
When CO ₂ is supplied into the combustible material handling chamber 3, the air existing in the room is released to the outside, and the combustible material handling chamber 3 is discharged.
It prevents the pressure from rising due to CO ₂ supply. It is considered that the gas flowing out from the pressure relief duct 21 contains not only air but also a small amount of released CO _2, but an amount of CO ₂ corresponding to the opening area of the pressure relief duct 21.
If the carbon dioxide fire extinguishing equipment 8 is supplied, there is no support for the fire extinguishing ability.

Here, the opening area of the pressure relief duct 21 can be obtained by the following calculation formula.

Where X is the opening area (mm ² ) and Q is the CO ₂ emission weight (kg
/ min), P is the room pressure (kg / cm ² ) of the fire extinguisher 3 in the combustible material handling room in the nuclear power plant after CO ₂ is released.
However, the room pressure P is 1.43 kg / cm ² when the combustible material handling chamber 3 is considered to be completely sealed.

In addition, since the fireproof section under the Building Standards Act requires the separation of the combustible material handling room 3 and other areas within the nuclear power plant building 1, it penetrates the fireproof wall 7 of the combustible material handling room 3 and directly outdoors. Even if a duct communicating with the atmosphere is connected, it does not have to have a damper, which has a fireproof property like the above-mentioned ventilation and air conditioning duct 18 and has a function of automatically closing in the event of a fire. However, in the portion where this duct passes through the inside of the nuclear power plant building 1 other than the combustible material handling room 3, the outer surface of the duct must be fireproofed to have fireproof performance.

Next, the operation will be described.

When a fire occurs in the combustible material handling chamber 3 that handles a large amount of combustible material, the valve of the carbon dioxide storage container 9 is opened. The CO ₂ flowing out from the carbon dioxide storage container 9 is transferred into the combustible material handling chamber 3 through the pipe 10 and is discharged from the jet head 11. At the same time, CO ₂ flowing through the pipe 10 is supplied to the damper 19,
The damper 19 is closed by the pressure of the CO ₂ to stop the ventilation in the combustible material handling chamber 3. The CO ₂ emitted from the jet head 11 fills the combustible material handling chamber 3 while pushing out the existing air in the combustible material handling chamber 3 from the pressure relief duct 21 that has been subjected to fireproofing to the outside of the nuclear power plant building 1. Then, reduce the oxygen concentration to extinguish the suffocation. Since the air in the combustible material handling chamber 3 is released to the outside of the nuclear power plant building 1 from the pressure relief duct 21 in this way, it is possible to prevent an increase in the indoor pressure in the combustible material handling chamber 3, so that the fireproof wall 7 Also, it is possible to prevent adverse effects because excessive pressure does not act on the nuclear power plant building 1.

〔The invention's effect〕

According to the present invention, the combustible material handling chamber is provided with the pressure relief duct that penetrates through the refractory wall to the outside of the nuclear power plant building, so when a fire occurs in the combustible material handling chamber or the carbon dioxide fire extinguishing equipment. Even if CO ₂ is released into the combustible material handling room during the release test, etc., the air existing in the room escapes to the outside through the pressure relief duct, so that the rise in the room pressure can be prevented. Therefore, it is possible to prevent adverse effects on the fire wall and the nuclear power plant building due to the pressure increase.

According to the present invention, since the pressure relief duct allows the air in the room to escape to the outside when carbon dioxide is supplied into the combustible material handling chamber at the time of a fire occurrence, the air escape action is performed immediately after the carbon dioxide supply. Since the exhaust action rises earlier, it is possible to more reliably prevent the rise of the indoor pressure, and it is possible to greatly improve the safety as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a fire extinguisher in a combustible material handling room in a nuclear power plant according to the present invention. 1 ... Nuclear power plant building, 3 ... Combustible material handling room, 7 ...
Fireproof wall, 8 ... Carbon dioxide extinguishing equipment, 21 ... Pressure relief duct.

Claims (1)

[Claims] 1. A fireproof wall structure, and a carbon dioxide fire extinguishing facility for supplying carbon dioxide to a combustible substance handling chamber, which becomes an airtight structure when a fire occurs, provided with a carbon dioxide fire extinguishing facility that penetrates the fireproof wall of the flammable substance handling chamber. A combustible material in a nuclear power plant characterized by being provided with a pressure relief duct that leads to the outside of the nuclear power plant building, and when carbon dioxide is supplied to the combustible material handling room in the event of a fire, releases the indoor air to the outside. Fire extinguisher in the handling room.