JP6784652B2 - Ventilation system - Google Patents

Description

The present invention relates to a ventilation system.

Conventionally, for example, the ventilation system described in Patent Document 1 and Patent Document 2 sends gas to a room through a filter unit that blocks the passage of radioactive gas in the event of an accident in a nuclear facility. When a radioactive rare gas that cannot be removed by the department is detected, the supply of outside air to the room is stopped. Further, this ventilation system supplies oxygen to the room by means of air supply from the cylinder when the carbon dioxide concentration inside the room becomes high while the supply of outside air to the room is stopped.

Japanese Patent No. 5714066 Japanese Patent No. 6133822

According to Patent Document 1 and Patent Document 2 described above, while removing radioactive gas and blocking radioactive rare gas, oxygen is supplied to the inside of the room when the radioactive rare gas is shut off to ensure the safety inside the room. can do.

Here, for example, in the case of a room capable of accommodating about 100 people, it is generally used to secure oxygen during the period of generation of radioactive rare gas (about 24 hours to 1 week after the accident of the nuclear facility). About 1000 47-liter cylinders are needed. Therefore, there is a problem that the installation area for installing such a large amount of cylinders, the equipment such as the storage place for storing the cylinders, and the cost for maintaining and managing the cylinders increase.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide a ventilation system capable of reducing equipment and costs related to means for supplying oxygen for ensuring the safety of the inside of a room.

In order to achieve the above object, in the ventilation system according to one aspect of the present invention, a room surrounded by walls, ceilings and floors and a liquefied oxygen storage unit for storing liquefied oxygen are arranged outside the room. An oxygen gas supply means that is provided through the inside of the room and supplies oxygen gas higher than the pressure outside the room to the inside of the room and a liquefied nitrogen storage unit that stores liquefied nitrogen are arranged outside the room. The room is provided with a nitrogen gas supply means for supplying nitrogen gas higher than the pressure outside the room to the inside of the room.

Further, in the ventilation system according to one aspect of the present invention, heat is generated between the gas supplied into the room from at least one of the oxygen gas supply means and the nitrogen gas supply means and the gas inside the room. It is preferable to further provide a carbon dioxide removing means for liquefying and removing carbon dioxide contained in the gas inside the room by exchanging.

Further, in the ventilation system according to one aspect of the present invention, the oxygen detection means for detecting the oxygen concentration inside the room, the oxygen gas supply means, and the nitrogen gas supply means based on the detection value of the oxygen detection means are used. It is preferable to provide a control means for controlling the gas supply amount.

Further, in the ventilation system according to one aspect of the present invention, an air supply means for sending gas outside the room to the inside of the room, a harmful gas detecting means for detecting harmful gas outside the room, and a harmful gas detecting means for the room. When a harmful gas is detected by the carbon dioxide detecting means for detecting the internal carbon dioxide concentration and the harmful gas detecting means, the air supply means is stopped and the oxygen gas supply means and the nitrogen gas supply means are operated. The gas supply amount from the oxygen gas supply means and the nitrogen gas supply means is controlled so that the carbon dioxide concentration detected by the carbon dioxide detection means is equal to or lower than a preset threshold value, while the harmful gas detection means is used. When no toxic gas is detected, it is preferable to further include a control means for stopping the oxygen gas supply means and the nitrogen gas supply means and operating the air supply means.

Further, in the ventilation system according to one aspect of the present invention, the air supply means for sending the gas outside the room to the inside of the room and the radioactive gas contained in the gas sent to the inside of the room by the air supply means. A filter unit that blocks the passage of the gas, a radioactive gas detecting means for detecting the radioactive gas outside the room, a radioactive rare gas detecting means for detecting the radioactive rare gas outside the room, and carbon dioxide inside the room. When the radioactive rare gas is detected by the carbon dioxide detecting means for detecting the concentration and the radioactive rare gas detecting means, the air supply means is stopped to operate the oxygen gas supply means and the nitrogen gas supply means, and the above. While controlling the amount of gas supplied from the oxygen gas supply means and the nitrogen gas supply means so that the carbon dioxide concentration detected by the carbon dioxide detection means is equal to or lower than a preset threshold value, the radioactive rare gas detection means is radioactive. When the rare gas is not detected and the radioactive gas is detected by the radioactive gas detecting means, the oxygen gas supplying means and the nitrogen gas supplying means are stopped, and the carbon dioxide concentration detected by the carbon dioxide detecting means is determined in advance. It is preferable to further provide a control means for controlling the gas supply amount by the air supply means so as to be equal to or less than the set threshold value.

According to the present invention, oxygen gas higher than the pressure outside the room is supplied to the inside of the room by liquefied oxygen from the liquefied oxygen storage part of the oxygen gas supply means, and liquefied nitrogen is used from the liquefied nitrogen storage part of the nitrogen gas supply means. Since nitrogen gas, which is higher than the pressure outside the room, is supplied to the inside of the room, oxygen can be supplied while keeping the inside of the room at a higher pressure than the outside, and breathing is hindered while blocking harmful gas. Can be prevented and the safety inside the room can be ensured. Moreover, according to the present invention, since liquefied oxygen is stored in the liquefied oxygen storage section and liquefied nitrogen is stored in the liquefied nitrogen storage section, the amount held can be reduced as compared with gas, and cylinders and tanks can be used. It is possible to reduce the installation area for installing the gas cylinder, the equipment such as the storage place for storing the cylinder and the tank, and the cost for maintaining the cylinder and the tank.

FIG. 1 is a schematic view of a ventilation system according to an embodiment of the present invention. FIG. 2 is a schematic view showing a filter unit of the ventilation system according to the embodiment of the present invention. FIG. 3 is a flowchart showing the operation of the ventilation system according to the embodiment of the present invention. FIG. 4 is a flowchart showing other operations of the ventilation system according to the embodiment of the present invention. FIG. 5 is a flowchart showing the operation of another example of the ventilation system according to the embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment. In addition, the components in the following embodiments include those that can be easily replaced by those skilled in the art, or those that are substantially the same.

[Embodiment 1]
FIG. 1 is a schematic view of a ventilation system according to the present embodiment, FIG. 2 is a schematic view showing a filter portion of the ventilation system according to the present embodiment, and FIG. 3 is a schematic view of the ventilation system according to the present embodiment. It is a flowchart which shows operation. FIG. 4 is a flowchart showing other operations of the ventilation system according to the present embodiment.

As shown in FIG. 1, the ventilation system 1 of the present embodiment includes a room 2, a radioactive gas removing means 3, a radioactive gas detecting means 4A, a radioactive rare gas detecting means 4B, an oxygen gas supplying means 5, and nitrogen. It includes a gas supply means 6, a carbon dioxide detecting means 7, an oxygen detecting means 8, an intra-chamber pressure detecting means 9, a carbon dioxide removing means 10, and a control means 11.

Room 2 is surrounded by walls, ceilings and floors. This room 2 is, for example, a control room installed in the reactor building for controlling and monitoring nuclear equipment, a living room installed in the reactor building for meetings and living, and in the event of an accident of nuclear equipment. An alternative control room installed outside the reactor building to control and monitor nuclear equipment, an alternative living room installed outside the reactor building to hold meetings and live in the event of a nuclear equipment accident, and a nuclear equipment accident There are emergency rooms for people engaged in nuclear facilities and residents near nuclear facilities to evacuate, and hospitals and nursing care facilities near nuclear facilities.

In the present embodiment, the room 2 is provided with an airlock 2A for moving in and out while minimizing the decrease in air pressure and the loss of air inside. Further, the room 2 is provided with an air conditioner 2B for appropriately maintaining the internal temperature and humidity. The air conditioner 2B has an indoor unit 2Ba and an outdoor unit 2Bb, and the indoor unit 2Ba detects the temperature and humidity inside the room 2 and controls the temperature and humidity to be suitable. Further, the room 2 has a pressure adjusting means 2C for adjusting the pressure inside the room 2 to be higher than the pressure outside the room 2 (atmospheric pressure). The pressure adjusting means 2C is, for example, a duct 2Ca that communicates the inside and the outside of the room 2 and a pressure adjusting valve that opens and closes or adjusts the opening degree of the duct 2Ca so as to discharge the air inside the room 2 to the outside of the room 2. It consists of 2Cb. Further, the room 2 is provided with a deodorizer 2D that adsorbs and removes the odor inside.

The radioactive gas removing means 3 is a radioactive gas containing a radioactive substance containing gaseous radioactive iodine (iodine I ₂ , organic iodine CH ₃ I), mist-like cesium (Cs), strontium (Sr), and the like. It blocks the passage of gas. The radioactive gas removing means 3 includes a filter unit 3A, an air supply pipe 3B, a blower 3C, and an on-off control valve 3D.

As shown in FIG. 2, the filter portion 3A has a continuous casing 3Aa whose circumference is surrounded by an outer wall and openings are formed on one end side and the other end side, respectively. The filter unit 3A is provided with a heating unit 3Ab, a coarse filter 3Ac, an upstream high-performance filter 3Ad, a radioactive gas filter 3Ae, and a downstream high-performance filter 3Af from one end side in the casing 3Aa.

The heating unit 3Ab is for heating the gas flowing inside the casing 3Aa. The heating unit 3Ab may be arranged on the upstream side of the gas flow with respect to the radioactive gas filter 3Ae.

As the coarse filter 3Ac, for example, an air filtration filter having a target particle size of 50 μm or more and a medium-high performance filter having a target particle size of 25 μm or more are applied.

For the upstream high-performance filter 3Ad and the downstream high-performance filter 3Af, for example, a HEPA filter (High Efficiency Particulate Air Filter) having a target particle size of 0.15 μm and a removal efficiency of 99.97% is applied.

The radioactive gas filter 3Ae adsorbs radioactive substances contained in the gas circulated inside the casing 3Aa. Specifically, the radioactive gas filter 3Ae contains a base material constituting the base material and an adhering substance attached to the base material. The material used for the base material is not particularly limited as long as it has a plurality of pores on the surface, and examples thereof include activated carbon, alumina, zeolite, silica gel, and activated clay. The zeolite may be either a natural zeolite or a synthetic zeolite. Further, examples of the zeolite include mordenite-based zeolite. The base materials can be used alone or in combination of two or more. In addition, the radioactive gas filter 3Ae contains triethylenediamine (TEDA: Tri-Ethylene-Di-Amine) or potassium iodide (KI) as an adhering substance. Due to the above configuration, this radioactive gas filter 3Ae is a radioactive substance containing gaseous radioactive iodine (iodine I ₂ , organic iodine CH ₃ I), mist-like cesium (Cs), strontium (Sr), and the like. By adsorbing, the passage of radioactive gas containing the radioactive substance is blocked.

Although not explicitly shown in the drawing, the filter unit 3A may be provided with a gas treatment filter inside the casing 3Aa and on the upstream side of the gas flow with respect to the radioactive gas filter 3Ae. The gas treatment filter collects the organic solvent gas component and the acid gas component contained in the gas distributed inside the casing 3Aa. Specifically, the gas treatment filter includes a base material constituting the base material and an adhering substance attached to the base material. The material used for the base material is not particularly limited as long as it has a plurality of pores on the surface, and examples thereof include activated carbon, alumina, zeolite, silica gel, and molecular sieve. The zeolite may be either a natural zeolite or a synthetic zeolite. Further, examples of the zeolite include mordenite-based zeolite. The base materials can be used alone or in combination of two or more. In addition, the gas treatment filter contains at least one of an acidic component, an alkaline component, tri-Ethylene-Di-Amine (TEDA), and potassium iodide (KI) as an adhering substance. With the above configuration, this gas treatment filter contains radioactive substances containing gaseous radioactive iodine (iodine I ₂ , organic iodine CH ₃ I), mist-like cesium (Cs), strontium (Sr), and the like. By adsorbing, it is possible to block the passage of radioactive gas containing the radioactive substance.

The air supply pipe 3B communicates with the downstream side of the filter unit 3A and the inside of the room 2.

The blower 3C is provided in the air blower pipe 3B and allows air to pass through the inside of the casing 3Aa of the filter unit 3A. The air passing through the inside of the casing 3Aa of the filter unit 3A by the blower 3C is sent to the inside of the room 2 through the air blower pipe 3B.

The opening / closing adjusting valve 3D is provided on the air supply pipe 3B to open / close or adjust the opening / closing of the air supply pipe 3B.

Except for the filter unit 3A, the air supply pipe 3B, the blower 3C, and the open / close adjustment valve 3D can be configured as an air supply means for sending the gas (outside air) outside the room 2 inside the room 2.

In FIG. 1, the blower 3C is provided on the downstream side of the on-off adjustment valve 3D in the air blower pipe 3B, but may be provided on the upstream side of the on-off adjustment valve 3D. Further, in FIG. 1, the blower 3C is provided in the air blower pipe 3B, but may be provided on the other end side (most downstream side) in the casing 3Aa of the filter unit 3A.

The radioactive gas detecting means 4A is provided outside the room 2, for example, outside one end side of the casing 3Aa in the filter unit 3A, and detects the radioactive gas. The radioactive gas detecting means 4A includes a gas chromatograph and a gamma ray detector. The radioactive gas detecting means 4A detects, for example, when radioactive gas is generated in the event of an accident at a nuclear facility, and then when the fuel in the reactor melts to generate radioactive rare gas, the radioactive gas detecting means 4A detects the radioactive gas. Radioactive rare gas can be detected when the detected value of radiation exceeds the detected value of detecting radioactive gas, and then the radiation of the radioactive rare gas is attenuated and the radioactive rare gas is reduced when the detected value of radiation falls below. It is possible to detect what has been done.

The radioactive rare gas detecting means 4B is provided outside the room 2, for example, outside one end side of the casing 3Aa in the filter unit 3A, and detects radioactive rare gas such as xenon (Xe) and argon (Ar). It is a thing. The radioactive rare gas detecting means 4B detects the radioactive rare gas, for example, when the fuel in the reactor melts and the radioactive rare gas is generated after the radioactive gas is generated in the event of an accident in a nuclear facility.

The radioactive gas detecting means 4A and the radioactive rare gas detecting means 4B are provided as harmful gas detecting means 4 for detecting harmful gas.

The oxygen gas supply means 5 supplies oxygen gas to the inside of the room 2. The oxygen gas supply means 5 includes a liquefied oxygen storage unit 5A, a supply pipe 5B, a flow rate adjusting valve 5C, and a flow meter 5D.

The liquefied oxygen storage unit 5A includes a cylinder that stores liquefied oxygen in a high pressure state (pressure higher than atmospheric pressure) and a tank that stores liquefied oxygen in a high pressure state (pressure higher than atmospheric pressure). A cylinder or tank for storing liquefied oxygen is provided so as to be movable by being loaded on a transportation means (not shown) such as a vehicle.

The supply pipe 5B communicates the liquefied oxygen storage unit 5A with the inside of the room 2.

The flow rate adjusting valve 5C is provided in the supply pipe 5B and adjusts the flow rate of liquid oxygen sent from the liquefied oxygen storage unit 5A passing through the supply pipe 5B. The flow rate adjusting valve 5C also constitutes a pressure adjusting means for adjusting the pressure inside the room 2 to be higher than the pressure outside the room 2 (atmospheric pressure).

The flow meter 5D measures the flow rate of liquid oxygen sent from the liquefied oxygen storage unit 5A provided in the supply pipe 5B and passing through the supply pipe 5B.

The nitrogen gas supply means 6 supplies nitrogen gas to the inside of the room 2. The nitrogen gas supply means 6 includes a liquefied nitrogen storage unit 6A, a supply pipe 6B, a flow rate adjusting valve 6C, and a flow meter 6D.

The liquefied nitrogen storage unit 6A includes a cylinder for storing liquefied nitrogen in a high pressure state (pressure higher than atmospheric pressure) and a tank for storing liquefied nitrogen in a high pressure state (pressure higher than atmospheric pressure). A cylinder or tank for storing liquefied nitrogen is provided so as to be movable by being loaded on a transportation means (not shown) such as a vehicle.

The supply pipe 6B communicates the liquefied nitrogen storage unit 6A with the inside of the room 2.

The flow rate adjusting valve 6C is provided in the supply pipe 6B and adjusts the flow rate of liquid nitrogen sent from the liquefied nitrogen storage unit 6A passing through the supply pipe 6B. The flow rate adjusting valve 6C also constitutes a pressure adjusting means for adjusting the pressure inside the room 2 to be higher than the pressure outside the room 2 (atmospheric pressure).

The flow meter 6D measures the flow rate of liquid nitrogen sent from the liquefied nitrogen storage unit 6A provided in the supply pipe 6B and passing through the supply pipe 6B.

The carbon dioxide detecting means 7 detects the carbon dioxide concentration in the air inside the room 2.

The oxygen detecting means 8 detects the oxygen concentration in the air inside the room 2.

The room pressure detecting means 9 detects the pressure inside the room 2.

The carbon dioxide removing means 10 removes carbon dioxide inside the room 2. The carbon dioxide removing means 10 is provided in the supply pipe 5B of the oxygen gas supply means 5 and the supply pipe 6B of the nitrogen gas supply means 6 inside the room 2.

The carbon dioxide removing means 10 provided in the supply pipe 5B of the oxygen gas supply means 5 exchanges heat with the liquid oxygen sent to the supply pipe 5B to exchange the carbon dioxide inside the room 2 with the air inside the room 2. Liquefaction or solidification. Since liquid oxygen has a boiling point of -183 ° C and carbon dioxide has a boiling point of -78.5 ° C, the temperature drops and liquefies by exchanging heat with the cold heat of liquid oxygen while applying pressure to carbon dioxide. , When the pressure of this liquid is suddenly lowered, it solidifies. Therefore, the carbon dioxide removing means 10 can liquefy or solidify the carbon dioxide in the air and take it out and remove it by exchanging heat with the liquid oxygen in the air inside the room 2. The liquefied or solidified carbon dioxide can be discharged from the airlock 2A to the outside of the room 2, for example. On the other hand, the liquid oxygen heat-exchanged by the carbon dioxide removing means 10 rises in temperature and becomes oxygen gas, which is discharged into the room 2. That is, by opening the flow rate adjusting valve 5C in the oxygen gas supply means 5 and sending the oxygen gas into the room 2, the carbon dioxide removing means 10 simultaneously removes the carbon dioxide inside the room 2.

Further, the carbon dioxide removing means 10 provided in the supply pipe 6B of the nitrogen gas supply means 6 exchanges heat with the liquid nitrogen sent to the supply pipe 6B for the air inside the room 2, thereby producing carbon dioxide inside the room 2. Liquidate or solidify carbon. Since liquid nitrogen has a boiling point of -196 ° C and carbon dioxide has a boiling point of -78.5 ° C, the temperature drops and liquefies by exchanging heat with the cold heat of liquid nitrogen while applying pressure to carbon dioxide. , When the pressure of this liquid is suddenly lowered, it solidifies. Therefore, the carbon dioxide removing means 10 can liquefy or solidify the carbon dioxide in the air and take it out and remove it by exchanging heat with the liquid nitrogen in the air inside the room 2. On the other hand, the temperature of the liquid nitrogen exchanged by the carbon dioxide removing means 10 rises to become nitrogen gas, which is discharged into the room 2. That is, by opening the flow rate adjusting valve 6C in the nitrogen gas supply means 6 and sending the nitrogen gas into the room 2, the carbon dioxide removing means 10 simultaneously removes the carbon dioxide inside the room 2.

The control means 11 controls the ventilation system 1 in an integrated manner. The control means 11 controls the blower 3C and the on-off control valve 3D of the radioactive gas removing means 3 based on the detection result of the radioactive gas detecting means 4A. Further, the control means 11 includes a blower 3C and an on-off control valve 3D of the radioactive gas removing means 3 and a flow rate adjusting valve 5C and a nitrogen gas supply means of the oxygen gas supply means 5 based on the detection result of the radioactive rare gas detecting means 4B. The flow rate adjusting valve 6C of 6 is controlled. Further, the control means 11 includes the blower 3C and the on / off adjusting valve 3D of the radioactive gas removing means 3 and the flow rate adjusting valve 5C and the nitrogen gas supply means 6 of the oxygen gas supply means 5 based on the detection result of the carbon dioxide detecting means 7. Controls the flow rate adjusting valve 6C. Further, the control means 11 controls the flow rate adjusting valve 5C of the oxygen gas supply means 5 and the flow rate adjusting valve 6C of the nitrogen gas supply means 6 based on the detection result of the oxygen detecting means 8. Further, the control means 11 controls the pressure adjusting means (pressure adjusting means 2C, flow rate adjusting valve 5C, flow rate adjusting valve 5C) based on the detection result of the room pressure detecting means 9.

The operation of the ventilation system 1 of the present embodiment will be described. When an accident occurs in a nuclear facility, as shown in FIG. 3, the control means 11 stops the radioactive gas removing means 3 and operates the oxygen gas supply means 5 and the nitrogen gas supply means 6 to correct the inside of the room 2. The pressure is applied (step S1). That is, the control means 11 stops the blower 3C of the radioactive gas removing means 3 to close the open / close adjusting valve 3D, opens the flow rate adjusting valve 5C of the oxygen gas supply means 5, and makes the nitrogen gas supply means 6 open. While the flow rate adjusting valve 6C is open, the pressure adjusting means is operated so that the pressure detected by the chamber pressure detecting means 9 is higher than the pressure outside the room 2 (for example, 10 mmAq or more) (pressure adjusting means 2C). The pressure regulating valve 2Cb of the above is closed, or the flow control valve 5C of the oxygen gas supply means 5 and the flow control valve 6C of the nitrogen gas supply means 6 are opened). As a result, oxygen gas and nitrogen gas are supplied to the room 2 in a state where the radioactive gas and the radioactive rare gas are blocked. As a result, it is possible to prevent a person inside the room 2 from being exposed to radioactive gas or a radioactive rare gas immediately after an accident occurs in the nuclear facility, and to prevent a situation where the person inside the room 2 is obstructed from breathing. it can.

After step S1, when the radioactive gas is detected by the radioactive gas detecting means 4A (step S2: Yes) and the radioactive rare gas is detected by the radioactive rare gas detecting means 4B (step S3: Yes), the control means 11 , The radioactive gas removing means 3 is stopped, the oxygen gas supply means 5 and the nitrogen gas supply means 6 are operated, and the inside of the room 2 is made a positive pressure (step S4). That is, the control means 11 continues the operation of step S1.

When the radioactive rare gas is not detected in step S3 (step S3: No), the control means 11 stops the oxygen gas supply means 5 and the nitrogen gas supply means 6 and operates the radioactive gas removing means 3 to operate the room 2. The inside of the pressure is positive (step S5). That is, the control means 11 opens and closes by operating the blower 3C of the radioactive gas removing means 3 with the flow rate adjusting valve 5C of the oxygen gas supply means 5 closed and the flow rate adjusting valve 6C of the nitrogen gas supply means 6 closed. While opening the adjusting valve 3D, the pressure adjusting means is operated so that the pressure detected by the chamber pressure detecting means 9 is higher than the pressure outside the chamber 2 (for example, 10 mmAq or more) (pressure adjusting of the pressure adjusting means 2C). Valve 2Cb is closed). As a result, it is possible to prevent a person inside the room 2 from being exposed to radioactive gas.

After step S4, when the carbon dioxide concentration exceeds the threshold value (step S6: Yes), the control means 11 controls the supply amounts of the oxygen gas supply means 5 and the nitrogen gas supply means 6 (step S7). That is, in step S6, the control means 11 acquires the detection result of the carbon dioxide concentration by the carbon dioxide detecting means 7, and when the carbon dioxide concentration exceeds the threshold value (for example, usually at about 300 ppm to 390 ppm, a human being). In step S7, the flow rate adjusting valve 5C of the oxygen gas supply means 5 and the flow rate adjusting valve 6C of the nitrogen gas supply means 6 are opened and operated so that the amount of oxygen supply increases in step S7. , The carbon dioxide concentration inside the room 2 is set to be below the threshold value (for example, 5000 ppm). As a result, the health of the person inside the room 2 can be maintained. After controlling the supply amounts of the oxygen gas supply means 5 and the nitrogen gas supply means 6 in step S7, the process returns to step S6 to monitor the carbon dioxide concentration. Further, in step S6, if the carbon dioxide concentration does not exceed the threshold value (step S6: No), the control means 11 returns to step S2 while maintaining the operation of step S4 (step S1), and the radioactive gas detecting means 4A The radioactive rare gas is monitored by the above, and the radioactive rare gas is monitored by the radioactive rare gas detecting means 4B.

On the other hand, when the carbon dioxide concentration exceeds the threshold value after step S5 (step S8: Yes), the control means 11 controls the air supply amount of the radioactive gas removing means 3 (step S9). That is, in step S8, the control means 11 acquires the detection result of the carbon dioxide concentration by the carbon dioxide detecting means 7, and when the carbon dioxide concentration exceeds the threshold value (for example, usually at about 300 ppm to 390 ppm, a person's body). (When the concentration is 5000 ppm or more, which impairs health), in step S9, the rotation speed of the blower 3C of the radioactive gas removing means 3 is rapidly operated or the opening / closing control valve 3D is increased so that the amount of air supplied by the radioactive gas removing means 3 increases. To bring the carbon dioxide concentration inside the room 2 below the threshold (for example, 5000 ppm). As a result, the health of the person inside the room 2 can be maintained. After controlling the air supply amount of the radioactive gas removing means 3 in step S9, the process returns to step S8 to monitor the carbon dioxide concentration. Further, in step S8, if the carbon dioxide concentration does not exceed the threshold value (step S8: No), the control means 11 returns to step S2 while maintaining the operation of step S5, and the radioactive gas is detected by the radioactive gas detecting means 4A. In addition to monitoring, the radioactive rare gas is monitored by the radioactive rare gas detecting means 4B.

If the radioactive gas is not detected by the radioactive gas detecting means 4A in step S2 (step S2: No), the control means 11 opens the room 2 to the outside air (step S10). That is, when the control means 11 does not detect the radioactive gas in step S2 and the safety is confirmed, in step S10, the radioactive gas removing means 3, the oxygen gas supply means 5, the nitrogen gas supply means 6 and the pressure adjusting means 2C To stop. Further, after step S10, the process returns to step S2 again, the radioactive gas is monitored by the radioactive gas detecting means 4A, and the radioactive rare gas is monitored by the radioactive rare gas detecting means 4B.

By the way, step S1 is not necessary, but in the event of an accident in the nuclear equipment, the effect of preventing the person inside the room 2 from being exposed to the radioactive gas or the radioactive rare gas is remarkably obtained. Before the radioactive gas is detected by the detecting means 4A, it is preferable to stop the radioactive gas removing means 3 and operate the oxygen gas supply means 5 and the nitrogen gas supply means 6 to make the inside of the room 2 a positive pressure.

Further, when operating the oxygen gas supply means 5 and the nitrogen gas supply means 6, the control means 11 controls the oxygen gas supply means 5 and the nitrogen gas supply means 6 based on the oxygen concentration detected by the oxygen detection means 8. .. Specifically, as shown in FIG. 4, after operating the oxygen gas supply means 5 and the nitrogen gas supply means 6 (step S11), when the oxygen concentration falls below the threshold value (step S12: Yes), the control means 11 , Control a large amount of oxygen gas supply (step S13). That is, in step S12, the control means 11 acquires the detection result of the oxygen concentration by the oxygen detecting means 8, and when the oxygen concentration falls below the threshold value (for example, when it becomes less than 18.5%), step S13. The opening degree of the flow control valve 5C of the oxygen gas supply means 5 is increased so that the oxygen concentration inside the room 2 becomes equal to or higher than the threshold value (for example, 18.5%) so that the oxygen supply amount increases. .. As a result, the health of the person inside the room 2 can be maintained. On the other hand, when the oxygen concentration exceeds the threshold value after step S11 (step S12: No), the control means 11 controls the oxygen gas supply amount to be small (step S14). That is, in step S12, the control means 11 acquires the detection result of the oxygen concentration by the oxygen detecting means 8, and when the oxygen concentration exceeds the threshold value (for example, when it exceeds 21%), the oxygen in step S14. The opening degree of the flow rate adjusting valve 5C of the oxygen gas supply means 5 is reduced so that the oxygen concentration inside the room 2 becomes an appropriate value (for example, 18.5% to 21%) so that the supply amount is reduced. To do. This operation is always performed when the oxygen gas supply means 5 and the nitrogen gas supply means 6 are operated. By this operation, consumption of oxygen gas (liquefied oxygen) can be suppressed.

As described above, according to the ventilation system 1 of the present embodiment, the liquefied oxygen storage unit 5A of the oxygen gas supply means 5 supplies oxygen gas higher than the pressure outside the room 2 to the inside of the room 2 by liquefied oxygen. Since the liquefied nitrogen storage unit 6A of the nitrogen gas supply means 6 supplies nitrogen gas higher than the pressure outside the room 2 to the inside of the room 2 by liquefied nitrogen, the inside of the room 2 is set to a higher pressure than the outside and oxygen is supplied. It is possible to prevent a situation in which breathing is hindered while blocking harmful gas, and it is possible to ensure the safety inside the room 2.

A nuclear facility requires a control room for controlling and monitoring the nuclear facility and a living space for people engaged in the control room. Then, in the unlikely event of an accident, the control room (an alternative control room that controls and monitors nuclear equipment if the control room is damaged) or a living room (an alternative living room if the living room is damaged), or Prevent exposure of people inside room 2 such as emergency rooms for evacuation of residents, or hospitals and long-term care facilities near nuclear facilities where it is difficult to evacuate urgently, and maintain breathing. There is a need.

Moreover, according to the ventilation system 1 of the present embodiment, since the liquefied oxygen is stored in the liquefied oxygen storage section 5A and the liquefied nitrogen is stored in the liquefied nitrogen storage section 6A, the retained amount is reduced as compared with the gas. This makes it possible to reduce the installation area for installing cylinders and tanks, equipment such as storage locations for storing cylinders and tanks, and costs for maintaining and managing cylinders and tanks. For example, when supplying oxygen gas for one week in room 2 accommodating 100 people, it is necessary to have about 1000 cylinders for storing oxygen gas, but 50 or less cylinders for storing liquefied oxygen and liquefied nitrogen. It can be reduced.

Further, according to the ventilation system 1 of the present embodiment, the liquefied oxygen of the oxygen gas supply means 5 and the liquefied nitrogen of the nitrogen gas supply means 6 are lower than the boiling point of carbon dioxide, so that the carbon dioxide removing means 10 By exchanging heat between the gas supplied to the inside of the room 2 from at least one of the oxygen gas supply means 5 and the nitrogen gas supply means 6 and the gas inside the room 2, the gas inside the room 2 is exchanged. The contained carbon dioxide is liquefied and removed. As a result, the carbon dioxide concentration inside the room 2 can be suppressed low, the safety inside the room 2 can be ensured, and the means for utilizing the cold heat of liquefied oxygen and liquefied nitrogen supplied to the inside of the room 2. Therefore, it can be simplified as compared with the means for removing carbon dioxide exclusively.

Further, according to the ventilation system 1 of the present embodiment, the oxygen detection means 8 detects the oxygen concentration inside the room 2, and the control means 11 detects the oxygen gas supply means 5 and nitrogen based on the detection value of the oxygen detection means 8. The amount of gas supplied by the gas supply means 6 is controlled. Therefore, the oxygen concentration inside the room 2 can be adjusted to an appropriate value.

Further, according to the ventilation system 1 of the present embodiment, the control means 11 includes a radioactive gas removing means 3, a radioactive gas detecting means 4A, a radioactive rare gas detecting means 4B, and a carbon dioxide detecting means 7. When the radioactive rare gas is detected by the radioactive rare gas detecting means 4B, the supply of gas from the radioactive gas removing means 3 to the inside of the room 2 is stopped, and the oxygen gas supplying means 5 and the nitrogen gas supplying means 6 are operated. The amount of gas supplied from the oxygen gas supply means 5 and the nitrogen gas supply means 6 is controlled so that the carbon dioxide concentration detected by the carbon dioxide detection means 7 is equal to or lower than a preset threshold value, while the radioactive rare gas detection means 4B is used. When the radioactive rare gas is not detected and the radioactive gas is detected by the radioactive gas detecting means 4A, the oxygen gas supplying means 5 and the nitrogen gas supplying means 6 are stopped, and the carbon dioxide concentration detected by the carbon dioxide detecting means is determined in advance. The amount of gas supplied from the radioactive gas removing means 3 to the inside of the room 2 is controlled so as to be equal to or less than the set threshold value.

Radioactive gas (gas containing gaseous radioactive iodine, mist-like radioactive substances such as cesium and strontium in the air) can be removed by the filter unit 3A, but the radioactive rare gas (xenone) generated in the early stage such as core meltdown , Gas containing krypton and the like in the air) cannot be sufficiently removed by the filter unit 3A. Therefore, according to the ventilation system 1 of the present embodiment, when the radioactive rare gas is detected, the room 2 is shut off from the outside air and oxygen gas and nitrogen gas are supplied, so that the radioactive rare gas containing the radioactive gas is contained in the room 2. It is possible to prevent the situation of being sent to the inside of the room 2 and to maintain the breathing of the person inside the room 2. In particular, according to this ventilation system 1, since the supply amounts of oxygen gas and nitrogen gas are controlled based on the detected value of the carbon dioxide concentration by the carbon dioxide detecting means 7, when the carbon dioxide concentration inside the room 2 is low, By suppressing the supply of oxygen gas and nitrogen gas, it is possible to save and secure the storage amount of liquefied oxygen and liquefied nitrogen, while when the carbon dioxide concentration inside the room 2 is high, the oxygen gas and nitrogen gas The carbon dioxide concentration inside the room 2 can be reduced by increasing the supply amounts of oxygen gas and nitrogen gas within the range in which the supply amount of oxygen gas and nitrogen gas is suppressed as much as possible.

By the way, in the above-described embodiment, the air from which the radioactive gas has been removed is sent to the inside of the room 2 by using the radioactive gas removing means 3, but the radioactive gas removing means 3 may not be used. In this case, although not clearly shown in the figure, the filter unit of the radioactive gas removing means 3 is used as an air supply means for sending the gas (outside air) outside the room 2 to the inside of the room 2 instead of the above-mentioned radioactive gas removing means 3. Except for 3A, the configuration includes an air blower pipe 3B, a blower 3C, and an on-off control valve 3D. Further, the ventilation system 1 described above blocks the passage of radioactive gas into the room 2, but is not limited to the radioactive gas, and into the room 2 of various harmful gases that affect the human body. It may be possible to block the passage of the gas. In that case, the above-mentioned radioactive gas detecting means 4A and radioactive rare gas detecting means 4B are provided as harmful gas detecting means 4 for detecting harmful gas. Further, the room 2 in which the harmful gas is blocked does not have to be attached to the above-mentioned nuclear power equipment, and can be attached to various equipments that may generate harmful gas.

The operation of the ventilation system 1 which has an air supply means for sending the gas (outside air) outside the room 2 inside the room 2 and blocks the passage of harmful gas including radioactive gas into the room 2 will be described below. To do. FIG. 5 is a flowchart showing the operation of another example of the ventilation system according to the present embodiment.

For example, when an accident occurs in the equipment, as shown in FIG. 5, the control means 11 stops the air supply means and operates the oxygen gas supply means 5 and the nitrogen gas supply means 6 to positively pressure the inside of the room 2. (Step S21). That is, the control means 11 stops the blower 3C of the air blowing means to close the opening / closing adjusting valve 3D, opens the flow rate adjusting valve 5C of the oxygen gas supply means 5, and adjusts the flow rate of the nitrogen gas supply means 6. While the valve 6C is open, the pressure adjusting means is operated so that the pressure detected by the chamber pressure detecting means 9 is higher than the pressure outside the chamber 2 (for example, 10 mmAq or more) (pressure of the pressure adjusting means 2C). The control valve 2Cb is closed, or the flow control valve 5C of the oxygen gas supply means 5 and the flow control valve 6C of the nitrogen gas supply means 6 are opened). As a result, oxygen gas and nitrogen gas are supplied to the room 2 in a state where harmful gas is blocked. As a result, it is possible to prevent the person inside the room 2 from being affected by the harmful gas immediately after the accident occurs in the equipment, and to prevent the person inside the room 2 from being hindered from breathing.

When the harmful gas is detected by the harmful gas detecting means 4 after step S21 (step S22: Yes), the control means 11 stops the air supply means and operates the oxygen gas supply means 5 and the nitrogen gas supply means 6. The inside of the room 2 is set to positive pressure (step S23). That is, the control means 11 continues the operation of step S21.

After step S23, when the carbon dioxide concentration exceeds the threshold value (step S24: Yes), the control means 11 controls the supply amounts of the oxygen gas supply means 5 and the nitrogen gas supply means 6 (step S25). That is, in step S24, the control means 11 acquires the detection result of the carbon dioxide concentration by the carbon dioxide detecting means 7, and when the carbon dioxide concentration exceeds the threshold value (for example, usually at about 300 ppm to 390 ppm, a person's body). (When the amount exceeds 5000 ppm, which impairs health), in step S25, the flow rate adjusting valve 5C of the oxygen gas supply means 5 and the flow rate adjusting valve 6C of the nitrogen gas supply means 6 are opened and operated so that the oxygen supply amount increases, and the room is opened. The carbon dioxide concentration inside 2 is set to be below the threshold value (for example, 5000 ppm). As a result, the health of the person inside the room 2 can be maintained. After controlling the supply amounts of the oxygen gas supply means 5 and the nitrogen gas supply means 6 in step S25, the process returns to step S24 to monitor the carbon dioxide concentration. Further, in step S24, if the carbon dioxide concentration does not exceed the threshold value (step S24: No), the control means 11 returns to step S22 while maintaining the operation of step S23 (step S21), and the harmful gas detecting means 4 Monitor for harmful gases.

If no harmful gas is detected by the harmful gas detecting means 4 in step S22 (step S22: No), the control means 11 stops the oxygen gas supplying means 5 and the nitrogen gas supplying means 6 and blows the air blowing means (blower). 3C) is operated to make the inside of the room 2 a positive pressure (step S26). In step S26, it is not necessary to operate the air blowing means (blower 3C).

By the way, step S21 is not necessary, but in the event of an accident in the nuclear power facility, the harmful gas detecting means 4 has a remarkable effect of preventing the person inside the room 2 from being affected by the harmful gas. It is preferable to stop the air supply means and operate the oxygen gas supply means 5 and the nitrogen gas supply means 6 to bring the inside of the room 2 to a positive pressure before detecting the harmful gas.

Further, when operating the oxygen gas supply means 5 and the nitrogen gas supply means 6, the control means 11 controls the oxygen gas supply means 5 and the nitrogen gas supply means 6 based on the oxygen concentration detected by the oxygen detection means 8. .. Specifically, it is shown in FIG. As a result, consumption of oxygen gas (liquefied oxygen) can be suppressed.

In the ventilation system 1 of this embodiment, oxygen gas higher than the pressure outside the room 2 is supplied from the liquefied oxygen storage unit 5A of the oxygen gas supply means 5 to the inside of the room 2 by liquefied oxygen, and the nitrogen gas supply means 6 Since the liquefied nitrogen storage unit 6A supplies nitrogen gas higher than the pressure outside the room 2 to the inside of the room 2 by the liquefied nitrogen, it is used for equipment such as the installation area of cylinders and tanks and the storage place for storing cylinders and tanks. Since there is a margin and a large storage capacity can be secured, it is possible to omit the configuration of the filter unit (for example, the filter unit 3A) for removing harmful gas.

In that case, according to the ventilation system 1 of the present embodiment, when a harmful gas is detected, the room 2 is shut off from the outside air and oxygen gas and nitrogen gas are supplied, so that the room contains radioactive rare gas including radioactive gas. It is possible to prevent the situation of being sent to the inside of the room 2 and to maintain the breathing of the person inside the room 2. In particular, according to this ventilation system 1, since the supply amounts of oxygen gas and nitrogen gas are controlled based on the detected value of the carbon dioxide concentration by the carbon dioxide detecting means 7, when the carbon dioxide concentration inside the room 2 is low, By suppressing the supply of oxygen gas and nitrogen gas, it is possible to save and secure the storage amount of liquefied oxygen and liquefied nitrogen, while when the carbon dioxide concentration inside the room 2 is high, the oxygen gas and nitrogen gas The carbon dioxide concentration inside the room 2 can be reduced by increasing the supply amounts of oxygen gas and nitrogen gas within the range in which the supply amount of oxygen gas and nitrogen gas is suppressed as much as possible.

1 Ventilation system 2 Room 2C Pressure adjusting means 3 Radioactive gas removing means 3A Filter part 3B Air supply pipe (air supply means)
3C blower (air supply means)
3D on-off adjustment valve (air supply means)
4 Harmful gas detecting means 4A Radioactive gas detecting means 4B Radioactive rare gas detecting means 5 Oxygen gas supply means 5A Liquefied oxygen storage part 6 Nitrogen gas supply means 6A Liquefied nitrogen storage part 7 Carbon dioxide detecting means 8 Oxygen detecting means 9 Room pressure detection Means 10 Carbon dioxide removal means 11 Control means

Claims (4)

A room surrounded by walls, ceilings and floors,
An oxygen gas supply means for arranging a liquefied oxygen storage unit for storing liquefied oxygen outside the room and providing it through the inside of the room to supply oxygen gas higher than the pressure outside the room to the inside of the room. When,
A nitrogen gas supply means for arranging a liquefied nitrogen storage unit for storing liquefied nitrogen outside the room and providing it through the inside of the room to supply nitrogen gas higher than the pressure outside the room to the inside of the room. When,
Carbon dioxide contained in the gas inside the room exchanges heat between the gas supplied to the inside of the room from at least one of the oxygen gas supply means and the nitrogen gas supply means and the gas inside the room. A carbon dioxide removal means that liquefies and removes carbon,
Ventilation system with. An oxygen detecting means for detecting the oxygen concentration inside the room and
A control means for controlling the amount of gas supplied by the oxygen gas supply means and the nitrogen gas supply means based on the detection value of the oxygen detection means, and
The ventilation system according to claim 1 . An air supply means that sends gas outside the room to the inside of the room, and
Hazardous gas detecting means for detecting harmful gas outside the room,
A carbon dioxide detecting means for detecting the carbon dioxide concentration inside the room,
When a harmful gas is detected by the harmful gas detecting means, the air supply means is stopped to operate the oxygen gas supplying means and the nitrogen gas supplying means, and the carbon dioxide concentration detected by the carbon dioxide detecting means is determined in advance. The gas supply amount from the oxygen gas supply means and the nitrogen gas supply means is controlled so as to be equal to or lower than the set threshold value, and when toxic gas is not detected by the harmful gas detection means, the oxygen gas supply means and the oxygen gas supply means and the said. A control means for stopping the nitrogen gas supply means and operating the air supply means,
The ventilation system according to claim 1 or 2 . An air supply means that sends gas outside the room to the inside of the room, and
A filter unit that blocks the passage of radioactive gas contained in the gas sent to the inside of the room by the air supply means, and
Radioactive gas detecting means for detecting radioactive gas outside the room, and
A radioactive rare gas detecting means for detecting a radioactive rare gas outside the room,
A carbon dioxide detecting means for detecting the carbon dioxide concentration inside the room,
When the radioactive rare gas is detected by the radioactive rare gas detecting means, the air supply means is stopped, the oxygen gas supply means and the nitrogen gas supply means are operated, and the carbon dioxide concentration detected by the carbon dioxide detecting means. The amount of gas supplied from the oxygen gas supply means and the nitrogen gas supply means is controlled so that is equal to or less than a preset threshold value, while the radioactive rare gas is not detected by the radioactive rare gas detecting means and the radioactive rare gas is not detected. When the radioactive gas is detected by the gas detecting means, the oxygen gas supplying means and the nitrogen gas supplying means are stopped so that the carbon dioxide concentration detected by the carbon dioxide detecting means is equal to or less than a preset threshold value. A control means that controls the amount of gas supplied by the air supply means,
The ventilation system according to claim 1 or 2 .

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