JPH05215365A - Ventilating air-conditioning equipment for atomic power plant - Google Patents

Abstract

PURPOSE:To improve reliability of isolation of radioactivity by a method wherein a rector building is isolated when a reactor accident occurs and control of an airflow of a building is carried out. CONSTITUTION:By means of a signal from a reactor accident detector 29 during the occurrence of a reactor accident, isolating valves 8a, 8b, 11a, and 11b of feed and discharge ducts 32 and 35 of a reactor building 7 are automatically closed. Feed and exhaust fans 4 and 14 are stopped, and the reactor building 7 is isolated from the open air. In this case, in an area except the reactor building 7, an airflow of the feed duct 32 is automatically regulated to a proper value. A proper airflow is fed through switching of the manual mode of selection switches 36 and 37 and operation of the feed and exhaust fan 4 and 14 and a given negative pressure is also maintained. Even by either the selection switch 36 or 37, the isolating valves 8a, 8b, 11a, and 11b are fully closed by means of an accident signal from an accident signal detector during a manual mode and the feed and exhaust fans 4 and 14 are also stopped. This constitution improves reliability isolation of radioactivity during the occurrence of a reactor accident.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation air conditioner for a nuclear power plant, and a ventilation air conditioner for a nuclear power plant which is integrated into a reactor building and a building independent of the reactor building. Regarding equipment.

[0002]

2. Description of the Related Art Ventilation and air-conditioning equipment installed in an area of a nuclear power plant that is likely to be contaminated by radioactivity is likely to be contaminated by radiation in addition to maintaining ventilation and temperature inside the station. It is required to maintain the area at negative pressure with respect to the atmosphere and other adjacent areas. In addition to the above, regarding the ventilation and air conditioning equipment of the reactor building that contains the reactor pressure vessel and the reactor containment vessel, the reactor building plays the role of secondary containment facility in the event of a reactor accident. Therefore, it is necessary to reliably close the supply / exhaust ducts that penetrate the reactor building by the reactor accident signal.

FIG. 2 is a system configuration diagram of a conventional ventilation and air-conditioning system for a nuclear power plant. The outside air is taken in through an outside air intake 1 and the air filtered by a supply air filter 2 is 3 times.
After passing through the air supply fan inlet manual dampers 3 connected in parallel, the pressure is increased by the three air supply fans 4 and gathered by the cooling heater 5 to adjust the temperature and humidity, and then the air supply side duct 6 is connected. As it is, it is fed to the reactor building 7 and blown out inside. In the air supply side duct 6, two inlet side isolation valves 8a,
8b and the air volume detector 9 of the reactor building 7 are provided.

In the reactor building 7, an outlet side isolation valve 11 is provided in an exhaust side duct 10 provided opposite to the air supply side duct 6.
Two a and 11b are provided. Further, three exhaust air filters 12 are connected in parallel on the outlet side of the exhaust side duct 10, and exhaust fans 14 each having a suction vane 13 are connected on the outlet side of the exhaust air filter 12. The outlet side of the exhaust fan 14 is collected and connected to a collecting duct 16 communicating with the main exhaust pipe 15.

On the other hand, for example, in a turbine building 17 adjacent to the reactor building 7, a ventilation air conditioning equipment of a system different from that of the reactor building 7 is provided with an air supply duct 18 like the reactor building 7. Has been. This air supply duct 18 sucks the outside air from the outside air intake 19, and the air filtered by the air supply air filter 20 passes through the manual damper 21 and is boosted by the intake fan 22, and is gathered by the cooling heater 23 to heat the air. Humidity-controlled air flows in. Further, an air flow detector 24 is provided in the air supply duct 18 in the turbine building 17, and is connected in parallel to an exhaust duct 25 provided in the turbine building 17 as in the reactor building 7. Three exhaust air filters 26, suction vanes 27, and exhaust fans 28 are installed.

The outlet side of the exhaust fan 28 is collected and connected to a collecting duct 16 communicating with the main exhaust pipe 16. Reference numeral 29 in FIG. 2 is a reactor accident detector, and the signal line S ₁ of the reactor accident detector 29 is connected to the suction vane 13 of the exhaust fan 14.

[0007] The signal lines S ₁ branches, the signal line S ₂ connecting to the air supply fan 4, the two inlet-side isolation valve 8a on the inlet side, a signal line S ₃ which respectively connect to 8b, S ₄ and signal lines S ₅ and S ₆ connected to the two outlet side isolation valves 11a and 11b on the outlet side, respectively. Further, the air volume detector 9 in the reactor building 7 is connected to the suction vane 13 by a signal line S ₇ . On the other hand, the air volume detector 24 in the turbine building 17 is connected to the suction vane 27 by a signal line S ₈ .

[0008]

The ventilation air conditioning equipment in the reactor building 7 is provided independently of the ventilation air conditioning equipment for other areas such as the turbine building 17. If ventilation in the reactor building 7 can be stopped reliably in the event of a nuclear reactor accident, the number of ventilation and air conditioning facilities can be reduced by integrating with ventilation and air conditioning facilities in other areas, and a more rational facility can be provided. .. However, the problem here is that if the outlet side isolation valves 11a and 11b in the reactor building 7 are closed during the reactor accident and the operation of other areas is continued, the air supply fan 4 and the exhaust fan are This is because there is an imbalance between the capacity of 14 and the ventilation air volume to be supplied other than to the reactor building 7, and it becomes impossible to perform ventilation with an appropriate air volume.

In some cases, the duct may be damaged due to an excessive air flow. Therefore, when planning the integration of ventilation and air conditioning equipment, there is a problem that a control means that can satisfy both normal operation and isolation of the reactor building has not been established.

The object of the present invention is to simplify the air-conditioning equipment by integrating the reactor building and the ventilation and air-conditioning equipment such as a building of an air-conditioning system independent of this reactor building, and at the time of a reactor accident, An object of the present invention is to provide a ventilation and air-conditioning system for a nuclear power plant that secures the same level of reliability of radioactivity isolation and operability for operators.

[0011]

[Means for Solving the Problem] The same air supply system and exhaust system equipment are connected to a reactor building and a building independent of the reactor building, and an air volume adjusting means is provided at the inlet of an exhaust fan of the exhaust system. The reactor building has a differential pressure detector and an isolation valve in the air supply and exhaust ducts, an automatic air flow rate adjusting means in the air supply duct of the building and a manual air flow rate adjusting means in the exhaust duct, and the air supply and exhaust air. An automatic / manual selection switch for fan operation is installed, the isolation valve of the reactor building is closed by the reactor accident signal to isolate the reactor building, and the differential pressure signal of the differential pressure detector supplies air to the building etc. The present invention is characterized in that the automatic air volume adjusting means of the duct and the air volume adjusting means of the exhaust fan are adjusted to control the air volume of the building or the like.

[0012]

[Function] The selection switch is normally set to "automatic mode". In the event of a reactor accident, an accident signal from the reactor accident detector automatically closes the air intake and exhaust duct isolation valves in the reactor building, and shuts off the air supply and exhaust fans. This isolates the reactor building from the outside air. At this time, in areas other than the reactor building, the automatic air volume adjusting means of the air supply duct is adjusted to an appropriate air volume, and the appropriate air volume is supplied by switching the "manual mode" of the selection switch and operating the air supply and exhaust fans. The predetermined negative pressure is also maintained. When either one of the selection switches is in the "manual mode", both isolation valves are fully closed by the accident signal from the accident signal detector, and the air supply and exhaust fans are also stopped.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. It should be noted that the same components as those of the above-described conventional technique are designated by the same reference numerals and detailed description thereof will be omitted. FIG. 1 is a system configuration diagram of ventilation air conditioning equipment. An air supply air filter 2 is provided at an outside air intake 1 that is partitioned by the building from the outside, which is an air supply system, and the outside air sucked from the outside air intake 1 is supplied as an air supply air. Filter with filter 2. The filtered air passes through the four air supply fan inlet manual dampers 3 connected in parallel, and the four air supply fans 4 are connected.
After being raised in pressure by the cooling heater 5 and adjusted in temperature and humidity by the cooling heater 5, it is fed to the reactor building 7 through the air supply side duct 6 and the two inlet side isolation valves 8a and 8b. It is blown out inside.

Further, the cooling / heating device 5 is provided with an air supply duct 32 connecting the turbine building 17 which is a ventilation and air conditioning area of another system through one manual damper 30 and one automatic damper 31. The air, which is provided and the temperature and humidity of which are adjusted, is also delivered to the turbine building 17. Here, four of the air supply fans 4 are installed, but three of them have a capacity to supply all of the required air flow to the reactor building 7 and the turbine building 17, and other One is a spare machine. A differential pressure detector 33 that detects the differential pressure between the reactor building 7 and the atmosphere is installed in the reactor building 7.

Next, as an exhaust system, an exhaust side duct 10 which is an exhaust path for the air supplied to the reactor building 7 is connected in parallel outside the reactor building 7 via two outlet side isolation valves 11a and 11b. The four exhaust air filters 12 are connected to each other. on the other hand,
The turbine building 17 is provided with an exhaust duct 35 connected to the exhaust side duct 10 outside the turbine building 17 via one manual damper 34, and is supplied from the air supply duct 32 into the turbine building 17. The generated air is collected in the exhaust air filter 12 together with the exhaust gas from the reactor building 7.

The air filtered by the exhaust air filter 12 is
After being sucked by the exhaust fan 14 through the suction vanes 13, the four exhaust fans 14 are collectively discharged to the atmosphere from the main exhaust pipe 15 through a collecting duct 16 connected to the main exhaust pipe 15. Although four exhaust fans 14 are provided as in the case of the air supply fan 4, three of them satisfy the exhaust volume of the total air volume of the reactor building 7 and the turbine building 17,
The remaining one is a standby machine. Further, the suction vanes 13 provided at the inlet of the exhaust fan 14 change the exhaust capacity of the exhaust fan 14, and four suction vanes 13 are installed so as to correspond to the exhaust fan 14 on a one-to-one basis.

The air supply fan 4 is provided with a switch (not shown) for operating and stopping each air supply fan 4, and an inlet side selection switch 36 for selecting the operation mode of the air supply fan 4. Similarly, the exhaust fan 14 is also provided with an operation switch (not shown) corresponding to each exhaust fan 14, and an outlet side selection switch 37 for selecting an operation mode of the exhaust fan 14.

The reactor accident detector 29 is connected to the inlet side selection switch 36 via the signal line S ₁₀ , and the inlet side selection switch 36 is also connected.
Is connected to the outlet side selection switch 37 by a signal line S ₁₁ , and the differential pressure detector 33 in the reactor building 7 is electrically connected to an air flow controller 38 via a signal line S _12. The air flow controller 38 is electrically connected to the suction vane 13, the inlet side selection switch 36, and the outlet side selection switch 37 via signal lines S ₁₃ , S ₁₄ and S ₁₅ .

The air supply fan 4 includes a signal line S ₁₆ and a signal line S.
_13, also the inlet side isolation valve 8a, 8b is the signal line S _17, S ₁₈
And the signal line S _13, are further automatic damper 31 via the signal line S ₁₉ and the signal line S _13, the inlet-side selection switch 36, and air volume control unit 38 electrically connected to the. Further, the outlet-side isolation valve 11a, 11b are each signal line S _20, S ₂₁ and the signal line S
₁₄ and the exhaust fan 14 through the signal line S ₂₂ and the signal line S ₁₄ , the outlet side selection switch 37 and the air flow controller 38.
Is electrically connected to.

The air supply fan 4 and the exhaust fan 14
Inlet side selection switch 36 and outlet side selection switch
37 is divided into "automatic operation mode" and "manual mode" respectively. Normally, the air supply fan 4 or the exhaust fan 4 is operated in the "automatic operation mode", and when either one of the four supply fans 4 or the exhaust fan 14 is out of order or is performing maintenance / inspection. The inlet side selection switch 36 or the outlet side selection switch 37 corresponding to 14 is configured to be in the "manual mode".

Next, the operation of the above configuration will be described. First, when performing automatic operation in the normal state,
Both the inlet side selection switch 36 and the outlet side selection switch 37 are set to the "automatic operation mode", and three air supply fans 4 and exhaust fans 14 are operated at their rated capacities by operation and stop switches (not shown). As a result, the reactor building 7
Predetermined ventilation and air conditioning is performed on the turbine building 17.

At this time, in the reactor building 7 which is required to have high airtightness, the differential pressure between the reactor building 7 and the atmosphere is detected by the differential pressure detector 33 to detect the difference between the atmosphere and the reactor building 7. The suction vane 13 is adjusted so that the differential pressure is always constant. Further, for the turbine building 17, the required air volume is initially set by the manual dampers 30 and 34. In a closed space such as a building in a nuclear power plant, in general, the ventilation air volume to the area and the differential pressure (negative pressure to the atmosphere) with respect to the atmosphere in the area have a constant relationship. The air volume can be controlled by controlling.

Conversely, the differential pressure can be controlled by controlling the air volume. Here, the reactor building 7 is controlled by differential pressure, and the turbine building 17 is controlled by air volume. In the unlikely event that a reactor accident occurs, the accident signal from the reactor accident detector 29
Immediately, the inlet side isolation valves 8a, 8b and the outlet side isolation valves 11a, 11b of the reactor building 7 are fully closed, and the air supply fan 4 and the exhaust fan 14 are closed.
Stops. At the same time, the automatic damper 31 installed in the air supply duct 32 of the turbine building 17 and the suction vane 13 close to the islanding operation set opening degree of the turbine building 17.

After that, when it is necessary to restart the operation of the turbine building 17, the inlet side selection switch 36 and the outlet side selection switch 37 are switched to the "manual mode" to supply the required number of supply fans 4 and exhaust gas. The fan 14 is started by the operation of the operator. By this operation, the reactor building 7 is isolated from the outside air, and as for the turbine building 17, the ventilation air-conditioning equipment is operated if necessary, and the turbine building 17 can be operated independently with an appropriate ventilation amount and negative pressure.

Therefore, according to this embodiment, the reactor building 7
It is possible to integrate the ventilation and air conditioning equipment of the turbine building 17 with the "automatic operation mode" during normal operation, and in the unlikely event of a reactor accident, the reactor building 7
Is automatically isolated by the inlet side isolation valves 8a, 8b and the outlet side isolation valves 11a, 11b, and the ventilation and air conditioning of the turbine building 17, which is not related to the state of the reactor building 7, is normally operated as necessary. You can continue to.

[0026]

As described above, according to the present invention, the ventilation and air-conditioning equipment of the reactor building and other areas can be integrated, so that the ventilation and air-conditioning equipment is simplified, and the operating conditions thereof are the same as those of the single equipment. It has the effects of being reliable and safe and reducing the burden on the operator due to the automation of driving.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of a ventilation air conditioning facility according to the present invention.

FIG. 2 is a system configuration diagram showing a conventional ventilation and air conditioning facility of a nuclear power plant.

[Explanation of symbols]

1 ... Outside air intake, 2 ... Air supply air filter, 3 ... Air supply fan inlet manual damper, 4 ... Air supply fan, 5 ... Cooling heater,
6 ... Air supply side duct, 7 ... Reactor building, 8a, 8b ... Inlet side isolation valve, 10 ... Exhaust side duct, 11a, 11b ... Outlet side isolation valve, 12 ... Exhaust air filter, 13 ... Suction vane, 14
… Exhaust fan, 15… Main exhaust stack, 16… Collecting duct, 17… Turbine building, 28… Reactor accident detector, 30, 34… Manual damper, 31… Automatic damper, 32… Air supply duct, 33… Difference Pressure detector, 35 ... Exhaust duct, 36 ... Inlet side selection switch, 37 ...
Exit side selection switch, 38 ... Air volume controller.

Claims (1)

[Claims] 1. The same air supply system and exhaust system equipment are connected to a nuclear reactor building and a building independent of the nuclear reactor building, and an air flow rate adjusting means is provided at the inlet of an exhaust fan of the exhaust system. A differential pressure detector and an isolation valve for the air supply and exhaust ducts in the furnace building, an automatic air volume adjustment means for the air supply duct of the building and a manual air volume adjustment means for the exhaust duct, and an automatic air supply and exhaust fan operation.・ A manual selection switch is installed, the isolation valve of the reactor building is closed by the reactor accident signal to isolate the reactor building, and the automatic air volume of the air supply duct in the building etc. is isolated by the differential pressure signal of the differential pressure detector. Ventilation and air conditioning equipment for a nuclear power plant, characterized in that the air volume control of the building etc. is performed by adjusting the air volume control means of the adjusting means and the exhaust fan.