JPH07229992A - Cooling facility for air recirculation system of reactor containment vessel - Google Patents

Abstract

PURPOSE:To reduce the entire facility capacity and the number of refrigerators in each cooling facility of a containment vessel air recirculation system (CAC) and a service building ventilation system in a reactor. CONSTITUTION:In order to make atmosphere temperature of the inside of a containment vessel 9 constant, a recirculation pump 1a for supplying cooling water to coolers for performing heat removal and a refrigerator 2d for performing the heat removal of the heat-exchanged cooling water in the coolers 3a-3d are equipped. Three refrigerators 4a-4c for removing heat load of a building ventilation system, SBV, and the inside of the containment vessel as the side of SBV, a CAC cooling water circulation pump 1b and refrigerator 2b as common spare, a flow control valve 17, cutoff valves 19a, 19b and a return valve 16 for removing the heat load of the inside of CAC at the time of normal operation, a flow control valve 13 for supplying the cooling water to a building ventilation system 13 and tubing 14 for connecting CAC and SBV are constituted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling facility for a containment vessel of a nuclear reactor and a cooling facility for a building ventilation system.

[0002]

2. Description of the Related Art The prior art is shown in FIG.

In FIG. 6, a containment vessel air recirculation system (hereinafter abbreviated as CAC) of a heavy water deceleration boiling light water cooling pressure tube type reactor is configured so that the warm air in the containment vessel 9 is exhausted from the exhaust duct 1.
1, a cooler 3a, 3b, 3c, 3d is inhaled and cooled, and a closed system for supplying air from the air supply duct 12 into the storage container 9 is constituted.

The air in the storage container 9 is recirculated in the storage container 9 by the circulation blower 10 to keep the ambient temperature in the storage container 9 constant.

Further, the cold water whose air is cooled by the coolers 3a, 3b, 3c, 3d rises in temperature, but the elevated cold water is cooled by the auxiliary cooling seawater pump 5 in the refrigerators 2a, 2b, 2c, 2d.
It is cooled again by exchanging heat with the seawater supplied at and is reused in the cooler. CAC refrigerators 2a, 2
The capacities of b, 2c, and 2d are the capacities for removing the heat load in the containment vessel 9 during normal operation and the heat load of some building ventilation local coolers, and the heat load in the containment vessel 9 at the time of loss of external power supply. Is determined by the cooling capacity required to remove

On the other hand, a refrigerator 4a of a service building ventilation system (hereinafter referred to as SBV, which is one of the building ventilation systems (hereinafter abbreviated as BV). Here, the service building ventilation system is taken as an example of the building ventilation system). , 4b, 4c, 4d have a cooling capacity capable of removing the heat load of the waste treatment building ventilation system, the turbine building ventilation system, and the own system.

Cooling of the refrigerators 4a, 4b, 4c and 4d is carried out by a regular auxiliary equipment cooling system.

That is, the cooling water is supplied to the refrigerators 4a, 4b, 4c, 4d by the normal auxiliary equipment cooling system circulation pump 8, and the cooling water heated here is cooled by the normal auxiliary equipment cooling system heat exchanger 7. As a result, the cooling function of the refrigerators 4a, 4b, 4c, 4d is maintained.

FIG. 7 shows a normal operation mode of CAC and SBV in the conventional example.

In FIG. 7, the refrigerators 2a, 2b,
2c, 2d, cold water circulation pump 1, CAC coolers 3a, 3
b, 3c, 3d, CAC circulation blower 10, 4a, 4 respectively
3a, 3b, 3c, 3d of b, 4c, 4d are operated (one for each is a standby machine) to remove the heat load in the storage container 9.

Further, by opening the shutoff valve 19 and the return valve 16 to the building ventilation system and automatically controlling the flow rate by the flow rate control valve 13, the heat load of the building ventilation system local cooler is removed. .

The SBV chilled water circulation pump 15 and the refrigerators 4a, 4b, 4c and 4d, which are connected to the service system, are operated three out of four units (each one is a standby unit) to heat the inside of the building. Remove the load.

FIG. 8 shows a mode when the external power source is lost.

In FIG. 8, the CAC cooling equipment (cold water circulation pumps 1a, 1b, 1c, 1d refrigerators 2a, 2b, 2c, 2) is used.
d) is connected to the emergency system power supply, and when the external power source is lost, the heat load of the building ventilation local cooler, which is the heat load of the regular system, is excluded (the cold water supply to the local ventilation system of the building ventilation system is controlled by the external power loss signal. It is automatically stopped by closing the shutoff valve 19 and the return valve 16), and the chilled water circulation pumps 1a, 1b, 1 for removing the heat load in the storage container 9
c, 1d, refrigerators 2a, 2b, 2c, 2d, two of each four are in operation, and the remaining two are spares.

That is, when the external power source is lost, one refrigerator for the building ventilation local cooler is not operated.

On the other hand, the SBV cooling equipment is not connected to the emergency power source and does not operate when the external power source is lost.

As described above, since the heat loads of the refrigerators 2a, 2b, 2c, 2d of the CAC cooling equipment, which is an emergency system, also take into consideration the heat load of the local cooler of the building ventilation system, which is a regular system, The capacity and the number of the CAC refrigerators 2a, 2b, 2c, 2d are larger than the capacity and the number of units required as an emergency system (capacity and number required when the external power source is lost).

Here, in order to reduce the capacity of the cooling equipment for the CAC, the load of the normal system is incorporated into the load of the refrigerator of the emergency system.

There is a conventional system with similar cooling equipment.

In consideration of the above, the cooling load of the CAC is separated into the normal system load and the emergency system load, and the heat load of the building ventilation system local cooler, which is the load of the CAC cooling equipment, is separated.
Incorporated into the SBV cooling load, CAC refrigerators 2a, 2b, 2
It is necessary to reduce the c and 2d capacities (excluding the load of the building ventilation local cooler, it is possible to reduce by one CAC refrigerator. See Fig. 9).

The refrigerators 2a, 2b, 2 can be removed by removing the service load from the capacity of the refrigerators 2a, 2b, 2c, 2d of the CAC.
The total capacity of c and 2d is about 25% (7.2 → 5.4 × 10 ⁶ kc
al / h), and the total number of refrigerators 2a, 2b, 2c, 2d is reduced by one (4 → 3).

On the other hand, the SBV refrigerators 4a, 4b, 4c,
The 4d capacity is increased by the heat load (1.8 × 10 ⁶ kcal / h) of the local cooler for the building ventilation system, and this heat load will be removed by three units operating normally, so the refrigerator 1 The capacity per unit is about 60% (1.0 → 1.6 × 10 ⁶ kc
al / h) increase, and SBV refrigerators 4a, 4
b, 4c, 4d Total capacity is about 60% (4.
0 → 6.4 × 10 ⁶ kcal / h) increase.

From the above results, it is possible to reduce the capacity and the number of refrigerators of the emergency system CAC, but the SBV of the regular system is correspondingly reduced.
Refrigerator capacity increases.

In this way, the total installed capacity of CAC and SBV is reduced only by incorporating the heat load of the local cooler of the building ventilation system of the regular system as the heat load of SBV ((7.
2 + 4.0) = 11.2 × 10 ⁶ kcal / h → (5.4+
6.4) = 11.8 × 10 ⁶ kcal / h).

Here, the removal of the heat load in the containment vessel 9 when the external power source is lost is premised on the fact that two CAC refrigerators for emergency use are used (a spare unit is also provided in consideration of a single failure). , In order to reduce the total installed capacity of CAC and SBV and the number of units, the capacity of the refrigerator of CAC and the capacity of the refrigerator of SBV were leveled.

Further, with the standardization of the cooling facilities for CAC and SBV, a spare machine was shared.

[0027]

Therefore, the removal of the heat load in the containment vessel 9 at the time of loss of the external power source is carried out by the CAC of the emergency system.
In order to reduce the total equipment capacity of CAC and SBV and the number of units, the capacity of the refrigerator of the CAC and the capacity of the SB of the
V refrigerator capacity should be leveled, and CAC and S
With the leveling of BV cooling equipment, it is desired to share the standby equipment.

The capacity of the cooling equipment of the CAC according to the prior art described above is that of the cooling equipment (refrigerator) of this system connected to the emergency system power supply because the load of the building ventilation system, which is the normal system load, is taken in. The total capacity and number were excessive.
(The load of the regular system can be cheaper if it is cooled by the cooling system of the regular system because of the equipment cost.) Moreover, although the SBV constitutes the same cooling facility as the CAC, the building ventilation system is a separate regular system load. Cold water is supplied to the refrigerator, etc., and the CAC and SBV refrigerators each have a spare unit with different equipment specifications.
Rationalization of equipment (common use of standby machines) is desired.

Further, in these cooling facilities, there is a demand for leveling of the refrigerator capacity for the purpose of reducing the total facility capacity, easiness of maintenance, and reducing the number of devices for rational arrangement.

It is an object of the present invention to achieve a combined simplification of CAC and SBV cooling equipment.

[0031]

In order to solve the above-mentioned problems, the heat of the building ventilation system of the normal system incorporated in the capacity of the CAC cooling equipment for cooling the atmosphere in the containment vessel 9 and keeping the atmosphere temperature constant. The load is taken into the heat load of the SBV cooling equipment, thereby reducing the load capacity of the refrigerator of the CAC, which is an emergency system.

Further, in order to reduce the capacity of the refrigerator of the CAC, the heat load in the PCV is divided into those required when the external power source is lost and those not, and only those required when the external power source is lost are stored in the CAC. Heat load, other heat load is S
The heat load of the BV cooling equipment was decided.

As described above, the capacity of the refrigerator, which is an emergency system, can be significantly reduced (about 40%) as compared with the conventional design.

Further, in order to reduce the total capacity and the number of CAC and SBV refrigerators, it is considered that the capacity of these refrigerators should be leveled and a spare machine should be shared.
That is, first, the capacity of the CAC refrigerator should be the capacity required by one unit when the external power supply is lost.
The refrigerator capacity of the SBV is set so that the capacity of the refrigerator of 1 is substantially equal to the capacity of the refrigerator of CAC. Then, a refrigerator having the same capacity as the CAC is installed on the CAC side, and this is used as a common standby machine with the SBV. By equalizing the capacity of the refrigerator and sharing the standby unit as described above, the number of equipment units can be reduced, the layout can be rationalized, and the maintainability of the equipment can be improved.

[0035]

According to the above means, the load capacity of the CAC refrigerator, which is an emergency system, can be minimized by using only the heat load of the CAC that needs cooling when the external power supply is lost,
The capacity of the CAC cooling equipment can be reduced. Also, CAC
By equalizing the capacity of refrigerators for SBV and SBV, and sharing the refrigerator spare with it, it is possible to reduce the total equipment capacity of refrigerators for CAC and SBV, reduce the number of equipment, streamline the layout, and maintainability of equipment. Can be improved.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, in this embodiment, a circulation pump 1a for supplying cold water to the coolers 3a, 3b, 3c, 3d for removing heat in order to keep the ambient temperature in the containment vessel 9 constant on the CAC side. 1 and a refrigerator 2a for removing heat from the cold water heat-exchanged by the coolers 3a, 3b, 3c, 3d, S
On the BV side, the heat load of the building ventilation system, the heat load of the BV, and three refrigerators 4a, 4b, 4c for removing the heat load of the storage container 9, and cold water for supplying cold water to each load Three units of circulation pumps 15a, 15b, 15c and a CAC cold water circulation pump 1b and a refrigerator 2 as a common spare
b One each, a flow control valve 17 for removing the heat load in the CAC during normal operation, a shutoff valve 19, a return valve 16 and a flow control valve 13 and CAC for supplying cold water to the building ventilation system
And SBV communication piping 14.

FIG. 2 shows a mode of removing the heat load in the containment vessel 9 during normal operation.

In FIG. 2, the heat load when the external power source of the CAC is lost can be cooled by one refrigerator, and in consideration of the reduction of the total equipment capacity of the CAC and SBV refrigerators, the operation of the CAC and SBV equipment is as follows. The heat load in the storage container 9 during normal operation is removed by a CAC and SBV refrigerator. Also,
When the external power supply is lost, the heat load inside the PCV 9 can be removed by only one CAC refrigerator. That is, the heat load in the storage container 9 during the normal operation is 1 in the CAC side refrigerator 2a.
The chilled cold water from the stand and the SBV refrigerators 4a, 4b, 4c is removed by supplying it to the coolers 3a, 3b, 3c, 3d.

The heat load of the building ventilation local cooler is removed by supplying the cooled cold water from the SBV refrigerators 4a, 4b, 4c. The supply of cold water to the CAC side and the building ventilation local cooler is controlled by the flow rate control valves 17 and 13, respectively.

Here, the heat load on the SBV side can be sufficiently removed by supplying the remaining cold water of the SBV cooling equipment supplied to the CAC side and the building ventilation system.

FIG. 3 shows a mode in which the SBV refrigerator 4a supplying cold water in order to remove the heat load in the containment vessel 9 and the building ventilation system local cooler has a single failure. In FIG. 3, the SBV side refrigerators 4a, 4 during normal operation
The cold water supplied from b and 4c for removing a part of the heat load in the containment vessel and the heat load of the building ventilation system local cooler is passed through the connection pipes 14 with the CAC side and the building ventilation system local cooler, respectively. The flow rate is adjusted by the flow rate control valves 13 and 17 to remove the heat load in the containment vessel 9 and the local cooler of the building ventilation system, but in the case of a single failure, C
Refrigerator 2 of CAC, which is a common standby machine for AC and SBV
b (including the cold water circulation pump 1b) is automatically activated to supply cold water to the storage container 9 and the building ventilation system local cooler, thereby removing the heat load on the storage container 9 and the building ventilation system local cooler.

FIG. 4 shows the mode when the external power supply is lost.

In FIG. 4, the heat load when the external power supply is lost is that the target heat load is only the heat load of the emergency system in the storage container 9, and about 7 of the heat load in the storage container 9 during normal operation.
The heat load is 5% (see FIG. 5).

Therefore, the shutoff valve 19 for the cold water from the SBV,
It is possible to cool by automatically closing the return valve 16 and automatically starting one of the CAC refrigerators 2a (including the chilled water circulation pump 1a). Even in the case of a single failure, it can be dealt with without problems by automatically starting the spare refrigerator 2b (including the chilled water circulation pump 1b).

As explained above, by separating the heat load of the building ventilation local cooler, which is the normal system load, from the heat load in the containment vessel, which is the emergency system load, the building ventilation local cooler that is the normal system load. The heat load can be applied to the SBV cooling equipment to reduce the capacity of the CAC refrigerator, which has been excessively large.

Further, by equalizing the capacity of the refrigerators of CAC and SBV, the number of equipments can be reduced, and accordingly, the number of maintenances of refrigerators can be reduced, the efficiency of equipment manufacturability can be improved, and the arrangement of equipments can be rationalized. It is possible to plan.

Further, by sharing the spare unit when a single failure of the refrigerator is taken into consideration, the facility capacity of the cooling facility, the number of devices can be reduced, and the layout configuration can be rationalized.

[0049]

As described above, according to the present invention, the combined simplification of the cooling facilities for the CAC and SBV can be achieved.

[Brief description of drawings]

FIG. 1 is a system diagram of a reactor containment air recirculation system cooling facility according to an embodiment of the present invention.

FIG. 2 is a system diagram in which a water flow state line in a normal operation mode in the system of FIG. 1 is represented by a thick line.

FIG. 3 is a system diagram in which a water flow state line in a single failure mode in the system of FIG. 1 is represented by a thick line.

FIG. 4 is a system diagram in which the water flow state line in the system of FIG. 1 at the time of loss of external power supply is represented by a thick line.

FIG. 5 is a bar graph showing a breakdown of the cooling capacity of the CAC refrigerator (removal machine).

FIG. 6 is a system diagram of a conventional containment vessel air recirculation system cooling facility.

FIG. 7 is a system diagram in which a water flow state line in the normal operation mode in the system of FIG. 6 is represented by a thick line.

FIG. 8 is a system diagram in which the water flow state line in the system of FIG. 6 when the external power supply is lost is represented by a thick line.

FIG. 9 is a system diagram when a building ventilation system heat load is taken into the SBV.

[Explanation of symbols]

1a, 1b, 1c, 1d ... CAC cold water circulation pump, 2
a, 2b, 2c, 2d ... CAC refrigerators 3a, 3b,
3c, 3d ... CAC cooler, 4a, 4b, 4c, 4d
... SBV refrigerator, 5a, 5b, 5c, 5d ... Auxiliary equipment cooling seawater pump, 6a, 6b ... Emergency accessory cooling system heat exchanger,
7a, 7b ... Regular auxiliary machine cooling system heat exchanger, 8a, 8b ... Regular auxiliary machine cooling system circulation pump, 9 ... Storage container, 10 ... CAC
Circulation fan, 11 ... Exhaust duct, 12 ... Air supply duct,
13 ... Building ventilation system flow control valve, 14 ... Communication pipe, 1
5a, 15b, 15c, 15d ... SBV cold water circulation pump, 16 ... Return valve, 17 ... CAC flow control valve, 19
a, 19b ... shut-off valve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumito Nakamura 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Seizo Hirao 3-chome, Saiwaicho, Hitachi, Ibaraki No. 1 No. 1 Stock Company Hitachi Ltd. Hitachi factory

Claims (3)

[Claims] 1. In a containment air recirculation system cooling facility of a nuclear reactor, a normal system load and an emergency system load of the facility are separated, and the normal system load is divided into the containment air recirculation system cooling facility and a building ventilation. The capacity of the refrigerator of the system is leveled, and it is taken in to the normal system of the building ventilation system, and each standby unit is shared for the cooling equipment of the containment air recirculation system and the refrigerator of the building ventilation system. An air recirculation system cooling facility for the containment vessel. 2. A containment air recirculation system cooling equipment for a nuclear reactor, wherein a cooler of said containment air recirculation system cooling equipment is provided with a refrigerator of said containment air recirculation system cooling equipment and said containment air. A refrigerator as a common standby machine for the recirculation system cooling equipment and the building ventilation system is connected by a pipe, and the refrigerator of the building ventilation system is piped by a connecting pipe through a shutoff valve to the pipe, and the shutoff is performed. A reactor containment vessel air recirculation system cooling equipment, wherein a building ventilation system local cooler is connected to the communication pipe from the building ventilation system refrigerator rather than a valve by another pipe. 3. A reactor containment vessel air re-cooling system according to claim 2, wherein a flow rate adjusting valve is provided in the connecting pipe and the other pipe, and the capacity of all the refrigerators is leveled. Circulation cooling equipment.