JP2014215250A - Air-cooling system of reactor containment vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air-cooling system of a reactor containment vessel that improves cooling efficiency of the containment vessel.SOLUTION: An air-cooling system 10 of a reactor containment vessel comprises: a baffle board 14 that is provided in a gap between a reactor containment vessel 11 and a building 12 covering the containment vessel 11 and that generates rising air 13 along an outer peripheral surface 11a of the containment vessel; and a shaped unit 20 that is provided on an inner peripheral surface 14a of the baffle board and that changes flow characteristics of a flow path 15 formed by the inner peripheral surface 14a and the outer peripheral surface 11a of the containment vessel.

Description

  The present invention relates to an air cooling system for a containment vessel in a pressurized water reactor.

In nuclear power plants, when severe accidents occur that cause piping to break inside the containment vessel, a cooling system that uses passive driving force is focused on to suppress an increase in internal pressure due to vaporization of the coolant. Has been.
A passive driving force is different from a dynamic driving force that operates a device such as a pump, and acts by relating the structural characteristics of the object to be cooled and natural physical phenomena.

  As one of the containment vessel cooling systems, there is a method in which cooling water is naturally dropped by gravity from a water supply tank (see reference numeral 18 in FIG. 1) installed in the upper part thereof. In this case, when the cooling water stored in the water supply tank is depleted, there is a problem that the cooling of the containment vessel cannot be continued unless the cooling water is newly supplied by dynamic driving force.

Therefore, as a permanent containment cooling system that uses passive driving force, there is a method in which a baffle plate is provided in the gap between the containment vessel and the building covering the outer periphery of the containment vessel to form a flow path through which outside air passes. Proposed.
According to this method, natural convection is generated by using the heat radiation of the storage container as a driving force, and the storage container is evacuated by the rising airflow along the outer peripheral surface of the storage container (for example, Patent Document 1).

JP 2009-150846 A

  However, in a conventional containment vessel cooling system using a baffle plate, the turbulence intensity of the air flow flowing along the outer peripheral surface of the containment vessel is weak, so the amount of heating is low, the fluid resistance of the air is large, and the flow velocity is improved. There was a problem not to be.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an air cooling system for a reactor containment vessel that improves the heat removal efficiency of the containment vessel.

  In an air cooling system for a containment vessel according to an embodiment of the present invention, a baffle plate that is provided in a gap between the containment vessel of the reactor and a building that covers the containment vessel and generates an updraft along the outer peripheral surface of the containment vessel; And a shaped body that is provided on the inner peripheral surface of the baffle plate and changes the flow characteristics of the flow path formed by the inner peripheral surface and the outer peripheral surface of the containment vessel.

  The present invention provides an air cooling system for a reactor containment vessel that improves the heat removal efficiency of the containment vessel.

(A) The longitudinal cross-sectional view which shows 1st Embodiment of the air cooling system of the reactor containment vessel which concerns on this invention, (B) The expanded view of the internal peripheral surface of the baffle board applied to 1st Embodiment. (A) (B) The expanded view which shows the other Example of the internal peripheral surface of the baffle board applied to 1st Embodiment. (A) Longitudinal sectional view showing a second embodiment of an air cooling system for a reactor containment vessel according to the present invention, (B1) (B2) BB partial horizontal sectional view of an air cooling system according to a second embodiment, (C1 (C2) The fragmentary longitudinal cross-sectional view of the air cooling system which concerns on 2nd Embodiment. (A) The longitudinal cross-sectional view which shows 3rd Embodiment of the air cooling system of the reactor containment vessel which concerns on this invention, (B) The BB horizontal sectional view. (A) The expanded view which shows the internal peripheral surface of the baffle board applied to 4th Embodiment, (B) The BB longitudinal cross-sectional view. (A) The expanded view which shows the internal peripheral surface of the baffle board applied to 5th Embodiment, (B) The BB longitudinal cross-sectional view. (A) The expanded view which shows the internal peripheral surface of the baffle board applied to 6th Embodiment, (B) The partial enlarged view. (A) The longitudinal cross-sectional view which shows 7th Embodiment of the air cooling system of the reactor containment vessel which concerns on this invention, (B) The BB horizontal sectional view.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1 (A), a reactor containment vessel air cooling system 10 according to the first embodiment is provided in a gap between a reactor containment vessel 11 and a building 12 covering the containment vessel 11. Flow of a flow path 15 formed by a baffle plate 14 that generates an updraft 13 along the outer peripheral surface 11a and an inner peripheral surface 14a of the baffle plate and formed by the inner peripheral surface 14a and the outer peripheral surface 11a of the storage container. And a shaped body 20 that changes the characteristics.

  The containment vessel 11 stores a pressure vessel (not shown) containing a reactor core, a steam generator (not shown), and primary cooling system equipment (not shown). When a severe accident occurs, Form a barrier to dissipation. The storage container 11 is surrounded by a building 12.

A baffle plate 14 is provided in the gap between the side wall of the building 12 and the outer peripheral surface 11a of the storage container.
The baffle plate 14 is a cylindrical body arranged concentrically with the storage container 11 in a horizontal sectional view, and is fixedly supported by the building 12 at the upper end thereof, and the lower end thereof is a free end.
Thereby, the flow path 15 is formed so as to communicate from the ventilation hole 16 provided in the upper part of the side wall of the building 12 to the exhaust hole 17 provided in the top of the building 12 via the lower end of the baffle plate 14. . The air in the flow path 15 is heated and expanded by the heat radiation of the storage container 11 to generate an ascending air flow 13 by natural convection, and continuously flows on the outer peripheral surface 11a of the storage container to remove heat.

The water supply tank 18 is provided around the exhaust hole 17 at the zenith of the building 12 and sprays water on the upper surface of the storage container 11 to improve the cooling effect.
The water sprayed from the water supply tank 18 flows down the outer peripheral surface 11a of the containment vessel as it is due to gravity. In this process, the water is vaporized by heat exchange, rises together with the rising air flow 13, and is discharged from the exhaust hole 17.
Then, even after the stored water in the water supply tank 18 is depleted, outside air is taken in from the ventilation holes 16, and the heat removal of the storage container 11 is maintained by the rising airflow 13 generated by the heat dissipation of the storage container 11.

As shown in FIG. 1B, the shaped body 20 is configured by arranging a plurality of columnar bodies 20A extending in the normal direction of the inner peripheral surface 14a of the baffle plate.
Since the shaped body 20 is provided on the inner peripheral surface 14a of the baffle plate as described above, the turbulent flow 27 is generated in the ascending air flow 13, the fluid resistance is reduced, the flow rate of natural convection is increased, and the heat removal efficiency is increased. Improve.
Thereby, by the passive air cooling system which does not use a dynamic driving force, the decay heat which generate | occur | produces inside the storage container 11 when a severe accident generate | occur | produces can be efficiently escaped outside.

As another example of the shaped body 20, a V-shaped body 20B as shown in FIG. 2A, a quadrangular pyramid 20C as shown in FIG. It can be constituted by an array of a plurality of protrusions having shapes such as a mold, an X shape, an arch shape, an inverted V shape, and a triangular pyramid shape.
As described above, the shaped body 20 is appropriately adopted in a shape capable of generating a turbulent flow in the ascending air flow 13 in view of workability to the baffle plate 14.

In general, the smaller the Reynolds number of the flow path 15, the more laminar the flow becomes, and the smaller the heat removal amount becomes. However, if the flow path 15 is designed so that the Reynolds number is on the order of 10 ⁴ , It is known that turbulence occurs.

(Second Embodiment)
As shown in FIG. 3A, in the reactor containment vessel air cooling system 10 according to the second embodiment, the shaped body 20D is formed on the inner peripheral surface 14a of the baffle plate as shown in FIGS. 3B1 and 3B2. It includes a support plate 21 that is fixed by the fixture 23 and provided to face the outer peripheral surface 11a of the storage container. A plurality of protrusions 22 are arranged on the surface of the support plate 21.
3, parts having the same configuration or function as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

The support plate 21 is annularly provided below the inner peripheral surface 14a of the baffle plate, and the protrusions 22 are formed on the inner peripheral surface (FIG. 3 (B1) (C1)) and the outer peripheral surface ( 3 (B2) (C2)).
When the protrusion 22 is provided on the inner peripheral surface of the support plate 21, as shown in FIG. 3 (C1), the support plate 21 is provided so as to incline as it goes upward. Thereby, the generated eddy current can be guided near the outer peripheral surface 11a of the containment vessel to enhance the heat removal effect.

  When the protrusion 22 is provided on the outer peripheral surface of the support plate 21, as shown in FIG. 3 (C 2), the inclined plate 24 is provided on the inner peripheral surface 14 a of the baffle plate on the upper side of the support plate 21. . Thereby, the generated eddy current can be guided near the outer peripheral surface 11a of the containment vessel to enhance the heat removal effect.

(Third embodiment)
As shown in FIGS. 4 (A) and 4 (B), the reactor containment vessel air cooling system 10 according to the third embodiment further includes a swirl plate 28 provided at the lower end of the baffle plate 14 and guiding the ascending airflow 13 in an oblique direction. I have.
4, parts having the same configuration or function as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

The swirl plate 28 causes the ascending air flow 13 to swirl in the circumferential direction along the outer peripheral surface 11a of the storage container from the folded portion of the flow path 15 at the lower end of the baffle plate 14.
Thereafter, the ascending air current 13 passes through the shaped body 20 while turning, thereby generating a turbulent flow, reducing the fluid resistance, and further turning the outer peripheral surface 11a of the storage container in the circulation direction.
Thereby, since the ascending airflow 13 increases the contact time with the outer peripheral surface 11a of the containment vessel, the amount of heat transfer is increased and the heat removal efficiency is improved.

(Fourth embodiment)
As shown in FIGS. 5 (A) and 5 (B), in the reactor containment vessel air cooling system 10 according to the fourth embodiment, the shaped body 20 is an annular body 20E having a pointed end toward the outer peripheral surface 11a of the containment vessel. A plurality of baffle plates are provided substantially in parallel on the inner peripheral surface 14a.
Note that in FIG. 5, portions having the same structure or function as those in FIG. 1B are denoted by the same reference numerals, and redundant description is omitted.

Since the cross-sectional shape of the annular body 20E is a triangle, the rising air flow 13 causes a turbulent flow in the wake portion over the annular body 20E, and this turbulent flow hits the outer peripheral surface 11a of the containment vessel. The heat removal effect is improved.
Further, water that has sprinkled from the water supply tank 18 that flows down the inner peripheral surface 14a of the baffle plate is guided from the tip of the triangular section of the annular body 20E to the outer peripheral surface 11a of the containment vessel, thereby contributing to an improvement in heat removal effect. .

(Fifth embodiment)
As shown in FIGS. 6A and 6B, in the reactor containment vessel air cooling system 10 according to the fifth embodiment, the shaped body 20 is a spiral body 20F having a pointed end toward the outer peripheral surface 11a of the containment vessel. At least one strip is provided on the inner peripheral surface 14a.
The spiral body 20F generates an ascending airflow 13 that circulates around the outer peripheral surface 11a of the storage container, and the contact time between the ascending airflow 13 and the outer peripheral surface 11a of the storage container increases, thereby increasing the amount of heat transfer and improving the heat removal efficiency.
Further, the rising air flow 13 over the spiral body 20F having a triangular cross section causes turbulence in the wake portion of the spiral body 20F, and this turbulent flow hits the outer peripheral surface 11a of the containment vessel, thereby improving the heat removal effect. Is planned.

(Sixth embodiment)
As shown in FIGS. 7 (A) and 7 (B), in the reactor containment vessel air cooling system 10 according to the sixth embodiment, the shaped body 20 includes a plurality of stationary blades 20G, the center of which is formed with a thick wall. It is arranged and arranged in a spiral.
As described above, by arranging the stationary blades 20G, the ascending airflow 13 that circulates around the outer peripheral surface of the storage container is generated, and the ascending airflow 13 that has passed through the stationary blade 20G becomes a turbulent flow, thereby improving the heat removal efficiency.

(Seventh embodiment)
As shown in FIGS. 8A and 8B, the reactor containment vessel air cooling system 10 according to the seventh embodiment induces a downdraft from the ventilation hole 16 provided in the upper part of the building 12 to the lower end of the baffle plate 14. In the flow path 15, a plurality of grooves 26 are formed along at least a part of the inner peripheral surface 12 a of the building and the outer peripheral surface 14 b of the baffle plate along the flow direction of the downdraft.

The cross-sectional shape of the groove 26 may be triangular, semicircular, or U-shaped, but is not particularly limited. Further, the cross-sectional shape of the groove 26 may be periodically changed along the flow direction.
With this configuration, the flow resistance of the downdraft is reduced, the flow velocity in the flow path 15 is increased, and the heat removal efficiency of the storage container is improved.

  According to the air cooling system for a reactor containment vessel according to at least one embodiment described above, the shaped body is provided on the inner peripheral surface of the baffle plate that generates the rising air flow along the outer peripheral surface of the containment vessel, thereby It is possible to improve the heat removal efficiency of the containment vessel by increasing the flow rate.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Air cooling system, 11 ... Containment container, 11a ... Outer peripheral surface of storage container, 12 ... Building, 12a ... Inner peripheral surface of building, 13 ... Ascending air flow, 14 ... Baffle plate, 14a ... Inner peripheral surface of baffle plate, 14b ... outer peripheral surface of baffle plate, 15 ... flow path, 16 ... ventilation hole, 17 ... exhaust hole, 18 ... water supply tank, 20 ... shaped body, 20A ... columnar body, 20B ... V-shaped body, 20C ... square pyramid, 20D ... Modeling body, 20E ... annular body, 20F ... helical body, 20G ... stationary wing, 21 ... support plate, 22 ... projection, 23 ... fixing tool, 24 ... tilt plate, 26 ... groove, 27 ... turbulent flow, 28 ... Swivel plate, 29 ... wing surface.

Claims (11)

A baffle plate that is provided in a gap between a containment vessel of the nuclear reactor and a building that covers the containment vessel and generates an upward air flow along the outer peripheral surface of the containment vessel;
A reactor containment vessel comprising: a shaped body that is provided on an inner circumferential surface of the baffle plate and changes a flow characteristic of a flow path formed by the inner circumferential surface and the outer circumferential surface of the containment vessel. Air cooling system.   2. The reactor containment vessel air cooling system according to claim 1, wherein the shaped body includes a plurality of columnar bodies extending in a normal direction of an inner peripheral surface of the baffle plate.   The shaped body includes a protrusion having any one of a U shape, a V shape, an X shape, an arch shape, an inverted V shape, a triangular pyramid shape, and a quadrangular pyramid shape. Item 3. A reactor containment vessel air cooling system according to Item 1 or Item 2.   The said model | molding body contains the support plate provided so that it may be fixed to the internal peripheral surface of the said baffle plate, and may be opposed to the outer peripheral surface of the said storage container. The reactor containment air cooling system described.   5. The reactor containment vessel air cooling system according to claim 1, further comprising a swivel plate provided at a lower end of the baffle plate to guide the ascending airflow in an oblique direction. 6.   6. The molded body according to claim 1, wherein the shaped body is an annular body having a tip pointed toward an outer peripheral surface of the storage container, and a plurality of the shaped bodies are provided substantially in parallel on the inner peripheral surface of the baffle plate. The air cooling system for a reactor containment vessel according to any one of the preceding claims.   6. The reactor containment vessel air cooling system according to claim 1, wherein the shaped body is a spiral body having a tip pointed toward an outer peripheral surface of the containment vessel.   6. The shaped body according to any one of claims 1 to 5, wherein a plurality of stationary blades having a thick center are aligned in a spiral manner with the blade surfaces aligned. Reactor containment air cooling system.   The flow direction of the downdraft on at least a part of the inner peripheral surface of the building and the outer peripheral surface of the baffle plate in the flow path for guiding the downflow air from the ventilation hole provided in the upper part of the building to the lower end of the baffle plate 9. A reactor containment vessel air cooling system according to any one of claims 1 to 8, wherein a plurality of grooves extending along the line are formed.   10. The reactor containment vessel air cooling system according to claim 9, wherein the groove has a triangular, semicircular, or U-shaped cross-sectional shape. 10.   The cross-sectional shape of the said groove | channel changes periodically along the said flow direction, The air cooling system of the nuclear reactor containment vessel of Claim 9 or Claim 10 characterized by the above-mentioned.

Images