A circumferential sealing structure for a steel containment vessel and a construction method thereof

Abstract

The application relates to a circumferential sealing structure and construction method for a steel containment, and belongs to the technical field of nuclear power structure engineering. The structure comprises a steel containment and a peripheral shielding plant wall body, the steel containment is provided with a steel containment ring beam on the periphery, the shielding plant wall body is provided with a wall body ring beam on the inner side, the steel containment ring beam and the wall body ring beam are connected through a plurality of hinge type connecting pieces, the upper surfaces of the steel containment ring beam, the hinge type connecting pieces and the wall body ring beam are paved with continuous flexible sealing materials; the hinge type connecting pieces comprise a plurality of leaf pieces, the leaf pieces are connected through pin shafts, and the sum of the lengths of the leaf pieces is greater than the straight line distance between the steel containment ring beam and the wall body ring beam. The hinge type connecting pieces can adjust the shape through the rotation of the plurality of leaf pieces, deform together with the flexible sealing materials when the steel containment deforms, maintain the sealing effect of the upper space of the circumferential sealing structure under the condition that the steel containment deforms, and expand the contact area between the cooling water and the steel containment to the side wall of the steel containment.

Description

Technical Field

[0001] This invention belongs to the field of nuclear power structure engineering technology, specifically relating to a circumferential sealing structure for a steel containment vessel and its construction method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] The containment vessel of a large passive pressurized water reactor nuclear power plant is the last line of defense against the release of radioactive materials. In the event of an accident, cooling water is supplied through tanks at the top of the containment building, continuously cooling the containment from the top. The evaporation of water and natural convection remove heat from the containment, maintaining the internal temperature and pressure within safe limits. On the other hand, the circumferential seal of the containment isolates the water vapor generated by the cooling water from the upper space of the circumferential seal, ensuring the normal operation of equipment such as penetrating components in the lower space.

[0004] In traditional steel containment structures, water from the top tank flows down the wall, carrying away heat, and is then directly discharged without storage. To fully utilize the heat dissipation capacity of this water, a water storage scheme is adopted. The water flowing down from the top tank is stored in the space between the shielded building and the steel containment structure, where its boiling dissipates heat. Therefore, it is necessary to develop reliable joints that can withstand the deformation of the steel containment structure under accident conditions while ensuring the airtightness of the cooling water source. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a circumferential sealing structure and construction method for steel containment buildings. A hinged connector is installed between the steel containment building and the shielded building, which can continue to support the cooling water around the containment building even when the containment building is deformed, thereby increasing the water cooling area and preventing cooling water leakage.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, a circumferential sealing structure for a steel containment vessel includes a steel containment vessel and a shielded building wall surrounding the steel containment vessel. A steel containment vessel ring beam is provided around the steel containment vessel, and a wall ring beam is provided inside the shielded building wall. The steel containment vessel ring beam and the shielded building wall ring beam are connected by multiple hinged connectors. A continuous flexible sealing material is laid on the upper surfaces of the steel containment vessel ring beam, the hinged connectors, and the shielded building wall ring beam. The hinge-type connector includes multiple leaf segments connected by a rotatable pin. The rotation axis of the pin is horizontal and parallel to the tangent on the outer surface of the steel containment vessel. The sum of the lengths of the multiple leaf segments is greater than the straight-line distance between the steel containment vessel ring beam and the wall ring beam.

[0007] Secondly, the construction method for the aforementioned circumferential sealing structure used in steel containment structures includes the following steps: S1. Prepare steel containment structures with ring beams, shielded workshop walls with wall ring beams, and hinged connectors respectively; S2. Install multiple hinged connectors between the steel containment ring beam and the wall ring beam, connecting one end of each hinged connector to the steel containment ring beam and the other end to the wall ring beam. S3. Lay a continuous flexible sealing material on the upper surface of the steel containment ring beam, hinged connector and wall ring beam to obtain the circumferential sealing structure for the steel containment.

[0008] The beneficial effects of this invention are as follows: 1. This invention provides a circumferential sealing structure for steel containment buildings, capable of accumulating cooling water within the steel containment building and shielded workshop, and removing heat from the steel containment building surface through boiling evaporation. The hinged connector can adjust its shape through the rotation of multiple flaps, and can deform in tandem with the flexible sealing material when the steel containment building undergoes radial and vertical deformation, maintaining the sealing effect of the upper space of the circumferential sealing structure even when the steel containment building is deformed.

[0009] 2. In this invention, the water head pressure is jointly borne by the steel safety shell ring beam, the wall ring beam, and the hinged connectors. The flexible sealing material ensures the water tightness of the upper space of the circumferential sealing structure. The connection angles of each component are obtuse angles, which effectively avoids the risk of the flexible sealing material breaking and can achieve a sealing effect under the water head pressure at a set height.

[0010] 3. The steel containment ring beam and hinged connecting components in this invention can be prefabricated in the factory and then hoisted as a whole or in sections. The concrete ring beam can be poured together with the shielded building wall in one go, reducing on-site construction and greatly improving construction efficiency and quality. Attached Figure Description

[0011] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0012] Figure 1 This is a schematic diagram of the circumferential sealing structure for the steel containment vessel in Example 1.

[0013] Figure 2 This is a schematic diagram of the hinge connector in Example 1, where (a) is the front view and (b) is the top view.

[0014] Figure 3 This is a schematic diagram of the wall ring beam in Example 1.

[0015] Figure 4 This is a schematic diagram of the steel containment ring beam in Example 1.

[0016] Figure 5 This is a schematic diagram of the embedded part in Example 1.

[0017] Among them, 1. Steel containment structure; 2. Shielded building wall; 3. Flexible sealing material; 4. Steel containment ring beam; 41. Horizontal diaphragm; 42. Top plate; 43. Stiffening rib; 44. Side plate; 45. Bottom plate; 5. Hinged connector; 51. Leaf blade; 52. Pin; 6. Wall ring beam; 61. Embedded part; 611. Embedded plate; 612. Stud. Detailed Implementation

[0018] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] One or more embodiments of the present invention provide a circumferential sealing structure for a steel containment vessel, including a steel containment vessel and a shielded building wall surrounding the steel containment vessel. A steel containment vessel ring beam is provided around the steel containment vessel, and a wall ring beam is provided inside the shielded building wall. The steel containment vessel ring beam and the wall ring beam are connected by multiple hinged connectors. A continuous flexible sealing material is laid on the upper surfaces of the steel containment vessel ring beam, the hinged connectors, and the wall ring beam. The hinge-type connector includes multiple leaf segments connected by a rotatable pin. The rotation axis of the pin is horizontal and parallel to the tangent on the outer surface of the steel containment structure. The straight-line distance between the hinge-type connector connection positions of the steel containment ring beam and the wall ring beam is less than the sum of the lengths of the multiple leaf segments.

[0021] In the event of a nuclear power plant accident, once the passive steel containment cooling system is activated, water from the roof water tanks of the shielded building is sprayed onto the top head of the steel containment vessel by gravity. Due to the high temperature of the steel containment vessel after the accident, some water evaporates, while some flows downwards along the containment vessel to the circumferential sealing structure, accumulating water head and immersing the sidewalls of the steel containment vessel in cooling water for water cooling. The steel containment ring beams, hinged connectors, and wall ring beams provide rigidity, and together they support the flexible sealing material, resisting water pressure to achieve a sealing effect under high water head pressure. Furthermore, because the steel containment vessel expands when heated, undergoing vertical and radial deformation, the hinged connectors deform in tandem, maintaining the watertightness of the upper space of the circumferential sealing structure and preventing leakage into the space below.

[0022] Optionally, the upper surface of the steel containment ring beam is higher than the upper surface of the shielding wall ring beam, so that more water head pressure is borne by the wall ring beam.

[0023] Optionally, the hinged connector has at least three blades, with the inner blades connected to the steel containment ring beam and the outer blades connected to the wall ring beam. As a deformable structure, it connects the two end ring beams, allowing the cooling water accumulation space to deform in tandem with the steel containment, ensuring a sealing effect and avoiding adverse constraints on the steel containment.

[0024] Optionally, the steel containment ring beam is made of metal, and the wall ring beam and the shielded workshop wall are made of concrete or reinforced concrete. Consistent with conventional settings in the field, the metal material with good thermal conductivity and pressure resistance can conduct heat out of the steel containment in a timely manner, maintaining stable internal temperature and pressure, while concrete has the dual functions of structural support and radiation shielding, enhancing the isolation effect.

[0025] Optionally, the hinged connector is attached to the embedded part of the wall ring beam, which facilitates construction.

[0026] Optionally, the inner leaf is connected to the side wall of the steel containment ring beam, and the outer leaf is connected to the upper surface of the wall ring beam; then the hinge-type connector is connected to the steel containment ring beam in a downward posture and to the wall ring beam in a horizontal posture, so that the hinge-type connector bends naturally, leaving a deformation margin for subsequent coordinated deformation with the steel containment.

[0027] Optionally, the leaf is rectangular, and the pin is located on the short side of the rectangle; the leaf of the adjacent hinged connector connected to the wall ring beam is spaced at a predetermined distance; multiple hinged connectors are radially connected to the outside of the steel containment ring beam, and the gap between adjacent hinged connectors gradually increases in the radial direction away from the steel containment ring beam. These gaps can prevent adjacent hinged connectors from squeezing each other and losing their cooperative deformation ability. On the other hand, these gaps are small enough that the strength of the flexible sealing material 3 at the gap position can resist the water head pressure within a predetermined height range.

[0028] Optionally, the flexible sealing material includes one or more of sealing silicone cloth, EPDM rubber gasket, PVC gasket, and polyethylene polypropylene gasket, which has multiple effects such as waterproofing, fireproofing, and dustproofing, effectively isolating the upper and lower spaces of the circumferential sealing structure and ensuring the normal operation of equipment such as penetrations at the bottom of the steel containment.

[0029] Optionally, the steel containment ring beam is a box girder, and the box girder is provided with vertical transverse diaphragms inside. The transverse diaphragms are arranged radially along the steel containment, and the upper part of the transverse diaphragms is provided with stiffening ribs connected to the upper surface of the box girder. The box girder structure with a set stiffness can not only resist water head pressure, but also improve the strength of the steel containment at the corresponding position, reduce the deformation range of the steel containment, and improve safety.

[0030] Optionally, the shielded workshop wall is made of concrete, and the construction joint is flush with the upper surface of the wall ring beam. The wall ring beam and the lower wall are an integral whole, which effectively transmits the water head pressure to the shielded workshop wall below and improves the stability of the cooling water accumulation space.

[0031] Optionally, the connection angle between the steel containment ring beam, the hinged connector, and the wall ring beam is greater than 90°, and the angle between the multiple leaf segments is an obtuse angle; to avoid the risk of the flexible sealing material being punctured by sharp angles.

[0032] One or more embodiments of the present invention provide a construction method for the above-described circumferential sealing structure for a steel containment vessel, comprising the following steps: S1. Prepare steel containment structures with steel containment ring beams, shielded building walls with wall ring beams, and hinged connectors respectively. S2. Install multiple hinged connectors between the steel containment ring beam and the wall ring beam, connecting one end of each hinged connector to the steel containment ring beam and the other end to the wall ring beam. S3. Lay a continuous flexible sealing material on the upper surface of the steel containment ring beam, hinged connector and wall ring beam to obtain the circumferential sealing structure for the steel containment.

[0033] In the above process, the steel safety shell ring beam, hinged connecting components and wall ring beam are prepared separately and then connected on the construction site. Precast components can be hoisted on the construction site as a whole ring or in sections. Concrete components can be poured together with the shielded plant wall at one time, reducing on-site construction procedures and improving the construction quality and efficiency of the entire structure.

[0034] Optionally, in S1, embedded parts are installed in the wall ring beam, and in S2, the hinged connector is connected to the embedded parts in the wall ring beam; this improves the connection strength between the concrete and the hinged parts.

[0035] Optionally, in S2, the connection angle between the steel containment ring beam, the hinged connector, and the wall ring beam is greater than 90°, and the angle between the multiple flaps of the hinged connector is an obtuse angle to prevent the flexible sealing material from being laid on the acute angle structure and reduce the risk of being punctured.

[0036] The present invention will be further described below with reference to the embodiments.

[0037] Example 1 A circumferential sealing structure for steel containment vessels, such as Figure 1 As shown, the structure includes a steel containment vessel 1 and a reinforced concrete shielded building wall 2 surrounding the steel containment vessel 1. The shielded building wall 2 surrounds the steel containment vessel 1 at predetermined intervals. A steel containment vessel ring beam 4 is provided around the steel containment vessel 1, and a reinforced concrete wall ring beam 6 is provided inside the shielded building wall 2. The steel containment vessel ring beam 4 and the wall ring beam 6 are arranged opposite to each other and are connected by multiple circumferentially arranged hinged connectors 5. The upper surfaces of the steel containment vessel ring beam 4, the hinged connectors 5, and the wall ring beam 6 are covered with a continuous flexible sealing material 3. like Figure 2 As shown in (a), each hinged connector 5 consists of multiple blades, including three leaf blades 51. These leaf blades 51 are connected by a rotatable pin 52. The axis of rotation of the pin 52 is horizontal and parallel to the tangent on the outer surface of the steel containment 1. The sum of the lengths of the multiple leaf blades 51 is greater than the straight-line distance between the steel containment ring beam 4 and the wall ring beam 6, meaning the hinged connector 5 is in a bent state, as shown in (a). Figure 1 As shown, the inner flap 51 is connected to the side wall of the steel containment ring beam 4, and the outer flap 51 is connected to the upper surface of the wall ring beam 6. This allows the hinged connector 5 to connect to the steel containment ring beam 4 in a drooping position and to the wall ring beam 6 in a horizontal position. Therefore, the straight-line distance between the connection point of the wall ring beam 6 and the connection point of the steel containment ring beam 4 is less than the sum of the lengths of the three flaps 51. The hinged connector 5 is in a bent state, leaving a deformation allowance for subsequent coordinated deformation with the steel containment 1; this allows for... Figure 1When the steel containment vessel 1 undergoes lateral displacement, it deforms further while maintaining its connection with the steel containment vessel ring beam 4 and the wall ring beam 6, so that the cooling water accumulation space can deform in tandem with the steel containment vessel 1 to ensure a sealing effect.

[0038] like Figure 1 As shown, the upper surface of the steel containment ring beam 4 is higher than the upper surface of the wall ring beam 6; and the upper surface of the steel containment ring beam 4 is inclined towards the wall ring beam 6 to reduce the water pressure borne by the steel containment ring beam 4.

[0039] like Figure 3 As shown, a metal embedded part 61 is provided in the wall ring beam 6. The structure of the embedded part 61 is as follows: Figure 5 As shown, it includes an embedded plate 611 and studs 612 connected below the embedded plate 611. The studs 612 are used to embed in the concrete to improve the bonding strength between the embedded part 61 and the wall ring beam 6. The embedded plate 611 is exposed on the upper surface of the wall ring beam 6 and is used for fixed connection with the hinged connector 5; as Figure 1 As shown, the metal hinge-type connector 5 is connected to the metal embedded part 61, which is easy to construct.

[0040] like Figure 2 As shown in (b), the leaf 51 is rectangular, and the pin 52 is located on the short side of the rectangle; the leaf 51 of adjacent hinged connectors 5 connected to the wall ring beam 6 are spaced apart by a set distance; multiple hinged connectors 5 are radially connected to the outside of the steel containment ring beam 4, and in the radial direction away from the steel containment ring beam 4, the gap between adjacent hinged connectors 5 gradually increases. These gaps can prevent adjacent hinged connectors 5 from squeezing each other and losing their cooperative deformation ability; on the other hand, the size of these gaps is small enough that the strength of the flexible sealing material at the gap position can resist the water head pressure within a set height range.

[0041] Figure 1 The flexible sealing material 3 includes sealing silicone cloth, which has multiple effects of waterproofing, fireproofing and dustproofing. It effectively isolates the upper and lower spaces of the circumferential sealing structure and prevents cooling water from leaking into the lower space of the circumferential sealing structure. The flexible sealing material 3 is fixed to the embedded parts 61 of the steel safety shell ring beam 4 and the shielded plant wall ring beam 6 by welding studs 612 respectively. The sealant around the studs 612 ensures the sealing performance.

[0042] like Figure 4 As shown, the steel containment ring beam 4 is a box beam, which is formed by a top plate 42, side plates 44 and bottom plate 45. The box beam is equipped with vertical diaphragms 41, which are arranged radially along the steel containment 1. The upper part of the diaphragms 41 is equipped with stiffening ribs 43 in the form of plate ribs connected to the top plate 42 of the box beam.

[0043] like Figure 1 As shown, the shielded plant wall 2 is made of concrete, and the construction joint 21 is flush with the upper surface of the wall ring beam 6. The wall ring beam 6 and the lower wall are an integral whole, which effectively transmits the water head pressure to the shielded plant wall 2 below, improving the stability of the cooling water accumulation space.

[0044] The connection angles between the steel containment ring beam 4, the hinged connector 5, and the wall ring beam 6 are all greater than 90°, and the angles between the multiple blades 51 are obtuse angles; this avoids the risk of the flexible sealing material 3 being punctured by sharp angles.

[0045] The construction method for the circumferential sealing structure of the steel containment vessel in this embodiment includes the following steps: S1. Prepare a prefabricated steel safety shell 1 with a steel safety shell ring beam 4 in the factory, prepare a set number of hinged connectors 5 in the factory, and cast the shielded factory wall 2 with a wall ring beam 6 in one go on site. During the casting process, embed the pre-embedded parts 61 on the upper surface of the wall ring beam 6. S2. The steel safety shell ring beam 4 is installed at the construction site using a whole-ring hoisting method. Multiple hinge-type connectors 5 are installed between the steel safety shell ring beam 4 and the wall ring beam 6. One end of each hinge-type connector 5 is welded to the steel safety shell ring beam 4, and the other end is welded to the embedded part 61 of the wall ring beam 6. During the installation process, the connection angle between the steel safety shell ring beam 4, the hinge-type connector 5 and the wall ring beam 6 is greater than 90°, and the angle between the multiple segments of the hinge-type connector 5 is an obtuse angle. S3. A continuous flexible sealing material 3 is laid on the upper surface of the steel containment ring beam 4, the hinged connector 5, and the wall ring beam 6 to obtain a circumferential sealing structure for the steel containment.

[0046] In the event of a nuclear power plant accident, after the passive steel containment cooling system is activated, water from the roof water tank of the shielded building is sprayed onto the top end cap of the steel containment 1 by gravity. At this time, due to the high temperature of the steel containment 1 after the accident, part of the cooling water evaporates, while the other part flows down the steel containment 1 to the circumferential sealing structure and is blocked, thus accumulating water head above the circumferential sealing structure, immersing the side walls of the steel containment 1 in cooling water for water cooling. The steel containment ring beam 4, the hinged connector 5, and the wall ring beam 6 provide rigidity, and the three together support the flexible sealing material 3 to resist water pressure, thereby achieving a sealing effect under high water head pressure. In addition, because the steel containment 1 expands when heated, it undergoes vertical and radial deformation. At this time, the hinged connector 5 can deform in tandem, maintaining the watertightness of the upper space of the circumferential sealing structure and preventing leakage to the lower space.

[0047] Example 2 An annular sealing structure for a steel containment vessel differs from Embodiment 1 in that: the steel containment vessel ring beam 4 is still a box beam structure, but the diaphragm 41 is provided with openings to meet the requirements of lightweighting; and the stiffening rib 43 is a T-shaped rib.

[0048] The flexible sealing material 3 is selected as a polyvinyl chloride gasket.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A circumferential sealing structure for a steel containment vessel, characterized in that, The structure includes a steel containment vessel and a shielded building wall surrounding the steel containment vessel. A steel containment vessel ring beam is provided around the steel containment vessel, and a wall ring beam is provided inside the shielded building wall. The steel containment vessel ring beam and the wall ring beam are connected by multiple hinged connectors. The upper surfaces of the steel containment vessel ring beam, the hinged connectors, and the wall ring beam are covered with a continuous flexible sealing material. The hinge-type connector includes multiple leaf segments connected by a rotatable pin. The rotation axis of the pin is horizontal and parallel to the tangent on the outer surface of the steel containment vessel. The sum of the lengths of the multiple leaf segments is greater than the straight-line distance between the steel containment vessel ring beam and the wall ring beam.

2. The circumferential sealing structure for a steel containment vessel as described in claim 1, characterized in that, The steel containment ring beam is made of metal, while the wall ring beam and the shielded workshop wall are made of concrete or reinforced concrete. Alternatively, the construction joint of the shielded factory building wall is flush with the upper surface of the wall ring beam; Alternatively, the hinged connector is connected to the embedded part of the wall ring beam.

3. The circumferential sealing structure for a steel containment vessel as described in claim 1, characterized in that, The hinge-type connector has no fewer than three leaf plates, with the inner leaf plate connected to the steel containment ring beam and the outer leaf plate connected to the wall ring beam.

4. The circumferential sealing structure for a steel containment vessel as described in claim 1, characterized in that, The inner flaps are connected to the sidewall of the containment ring beam, and the outer flaps are connected to the upper surface of the wall ring beam; Alternatively, the leaf is rectangular, and the pin is located on the short side of the rectangle; the leaves of adjacent hinged connectors connected to the wall ring beam are spaced a predetermined distance apart.

5. The circumferential sealing structure for a steel containment vessel as described in claim 1, characterized in that, The flexible sealing material includes sealing silicone cloth.

6. The circumferential sealing structure for a steel containment vessel as described in claim 1, characterized in that, The steel containment ring beam is a box girder, and the box girder is provided with vertical transverse diaphragms inside. The transverse diaphragms are arranged radially along the steel containment, and the upper part of the transverse diaphragms is provided with stiffening ribs that are connected to the upper surface of the box girder.

7. The circumferential sealing structure for a steel containment vessel as described in claim 1, characterized in that, The connection angle between the steel safety shell ring beam, the hinged connector, and the wall ring beam is greater than 90°, and the angle between the multiple leaf blades is an obtuse angle.

8. The circumferential sealing structure for a steel containment vessel as described in claim 1, characterized in that, The upper surface of the steel containment ring beam is higher than the upper surface of the wall ring beam.

9. A construction method for a circumferential sealing structure for a steel containment vessel as described in any one of claims 1-8, characterized in that, Including the following steps: S1. Prepare steel containment structures with steel containment ring beams, shielded building walls with wall ring beams, and hinged connectors respectively. S2. Install multiple hinged connectors between the steel containment ring beam and the wall ring beam, connecting one end of each hinged connector to the steel containment ring beam and the other end to the wall ring beam. S3. Lay a continuous flexible sealing material on the upper surface of the steel containment ring beam, hinged connector and wall ring beam to obtain the circumferential sealing structure for the steel containment.

10. The construction method for the circumferential sealing structure for a steel containment vessel as described in claim 9, characterized in that, In S1, embedded parts are installed in the wall ring beam; in S2, the hinge-type connector is connected to the embedded parts in the wall ring beam. Alternatively, in S2, the connection angle between the steel containment ring beam, the hinged connector, and the wall ring beam is greater than 90°, and the angle between the multiple flaps of the hinged connector is an obtuse angle.

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