A spherical containment inner water tank structure

Abstract

The application discloses a kind of spherical containment built-in water tank structure, the built-in water tank is arranged in the inside of containment, containment is spherical structure, inside is equipped with ring wall, ring wall is cylindrical structure, it is arranged in containment along vertical direction, to be separated into first space and second space in containment, first space is the cylindrical space located in the inboard of ring wall, for installing main equipment, second space is the special-shaped space located between ring wall and containment, built-in water tank is set in the set region of this special-shaped space, water in built-in water tank can be submerged to the height of main pipeline under the action of gravity under accident condition.The built-in water tank structure of spherical containment of the application is reasonably arranged, layout is compact, stress is good, and enough stack cavity cooling water tank space can be provided, to meet the submergence height requirement of heat export after accident.

Description

Technical Field

[0001] This invention belongs to the field of nuclear industry technology, specifically relating to a spherical containment vessel with an internal water tank structure. Background Technology

[0002] Nuclear power plant safety has always been a top priority in nuclear industry production. The passive safety system concept introduced by AP1000 has revolutionized the design of nuclear power plant safety systems, and this concept is gradually being incorporated into the top-level design of nuclear power plants. As a backup measure for active safety systems, passive safety systems greatly enhance the diversity and reliability of defense-in-depth measures.

[0003] To prevent containment overpressure, mainstream advanced pressurized water reactors are equipped with various severe accident mitigation measures, such as rapid depressurization of the primary loop, hydrogen concentration control, and containment heat removal after an accident. To prevent bottom plate melt-through, the AP1000 relies on gravity to submerge the reactor cavity in the refueling pool to the height of the main piping, thereby cooling the molten material inside the reactor and keeping it within the reactor. In addition, some reactors also use a core trap located below the pressure vessel to trap and cool the molten core.

[0004] To improve the reliability of the Cavity Injection Cooling System (CIS), the adoption of a fully passive approach is the general trend. Therefore, a larger capacity water tank is needed to achieve complete flooding and long-term cooling of the reactor core and main piping after an accident by entirely passive means. That is, the cooling water needs to submerge the reactor cavity to the height of the main piping in the main equipment.

[0005] However, the current three-ring design makes the space layout within the cylindrical containment even more cramped. Therefore, the cavity water injection cooling system must be located outside the cooling cavity (outside the containment), requiring additional through-pipelines on the containment, reducing the reliability of the safety system. Furthermore, due to economic considerations, the volume of the cavity cooling water tank in the cavity water injection cooling system is limited, making it difficult to completely submerge the area below the main pipes to achieve inter-reactor (IVR) cooling after a severe accident. Long-term recirculation cooling after an accident requires active methods. Currently, there are also layout options using a spherical containment. However, the internal structure of a spherical containment is not regular enough; the curved edges not only make it difficult to place equipment but also require structural support, resulting in low space utilization and increased facility construction costs.

[0006] Therefore, the commonly used reactor cavity water injection cooling system is located outside the cylindrical containment vessel. It involves injecting water into the pressure vessel insulation layer inside the reactor cavity after a severe accident to cool the outer wall of the pressure vessel, dissipate heat from the molten core, and prevent the pressure vessel from melting down. Furthermore, to maximize the passive injection time, condensate and spray water collection lines for the heat exchangers inside the containment vessel must be installed. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art by providing a spherical containment vessel with an internal water tank structure. The structure is reasonably designed, compact, and has good stress distribution. It can also provide sufficient space for the reactor cavity cooling water tank to meet the submersion height requirements for heat removal after an accident.

[0008] This invention provides a spherical containment vessel with an internal water tank. The internal water tank is disposed inside the containment vessel, which has a spherical structure and an internal ring wall. The ring wall has a cylindrical structure and is disposed vertically inside the containment vessel to divide the containment vessel into a first space and a second space. The first space is a columnar space located inside the ring wall and is used to install the main equipment. The second space is an irregularly shaped space located between the ring wall and the containment vessel. The internal water tank is disposed within a designated area of ​​the irregularly shaped space. Under accident conditions, the water in the internal water tank can submerge the first space to the height of the main pipeline in the main equipment under the action of gravity.

[0009] Preferably, the bottom height of the designated area is not lower than the height of the main pipe, and the spatial volume of the designated area is not less than the spatial volume below the height of the main pipe in the first space.

[0010] Preferably, a plate-like structure is provided on the top surface of the designated area where the built-in water tank is located. The inner and outer sides of the plate-like structure are connected to the ring wall and the containment vessel, respectively, serving as an operating platform for placing auxiliary equipment. The built-in water tank is formed by the operating platform, the ring wall, and the containment vessel, creating an irregular ring-shaped structure with a vertical line on the inner side, a convex curve on the outer side, and a horizontal line on the top side.

[0011] Preferably, the containment is provided with a gate for the main equipment to enter and exit the containment, and the bottom edge of the gate is flush with the operating platform.

[0012] Preferably, the bottom of the first space is provided with an equipment support platform. The equipment support platform is formed by filling the bottom of the first space with concrete to a height not lower than the bottom of the ring wall, so as to occupy the empty space at the bottom of the first space. A stacking pit is opened on the equipment support platform. The main equipment is installed on the equipment support platform. The main equipment has a pressure vessel. The main pipeline is connected to one side of the pressure vessel in a horizontal direction. The pressure vessel is set in the stacking pit to reduce the height of the pressure vessel and the main pipeline.

[0013] Preferably, the axis of the ring wall coincides with the axis of the containment vessel.

[0014] Preferably, the main equipment also includes a refill water tank, which is located above the pressure vessel. The top cover of the pressure vessel extends into the refill water tank through the bottom of the tank. The refill water tank is connected to an internal water tank via a pump, so that water is introduced from the internal water tank into the refill water tank before the top cover of the pressure vessel is opened, thereby sealing the pressure vessel.

[0015] Preferably, the spherical containment vessel with built-in water tank structure also includes a ring crane for hoisting the main equipment. The bracket components of the ring crane are located at the top of the ring wall so that the ring crane can operate at the top of the ring wall.

[0016] Preferably, the ring wall includes an inner ring wall and an outer ring wall, both of which are cylindrical structures. The inner ring wall serves as a biological shielding ring wall and is coaxially fitted inside the outer ring wall. The main equipment is installed in the first space inside the inner ring wall, and the bracket component of the annular crane is located at the top of the outer ring wall.

[0017] The spherical containment vessel with built-in water tank structure provided by this invention features a spherical containment vessel, which offers good mechanical properties, is easy to design, and facilitates prestressing. The containment vessel's interior is divided into two spatial regions by a ring wall. The first, columnar space inside the ring wall is well-organized, facilitating the installation and layout of main equipment, and can accommodate main pipelines, evaporators, pressure vessels, and other equipment. The second, irregularly shaped space formed by the outer ring wall and the inner wall of the containment vessel is less convenient for arranging main equipment; however, water, being a fluid, can be filled within this irregularly shaped space to form a built-in water tank located inside the containment vessel.

[0018] The containment structure of this invention uses a ring wall to divide the original spherical space. This allows the main equipment to be placed within a regular space while effectively utilizing the irregular space at the curved corners to form an internal water tank. The internal water tank does not occupy the space occupied by the main equipment, resulting in a reasonable layout and high space utilization. Furthermore, the water in the internal water tank provides support, eliminating the need for additional cost to construct a support structure and ensuring good structural performance of the containment structure. It also effectively utilizes the space, placing the internal water tank entirely within the containment structure. Therefore, it avoids the need for additional through pipelines on the outer wall of the containment structure, ensuring the reliability of the safety system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the spherical containment vessel with an internal water tank in an embodiment of the present invention.

[0020] In the diagram: 1. Containment vessel; 11. First space; 12. Second space; 13. Equipment support platform; 131. Stacking pit; 14. Operating platform; 15. Gate; 16. Main equipment support layer; 2. Ring wall; 21. Inner ring wall; 22. Outer ring wall; 3. Internal water tank; 4. Main equipment; 41. Main pipeline; 42. Pressure vessel; 43. Refueling pool; 44. Evaporator; 5. Circular crane. Detailed Implementation

[0021] The technical solutions of the invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without creative effort are within the scope of the invention.

[0022] In the description of this invention, it should be noted that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience and simplification of the description and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] In the description of this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection," "setting," "installation," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Example

[0026] like Figure 1As shown, this embodiment features a spherical containment vessel with an internal water tank structure. The internal water tank 3 is located inside the containment vessel 1. The containment vessel 1 has a spherical structure and an internal ring wall 2. The ring wall 2 has a cylindrical structure and is vertically arranged inside the containment vessel 1 to divide the containment vessel 1 into a first space 11 and a second space 12. The first space 11 is a columnar space located inside the ring wall 2, used to install the main equipment 4. The main equipment 4 includes a main pipe 41, a pressure vessel 42, and an evaporator 44. The main pipe 41 connects the pressure vessel 42 and the evaporator 44. The height of the main pipe 41 is slightly above the bottom surface of the first space 11. The second space 12 is an irregularly shaped space located between the ring wall 2 and the containment vessel 1. The internal water tank 3 is located within a defined area of ​​this irregularly shaped space. Under accident conditions, the water in the internal water tank 3 can submerge the first space 11 to the height of the main pipe 41 in the main equipment 4 under the action of gravity.

[0027] This spherical containment vessel has an internal water tank structure. The containment vessel 1 itself adopts a spherical structure, which has good mechanical properties, is easy to design, and facilitates prestressing. Moreover, the bottom space of the spherical structure is smaller than that of the cylindrical structure, thus reducing the amount of water required for flooding. The interior of the containment vessel 1 is divided into two spatial regions by a ring wall 2. The cylindrical first space 11 inside the ring wall 2 has a regular structure, which facilitates the installation and layout of the main equipment 4 and can accommodate the main pipes 41, evaporator 44, pressure vessel 42, and other main equipment 4. The irregular arc-shaped second space 12 formed by the outer side of the ring wall 2 and the inner wall of the containment vessel 1 is not convenient for arranging the main equipment 4, but water is a fluid, so it can be filled in this irregular space to form an internal water tank 3 located inside the containment vessel 1.

[0028] In this embodiment, the original spherical space is divided by a ring wall 2. This allows the main equipment to be laid out in a regular space area, while also effectively utilizing the irregular space area at the curved corners to form an internal water tank 3. The internal water tank 3 does not occupy the space where the main equipment 4 is located. The layout is reasonable and the space utilization rate is high, making it suitable for the main circuit systems of three-ring and four-ring roads where space is relatively tight. The water in the internal water tank 3 also provides support, eliminating the need to invest in building a support structure and ensuring good stress performance of the containment 1. At the same time, it effectively utilizes the space here, so that the internal water tank 3 is completely inside the containment 1. Therefore, it avoids the need to add through pipelines on the outer wall of the containment and ensures the reliability of the safety system.

[0029] The built-in water tank 3 is located in a designated area within the second space 12. The bottom of the designated area is not lower than the height of the main pipe 41, and the volume of the designated area is not less than the volume of the space below the height of the main pipe 41 in the first space 11. This ensures that, under the influence of gravity, the water in the built-in water tank 3 can submerge the first space 11 up to the height of the main pipe 41 in the event of an accident, thus meeting the passive requirements for heat removal after an accident and the submersion height requirements.

[0030] In this embodiment, a through-line is provided on the ring wall 2, which connects the first space 11 and the built-in water tank 3. A normally closed electric isolation valve is provided on the through-line. Under normal working conditions, the normally closed electric isolation valve is in the closed state. Under emergency conditions, the normally closed electric isolation valve automatically opens according to the control signal.

[0031] In this embodiment, a plate-like structure is provided on the top surface of the designated area where the built-in water tank 3 is located. The inner and outer sides of the plate-like structure are connected to the ring wall 2 and the containment vessel 1, respectively, serving as an operating platform 14 for placing auxiliary equipment, such as necessary ventilation equipment and injection boxes. The built-in water tank 3 is formed by the operating platform 14, the ring wall 2, and the containment vessel 1, creating an irregular ring-shaped structure with a vertical line on the inner side, a convex curve on the outer side, and a horizontal line on the top side.

[0032] A gate 15 is provided on the containment vessel 1 for the main equipment 4 to enter and exit the containment vessel 1. The bottom edge of the gate 15 is flush with the operating platform 14, thus facilitating the passage of the main equipment 4. To facilitate the introduction of the main equipment 4, necessary openings are reserved in the ring wall 2. After the main equipment 4 enters the operable area of ​​the ring crane 5, it is hoisted into place by the ring crane 5. In this embodiment, an equipment support platform 13 is provided at the bottom of the first space 11. The equipment support platform 13 is formed by filling the bottom of the first space 11 with concrete to a height not lower than the bottom of the ring wall 2, so as to occupy the empty space at the bottom of the first space 11. At the same time, it fills the bottom surface of the first space 11 to make it flat, which facilitates the installation of the main equipment 4. A storage pit 131 is opened on the equipment support platform 13. The main equipment 4 is installed on the equipment support platform 13. The main pipeline 41 is connected to one side of the pressure vessel 42 in a horizontal direction. The pressure vessel 42 is placed in the storage pit 131 to reduce the height of the pressure vessel 42, thereby reducing the height of the main pipeline 41 and reducing the amount of water required for flooding in an accident.

[0033] To avoid an excessively large free volume in the area to be flooded after an accident, which would result in insufficient water in the built-in water tank 3, the pressure vessel 42 and the main pipeline 41 are both located at the bottom layer of the internal structure of the containment 1. After reserving the crater 131 and its necessary arrangement space, the bottom layer is filled with plain concrete to form the equipment support platform 13. This can further reduce the volume of the space that needs to be completely flooded after an accident, thus reducing the space required for the built-in water tank 3, and thus leaving more space for the arrangement of the main equipment 4.

[0034] The containment vessel 1 has a main equipment support layer 16 at the bottom of the first space 11. The lower cylinder of the pressure vessel 42 and the main pipeline 41 are both arranged at or below the main equipment support layer 16, and the internal water tank 3 is arranged above the main equipment support layer 16. Therefore, in the event of a severe accident, the water inside the internal water tank 3 can, under the action of gravity, flood the main equipment support layer 16 and the crater 131 area through the injection pipe, carrying away the heat in the reactor core, preventing the reactor core from melting and ensuring in-core containment (IVR) of the molten material.

[0035] In this embodiment, the axis of the ring wall 2 coincides with the axis of the containment 1, which is beneficial for the uniform distribution of the ring load and the structural design.

[0036] In this embodiment, the main equipment 4 also includes a refueling water tank 43, which is located above the pressure vessel 42. The top cover of the pressure vessel 42 extends through the bottom of the refueling water tank 43 and into it. The refueling water tank 43 is connected to the internal water tank 3 via a water pump, so that water can be introduced from the internal water tank 3 into the refueling water tank 43 before the top cover of the pressure vessel 42 is opened, thereby sealing the pressure vessel 42 and enabling underwater operation. Under normal circumstances (i.e., when the pressure vessel 42 is not open), the refueling water tank 43 is empty. When the unit is refueling or undergoing major repairs, water from the internal water tank 3 can be pumped into the refueling water tank 43 by the water pump, covering the storage area of ​​the stack components. The volume of the internal water tank 3 is not less than the volume of the refueling water tank 43, thus meeting the refueling requirements.

[0037] In this embodiment, the spherical containment vessel with built-in water tank structure also includes a ring crane 5 for hoisting the main equipment 4. The bracket component of the ring crane 5 is set at the top of the ring wall 2 so that the ring crane 5 can operate at the top of the ring wall 2.

[0038] In this embodiment, the ring wall 2 includes an inner ring wall 21 and an outer ring wall 22. Both the inner ring wall 21 and the outer ring wall 22 are cylindrical structures. The inner ring wall 21 serves as a biological shielding ring wall, relying on its concrete wall with a certain thickness to achieve radiation shielding. It is coaxially fitted inside the outer ring wall 22. The main equipment 4 is installed in the first space 11 inside the inner ring wall 21. The bracket component of the ring crane 5 is set on the top of the outer ring wall 22.

[0039] The spherical containment vessel's internal water tank structure is divided by ring wall 2. Inside ring wall 2 is the area for the reactor plant's main equipment and necessary auxiliary and support systems, such as the main equipment support layer 16 and the refueling pool 43. Outside ring wall 2 is the area for the internal water tank 3 and the space for the operating platform 14 above the tank. Vertically, from bottom to top, it is divided into four parts: the concrete-filled equipment support platform 13, the process layout area (main equipment support layer 16, refueling pool 43, internal water tank 3), the operating platform 14, and the circular crane 5. The overall structure is compact and rationally zoned.

[0040] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A spherical containment vessel with an internal water tank, characterized in that: The built-in water tank (3) is located inside the containment vessel (1). The containment structure (1) is spherical and has an internal ring wall (2). The ring wall (2) has a cylindrical structure and is set vertically inside the containment (1) to divide the containment (1) into a first space (11) and a second space (12). The first space (11) is a columnar space located inside the ring wall (2) and is used to install the main equipment (4). The second space (12) is an irregular space located between the ring wall (2) and the containment (1). The built-in water tank (3) is an irregular ring structure, which is set in a designated area of ​​the irregular space. The bottom height of the designated area is not lower than the height of the main pipe (41), and the volume of the designated area is not less than the volume of the space below the height of the main pipe (41) in the first space (11). A through pipe is provided on the ring wall (2). The through pipe connects the first space (11) and the built-in water tank (3). A normally closed electric isolation valve is provided on the through pipe. Under normal working conditions, the normally closed electric isolation valve is closed. Under accident conditions, the normally closed electric isolation valve automatically opens according to the control signal, so that under accident conditions, the water in the built-in water tank (3) can submerge the first space (11) to the height of the main pipe (41) in the main equipment (4) under the action of gravity.

2. The spherical containment vessel with built-in water tank structure according to claim 1, characterized in that: A plate-like structure is installed on the top surface of the designated area where the built-in water tank (3) is located. The inner and outer sides of the plate-like structure are connected to the ring wall (2) and the containment vessel (1) respectively, serving as an operating platform (14) for placing auxiliary equipment. The built-in water tank (3) is formed by the operation platform (14), the ring wall (2) and the safety shell (1), forming an irregular ring structure with a vertical line on the inner side, a convex curve on the outer side and a horizontal line on the top side.

3. The spherical containment vessel with built-in water tank structure according to claim 2, characterized in that: The containment (1) is provided with a gate (15) for the main equipment (4) to enter and exit the containment (1). The bottom edge of the gate (15) is flush with the operating platform (14).

4. The spherical containment vessel with built-in water tank structure according to claim 1, characterized in that: The bottom of the first space (11) is provided with an equipment support platform (13). The equipment support platform (13) is formed by filling the bottom of the first space (11) with concrete to a height not lower than the bottom of the ring wall (2), so as to occupy the empty space at the bottom of the first space (11). A stacking pit (131) is provided on the equipment support platform (13). The main equipment (4) is mounted on the equipment support platform (13). The main equipment (4) has a pressure vessel (42), and the main pipeline (41) is connected to one side of the pressure vessel (42) in a horizontal direction. The pressure vessel (42) is placed inside the crater (131) to reduce the height of the pressure vessel (42) and the main pipeline (41).

5. The spherical containment vessel with built-in water tank structure according to claim 4, characterized in that: The axis of the ring wall (2) coincides with the axis of the containment (1).

6. The spherical containment vessel with built-in water tank structure according to claim 4, characterized in that: The main equipment (4) also has a refueling water tank (43), which is located above the pressure vessel (42). The top cover of the pressure vessel (42) extends through the bottom of the refueling tank (43) into the refueling tank (43). The refill pool (43) is connected to the built-in water tank (3) by a pump so that water is introduced from the built-in water tank (3) into the refill pool (43) before the top cover of the pressure vessel (42) is opened, thereby sealing the pressure vessel (42).

7. The spherical containment vessel with built-in water tank structure according to claim 1, characterized in that: It also includes a circular crane (5) for hoisting the main equipment (4). The bracket component of the ring crane (5) is set on the top of the ring wall (2) so that the ring crane (5) can run on the top of the ring wall (2).

8. The spherical containment vessel with built-in water tank structure according to claim 7, characterized in that: The ring wall (2) includes an inner ring wall (21) and an outer ring wall (22). Both the inner ring wall (21) and the outer ring wall (22) are cylindrical structures. The inner ring wall (21) serves as a biological shielding ring wall and is coaxially fitted inside the outer ring wall (22). The main equipment (4) is installed in the first space (11) inside the inner ring wall (21). The bracket component of the ring crane (5) is set on the top of the outer ring wall (22).

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