A small modular reactor

Abstract

The application discloses a small modular reactor, comprising a reactor vessel provided with a bottom head; a reactor core arranged in the reactor vessel; a shielding cover surrounding the reactor core; a riser connected to one end of the shielding cover away from the bottom head; a coolant in which the reactor core is immersed; and a guide structure arranged between the reactor core and the bottom head, the guide structure being configured to enable the coolant to enter the reactor core through the guide structure. The application prevents local flow disturbance caused by direct contact and collision of the refluxing coolant in different directions, and improves the natural circulation capacity of the reactor by arranging the guide structure between the bottom head of the reactor vessel and the reactor core, so that the condensed coolant flows back to the guide structure and is guided into the reactor core.

Description

Technical Field

[0001] This application belongs to the field of nuclear reactor technology, specifically relating to a small modular reactor. Background Technology

[0002] During normal operation, the reactor core in the reactor vessel is immersed in coolant and placed in a shield. When the coolant is heated by the reactor core due to a fission event, liquid water is guided upward from the shield to the riser pipe located above the reactor core. After being cooled in the steam generator at the top of the reactor vessel, it returns to the bottom of the reactor vessel from the outside of the riser pipe and the shield, and then re-enters the reactor core.

[0003] However, since the coolant flows back from the outside of the shield to the reactor core in the middle, the coolant flowing in opposite directions will collide with each other, causing local flow disturbances and weakening the natural circulation driving force to some extent.

[0004] Therefore, a small modular reactor needs to be designed to guide the recirculated coolant and reduce local flow disturbances. Summary of the Invention

[0005] The purpose of this application is to provide a small modular reactor to solve the problem of coolant flow guidance in the prior art.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] A small modular reactor includes a reactor vessel with a bottom head; a reactor core disposed within the reactor vessel; a shield surrounding the reactor core; a riser connected to one end of the shield away from the bottom head; a coolant immersed in the coolant; and a guide structure disposed between the reactor core and the bottom head, the guide structure being configured to allow the coolant to enter the reactor core through the guide structure.

[0008] This application provides a guiding structure between the reactor vessel bottom head and the reactor core, allowing the condensed coolant to flow back onto the guiding structure and be guided into the reactor core. This prevents local flow disturbances caused by direct contact and collision of coolants flowing back from different directions, thereby improving the reactor's natural circulation capability.

[0009] Furthermore, a gap is provided between the highest point of the guide structure and the bottom of the reactor core.

[0010] Furthermore, the guide structure is configured to be approximately a rotating body, with the axis of rotation of the guide structure coinciding with the axis of rotation of the bottom end cap.

[0011] Furthermore, the axial cross-section of the guide structure arches upward to form a protrusion.

[0012] Furthermore, the protrusion is arc-shaped.

[0013] Furthermore, the guide structure smoothly transitions downwards from the center of its axial cross-section to the outer periphery on both sides to the bottom end cap.

[0014] This application sets the lower contour edge of the axial section of the guide structure to match the shape of the bottom head of the reactor vessel. The middle of the upper contour edge of the section arches upward to form a protrusion, which is arc-shaped. The protrusion smoothly transitions downward from the middle to the outer periphery on both sides to the bottom head. The arc-shaped guide surface can improve the fluid flow pattern, reduce flow dead zones and eddy disturbances, and reduce fluid scouring and wear. Thus, the guide structure can form a longer and smoother guide path, which is convenient for guiding the coolant into the reactor core.

[0015] Furthermore, a hollow cavity is provided between the guide structure and the bottom end cap.

[0016] Furthermore, the guide structure has multiple through holes along the circumferential direction, and the through holes are connected to the cavity.

[0017] Furthermore, the guide structure is a solid component. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a small modular reactor structure.

[0019] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0020] Figure 3 for Figure 1 A schematic diagram of the structure along the E direction. Detailed Implementation

[0021] In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can mean A or B. "And / or" in this application is merely a description of the relationship between the related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural.

[0022] In the description of this application, unless otherwise stated, "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0023] Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" are not necessarily different. Meanwhile, in the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is being used as an example, illustration, or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of terms such as "exemplary" or "for example" is intended to present related concepts in a concrete manner for ease of understanding.

[0024] It is understood that the term "embodiment" used throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, various embodiments throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0025] It is understood that in this application, "...when" and "if" both refer to the corresponding processing that will be carried out under certain objective circumstances, and are not limited to a specific time, nor do they require a judgment action to be performed during implementation, nor do they imply any other limitations.

[0026] It is understood that the predefined in this application can be understood as defined, predefined, stored, pre-stored, pre-negotiated, pre-configured, solidified, or pre-burned.

[0027] It is understood that some optional features in the embodiments of this application can be implemented independently in certain scenarios without relying on other features, such as the current solution on which they are based, to solve the corresponding technical problems and achieve the corresponding effects. Alternatively, they can be combined with other features as needed in certain scenarios. Correspondingly, the apparatus given in the embodiments of this application can also implement these features or functions, which will not be elaborated here.

[0028] In this application, unless otherwise specified, the same or similar parts between the various embodiments can be referred to each other. In the various embodiments of this application, and in the various implementation methods / methods / implementations within each embodiment, unless otherwise specified or logically conflicting, the terminology and / or descriptions between different embodiments and between the various implementation methods / methods / implementations within each embodiment are consistent and can be mutually referenced. The technical features in different embodiments and the various implementation methods / methods / implementations within each embodiment can be combined according to their inherent logical relationships to form new embodiments, implementation methods, methods, or implementation approaches. The embodiments described below do not constitute a limitation on the scope of protection of this application.

[0029] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1-3 As shown, this application discloses a small modular reactor, including a reactor vessel 1 with a bottom head 8; a reactor core 2 disposed in the reactor vessel 1; a shield 3 surrounding the reactor core 2; a riser 4 connected to one end of the shield 3 away from the bottom head; a coolant 5 immersed in the coolant 5; and a guide structure 6 disposed between the reactor core 2 and the bottom head, the guide structure 6 being configured to allow the coolant 5 to enter the reactor core 2 through the guide structure 6.

[0031] Specifically, this application provides a guide structure 6 between the bottom head of the reactor vessel 1 and the reactor core 2, allowing the condensed coolant 5 to flow back onto the guide structure 6 and be guided into the reactor core 2. This prevents the coolant 5 flowing back from different directions from directly contacting and colliding, thus improving the reactor's natural circulation capability.

[0032] Furthermore, a gap is provided between the highest point of the guide structure 6 and the bottom of the reactor core 2 to form a flow space for the coolant 5, thereby preventing obstruction of the coolant 5 flowing into the reactor core 2.

[0033] In some embodiments, the guide structure 6 is configured to be approximately a body of revolution, that is, the axial cross-sectional shape passing through the axis of revolution is substantially the same, and the axis of revolution of the guide structure 6 coincides with the axis of revolution of the bottom end cap 8.

[0034] Furthermore, the lower contour edge of the axial section of the guide structure 6 is adapted to the shape of the bottom head 8 of the reactor vessel 1, and the middle of the upper contour edge of the section arches upward to form a protrusion, which is arc-shaped; from the middle to the outer periphery on both sides, it smoothly transitions downward to the bottom head. The shaped guide surface can improve the fluid flow pattern, reduce flow dead zones and eddy disturbances, and reduce fluid scouring and wear, so that the guide structure 6 can form a longer and smooth guide path, which is convenient for guiding the coolant 5 into the reactor core 2.

[0035] Furthermore, the guide structure 6 is detachably installed on the bottom head 8 of the reactor vessel 1, which facilitates maintenance and replacement after wear.

[0036] Furthermore, a hollow cavity is provided between the guide structure 6 and the bottom end cap. The guide structure 6 has multiple through holes 7 along the circumference, preferably four. By providing through holes 7, a closed cavity is avoided between the guide structure 6 and the bottom end cap 8. During operation, the internal gas expands, causing the guide structure 6 to be damaged by pressure.

[0037] In some embodiments, the guide structure 6 is a solid component with no hollow cavity between it and the bottom end cap.

[0038] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A small modular reactor, comprising a reactor vessel with a bottom head; a reactor core disposed within the reactor vessel; a shield surrounding the reactor core; a riser connected to one end of the shield opposite to the bottom head; a coolant, the reactor core being immersed in the coolant; and a guide structure disposed between the reactor core and the bottom head, the guide structure being configured to allow the coolant to enter the reactor core through the guide structure.

2. The reactor according to claim 1, characterized in that, A gap is provided between the highest point of the guide structure and the bottom of the reactor core.

3. The reactor according to claim 2, characterized in that, The guide structure is configured to be approximately a rotating body, and the axis of rotation of the guide structure coincides with the axis of rotation of the bottom end cap.

4. The reactor according to claim 3, characterized in that, The axial cross-section of the guide structure arches upward to form a protrusion.

5. The reactor according to claim 4, characterized in that, The protrusion is arc-shaped.

6. The reactor according to claim 4, characterized in that, The axial cross-section of the guide structure smoothly transitions downwards from the middle to the outer periphery on both sides to the bottom end cap.

7. The reactor according to any one of claims 1-6, characterized in that, A hollow cavity is provided between the guide structure and the bottom end cap.

8. The reactor according to claim 7, characterized in that, The guide structure has multiple through holes along the circumference, and the through holes are connected to the cavity.

9. The reactor according to any one of claims 1-6, characterized in that, The guide structure is a solid component.

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