An upper nozzle connecting plate and upper nozzle for a nuclear fuel assembly

Abstract

The present application relates to the technical fields of nuclear fuel assembly, and particularly relates to a nuclear fuel assembly upper nozzle connecting plate and upper nozzle. The connecting plate comprises a connecting plate body, which comprises: a middle part body located in the middle part region of the connecting plate body, the middle part body being provided with a plurality of first water passing holes; a plurality of corner part bodies, each corner part body being connected to the corresponding corner part of the middle part body, the corner part body being provided with a plurality of second water passing holes; and a plurality of side edge bodies, each side edge body being located between the corresponding two adjacent corner part bodies, the side edge body being connected to the corresponding side edge of the corner part body and the middle part body, and the side edge body being provided with a plurality of third water passing holes. The distribution density of the plurality of second water passing holes in the corner part body is greater than the distribution density of the plurality of first water passing holes in the middle part body, and is less than the distribution density of the plurality of third water passing holes in the side edge body, so that the strength and stress of different regions of the connecting plate can be matched. The upper nozzle comprises the aforementioned connecting plate.

Description

Technical Field

[0001] This invention relates to the field of nuclear fuel assembly technology, specifically to a nuclear fuel assembly upper tube socket connecting plate and upper tube socket. Background Technology

[0002] A nuclear fuel assembly refers to a complete set of fuel elements assembled together. A nuclear fuel assembly consists of components such as an upper tube seat, a lower tube seat, guide tubes, instrument tubes, fuel rods, and a grid. The upper tube seat itself consists of a connecting plate, a surrounding plate, and a top plate. The connecting plate has guide tube holes and water flow holes. The guide tube holes are used to connect the guide tubes, and the water flow holes are used to allow water to pass through and cool the fuel rods.

[0003] The inventors discovered that in practical applications, different areas of the connecting plate experience different stresses, and the strength of different areas of the connecting plate does not match the stress, which reduces the reliability of the connecting plate and thus reduces the safety of the nuclear fuel assembly. Summary of the Invention

[0004] To address the technical problem of mismatched strength and stress in different areas of the existing nuclear fuel assembly upper tube socket connection plate, this invention provides a nuclear fuel assembly upper tube socket connection plate and upper tube socket, which enables the strength and stress in different areas of the nuclear fuel assembly upper tube socket connection plate to match, thereby improving the reliability of the connection plate and thus improving the safety of the nuclear fuel assembly.

[0005] This invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides a nuclear fuel assembly upper tube socket connecting plate, comprising a connecting plate body, the connecting plate body comprising: a central structure located in the central region of the connecting plate body, the central structure having a plurality of first water passage holes through it; a plurality of corner structures connected to a corresponding corner of the central structure, the corner structures having a plurality of second water passage holes through them; and a plurality of side structures located between two adjacent corner structures, the side structures being connected to the corresponding side of the corner structure and the central structure, the side structures having a plurality of third water passage holes through them; wherein the distribution density of the plurality of second water passage holes in the corner structures is greater than the distribution density of the plurality of first water passage holes in the central structure, and less than the distribution density of the plurality of third water passage holes in the side structures.

[0007] In practical applications, different areas of the connecting plate experience different stresses. If the distribution density of the water flow holes on the connecting plate is the same, there will be a mismatch between the strength and the stress in different areas of the connecting plate, which will reduce the reliability of the connecting plate and thus reduce the safety of the nuclear fuel assembly.

[0008] In view of this, the nuclear fuel assembly upper tube seat connection plate provided by the present invention includes a connection plate body, which includes a central structure, multiple corner structures, and multiple side structures. The central structure is located in the central region of the connection plate body and experiences the lowest stress. The central structure is also provided with multiple first water passage holes. Each corner structure is connected to the corresponding corner of the central structure and experiences moderate stress. The corner structures are also provided with multiple second water passage holes. Each side structure is located between two adjacent corner structures and is connected to the corresponding corner structure and the corresponding side of the central structure. The side structure experiences the highest stress. The side structures are also provided with multiple third water passage holes. The distribution density of the multiple second water passage holes in the corner structure is greater than the distribution density of the multiple first water passage holes in the central structure and less than the distribution density of the multiple third water passage holes in the side structure.

[0009] Because the distribution density of multiple third-level drainage holes is highest in the side structure, the number of ribs defined within the side structure is also the highest, resulting in the highest relative strength of the side structure (among the central, side, and corner structures), matching the maximum force it experiences. Similarly, the distribution density of multiple first-level drainage holes is lowest in the central structure, resulting in the fewest ribs defined within the central structure, resulting in the lowest relative strength of the central structure (among the central, side, and corner structures), matching the smaller force experienced by the central structure. Conversely, the distribution density of multiple second-level drainage holes is moderate in the corner structure, resulting in a moderate number of ribs defined within the corner structure, resulting in a moderate relative strength of the corner structure (among the central, side, and corner structures), matching the moderate force experienced by the corner structure. This ensures that the strength of each part of the connecting plate structure is matched to the magnitude of the force it experiences.

[0010] In summary, the nuclear fuel assembly upper tube socket connecting plate provided by the present invention enables the strength and stress magnitude of different regions of the nuclear fuel assembly upper tube socket connecting plate to be matched, thereby improving the reliability of the connecting plate and thus improving the safety of the nuclear fuel assembly.

[0011] In an optional embodiment of this application, the cross-sectional areas of the first, second, and third water passages decrease sequentially. Thus, the first water passage has the largest cross-sectional area, defines the longest rib within the central structure, and has the largest spacing between the ribs, ensuring the lowest relative strength of the central structure. The third water passage has the smallest cross-sectional area, defines the shortest rib within the side structure, and has the smallest spacing between the ribs, ensuring the highest relative strength of the side structure. The second water passage has a moderate cross-sectional area, defines a moderately long rib within the corner structure, and has a moderate spacing between the ribs, ensuring the moderately moderate strength of the corner structure.

[0012] In an optional embodiment of this application, the cross-sections of the first, second, and third water passages are all polygonal. It is understood that the polygonal cross-sections of the first, second, and third water passages allow for a reasonable arrangement on the connecting plate, maximizing the utilization of the connecting plate's area. Furthermore, the polygonal cross-sections provide better obstruction for fuel rods with circular radial cross-sections, thereby preventing the fuel rods from detaching from the grid and ejecting from the corresponding water passages under the impact of high-speed water flow.

[0013] In an optional embodiment of this application, the connecting plate is rectangular, the central structure is located at the center of the connecting plate, the side structures are arranged around the periphery of the central structure, and the four corner structures are respectively located at the four apex corners of the connecting plate, so that the cross-sectional area and distribution density of the second water passage are between the third water passage and the first water passage, and are distributed at the four apex corners of the connecting plate, ensuring good connectivity of the remaining plate material of the connecting plate.

[0014] In an optional embodiment of this application, an instrument tube hole is provided through the center of the central structure, and a plurality of first water passage holes are sequentially distributed around the periphery of the instrument tube hole. The instrument tube hole is used to house an instrument tube for measuring the internal environment of the fuel assembly.

[0015] In an optional embodiment of this application, the central structure is provided with a plurality of first guide holes, which are sequentially distributed circumferentially around the periphery of the central structure.

[0016] In an optional embodiment of this application, a plurality of first water passage holes and a plurality of second water passage holes are circumferentially distributed around the periphery of the plurality of first guide tube holes.

[0017] In an optional embodiment of this application, the side structure is provided with a plurality of second guide tube holes, and the arrangement trajectory of the plurality of second guide tube holes surrounds the plurality of first guide tube holes.

[0018] In an optional embodiment of this application, a plurality of second water passage holes are circumferentially distributed around the periphery of the plurality of second guide tube holes.

[0019] Secondly, the present invention provides a nuclear fuel assembly upper tube seat, including a top plate, a surrounding plate, and the aforementioned nuclear fuel assembly upper tube seat connecting plate.

[0020] The nuclear fuel assembly upper tube socket provided by the present invention includes the above-mentioned nuclear fuel assembly upper tube socket connecting plate, which enables the strength and stress magnitude of different regions of the nuclear fuel assembly upper tube socket connecting plate to be matched, thereby improving the safety of the nuclear fuel assembly.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] 1. The multi-layer upper pipe support structure provided by the present invention includes a connecting plate, which comprises a central component, multiple corner components, and multiple side components. The central component is located in the central region of the connecting plate and experiences the lowest stress. Multiple first water passage holes are provided through the central component. Each corner component is connected to the corresponding corner of the central component and experiences moderate stress. Multiple second water passage holes are provided through the corner components. Each side component is located between two adjacent corner components and is connected to the corresponding side of the corner and central components, experiencing the highest stress. Multiple third water passage holes are provided through the side components. The distribution density of the multiple second water passage holes in the corner components is greater than the distribution density of the multiple first water passage holes in the central component, but less than the distribution density of the first water passage holes in the central component. The distribution density of multiple third water passages within the side structure results in the largest number of ribs defined within the side structure, thus maximizing the strength of the side structure and matching the maximum force it experiences. Conversely, the distribution density of multiple first water passages within the central structure is the lowest, resulting in the fewest ribs defined within the central structure and maximizing its strength, matching the smaller force it experiences. Similarly, the distribution density of multiple second water passages within the corner structure is moderate, resulting in a moderate number of ribs defined within the corner structure and maximizing its strength, matching the moderate force it experiences. This ensures that the strength of each component of the connecting plate matches the magnitude of the force it experiences, improving the reliability of the connecting plate and thus enhancing the safety of the nuclear fuel assembly.

[0023] 2. The nuclear fuel assembly upper tube seat provided by the present invention includes the above-mentioned nuclear fuel assembly upper tube seat connecting plate, which enables the strength and stress magnitude of different areas of the nuclear fuel assembly upper tube seat connecting plate to be matched, thereby improving the safety of the nuclear fuel assembly. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] In the attached diagram:

[0026] Figure 1 A schematic diagram of the stress zoning structure of the upper tube connector plate of the nuclear fuel assembly provided in an embodiment of the present invention;

[0027] Figure 2A top view of the structure of the upper tube connection plate of the nuclear fuel assembly provided in an embodiment of the present invention;

[0028] Figure 3 This is a cross-sectional view of the upper tube seat of a nuclear fuel assembly provided for an embodiment of the present invention.

[0029] The attached figures include reference numerals and their corresponding component names:

[0030] 10-Upper pipe seat body; 11-Top plate; 12-Enclosure plate; 100-Connecting plate body; 110-Connecting plate body; 111-Central structure; 112-Corner structure; 113-Side structure; 114-First water passage hole; 115-Second water passage hole; 116-Third water passage hole; 117-Instrument pipe hole; 118-First guide pipe hole; 119-Second guide pipe hole. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0033] It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0034] In the description of the embodiments of this application, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in when in use, or the orientation or positional relationship that is commonly understood by those skilled in the art. It is only for the convenience of describing this application and simplifying the description, and is not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0035] In the description of this application, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0037] It should be noted that a nuclear fuel assembly refers to a complete set of fuel elements assembled together, consisting of several fuel elements, connecting components, an upper tube seat, control rod guide tubes, and positioning grids, among other parts. The upper tube seat itself is composed of a connecting plate, a surrounding plate, and a top plate. In practical applications, different areas of the connecting plate experience varying degrees of stress. If the distribution density of the drainage holes on the connecting plate is the same, there will be a mismatch between the strength and stress in different areas of the connecting plate, leading to reduced reliability of the connecting plate and thus lowering the safety of the nuclear fuel assembly.

[0038] In response, the inventor has innovatively designed the following technical solution, and the specific implementation scheme of this application will be described in detail below with reference to the accompanying drawings.

[0039] Example 1

[0040] Combination Figure 1 This embodiment provides a nuclear fuel assembly upper tube connector plate, including a connector plate body 110. The connector plate body 110 includes: a central structure 111, located in the central region of the connector plate body 110, with a plurality of first water passage holes 114 penetrating through the central structure 111; a plurality of corner structures 112, each corner structure 112 connected to a corresponding corner of the central structure 111, with a plurality of second water passage holes 115 penetrating through the corner structure 112; and a plurality of side structures 113, each side structure... 113 is located between two adjacent corner structures 112. The side structure 113 is connected to the corresponding side of the corner structure 112 and the middle structure 111. The side structure 113 is provided with a plurality of third water passage holes 116. The distribution density of the plurality of second water passage holes 115 in the corner structure 112 is greater than the distribution density of the plurality of first water passage holes 114 in the middle structure 111, and less than the distribution density of the plurality of third water passage holes 116 in the side structure 113.

[0041] In this embodiment, the inventors performed a static simulation analysis on the connecting plate 110 without drainage holes. Based on the simulation results, according to the magnitude of the force on each region of the connecting body, the connecting plate 110 was divided into a central structure 111, a corner structure 112, and a side structure 113 from low to high. The central structure 111 is the region with the least force on the connecting plate 110, the side structure 113 is the region with the greatest force on the connecting plate 110, and the corner structure 112 is the region with the force in the middle.

[0042] After dividing the central structure 111, corner structure 112, and side structure 113 on the connecting plate 110, a plurality of first water passage holes 114 are opened in the central structure 111, a plurality of second water passage holes 115 are set in the corner structure 112, and a plurality of third water passage holes 116 are set in the side structure 113. The distribution density of the plurality of first water passage holes 114 in the central structure 111 is minimized, the distribution density of the plurality of third water passage holes 116 in the side structure 113 is maximized, and the distribution density of the plurality of second water passage holes 115 in the corner structure 112 is in the middle.

[0043] Because the distribution density of the multiple third water passages 116 is the highest in the side structure 113, the largest number of ribs are defined in the side structure 113, resulting in the highest relative strength of the side structure 113, matching the greater force it receives. Because the distribution density of the multiple first water passages 114 is the lowest in the central structure 111, the fewest number of ribs are defined in the central structure 111, resulting in the lowest relative strength of the central structure 111, matching the smaller force it receives.

[0044] Combination Figure 2 In this embodiment, the cross-sectional areas of the first water passage 114, the second water passage 115, and the third water passage 116 decrease sequentially. The first water passage 114 has the largest cross-sectional area and the lowest distribution density, which can reduce the obstruction of the central structure 111 to water and increase the water flow. The third water passage 116 has the smallest cross-sectional area and the highest distribution density, which can significantly improve the strength of the side structure 113.

[0045] Furthermore, the first water passage 114 has the largest cross-sectional area, the longest rib defined within the central structure 111, the largest spacing between the multiple ribs, and the lowest relative strength. The third water passage 116 has the smallest cross-sectional area, the shortest rib defined within the side structure 113, the smallest spacing between the multiple ribs, and the highest relative strength.

[0046] Specifically, in this embodiment, the cross-sections of the first water passage 114, the second water passage 115, and the third water passage 116 are all polygonal. In fact, the cross-sections of the first water passage 114, the second water passage 115, and the third water passage 116 are all irregular polygons, which can achieve a reasonable combination on the connecting plate 110 to make the most of the area of ​​the connecting plate 110 and avoid waste.

[0047] Meanwhile, the cross-sections of the first water passage 114, the second water passage 115, and the third water passage 116 are all polygonal, allowing for a reasonable arrangement on the connecting plate 110 and maximizing the utilization of the connecting plate 110's area. Furthermore, the polygonal cross-sections provide better protection for fuel rods with circular radial cross-sections, preventing them from detaching from the grid and ejecting from the corresponding water passages under the impact of high-speed water flow.

[0048] Furthermore, the multiple ribs defined by multiple first water passage holes 114, multiple second water passage holes 115 and multiple third water passage holes 116 on the connecting plate 110 are interconnected, thereby achieving a longitudinal cover of multiple fuel rods below the connecting plate body 100 and preventing the fuel rods from popping upward.

[0049] It is understood that the connecting plate 110 is rectangular, with the central component 111 located at the center of the connecting plate 110, the side components 113 surrounding the periphery of the central component 111, and the four corner components 112 located at the four apex corners of the connecting plate 110. The cross-sectional area and distribution density of the second water passage 115 are between those of the third water passage 116 and the first water passage 114, and are distributed at the four apex corners of the connecting plate 110, ensuring good connectivity of the remaining plate material of the connecting plate 110.

[0050] It is understandable that if the relative positions of the central structure 111, corner structure 112 and side structure 113 on the connecting plate 110 are different due to different actual application conditions, the distribution density and area of ​​the corresponding water passage holes in each area can be adjusted accordingly.

[0051] It should be understood that an instrument tube hole 117 is provided through the center of the central structure 111, and a plurality of first water passage holes 114 are distributed around the periphery of the instrument tube hole 117. The instrument tube hole 117 is used to house an instrument tube for measuring the internal environment of the fuel assembly.

[0052] Combined again Figure 2 The central structure 111 is also provided with a plurality of first guide pipe holes 118, which are distributed circumferentially around the periphery of the central structure 111. A plurality of first water passage holes 114 and a plurality of third water passage holes 116 are distributed circumferentially around the periphery of the plurality of first guide pipe holes 118.

[0053] based on Figure 2 In this embodiment, there are eight first guide holes 118, and the eight first guide holes 118 form a closed loop trajectory surrounding the instrument hole 117.

[0054] Correspondingly, the side structure 113 is provided with a plurality of second guide pipe holes 119, and a plurality of third water passage holes 116 are distributed circumferentially around the periphery of the plurality of second guide pipe holes 119, and the arrangement trajectory of the plurality of second guide pipe holes 119 surrounds the plurality of first guide pipe holes 118.

[0055] In fact, in a conventional nuclear reactor, there are sixteen second guide pipes, and the sixteen second guide pipe holes 119 form a closed loop surrounding the eight first guide pipe holes 118. It can be understood that adjacent second guide pipe holes 119 in the circumferential direction are connected by ribs formed by third water passage holes 116. That is, along the arrangement of the sixteen second guide pipe holes 119, multiple ribs are interconnected to form a closed loop, which can further enhance the strength of the connecting plate 110.

[0056] Similarly, two adjacent first guide pipe holes 118 in the circumferential direction are connected by ribs defined by the first water passage hole 114. That is, along the arrangement trajectory of the eight first guide pipe holes 118, multiple ribs are connected to each other to form a closed loop trajectory, which can further enhance the strength of the connecting plate 110.

[0057] In addition, the eight first guide holes 118 and the sixteen second guide holes 119 respectively form two concentric tracks including the instrument hole 117. In this embodiment, the eight first guide holes 118 form a rectangular closed-loop track. The sixteen second guide holes 119 form an approximately rectangular closed-loop track, wherein twelve of the second guide holes 119 form the four sides of the closed-loop track in groups of three, and the remaining four second guide holes 119 are moved from the four vertices of the closed-loop track toward the instrument hole 117 by one-third of the hole distance.

[0058] In this embodiment, both the first guide tube hole 118 and the second guide tube hole 119 are stepped holes, meaning one end has a larger diameter and the other end has a smaller diameter, forming a stepped surface inside. The larger diameter portion is used to house a quick-detachable connection structure to establish a connection between the guide tube and the guide tube hole, while the smaller diameter portion is used for the guide tube to pass through when installing or removing the upper tube seat, and to position the upper tube seat.

[0059] Combination Figure 2In this embodiment, the first water passage 114 is roughly triangular. To reduce local stress, solid filling is performed at the two vertices of the triangle, and the remaining vertices are rounded. Eight first water passages 114 are arranged sequentially around the circumference of the instrument pipe hole 117, and the eight first water passages 114 sequentially define eight ribs.

[0060] Therefore, it is equivalent to the eight ribs radiating outwards evenly from the instrument pipe hole 117 as the center, that is, the eight ribs provide axial uniform support for the instrument pipe hole 117, thereby improving the structural strength of the instrument pipe hole 117. One end of each of the eight ribs defined by the eight first water passage holes 114 is connected to the area opened in the instrument pipe hole 117, and the other end of each of the eight ribs is connected to a first guide pipe hole 118.

[0061] Furthermore, multiple first water passage holes 114 and multiple third water passage holes 116 are distributed around any first guide hole 118. The multiple ribs defined by the multiple first water passage holes 114 and multiple third water passage holes 116 provide circumferential support for the first guide hole 118, thereby improving the structural strength of the first guide hole 118.

[0062] The eight first guide holes 118 located in the central structure 111 are distributed in a rectangular pattern, with four of the first guide holes 118 located at the four vertices of the rectangular pattern and the remaining four first guide holes 118 located on the four sides of the rectangular pattern.

[0063] In this embodiment, the periphery of the first guide hole 118 located at the top corner has four first water passage holes 114 and four third water passage holes 116, defining eight ribs. The periphery of the first guide hole 118 located on the four sides has six first water passage holes 114 and two third water passage holes 116.

[0064] Because the area of ​​the first water passage 114 is larger than that of the third water passage 116, the length of the rib defined by two adjacent first water passages 114 is greater than the length of the rib defined by two adjacent third water passages 116. That is, the ribs of the first guide pipe holes 118 distributed on one side of the central structure 111 are longer and have lower strength, corresponding to a smaller impact force on the central structure 111; the ribs of the first guide pipe holes 118 distributed on one side of the side structure 113 are shorter and have higher strength, corresponding to a greater impact force on the side structure 113.

[0065] For any second guide hole 119 in the side structure 113, there are multiple third water passage holes 116 distributed around its periphery. The multiple third water passage holes 116 define multiple shorter ribs. The multiple short ribs are stronger and provide stronger support for the second guide hole 119, matching the greater impact force received by the side structure 113.

[0066] In summary, the connecting plate body 100 provided in this embodiment adjusts the strength of different regions by setting water flow holes with different cross-sectional areas and distribution densities in different areas, so that the strength of different regions matches the magnitude of the stress. This ensures that the side structure 113, which is subjected to greater stress, has sufficient strength, and ensures that the middle structure 111, which is subjected to less stress, has sufficient water flow, thereby improving safety.

[0067] Compared to existing technologies, the nuclear fuel assembly upper tube connector plate provided in this embodiment divides the connector plate body 110 into a central structure 111, a corner structure 112, and a side structure 113, from low to high, according to the magnitude of the force on each region of the connector body. The force on the corner structure 112 is greater than that on the central structure 111, but less than that on the side structure 113. The distribution density of the plurality of first water passage holes 114 distributed in the central structure 111 is less than the distribution density of the plurality of second water passage holes 115 distributed in the corner structure 112, and the distribution density of the plurality of third water passage holes 116 distributed in the side structure 113 is greater than the distribution density of the plurality of second water passage holes 115 distributed in the corner structure 112. The greater the distribution density of water passage holes in the region, the more ribs will be defined on the connecting plate 110, and thus the higher the strength of the region. That is, the side structure 113 with the greatest force has the greatest strength, and the middle structure 111 with the least force has the least strength.

[0068] Therefore, the nuclear fuel assembly upper tube connection plate provided in this embodiment can ensure that the strength and stress magnitude of different areas are matched, thereby improving safety.

[0069] Example 2

[0070] Combination Figure 3 This embodiment provides a nuclear fuel assembly upper tube seat, including a top plate 11 and a surrounding plate 12, and also includes the nuclear fuel assembly upper tube seat connecting plate described in Embodiment 1.

[0071] Specifically, the nuclear fuel assembly upper tube connector connecting plate described in Embodiment 1 is the connecting plate body 100. The lower end of the surrounding plate 12 is connected to the connecting plate body 100, and the connecting plate body 100 can cover the lower end of the surrounding plate 12. At the same time, the lower end of the top plate 11 is connected to the upper end of the surrounding plate 12, and the top plate 11 can cover the upper end of the surrounding plate 12.

[0072] Generally, the top plate 11 is welded to the surrounding plate 12, the surrounding plate 12 is welded to the connecting plate body 100, and four leaf springs are bolted to the top of the top plate 11. The four leaf springs abut against the upper core to achieve elastic fixation of the fuel assembly.

[0073] In other words, in this embodiment, the upper tube seat 10 is composed of the connecting plate body 100, the top plate 11, and the surrounding plate 12 described in Embodiment 1. In practical applications, the upper tube seat 10, together with the lower tube seat, guide tube, instrument tube, fuel rods, and grid, forms a nuclear fuel assembly. The upper and lower ends of the guide tube are connected to the upper tube seat 10 and the lower tube seat, respectively. The fuel rods are arranged on the grid, and the grid is connected to the guide tube.

[0074] Therefore, the nuclear fuel assembly upper tube socket provided in this embodiment can match the strength and stress magnitude of different areas of the nuclear fuel assembly upper tube socket connecting plate, thereby improving the safety of the nuclear fuel assembly.

[0075] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. 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 nuclear fuel assembly upper tube socket connecting plate, characterized in that, Includes a connecting plate (110), the connecting plate (110) comprising: The central structure (111) is located in the central region of the connecting plate (110), and the central structure (111) is provided with a plurality of first water passage holes (114). Multiple corner components (112) are connected to the corresponding corner of the central component (111), and multiple second water passage holes (115) are provided through the corner components (112). Multiple side structures (113) are provided, each side structure (113) is located between two adjacent corner structures (112), the side structure (113) is connected to the corresponding side of the corner structure (112) and the middle structure (111), and the side structure (113) is provided with multiple third water passage holes (116). The distribution density of the plurality of second water passages (115) in the corner structure (112) is greater than the distribution density of the plurality of first water passages (114) in the middle structure (111), and less than the distribution density of the plurality of third water passages (116) in the side structure (113). The cross-sectional areas of the first water passages (114), the second water passages (115), and the third water passages (116) decrease sequentially to define the area within the side structure (113). The side structure (113) has the highest number of ribs, which matches the maximum force exerted on it. The middle structure (111) has the lowest number of ribs, which matches the smaller force exerted on it. The corner structure (112) has a moderate number of ribs, which matches the moderate force exerted on it.

2. The nuclear fuel assembly upper tube socket connecting plate according to claim 1, characterized in that, The cross-sections of the first water passage (114), the second water passage (115), and the third water passage (116) are all polygonal.

3. The nuclear fuel assembly upper tube socket connecting plate according to claim 1, characterized in that, The connecting plate (110) is rectangular, the central structure (111) is located at the center of the connecting plate (110), the side structure (113) is arranged around the periphery of the central structure (111), and the four corner structures (112) are respectively located at the four top corners of the connecting plate (110).

4. The nuclear fuel assembly upper tube socket connecting plate according to claim 1, characterized in that, The central part (111) has an instrument pipe hole (117) through it, and a plurality of first water passage holes (114) are distributed around the instrument pipe hole (117).

5. The nuclear fuel assembly upper tube socket connecting plate according to claim 1, characterized in that, The central structure (111) is provided with a plurality of first guide holes (118), which are distributed circumferentially around the periphery of the central structure (111).

6. The nuclear fuel assembly upper tube socket connecting plate according to claim 5, characterized in that, The periphery of the plurality of first guide tube holes (118) is provided with a plurality of first water passage holes (114) and a plurality of second water passage holes (115).

7. The nuclear fuel assembly upper tube socket connecting plate according to claim 5, characterized in that, The side structure (113) is provided with a plurality of second guide holes (119), and the arrangement trajectory of the plurality of second guide holes (119) surrounds the plurality of first guide holes (118).

8. The nuclear fuel assembly upper tube socket connecting plate according to claim 7, characterized in that, Multiple second water passage holes (115) are circumferentially distributed around the periphery of the multiple second guide tube holes (119).

9. A nuclear fuel assembly upper tube seat, comprising a top plate (11) and a surrounding plate (12), characterized in that, It also includes the nuclear fuel assembly upper tube connection plate as described in any one of claims 1 to 8.

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