Nuclear fuel assembly upper tube seat connecting plate and upper tube seat

Abstract

The invention relates to the technical field of nuclear fuel assemblies, in particular to a nuclear fuel assembly upper tube base connecting plate and an upper tube base, the connecting plate comprises a connecting plate body, the connecting plate body comprises a middle structure, the middle structure is located in the middle area of the connecting plate body, and a plurality of first water passing holes are formed in the middle structure in a penetrating mode; each corner structure body is connected to the corresponding corner part of the middle structure body, and a plurality of second water passing holes are formed in the corner structure bodies in a penetrating mode; each side edge structure body is located between the corresponding two adjacent corner structure bodies, the side edge structure bodies are connected with the corresponding side edges of the corresponding corner structure bodies and the middle structure body, and a plurality of third water passing holes are formed in the side edge structure bodies in a penetrating mode; the distribution density of the second water passing holes in the corner structures is larger than the distribution density of the first water passing holes in the middle structures and smaller than the distribution density of the third water passing holes in the side structures, and therefore the strength and stress of different areas of the connecting plate can be matched. The upper tube seat comprises the connecting plate.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear fuel assemblies, and in particular to an upper tube seat connecting plate and an upper tube seat of a nuclear fuel assembly. Background Art

[0002] A nuclear fuel assembly refers to a whole group of fuel elements assembled together. A nuclear fuel assembly consists of an upper tube seat, a lower tube seat, a guide tube, an instrument tube, a fuel rod, a grid, and other components. The upper tube seat consists of a connecting plate, a shroud, and a top plate. The connecting plate is provided with guide tube holes and water holes. The guide tube holes are used to connect the guide tubes, and the water holes are used to pass water to cool the fuel rods.

[0003] The inventors have found that in actual applications, different areas of the connecting plate are subjected to different forces, and the strength of different areas of the connecting plate does not match the force magnitude, resulting in reduced reliability of the connecting plate and thus reduced safety of the nuclear fuel assembly. Summary of the invention

[0004] In view of the technical problem that the strength of different areas of the upper tube socket connecting plate of the existing nuclear fuel assembly do not match the force size, the present invention provides an upper tube socket connecting plate and an upper tube socket of a nuclear fuel assembly, which can match the strength of different areas of the upper tube socket connecting plate of the nuclear fuel assembly with the force size, so as to improve the reliability of the connecting plate and thus improve the safety of the nuclear fuel assembly.

[0005] The present invention is achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a connection plate for a nuclear fuel assembly upper tube seat, comprising a connection plate body, the connection plate body comprising: a middle structure, the middle structure is located in the middle area of ​​the connection plate body, and a plurality of first water holes are provided through the middle structure; a plurality of corner structures, each of the corner structures is connected to a corresponding corner of the middle structure, and a plurality of second water holes are provided through the corner structure; a plurality of side structures, each of the side structures is located between two corresponding adjacent corner structures, the side structures are connected to the corresponding corner structures and the corresponding sides of the middle structure, and a plurality of third water holes are provided through the side structures; wherein the distribution density of the plurality of second water holes in the corner structures is greater than the distribution density of the plurality of first water holes in the middle structure, and is less than the distribution density of the plurality of third water holes in the side structures.

[0007] In practical applications, different areas of the connecting plate are subjected to different forces. If the distribution density of the water holes on the connecting plate is the same, there will be a mismatch between the strength and force magnitude of different areas of the connecting plate, resulting in reduced reliability of the connecting plate and thus reduced safety of the nuclear fuel assembly.

[0008] In view of this, the present invention provides a connection plate for a nuclear fuel assembly upper tube seat, comprising a connection plate body, wherein the connection plate body comprises a middle structure, a plurality of corner structures and a plurality of side structures, wherein the middle structure is located in the middle region of the connection plate body and is subjected to the lowest stress, and wherein a plurality of first water holes are provided through the middle structure, wherein each corner structure is connected to a corner corresponding to the middle structure and is subjected to a medium stress, and wherein a plurality of second water holes are provided through the corner structure, wherein each side structure is located between two corresponding adjacent corner structures, wherein a side structure is connected to a corresponding corner structure and a side corresponding to the middle structure and is subjected to the maximum stress, and wherein a plurality of third water holes are provided through the side structure, wherein a distribution density of the plurality of second water holes in the corner structure is greater than a distribution density of the plurality of first water holes in the middle structure and is less than a distribution density of the plurality of third water holes in the side structure.

[0009] Since the distribution density of the multiple third water holes in the side structures is the largest, the number of ribs defined in the side structures is the largest, so that the strength of the side structures is relatively the highest (in the middle structures, side structures and corner structures), matching the maximum force it is subjected to. Similarly, the distribution density of the multiple first water holes in the middle structures is the smallest, so the number of ribs defined in the middle structures is the smallest, so that the strength of the middle structures is relatively the lowest (in the middle structures, side structures and corner structures), matching the smaller force the middle structures are subjected to. The distribution density of the multiple second water holes in the corner structures is moderate, so the number of ribs defined in the corner structures is moderate, so that the strength of the corner structures is relatively moderate (in the middle structures, side structures and corner structures), matching the medium force the corner structures are subjected to. In this way, the strength of the structures of each part of the connecting plate body matches the magnitude of the force it is subjected to.

[0010] In summary, the upper tube socket connecting plate of the nuclear fuel assembly provided by the present invention can match the strength and force magnitude of different areas of the upper tube socket connecting plate of the nuclear fuel assembly to improve the reliability of the connecting plate, thereby improving the safety of the nuclear fuel assembly.

[0011] In an optional embodiment of the present application, the cross-sectional areas of the first water hole, the second water hole and the third water hole are reduced in sequence. Thus, the first water hole has the largest cross-sectional area, the rib length defined in the middle body is the longest, and the spacing between the multiple ribs is the largest, ensuring that the strength of the middle body is relatively the lowest. The third water hole has the smallest cross-sectional area, the rib length defined in the side body is the smallest, and the spacing between the multiple ribs is the smallest, ensuring that the strength of the side body is relatively the highest. The second water hole has a medium cross-sectional area, the rib length defined in the corner body is medium, and the spacing between the multiple ribs is medium, ensuring that the strength of the corner body is relatively medium.

[0012] In an optional embodiment of the present application, the cross-sections of the first water hole, the second water hole, and the third water hole are all polygonal. It is known that the cross-sections of the first water hole, the second water hole, and the third water hole are all polygonal, and can be reasonably arranged on the connecting plate body to maximize the use of the connecting plate body area. In addition, the polygonal cross-section can better block the fuel rods with circular radial cross-sections, thereby preventing the fuel rods from detaching from the grid and popping out of the corresponding water holes under the impact of high-speed water flow.

[0013] In an optional embodiment of the present application, the connecting plate body is rectangular, the middle structure is arranged at the center position of the connecting plate body, the side structure is arranged around the periphery of the middle structure, and the four corner structures are respectively arranged at the four top corners of the connecting plate body, so that the cross-sectional area and distribution density of the second water through hole are between the third water through hole and the first water through hole, and are distributed at the four top corners of the connecting plate body, thereby ensuring that the remaining plate material of the connecting plate body has good connectivity.

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

[0015] In an optional embodiment of the present application, a plurality of first guide tube holes are provided through the middle body, and the plurality of first guide tube holes are sequentially distributed circumferentially around the periphery of the middle body.

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

[0017] In an optional embodiment of the present application, a plurality of second guide tube holes are provided through the side structure, 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 the present application, a plurality of second water holes are circumferentially distributed around the periphery of the plurality of second guide pipe holes.

[0019] In a second aspect, the present invention provides an upper tube socket for a nuclear fuel assembly, comprising a top plate, a surrounding plate and the above-mentioned upper tube socket connecting plate for the nuclear fuel assembly.

[0020] The upper tube seat of a nuclear fuel assembly provided by the present invention includes the above-mentioned upper tube seat connecting plate of the nuclear fuel assembly, which can match the strength and force magnitude of different areas of the upper tube seat connecting plate of the nuclear fuel assembly, 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 structure upper pipe seat support structure provided by the present invention comprises a connecting plate body, wherein the connecting plate body comprises a middle body, a plurality of corner bodies and a plurality of side bodies, wherein the middle body is located in the middle region of the connecting plate body and is subjected to the lowest stress, and the middle body is provided with a plurality of first water holes, each corner body is connected to the corresponding corner of the middle body and is subjected to medium stress, and the corner body is provided with a plurality of second water holes, each side body is located between two corresponding adjacent corner bodies, the side body is connected to the corresponding corner body and the corresponding side of the middle body and is subjected to the maximum stress, and the side body is provided with a plurality of third water holes, wherein the distribution density of the plurality of second water holes in the corner body is greater than the distribution density of the plurality of first water holes in the middle body and is less than The distribution density of the multiple third water-through holes in the side structure is the largest number of ribs defined in the side structure, so that the strength of the side structure is relatively the highest, matching the maximum force it is subjected to; the distribution density of the multiple first water-through holes in the middle structure is the smallest, so the number of ribs defined in the middle structure is the smallest, so that the strength of the middle structure is relatively the lowest, matching the smaller force it is subjected to; the distribution density of the multiple second water-through holes in the corner structure is moderate, so the number of ribs defined in the corner structure is moderate, so that the strength of the corner structure is relatively moderate, matching the medium force it is subjected to; thereby, the strength of each part of the structure of the connecting plate body matches the magnitude of the force it is subjected to, so as to improve the reliability of the connecting plate, thereby improving the safety of the nuclear fuel assembly.

[0023] 2. The upper tube socket of the nuclear fuel assembly provided by the present invention includes the above-mentioned upper tube socket connecting plate of the nuclear fuel assembly, which can match the strength and force magnitude of different areas of the upper tube socket connecting plate of the nuclear fuel assembly, thereby improving the safety of the nuclear fuel assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can also be obtained based on these drawings without creative work.

[0025] In the attached picture:

[0026] Figure 1 A schematic diagram of the stress partition structure of the upper tube socket connecting plate of a nuclear fuel assembly provided by an embodiment of the present invention;

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

[0028] Figure 3 A schematic cross-sectional structure diagram of an upper tube socket of a nuclear fuel assembly provided in an embodiment of the present invention.

[0029] Reference numerals and corresponding component names in the accompanying drawings:

[0030] 10-upper tube seat body; 11-top plate; 12-enclosing plate; 100-connecting plate body; 110-connecting plate body; 111-middle structure; 112-corner structure; 113-side structure; 114-first water hole; 115-second water hole; 116-third water hole; 117-instrument tube hole; 118-first guide tube hole; 119-second guide tube hole. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0033] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0034] In the description of the embodiments of the present application, the indicated orientation or position relationship is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the application is conventionally placed when in use, or is the orientation or position relationship conventionally understood by those skilled in the art. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0035] In the description of this application, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] Furthermore, the terms “first”, “second”, “third”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0037] It should be noted that a nuclear fuel assembly refers to a whole group of fuel elements assembled together, which is composed of several fuel elements, connection assemblies, upper tube seats, upper tube seats, control rod guide tubes and positioning grids. The upper tube seat is composed of a connection plate, a shroud and a top plate. In actual applications, different areas of the connection plate are subjected to different forces. If the distribution density of the water holes on the connection plate is the same, there is a mismatch between the strength and force of different areas of the connection plate, resulting in a reduction in the reliability of the connection plate, thereby reducing the safety of the nuclear fuel assembly.

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

[0039] Example 1

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

[0041] In this embodiment, the inventors conducted a static simulation analysis on the connecting plate body 110 without a water flow hole. Based on the simulation results, the connecting plate body 110 is divided into a middle body 111, a corner body 112 and a side body 113 from low to high according to the magnitude of the force in each area of ​​the connecting body. The middle body 111 is the area on the connecting plate body 110 with the least force, the side body 113 is the area on the connecting plate body 110 with the greatest force, and the corner body 112 is the area with the force magnitude in the middle.

[0042] After the middle body 111, the corner body 112 and the side body 113 are divided on the connecting plate body 110, a plurality of first water passing holes 114 are opened in the middle body 111, a plurality of second water passing holes 115 are arranged in the corner body 112, and a plurality of third water passing holes 116 are arranged in the side body 113. It is ensured that the distribution density of the plurality of first water passing holes 114 in the middle body 111 is the smallest, the distribution density of the plurality of third water passing holes 116 in the side body 113 is the largest, and the distribution density of the plurality of second water passing holes 115 in the corner body 112 is in the middle.

[0043] Since the distribution density of the plurality of third water holes 116 in the side body 113 is the largest, the largest number of ribs are defined in the side body 113, so that the strength of the side body 113 is relatively the highest, matching the greater force applied to it. Since the distribution density of the plurality of first water holes 114 in the middle body 111 is the smallest, the smallest number of ribs are defined in the middle body 111, so that the strength of the middle body 111 is relatively the lowest, matching the smaller force applied to the middle body 111.

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

[0045] Moreover, the first water-passing hole 114 has the largest cross-sectional area, the ribs defined in the middle body 111 are the longest, the spacing between the ribs is the largest, and the strength is relatively the lowest. The third water-passing hole 116 has the smallest cross-sectional area, the ribs defined in the side body 113 are the smallest, the spacing between the ribs is the smallest, and the strength is relatively the highest.

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

[0047] At the same time, the cross-sections of the first water hole 114, the second water hole 115 and the third water hole 116 are all polygonal, and can be reasonably arranged on the connecting plate body 110 to maximize the use of the area of ​​the connecting plate body 110. In addition, the polygonal cross-section can better block the fuel rods with circular radial cross-sections, thereby preventing the fuel rods from detaching from the grid and popping out of the corresponding water holes under the impact of high-speed water flow.

[0048] In addition, the plurality of ribs defined by the plurality of first water holes 114, the plurality of second water holes 115 and the plurality of third water holes 116 on the connecting plate body 110 are connected to each other, thereby realizing the longitudinal sealing of the plurality of fuel rods below the connecting plate body 100 and preventing the fuel rods from popping up.

[0049] It can be understood that the connecting plate body 110 is rectangular, the middle body 111 is arranged at the center of the connecting plate body 110, the side body 113 is arranged around the periphery of the middle body 111, and the four corner bodies 112 are respectively arranged at the four vertex positions of the connecting plate body 110. The cross-sectional area and distribution density of the second water holes 115 are between the third water holes 116 and the first water holes 114, and are distributed at the four vertex positions of the connecting plate body 110, ensuring that the remaining plate material of the connecting plate body 110 has good connectivity.

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

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

[0052] Combine again Figure 2 The middle body 111 is also provided with a plurality of first guide pipe holes 118, which are sequentially distributed circumferentially around the periphery of the middle body 111. The periphery of the plurality of first guide pipe holes 118 is respectively circumferentially distributed with a plurality of first water holes 114 and a plurality of third water holes 116.

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

[0054] Correspondingly, a plurality of second guide pipe holes 119 are provided through the side body 113 , and a plurality of third water holes 116 are circumferentially distributed around the periphery of the plurality of second guide pipe holes 119 . 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, the number of second wire tubes is sixteen, and the sixteen second guide tube holes 119 form a closed loop trajectory surrounding the eight first guide tube holes 118. It can be understood that two adjacent second guide tube holes 119 in the circumferential direction of the sixteen second guide tube holes 119 are connected by ribs surrounded by the third water holes 116, that is, along the arrangement trajectory of the sixteen second guide tube holes 119, multiple ribs are connected to each other to form a closed loop trajectory, which can further improve the strength of the connecting plate body 110.

[0056] Similarly, every two circumferentially adjacent first guide tube holes 118 are connected by ribs defined by the first water holes 114 , that is, along the arrangement trajectory of the eight first guide tube holes 118 , a plurality of ribs are interconnected to form a closed loop trajectory, which can also further enhance the strength of the connecting plate body 110 .

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

[0058] In fact, in this embodiment, the first guide tube hole 118 and the second guide tube hole 119 are both stepped holes, that is, one end has a larger hole diameter and the other end has a smaller hole diameter, and a step surface is formed inside. The larger hole diameter portion is used to place a quick detachable connection structure to establish a connection between the guide tube and the guide tube hole, and the smaller hole diameter portion is used to allow the guide tube to pass through when disassembling the upper tube seat and to achieve positioning of the upper tube seat.

[0059] Combination Figure 2In this embodiment, the first water hole 114 is roughly triangular. In order to reduce local stress, two vertex positions of the triangle are solidly filled, and the remaining vertex position is rounded. Eight first water holes 114 are arranged in sequence in the circumferential direction of the instrument tube hole 117, and the eight first water holes 114 define eight ribs in sequence.

[0060] Thus, it is equivalent to that eight ribs are uniformly diverged outward with the instrument tube hole 117 as the center, that is, the eight ribs play a role of uniform axial support for the instrument tube hole 117, so that the structural strength of the instrument tube hole 117 is improved. One end of each of the eight ribs defined by the eight first water holes 114 is connected to the area where the instrument tube hole 117 is opened, and the other end of each of the eight ribs is connected to a first guide tube hole 118.

[0061] In addition, a plurality of first water holes 114 and a plurality of third water holes 116 are distributed around the periphery of any first guide pipe hole 118 . The plurality of ribs defined by the plurality of first water holes 114 and the plurality of third water holes 116 provide annular support for the first guide pipe hole 118 , thereby improving the structural strength of the first guide pipe hole 118 .

[0062] The eight first guide tube holes 118 in the middle body 111 are distributed in a rectangular track, wherein four first guide tube holes 118 are located at the four vertices of the rectangular track, and the remaining four first guide tube holes 118 are located on the four sides of the rectangular track.

[0063] In this embodiment, four first water holes 114 and four third water holes 116 are distributed around the first guide tube hole 118 at the top corner, defining eight ribs. Six first water holes 114 and two third water holes 116 are distributed around the first guide tube hole 118 at the four sides.

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

[0065] For any second guide pipe hole 119 in the side body 113, a plurality of third water holes 116 are distributed around the periphery thereof. The plurality of third water holes 116 define a plurality of shorter ribs. The plurality of short ribs have higher strength and provide stronger support for the second guide pipe hole 119, thereby matching the greater impact force on the side body 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 regions, so that the strength of different regions matches the stress magnitude, thereby ensuring that the side structures 113 subjected to greater stress have sufficient strength, and ensuring that the middle structures 111 subjected to less stress have sufficient water flow, thereby improving safety.

[0067] Compared with the prior art, the connection plate of the upper tube socket of the nuclear fuel assembly provided in this embodiment divides the connection plate body 110 into a middle body 111, a corner body 112 and a side body 113 from low to high according to the magnitude of the force applied to each area of ​​the connection body, and the force applied to the corner body 112 is greater than that applied to the middle body 111 and less than that applied to the side body 113. The distribution density of the plurality of first water holes 114 distributed in the middle body 111 is less than that of the plurality of second water holes 115 distributed in the corner body 112, and the distribution density of the plurality of third water holes 116 distributed in the side body 113 is greater than that of the plurality of second water holes 115 distributed in the corner body 112. The greater the distribution density of the water holes in the area, the more ribs will be defined on the connecting plate body 110, so that the strength of the area is higher, that is, the side body 113 with the greatest force has the greatest strength, and the middle body 111 with the least force has the least strength.

[0068] Therefore, the nuclear fuel assembly upper tube socket connection plate provided in this embodiment can ensure that the strength and force magnitude of different regions match each other, thereby improving safety.

[0069] Example 2

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

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

[0072] Generally, the top plate 11 is welded to the shroud 12, and the shroud 12 is welded to the connecting plate body 100. Four leaf springs are connected above the top plate 11 by bolts, and the four leaf springs abut against the upper core to achieve elastic fixation of the fuel assembly.

[0073] That is, in this embodiment, the connection plate body 100, the top plate 11 and the enclosure plate 12 described in Embodiment 1 form an upper tube seat body 10, and in actual application, the upper tube seat body 10, together with the lower tube seat, the guide tube, the instrument tube, the fuel rod and the grid, form a nuclear fuel assembly. The upper end and the lower end of the guide tube are connected to the upper tube seat body 10 and the lower tube seat respectively, the fuel rod is arranged on the grid, and the grid is connected to the guide tube.

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

[0075] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method 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 in the scope of protection of the present invention.

Claims

1. A nuclear fuel assembly upper tube socket connection plate, characterized in that: The invention comprises a connecting plate body (110), wherein the connecting plate body (110) comprises: A middle body (111), the middle body (111) being located in a middle region of the connecting plate body (110), and the middle body (111) being provided with a plurality of first water holes (114); A plurality of corner structures (112), each of the corner structures (112) being connected to a corresponding corner of the middle structure (111), and a plurality of second water holes (115) being provided through the corner structures (112); A plurality of side structures (113), each of the side structures (113) being located between two corresponding adjacent corner structures (112), the side structures (113) being connected to the corresponding corner structures (112) and the corresponding side of the middle structure (111), and the side structures (113) being provided with a plurality of third water holes (116) running through them; The distribution density of the plurality of second water passage holes (115) in the corner body (112) is greater than the distribution density of the plurality of first water passage holes (114) in the middle body (111), and is less than the distribution density of the plurality of third water passage holes (116) in the side body (113).

2. The nuclear fuel assembly upper tube socket connection plate according to claim 1, characterized in that: The cross-sectional areas of the first water passage hole (114), the second water passage hole (115) and the third water passage hole (116) decrease in sequence.

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

4. The nuclear fuel assembly upper tube socket connection plate according to claim 1, characterized in that: The connecting plate body (110) is rectangular, the middle body (111) is arranged at the center of the connecting plate body (110), the side body (113) is arranged around the periphery of the middle body (111), and the four corner bodies (112) are respectively arranged at the four vertex positions of the connecting plate body (110).

5. The nuclear fuel assembly upper tube socket connection plate according to claim 1, characterized in that: An instrument pipe hole (117) is provided through the center of the middle structure (111), and a plurality of the first water holes (114) are sequentially distributed around the periphery of the instrument pipe hole (117).

6. The nuclear fuel assembly upper tube socket connection plate according to claim 1, characterized in that: The middle body (111) is penetrated by a plurality of first guide tube holes (118), and the plurality of first guide tube holes (118) are sequentially distributed circumferentially around the periphery of the middle body (111).

7. The nuclear fuel assembly upper tube socket connection plate according to claim 6, characterized in that: A plurality of first water passing holes (114) and a plurality of second water passing holes (115) are respectively distributed circumferentially around the periphery of the plurality of first guide pipe holes (118).

8. The nuclear fuel assembly upper tube socket connection plate according to claim 6, characterized in that: The side body (113) is penetrated by a plurality of second guide tube holes (119), and the arrangement tracks of the plurality of second guide tube holes (119) surround the plurality of first guide tube holes (118).

9. The nuclear fuel assembly upper tube socket connection plate according to claim 8, characterized in that: A plurality of second water holes (115) are respectively distributed circumferentially around the periphery of the plurality of second guide pipe holes (119).

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

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