Guide pipe, guide pipe assembly and pressurized water reactor fuel assembly

Abstract

The utility model belongs to the technical field of fuel elements for nuclear reactors, and discloses a guide pipe, a guide pipe assembly and a pressurized water reactor fuel assembly. The guide pipe comprises a pipe body and two water hole assemblies, the pipe body is oppositely provided with a first end and a second end in the axial direction of the pipe body, the two water hole assemblies are arranged at the position, close to the first end, of the pipe body and the position, close to the second end, of the pipe body respectively, and the two water hole assemblies are symmetrically arranged in the radial direction of the center of the pipe body; the water hole assemblies are arranged at the two ends of the pipe body in the axial direction of the pipe body and used for discharging water flow during rod falling, that is, the pipe body has a mistake-proof function, so that when the guide pipe is installed, whether the guide pipe and the end plug are installed reversely or not does not need to be considered, the problems that the guide pipe assembly, a framework and a pressurized water reactor fuel assembly are scrapped and the like are avoided, and the production efficiency is improved. The installation reliability of the guide pipe is improved, and the safety of the pressurized water reactor fuel assembly loaded with the guide pipe is further improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to nuclear reactor fuel element technical field especially relates to a guide tube, guide tube subassembly and pressurized water reactor fuel assembly. BACKGROUND

[0002] The pressurized water reactor fuel assembly is composed of fuel rods and a skeleton, and the skeleton includes a grid, a guide tube subassembly, an instrument tube and a tube base. The guide tube subassembly is composed of a guide tube and a guide tube end plug, and the guide tube end plug is welded to the lower end of the guide tube. A water flow hole is arranged near the lower end of the guide tube to provide a drainage passage for the control rod assembly to drop the rods quickly when an emergency shutdown or other emergency situations occur.

[0003] However, when the guide tube end plug is welded to the guide tube, the position of the lower end of the guide tube needs to be determined first, and the end with the water flow hole is inserted into the guide tube end plug and welded. However, due to human carelessness, the position of the end with the water flow hole of the guide tube on the production line may be placed incorrectly, which causes the installation direction of the guide tube and its guide tube end plug to be opposite, resulting in the guide tube subassembly being scrapped. Moreover, if it is not discovered in time, the guide tube subassembly is made into a skeleton and a fuel assembly, which will further cause the skeleton and the fuel assembly to be scrapped; even worse, the fuel assembly assembled with the guide tube and its end plug in reverse is installed in the reactor, and when an emergency shutdown or other emergency situations occur, the control rod assembly cannot drop the rods within the specified time due to the incorrect position of the water flow hole, which affects the normal shutdown of the nuclear power plant unit and poses a risk of safety hazards.

[0004] Therefore, there is an urgent need for a guide tube, a guide tube subassembly and a pressurized water reactor fuel assembly to solve the above technical problems. UTILITY MODEL CONTENTS

[0005] One purpose of the utility model is to provide a guide tube that can be symmetrically provided with water flow holes at both ends of the guide tube to avoid the problem of being installed in reverse and improve the reliability of the installation of the guide tube.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] The guide tube includes a tube body and two water hole assemblies. The tube body has a first end and a second end along its own axial direction. The two water hole assemblies are arranged near the first end and the second end of the tube body, respectively, and are radially symmetrically arranged along the center of the tube body.

[0008] Optionally, the pipe body comprises a first section pipe, an intermediate section pipe and a second section pipe connected in sequence, the first section pipe and the second section pipe are symmetrically arranged along the intermediate section pipe, and the two water hole assemblies are respectively arranged on the first section pipe and the second section pipe and symmetrically arranged along the intermediate section pipe.

[0009] Optionally, the water hole assembly comprises:

[0010] Two first water flow holes, the two first water flow holes are symmetrically arranged on the outer peripheral wall of the pipe body respectively;

[0011] Two second water flow holes, the two second water flow holes are symmetrically arranged on the outer peripheral wall of the pipe body respectively and are arranged at intervals with the two first water flow holes.

[0012] Optionally, in the same water hole assembly, the distance between the first water flow hole and any end of the pipe body along the axial direction thereof is different from the distance between the second water flow hole and the same end of the pipe body along the axial direction thereof.

[0013] Optionally, in the same water hole assembly, the connecting axes between the two first water flow holes and the connecting axes between the two second water flow holes are arranged perpendicularly.

[0014] Optionally, the pipe body is made of a zirconium alloy material.

[0015] Optionally, the pipe body comprises an inner pipe and an outer pipe, and the outer pipe is sleeved on the outer periphery of the inner pipe.

[0016] Another purpose of the utility model is to provide a guide pipe assembly, which is provided with water flow holes symmetrically at both end portions of the guide pipe to avoid the problem of incorrect installation and improve the reliability of installation of the guide pipe assembly.

[0017] To achieve the purpose, the utility model adopts the following technical scheme:

[0018] The guide pipe assembly comprises an end plug and the guide pipe according to any one of the preceding schemes, and the end plug is arranged at the first end portion of the guide pipe or the second end portion of the guide pipe.

[0019] Optionally, the end plug and the guide pipe are connected by welding.

[0020] Another purpose of the utility model is to provide a pressurized water reactor fuel assembly comprising the guide pipe assembly according to any one of the preceding schemes, which is provided with water flow holes symmetrically at both end portions of the guide pipe to avoid the problem of incorrect installation and improve the safety of the pressurized water reactor fuel assembly during control rod drop time of a nuclear power plant.

[0021] The utility model has the advantages of:

[0022] The utility model provides a kind of guide tube, guide tube assembly and pressurized water reactor fuel assembly, by being provided with water hole assembly in the first end portion and the second end portion being relatively arranged along self axial direction in tubular body, and make two water hole assemblies be arranged along the center radial symmetry of tubular body, so that the both ends of the tubular body along self axial direction are provided with water hole assembly to be used for the discharge of water flow when fuel rod drops, i.e. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the axial drawing of guide tube provided by the utility model specific embodiment.

[0024] In the drawing:

[0025] 10, tubular body;101, first end portion;102, second end portion;11, first section pipe;12, intermediate section pipe;13, second section pipe;

[0026] 20, water hole assembly;21, first water hole;22, second water hole. DETAILED DESCRIPTION

[0027] The utility model will be further described in detail in combination with the drawings and examples.It can be understood that the specific examples described here are only used to explain the utility model, and not limit the utility model.In addition, it needs to be explained that, for the convenience of description, only part of the structure related to the utility model is shown in the drawing, not all structures.

[0028] In the description of the utility model, unless there is explicit definition and limitation, the terms "connection", "connect", "fix" should be understood broadly, for example, it can be fixed connection, can be detachable connection, or integral;It can be directly connected, or indirectly connected through intermediate medium, it can be the communication or mutual action relationship of two elements inside two elements.For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to specific circumstances.

[0029] In the utility model, unless another definite provision and limitation, first feature is "on" or "under" second feature can include that first and second features are in direct contact, also can include that first and second features are not in direct contact but contact through other features between them. Moreover, first feature "on", "above" and "upper surface of" second feature includes that first feature is directly above and obliquely above second feature, or only indicates that horizontal height of first feature is higher than second feature. First feature "under", "below" and "under surface of" second feature includes that first feature is directly below and obliquely below second feature, or only indicates that horizontal height of first feature is less than second feature.

[0030] In the description of the embodiment, the terms "upper", "lower", "left", "right", and the like orientation or position relationship are based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second" are only used to distinguish in description, and have no special meaning.

[0031] Reference will be made to the drawings below Figure 1 The utility model provides a guide pipe, guide pipe subassembly and pressurized water reactor fuel assembly.

[0032] Please refer to Figure 1 The utility model provides a guide pipe, guide pipe subassembly and pressurized water reactor fuel assembly.

[0033] The guide pipe in the embodiment, through setting water hole subassembly 20 at the position close to first end portion 101 and second end portion 102 who are oppositely arranged along the self axial direction of pipe body 10, and making two water hole subassembly 20 along the center radial symmetry of pipe body 10, make the both ends of pipe body 10 along the self axial direction have water hole subassembly 20 for the discharge of water flow when fuel rod falls, that is, it has the error proof function, so that when installing guide pipe, it is not necessary to consider whether guide pipe and end plug are installed reversely, and further avoid the problems such as guide pipe subassembly, framework, pressurized water reactor fuel assembly scrap, improve the installation reliability of the guide pipe, and further improve the safety of the pressurized water reactor fuel assembly loaded with the guide pipe.

[0034] Specifically, the pipe body 10 comprises a first section pipe 11, an intermediate section pipe 12 and a second section pipe 13 connected in sequence, the first section pipe 11 and the second section pipe 13 are symmetrically arranged along the intermediate section pipe 12, and two water hole assemblies 20 are respectively arranged on the first section pipe 11 and the second section pipe 13 and symmetrically arranged along the intermediate section pipe 12. That is, the pipe body 10 is manufactured into an axisymmetric structure, so that the guide pipe has the water hole assembly 20 meeting the design requirements for effective drainage whether the first end portion 101 or the second end portion 102 serves as the bottom, thereby improving the installation reliability of the guide pipe.

[0035] More specifically, the pipe body 10 comprises an inner pipe and an outer pipe, the outer pipe is sleeved on the outer periphery of the inner pipe. The inner pipe is used for guiding the movement of the fuel rod, and the outer pipe is used for supporting and protecting the inner pipe from the external environment.

[0036] Please continue to refer to Figure 1 Further, the water hole assembly 20 comprises two first water holes 21 and two second water holes 22, the two first water holes 21 are symmetrically arranged on the outer peripheral wall of the pipe body 10 respectively; the two second water holes 22 are symmetrically arranged on the outer peripheral wall of the pipe body 10 respectively and are arranged at intervals with the two first water holes 21. The arrangement of multiple water holes improves the drainage effect of the guide pipe when the rod drops, avoiding the problem that water cannot be drained, causing safety hazards of the nuclear power plant unit.

[0037] Optionally, in the same water hole assembly 20, the distance between the first water hole 21 and any end of the pipe body 10 along the axial direction thereof is different from the distance between the second water hole 22 and the same end of the pipe body 10 along the axial direction thereof. Such arrangement allows the water holes to be distributed at different heights, thereby ensuring the drainage effect of the guide pipe when the rod drops.

[0038] Optionally, in the same water hole assembly 20, the connecting axes between the two first water holes 21 and the connecting axes between the two second water holes 22 are arranged perpendicularly, that is, the positions of the first water holes 21 and the second water holes 22 are distinguished, and the four water holes are arranged uniformly along the circumferential direction of the pipe body 10, which is more convenient for water to flow out uniformly from each water hole.

[0039] Further, the pipe body 10 is made of zirconium alloy material. Zirconium has very low thermal neutron absorption cross section, high hardness, ductility and corrosion resistance, zirconium alloy has good corrosion resistance in high temperature and high pressure water and steam, moderate mechanical properties, low atomic thermal neutron absorption cross section, good compatibility with nuclear fuel, and can be used as the core structure material of nuclear reactor, which is beneficial to the high burnup operation of the pressurized water reactor fuel assembly.

[0040] The embodiment also provides a guide tube assembly, which comprises an end plug and the guide tube according to any one of the above solutions, and the end plug is arranged at the first end 101 of the guide tube or the second end 102 of the guide tube. By using the guide tube, the two ends of the guide tube can be fixedly connected with the end plug, and the problem of reverse assembly in the production and assembly is not needed to be considered, and the mistake-proof effect and reliability in the assembly process of the guide tube assembly are improved.

[0041] Specifically, the end plug comprises an inner pipe plug and an outer pipe plug connected to each other, so as to seal the inner pipe and the outer pipe of the guide tube.

[0042] Optionally, the end plug and the guide tube are welded to be connected, so as to realize the fixed connection of the two.

[0043] The embodiment also provides a pressurized water reactor fuel assembly, which comprises the guide tube assembly according to any one of the above solutions, and by using the guide tube, the safety problem of the pressurized water reactor fuel assembly caused by the reverse assembly of the guide tube and the drainage failure is avoided, and the safety of the pressurized water reactor fuel assembly is improved.

[0044] It should be noted that the pressurized water reactor fuel assembly comprises fuel rods and a skeleton, wherein the skeleton comprises a grid, the guide tube assembly, an instrument tube and a tube seat, which are all conventional settings in the field, and will not be described here.

[0045] Obviously, the above embodiment of the utility model is only for clear illustration of the utility model, and is not a limitation on the implementation mode of the utility model. For ordinary skilled persons in the field, various obvious changes, re-adjustment and replacement can be made without departing from the protection scope of the utility model. Here, it is not necessary and impossible to enumerate all the implementation modes. Any modification, equivalent replacement and improvement made within the spirit and principle of the utility model should be included in the protection scope of the utility model claim.

Claims

1. A guide tube characterized by, The pipe body (10) comprises a first end (101) and a second end (102) arranged opposite along the axial direction of the pipe body (10), and two water hole assemblies (20) are arranged on the pipe body (10) near the first end (101) and the second end (102) respectively, and the two water hole assemblies (20) are symmetrically arranged along the central direction of the pipe body (10).

2. The guide tube of claim 1, wherein, The pipe body (10) comprises a first pipe segment (11), an intermediate pipe segment (12) and a second pipe segment (13) connected in sequence, the first pipe segment (11) and the second pipe segment (13) are symmetrically arranged along the intermediate pipe segment (12), and the two water hole assemblies (20) are arranged on the first pipe segment (11) and the second pipe segment (13) respectively and symmetrically along the intermediate pipe segment (12).

3. The guide tube of claim 1, wherein, The water hole assembly (20) comprises: Two first water flow holes (21) symmetrically arranged on the outer circumferential wall of the pipe body (10); Two second water flow holes (22) symmetrically arranged on the outer circumferential wall of the pipe body (10) and spaced apart from the two first water flow holes (21).

4. The guide tube of claim 3, wherein, In the same water hole assembly (20), the distance between the first water flow hole (21) and any end of the pipe body (10) along the axial direction of the pipe body (10) is different from the distance between the second water flow hole (22) and the same end of the pipe body (10) along the axial direction of the pipe body (10).

5. The guide tube of claim 3, wherein, In the same water hole assembly (20), the connecting axis between the two first water flow holes (21) is arranged perpendicularly to the connecting axis between the two second water flow holes (22).

6. The guide tube of claim 1, wherein, The pipe body (10) is made of zirconium alloy material.

7. The guide tube of any one of claims 1-6, wherein, The pipe body (10) comprises an inner pipe and an outer pipe, and the outer pipe is sleeved on the outer periphery of the inner pipe.

8. A guide tube assembly characterized by, The guide pipe assembly comprises an end plug and a guide pipe as claimed in any one of claims 1-7, and the end plug is arranged on the first end (101) of the guide pipe or the second end (102) of the guide pipe.

9. The guide tube assembly of claim 8, wherein, The end plug and the guide pipe are welded together.

10. A pressurized water reactor fuel assembly characterized by, The guide pipe assembly comprises an end plug and a guide pipe as claimed in any one of claims 1-7, and the end plug is arranged on the first end (101) of the guide pipe or the second end (102) of the guide pipe. The end plug and the guide pipe are welded together. The guide pipe assembly comprises an end plug and a guide pipe as claimed in any one of claims 1-7, and the end plug is arranged on the first end (101) of the guide pipe or the second end (102) of the guide pipe. The end plug and the guide pipe are welded together. The guide pipe assembly comprises an end plug and a guide pipe as claimed in any one of claims 1-7, and the end plug is arranged on the first end (101) of the guide pipe or the second end (102) of the guide pipe. The end plug and the guide pipe are welded together.

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