Nuclear primary pump main bolt tensioner installation device and method

Abstract

The application provides a nuclear main pump main bolt tensioner mounting device and method, the mounting device comprises a guide stud, an elastic support mechanism and a support nut, one end of the guide stud is provided in a tensioner cylinder and is threadedly connected with a center hole provided on the main bolt; the elastic support mechanism is sleeved outside the guide stud and is located at the bottom of the tensioner cylinder and connected with the tensioner cylinder; the support nut is sleeved on the guide stud and abuts against the elastic support mechanism at one end, and the support nut is located on the side of the elastic support mechanism away from the main bolt; wherein the support nut follows the movement of the tensioner cylinder along the guide stud. The above-mentioned nuclear main pump main bolt tensioner mounting device uses the center hole thread of the main bolt as a device mounting interface, does not need to additionally increase an interface, the size of the mounting device is very small, and therefore the installation process does not affect the accessories around the main pump.

Description

Technical Field

[0001] This invention relates to the field of nuclear main pump tensioning technology, specifically to a nuclear main pump main bolt tensioner installation device and method. Background Technology

[0002] In passive nuclear power plants, the main pump is one of the key pieces of equipment in the primary coolant system. The main pump core is a removable core structure and is connected to the pump casing by main bolts.

[0003] Because the main bolt requires a large preload, conventional methods cannot meet the preload requirements, and a bolt tensioner is needed to apply the preload.

[0004] In some different types of main pumps, such as the AP1000 / CAP1400 main pump, the installation method is inverted, and the main nut must be installed from bottom to top. However, a single bolt tensioner is quite heavy, and the pump casing above it obstructs the view, making it inconvenient to install with conventional bolt tensioners. Moreover, conventional bolt tensioners occupy a large area and cannot meet the requirement of applying preload to the main bolts after the entire AP1000 / CAP1400 nuclear main pump and its accessories are installed.

[0005] Based on this, the inventors of this application propose a device and method for installing a main bolt tensioner for a nuclear main pump, in order to solve the above-mentioned technical problems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the inconvenience of bolt tensioner installation in the prior art, and to provide a device and method for installing the main bolt tensioner of a nuclear main pump.

[0007] The present invention solves the above-mentioned technical problems through the following technical solution:

[0008] This invention provides a mounting device for the main bolt tensioner of a nuclear main pump, characterized in that it includes:

[0009] The guide stud has one end inserted into the tensioner cylinder and threadedly connected to the center hole on the main bolt.

[0010] An elastic support mechanism is sleeved on the outside of the guide stud and located at the bottom of the tensioner cylinder and connected to the tensioner cylinder;

[0011] A support nut is fitted onto the guide stud, with one end abutting against the elastic support mechanism. The support nut is located on the side of the elastic support mechanism away from the main bolt.

[0012] The support nut moves along the guide stud as the tensioner cylinder moves.

[0013] According to one embodiment of the present invention, the elastic support mechanism includes a first spring support seat and a second spring support seat stacked together, wherein the first spring support seat and the second spring support seat are elastically connected by at least one elastic element.

[0014] According to one embodiment of the present invention, an installation gap is formed in the middle of the first spring support and the second spring support, and a bearing is sleeved in the installation gap;

[0015] The guide stud passes through the inner ring of the bearing, and the first spring support and the second spring support are connected to the outer ring of the bearing.

[0016] According to one embodiment of the present invention, the first spring support and the second spring support are mounted to the tensioner cylinder by at least two threaded connections.

[0017] According to one embodiment of the present invention, the first spring support and the second spring support cooperate to form a snap-fit ​​chamber for snapping the elastic element. A connecting stud is provided inside the elastic element. One end of the connecting stud is fixedly connected to the second spring support, and the other end passes through to the first spring support and is movably engaged with the first spring support.

[0018] According to one embodiment of the present invention, the elastic element is a spring, and the number of elastic elements is multiple;

[0019] The multiple springs are arranged at even intervals around the outer circumference of the elastic support mechanism.

[0020] According to one embodiment of the present invention, the first spring support is disposed on the side close to the tensioner cylinder;

[0021] The second spring support seat has a bearing support plate on the side opposite to the first spring support seat, and one end of the support nut abuts against the bearing support plate.

[0022] According to one embodiment of the present invention, the circumferential dimension of the bearing support plate is larger than the circumferential dimension of the bearing.

[0023] This invention also provides a method for installing a main bolt tensioner for a nuclear main pump, which is implemented using the nuclear main pump main bolt tensioner installation device described above. The installation method includes:

[0024] Step 1: Place the elastic support mechanism and the tensioner cylinder sleeve on the outside of the guide stud, and connect the elastic support mechanism to the tensioner cylinder;

[0025] Step 2: Install a support nut on the outside of the guide stud and screw the support nut in so that the elastic support mechanism is in an elastic compression state;

[0026] Step 3: Move the tensioner cylinder below the main bolt and connect the guide stud to the main bolt;

[0027] Step 4: By rotating the tensioner cylinder and simultaneously rotating the support nut, the tensioner cylinder is connected upward to the main bolt.

[0028] According to one embodiment of the present invention, the elastic force of the elastic support mechanism is consistent with the gravity of the tensioner cylinder.

[0029] The positive and progressive effects of this invention are as follows:

[0030] The present invention relates to a main bolt tensioner installation device for a nuclear main pump. It utilizes the threaded center hole of the main bolt as the installation interface, eliminating the need for additional interfaces. The installation device is very small in size, so the installation process will not affect the surrounding accessories of the main pump.

[0031] An elastic support mechanism is used to support the tensioner cylinder, providing a continuous upward thrust during the installation process. This eliminates the need for the main bolt threads to bear the weight of the tensioner, thus avoiding thread damage. Attached Figure Description

[0032] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0033] Figure 1 This is a schematic diagram of the installation state of the main bolt tensioner installation device for the nuclear main pump of the present invention;

[0034] Figure 2 for Figure 1 Schematic diagram of the mating structure between the guide stud and the main bolt;

[0035] Figure 3 for Figure 1 Schematic diagram of the connection structure between the elastic support mechanism and the tensioner cylinder;

[0036] Figure 4 for Figure 1 Schematic diagram of the flexible support mechanism;

[0037] Figure 5 This is a flowchart of the installation method for the main bolt tensioner of the nuclear main pump according to the present invention.

[0038] 1. Guide stud;

[0039] 2. Tensioner cylinder;

[0040] 3. Main bolts;

[0041] 4. Elastic support mechanism; 41. First spring support seat; 42. Second spring support seat; 421. Bearing support plate; 43. Elastic element; 44. Installation gap; 45. Bearing; 46. Threaded connector; 47. Snap-fit ​​chamber; 48. Connecting stud;

[0042] 5. Support nut. Detailed Implementation

[0043] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0045] Please refer to Figures 1 to 4 This invention proposes a main bolt tensioner installation device for a nuclear main pump, comprising a guide stud 1, an elastic support mechanism 4, and a support nut 5. One end of the guide stud 1 passes through the tensioner cylinder 2 and is threadedly connected to the center hole on the main bolt 3. The elastic support mechanism 4 is sleeved on the outside of the guide stud 1 and located at the bottom of the tensioner cylinder 2 and connected to the tensioner cylinder 2. The support nut 5 is sleeved on the guide stud 1, and one end abuts against the elastic support mechanism 4. The support nut 5 is located on the side of the elastic support mechanism 4 away from the main bolt 3. The support nut 5 moves with the tensioner cylinder 2 along the guide stud 1.

[0046] During actual installation, the tensioner cylinder 2 needs to be screwed onto the main bolt 3 from bottom to top. The tensioner cylinder 2 has internal threads, and the main bolt 3 has external threads on the outside that can mate with the internal threads on the outside of the tensioner cylinder 2. During the screwing process, the tensioner cylinder 2 needs to maintain a high degree of verticality. Otherwise, the tensioner cylinder 2 cannot be screwed into the main bolt 3 smoothly, and the threads of the main bolt 3 and the tensioner cylinder 2 may be damaged, thus hindering the installation of the tensioner cylinder 2.

[0047] It is known that the tensioner cylinder 2 is part of the tensioner and is mainly used to be sleeved on the outside of the main bolt 3. In the actual installation process, because the tensioner cylinder 2 needs to overcome its own weight and provide its own rotational force when screwed in, it may be difficult to screw it in upwards due to insufficient force to overcome its own weight; or, due to insufficient rotational force, it may be impossible to screw it in upwards smoothly.

[0048] That is, while the tensioner cylinder 2 needs to move upward, it also needs to rotate synchronously, which causes great trouble to the synchronization of applying rotational force and overcoming gravity.

[0049] Based on this, the present invention utilizes a guide stud 1 to connect with the main bolt 3, and provides an elastic support mechanism 4 and a support nut 5 on the guide stud 1. The elastic support mechanism 4 provides support force for the tensioner cylinder 2 to overcome the upward gravity of the tensioner cylinder 2; simultaneously, the support nut 5 supports the elastic support mechanism 4 and the tensioner cylinder 2 with the help of the main bolt 3, and moves in tandem with the tensioner cylinder 2 during its upward movement. This makes it easier for the tensioner cylinder 2 to move upward and engage with the main bolt 3.

[0050] That is, under the action of the guide stud 1, the elastic support mechanism 4 provides an upward elastic thrust during the upward movement of the tensioner cylinder 2, without the main bolt 3 thread bearing the weight of the tensioner cylinder 2, thereby avoiding damage to the threads between the main bolt 3 and the tensioner cylinder 2 due to the gravity of the tensioner cylinder 2.

[0051] Furthermore, due to the continuous elastic support of the elastic support mechanism 4, the tensioner cylinder 2 does not need to consider its own weight during the installation process; it only needs to provide its own rotational force. The installation process of the bolt tensioner is simple and easy to operate.

[0052] Please refer to Figure 3 and Figure 4 The elastic support mechanism 4 includes a first spring support seat 41 and a second spring support seat 42 stacked together, and the first spring support seat 41 and the second spring support seat 42 are elastically connected by at least one elastic element 43.

[0053] It is known that the elastic element 43 is used to provide support force for the tensioner cylinder 2, and dividing the elastic support mechanism 4 into a first spring support seat 41 and a second spring support seat 42 is more suitable for providing a suitable support force for the tensioner cylinder 2.

[0054] Specifically, an installation gap 44 is formed in the middle of the first spring support 41 and the second spring support 42, and a bearing 45 is sleeved in the installation gap 44; the guide stud 1 passes through the inner ring of the bearing 45, and the first spring support 41 and the second spring support 42 are connected to the outer ring of the bearing 45.

[0055] During the installation of the tensioner cylinder 2 and the main bolt 3, the tensioner cylinder 2 rotates upward. At this time, the guide stud 1 only plays a guiding role and will not move synchronously with the tensioner cylinder 2. Therefore, a bearing 45 is set in the middle of the first spring support 41 and the second spring support 42. The bearing 45 can reduce the frictional force generated by the first spring support 41 and the second spring support 42 moving with the tensioner cylinder 2, so that the first spring support 41, the second spring support 42 and the tensioner cylinder 2 can rotate flexibly about the guide stud 1 as the axis.

[0056] It should be noted that the first spring support 41 and the second spring support 42 are mounted on the tensioner cylinder 2 via at least two threaded connectors 46.

[0057] The threaded connector 46 can be a bolt, screw, etc., and there is no limitation here.

[0058] When the tensioner cylinder 2 moves upward, the first spring support 41 and the second spring support 42 move with the tensioner cylinder 2. Therefore, the first spring support 41 and the second spring support 42 are connected to the tensioner cylinder 2 by a threaded connector 46.

[0059] The number of threaded fasteners 46 is illustrated here using two as an example, but this number is not limited. It can also be three, four, etc.

[0060] The elastic support mechanism 4 is detachably connected to the tensioner cylinder 2 via a threaded connector 46. This makes it easier to disassemble and reassemble when the elastic support mechanism 4 fails and needs to be repaired or replaced, thus saving the overall cost of the installation device.

[0061] Please continue to refer to Figure 4 The first spring support 41 and the second spring support 42 cooperate to form a snap-fit ​​chamber 47 for snapping the elastic member 43. A connecting stud 48 is provided inside the elastic member 43. One end of the connecting stud 48 is fixedly connected to the second spring support 42, and the other end is inserted into the first spring support 41 and is movably engaged with the first spring support 41.

[0062] The connecting stud 48 is used to connect the first spring support 41 and the second spring connecting seat. Specifically, one end of the connecting stud 48 is fixedly connected to the second spring support 42, and the other end is movably engaged with the first spring support 41 along the axial direction of the guide stud 1.

[0063] With this configuration, the first spring support 41 compresses the elastic element 43 under the gravity of the tensioner cylinder 2, and the first spring support 41 moves toward the second spring support 42 along the axial direction of the connecting stud 48.

[0064] Once the supporting function is complete and the tensioner cylinder 2 is removed, the elastic element 43 will push the first spring support seat 41 back to its initial position.

[0065] It is known that the first spring support 41 and the second spring support 42 are installed on the tensioner cylinder 2 through the threaded connector 46. At this time, the first spring support 41 is movably disposed between the tensioner cylinder 2 and the second spring support 42. The weight of the tensioner cylinder 2 will be applied to the first spring support 41, and the elastic element 43 between the first spring support 41 and the second spring support 42 will be compressed. The compressed elastic element 43 moves along the axial direction of the connecting stud 48, thus avoiding the compression deformation of the elastic element 43, and also guiding the movement of the first spring support 41, so as to prevent the first spring support 41 and the second spring support 42 from being offset due to the gravity of the tensioner cylinder 2.

[0066] Preferably, the elastic element 43 is a spring, and there are multiple elastic elements 43; the multiple springs are evenly spaced around the outer circumference of the elastic support mechanism 4.

[0067] By distributing the elastic element 43 evenly, the stress stability of the tensioner cylinder 2 can be improved.

[0068] In one embodiment, the first spring support seat 41 is disposed on the side close to the tensioner cylinder 2; the second spring support seat 42 is provided with a bearing support plate 421 on the side opposite to the first spring support seat 41, and one end of the support nut 5 abuts against the bearing support plate 421.

[0069] The bearing support plate 421 is used to support the first spring support seat 41 and the second spring support seat 42, thereby improving the support stability of the support nut 5 for the first spring support seat 41 and the second spring support seat 42.

[0070] It can be seen that the circumferential dimension of the bearing support plate 421 is greater than the circumferential dimension of the bearing 45.

[0071] Because the support nut 5 is small in size, and the support nut 5 needs to support the elastic support mechanism 4, the inner ring of the bearing 45 in the elastic support mechanism 4 is movable. In order to avoid affecting the movement of the bearing 45, a bearing support plate 421 is set at the bottom of the second spring support seat 42. The bearing support plate 421 is spaced apart from the bearing 45 and will not affect the movement of the inner ring of the bearing 45.

[0072] Specifically, a mounting bracket is provided on the side of the second spring support 42 away from the first spring support 41. The mounting bracket is installed on the second spring support 42 and has a mounting groove. The bottom of the mounting bracket is spaced apart from the bearing 45, so the bearing support plate 421 is snapped into the mounting groove and the bearing support plate 421 will not affect the movement of the bearing 45.

[0073] In summary, the main bolt tensioner installation device for the nuclear main pump of the present invention utilizes the threaded center hole of the main bolt 3 as the installation interface, eliminating the need for additional interfaces. The installation device is very small in size, so the installation process will not affect the accessories around the main pump.

[0074] An elastic support mechanism 4 is used to support the tensioner cylinder 2, providing a continuous upward thrust during the installation of the tensioner cylinder 2. This eliminates the need for the main bolt 3 to bear the weight of the tensioner, thus avoiding damage to the threads.

[0075] Please refer to Figure 5 The present invention also proposes a method for installing a main bolt tensioner for a nuclear main pump, which is implemented using the above-mentioned installation device for the main bolt tensioner of the nuclear main pump. The installation method includes:

[0076] Step 1: Place the elastic support mechanism and the tensioner cylinder sleeve on the outside of the guide stud, and connect the elastic support mechanism to the tensioner cylinder.

[0077] Step 2: Install the support nut on the outside of the guide stud and screw the support nut in so that the elastic support mechanism is in an elastic compression state;

[0078] Step 3: Move the tensioner cylinder below the main bolt and connect the guide stud to the main bolt;

[0079] Step 4: By rotating the tensioner cylinder and simultaneously rotating the support nut, connect the tensioner cylinder upwards to the main bolt.

[0080] It can be seen that the elastic force of the elastic support mechanism is consistent with the gravity of the tensioner cylinder.

[0081] The guide stud is connected to the main bolt. Based on the guide stud, an elastic support mechanism, a tensioner cylinder, and a support nut are installed on the guide stud. The support nut can support the elastic support mechanism and the tensioner cylinder. In this way, during the upward movement of the tensioner cylinder and the installation of the main bolt, the weight of the tensioner cylinder itself will not affect the thread between the tensioner cylinder and the main bolt. Therefore, damage to the main bolt and tensioner cylinder structure can be avoided. At the same time, the upward movement of the tensioner cylinder only requires its rotation, and the overhead installation is also very convenient.

[0082] In other words, the present invention allows for the overhead installation of the main bolt tensioner without affecting the surrounding auxiliary facilities. The installation method of the tensioner of the present invention can overcome the difficulties such as limited on-site space and high-altitude operation, making the bolt tensioner installation process simple and easy to operate.

[0083] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation", "connection", "joining", and "fixing" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can also refer to mechanical connections. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0084] This application uses specific terms to describe embodiments of the application. Terms such as "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0085] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A mounting device for a main bolt tensioner of a nuclear main pump, characterized in that, include: The guide stud has one end inserted into the tensioner cylinder and threadedly connected to the center hole on the main bolt. An elastic support mechanism is sleeved on the outside of the guide stud and located at the bottom of the tensioner cylinder and connected to the tensioner cylinder; A support nut is fitted onto the guide stud, with one end abutting against the elastic support mechanism. The support nut is located on the side of the elastic support mechanism away from the main bolt. The elastic support mechanism includes a first spring support seat and a second spring support seat stacked together, and the first spring support seat and the second spring support seat are elastically connected by at least one elastic element. A mounting gap is formed in the middle of the first spring support and the second spring support, and a bearing is sleeved in the mounting gap; The guide stud passes through the inner ring of the bearing, and the first spring support and the second spring support are connected to the outer ring of the bearing; The first spring support and the second spring support cooperate to form a snap-fit ​​chamber for snapping the elastic element. A connecting stud is inserted inside the elastic element. One end of the connecting stud is fixedly connected to the second spring support, and the other end is inserted into the first spring support and movably engaged with the first spring support.

2. The installation device for the main bolt tensioner of the nuclear main pump according to claim 1, characterized in that, The first spring support and the second spring support are mounted to the tensioner cylinder via at least two threaded connections.

3. The installation device for the main bolt tensioner of the nuclear main pump according to claim 1, characterized in that, The elastic element is a spring, and there are multiple elastic elements; The multiple springs are arranged at even intervals around the outer circumference of the elastic support mechanism.

4. The installation device for the main bolt tensioner of the nuclear main pump according to claim 1, characterized in that, The first spring support is located on the side near the tensioner cylinder; The second spring support seat has a bearing support plate on the side opposite to the first spring support seat, and one end of the support nut abuts against the bearing support plate.

5. The installation device for the main bolt tensioner of the nuclear main pump according to claim 4, characterized in that, The circumferential dimension of the bearing support plate is larger than the circumferential dimension of the bearing.

6. A method for installing a main bolt tensioner for a nuclear main pump, characterized in that, The installation is achieved using the nuclear main pump main bolt tensioner installation device as described in any one of claims 1-5, wherein the installation method includes: Step 1: Place the elastic support mechanism and the tensioner cylinder sleeve on the outside of the guide stud, and connect the elastic support mechanism to the tensioner cylinder; Step 2: Install a support nut on the outside of the guide stud and screw the support nut in so that the elastic support mechanism is in an elastic compression state; Step 3: Move the tensioner cylinder below the main bolt and connect the guide stud to the main bolt; Step 4: By rotating the tensioner cylinder and simultaneously rotating the support nut, the tensioner cylinder is connected upward to the main bolt.

7. The method for installing the main bolt tensioner of the nuclear main pump according to claim 6, characterized in that, The elastic force of the elastic support mechanism is consistent with the gravity of the tensioner cylinder.

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