Guide rail for a nuclear power ship and method of installing the same

Abstract

The present application belongs to the field of ship design, and particularly relates to a guide rail for a nuclear power ship loading and unloading box and a mounting method thereof. The guide rail comprises a plurality of loading and unloading box corner guide rails. The present application has the following advantages: 1) the present application sets the loading and unloading box guide rail to avoid the shaking and impact of the box hoisting on the ship structure; 2) the present application sets the reserved backing plate, rib plate and lining plate to provide support and convenience for the installation of the guide rail, and to avoid the damage of the installation operation to the ship structure; 3) the guide rail design of the present application has high flexibility, and can adapt to different sizes of the loading and unloading box, so that the ship can adapt to the design of different sizes of the loading and unloading box after the change of the years and the innovation of the technology; 4) the mounting scheme of the buffer pad provided by the present application can effectively solve the adverse effects of the falling impact on the safety shell, and the flatness problem of the deck and the box bottom plate, and ensure the operation in a closed environment.

Description

Technical Field

[0001] This invention belongs to the field of ship design, specifically relating to a guide rail for loading and unloading containers on a nuclear-powered ship and its installation method. Background Technology

[0002] Nuclear-powered ships require refueling after a certain period of operation. Refueling is a complex process with extremely high safety requirements (such as preventing radioactive material leakage during refueling and ensuring the structural safety of the containment vessel). Therefore, current refueling technology involves opening the ship's loading / unloading passage, hoisting the refueling container to the top of the containment vessel, and then opening the cover to perform the loading / unloading operation.

[0003] However, loading and unloading containers often have a large self-weight, while the loading and unloading channels of ships are often only slightly larger than the size of the loading and unloading containers to take into account the needs of use. During hoisting, they are very easy to collide with the ship's structure (especially in offshore hoisting operations), which can lead to structural damage. Therefore, high requirements are placed on the hoisting accuracy of loading and unloading containers.

[0004] At the same time, hoisting operations cannot be absolutely safe. If we consider extremely low-probability events such as hoisting hook detachment or crane collapse, there is a risk that loading and unloading containers may fall from above onto the top of the containment structure, causing damage to the containment structure or other hull structures.

[0005] Furthermore, the ship's deck and the bottom plate of the loading and unloading tank cannot be guaranteed to be absolutely flat, which means that the loading and unloading tank is directly installed on the ship's deck. After the loading and unloading tank cover is opened, it cannot be guaranteed that radioactive materials will not leak through the gaps.

[0006] Therefore, ensuring that the hoisting operation does not collide with the ship's structure, minimizing the impact of falling loading and unloading containers on the containment structure, and guaranteeing the shielding of radioactive materials during loading and unloading operations are all key technologies for loading and unloading operations, based on existing hoisting technologies and precision. Summary of the Invention

[0007] The purpose of this invention is to provide a guide rail for loading and unloading containers on nuclear-powered ships and its installation method, so that the ship can adapt to loading and unloading containers of different sizes for loading and unloading operations, and avoid damage to the ship's structure caused by hoisting, shaking and collision.

[0008] The technical solution of the present invention is as follows: a guide rail for loading and unloading containers of nuclear-powered ships, including a refueling guide rail, wherein the refueling guide rail includes multiple corner guide rails for loading and unloading containers.

[0009] Including the intermediate guide rail.

[0010] The upper end of the material changing guide rail is provided with a flared opening.

[0011] The flared opening is tilted at 5 to 15 degrees.

[0012] Both the material changing guide rail and the flared mouth are connected to guide rail supports.

[0013] The guide rail support is welded to the permanent cover plate, which is pre-placed on the surface of the hull structure.

[0014] The area where the permanent composite plate is located should be reinforced with a pre-installed permanent support.

[0015] A buffer pad is provided at the bottom of the material changing guide rail.

[0016] The shape of the corner guide rail is matched to the shape of the loading and unloading box.

[0017] A method for installing a guide rail for a loading and unloading container on a nuclear-powered ship includes the following steps:

[0018] Step 1: During the shipbuilding phase, estimate the loading and unloading range in advance, strengthen the area that can support the guide rails, and install permanent backing plates as the welding base plates for the guide rail supports;

[0019] Step 2: Before loading and unloading operations, arrange the guide rails and design the guide rail supports according to the actual shape and size of the loading and unloading boxes provided by the base.

[0020] Step 3: Weld the designed guide rail supports and material changing guide rails onto each permanent composite plate;

[0021] Step 4: Create a simulation box that is exactly the same size as the loading and unloading box;

[0022] Step 5: Conduct a hoisting test using a simulation box to ensure the accurate arrangement of the material changing guide rails;

[0023] Step 6: Hoist the loading / unloading box to the area defined by the flared opening;

[0024] Step 7: Hoist the loading / unloading box into the designated area of ​​the material changing guide rail;

[0025] Step 8: After the loading / unloading box is lowered into the designated position, secure it.

[0026] Step 9: After the loading and unloading operations are completed, remove the material replacement guide rail and guide rail support;

[0027] Step 10: Sand the permanent cladding board smooth and apply paint to prevent corrosion.

[0028] The beneficial effects of this invention are as follows: 1) By setting guide rails for loading and unloading boxes, this invention avoids the impact of box swaying on the ship's structure during hoisting; 2) By setting reserved pads, stiffeners, and liners, this invention provides support and convenience for the installation of guide rails, and ensures that the installation operation does not damage the ship's components; 3) The guide rail design of this invention has extremely high flexibility and can adapt to loading and unloading boxes of different sizes, enabling the ship to adapt to different sizes of loading and unloading boxes designed with technological innovations over time; 4) The buffer pad installation scheme provided by this invention can effectively solve the adverse effects of falling impacts on the containment vessel, as well as the problem of the flatness of the deck and box bottom plate, ensuring that the operation is carried out in a closed environment. Attached Figure Description

[0029] Figure 1 This is a schematic diagram illustrating the swaying motion of the material changing box during lifting.

[0030] Figure 2 A diagram illustrating the falling of the material changing box during hoisting;

[0031] Figure 3-1 This invention provides a guide rail arrangement diagram for a square box in a nuclear-powered ship's loading and unloading container.

[0032] Figure 3-2 This invention provides a guide rail arrangement diagram for a near-circular container in a nuclear-powered ship's loading and unloading container.

[0033] Figure 4 Top view of the guide rail node;

[0034] Figure 5 This is a schematic diagram of the cladding installation;

[0035] Figure 6 For nodes with hatch coaming supports;

[0036] Figure 7 For hatchless cofferdam support nodes;

[0037] Figure 8 It is a support node for the intermediate deck with bulkheads;

[0038] Figure 9 For bulkhead-free intermediate deck support nodes;

[0039] Figure 10 For the end support node of the guide rail;

[0040] Figure 11 Force diagram for an unrestricted fall;

[0041] Figure 12 Force diagram for a guide rail falling;

[0042] Figure 13 This is a schematic diagram showing the placement of the cushioning pads;

[0043] Figure 14 This is a force diagram of a fall with a cushioning pad.

[0044] Figure 15 A schematic diagram illustrating radiation leakage from direct installation;

[0045] Figure 16 A diagram showing how a buffer pad can improve radiation leakage.

[0046] In the diagram: 0 Reactor compartment, 1 Hull structure, 2 Refueling container, 11 Containment top deck, 14 Permanent cladding plate, 15 Support top reinforcement, 21 Hoisting cable, 31 Refueling guide rail, 33 Bell mouth, 34 Guide rail support, 35 Intermediate guide rail, 41 Containment top deck bearing point load. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] like Figure 1 As shown, the main areas involved in this invention are the reactor compartment 0, the hull structure 1, and the loading and unloading container 2. When the loading and unloading container 2 is hoisted, lateral swaying is inevitable. Since the loading and unloading channel is usually only slightly larger than the size of the loading and unloading container, the swaying container is likely to collide with the hull structure 1. The inertial force of the swaying loading and unloading container, which weighs more than 100 tons, is very likely to cause deformation or damage to the hull structure.

[0049] like Figure 2 As shown, the hoisting operation cannot completely avoid problems such as hook detachment or sling breakage, which may cause the loading and unloading container to fall onto the top deck 11 of the containment vessel. According to the law of conservation of energy, this accident will generate a huge impact force, which may cause the top deck 11 of the containment vessel to be damaged, and thus lead to problems such as the leakage of radioactive materials.

[0050] To avoid or mitigate the severe impact of the aforementioned accidents, as shown in Figure 3, a guide rail for loading and unloading refueling containers on a nuclear-powered ship includes a refueling guide rail 31. The refueling guide rail 31 comprises four corner guide rails for the loading and unloading containers, such as... Figure 3-1 As shown, if the length of one side of the loading / unloading box 2 is too large, an intermediate guide rail 35 can be added appropriately. Figure 3-2 As shown, if the loading / unloading box 2 is nearly circular, the corner guide rail is set as an arc guide rail. The total size of the area defined by the material changing guide rail 31 should be slightly larger than the total size of the loading / unloading box 2 by 20mm to ensure that the loading / unloading box 2 can be smoothly hoisted in or out through the guide rail. If the loading / unloading box 2 is 10000mm long and 10000mm wide, the area defined by the guide rail is 10020mm long and 10020mm wide. The dimensions of the guide rail defined area for other types of loading / unloading boxes are deduced accordingly.

[0051] like Figure 6 and 7As shown, the upper end of the material changing guide rail 31 is provided with a flared opening 33, which is inclined at 5-15° and has a length of not less than 100mm. The function of the flared opening 33 is to facilitate hoisting operations and ensure that the loading and unloading box 2 can be smoothly inserted into the material changing guide rail 31. Both the material changing guide rail 31 and the flared opening 33 are connected to guide rail supports 34, which are used to fix the material changing guide rail 31 and provide sufficient support. The guide rail support 34 of the flared opening 33 is in the form of... Figure 6 , Figure 7 As shown (where Figure 6 For nodes with hatch coaming 13, Figure 7 (For nodes without hatch coamings on open deck 10); the guide rail support 34 on the intermediate deck is in the form of... Figure 8 As shown in Figure 9; the guide rail support at the end of the refueling guide rail 31 (i.e., near the top deck 11 of the containment) is as follows. Figure 10 As shown, the end of the refueling guide rail 31 does not need to be directly connected to the top deck 11 of the containment.

[0052] The guide rail support 34 provides sufficient support for the guide rail and restricts its displacement. Before loading and unloading operations, the size and form of the support are determined according to the actual dimensions of the loading and unloading containers, and then welded to the hull structure 1 (including decks, bulkheads, cofferdams, stiffening plates, etc.). Since the support structure and guide rail will be removed after loading and unloading, to avoid damage to the hull structure 1 during removal, a permanent cover plate 14 is pre-installed on the surface of the hull structure 1 to support and weld the guide rail support 34. The permanent cover plate is as follows: Figure 5 As shown. The area where the permanent composite plate 14 is located should be pre-installed with a permanent support counter-support 15 for reference in the design of the guide rail support 34.

[0053] Without guide rails, a fall accident would cause the top deck of the containment to bear a point load of 41, such as... Figure 11 As shown; with guide rails, the falling pattern of the loading and unloading box is limited; however, since the containment top deck 11 is usually made of steel plate and supported by ribs, it cannot guarantee absolute flatness and will exhibit wavy tolerances. Therefore, the containment top deck 11 still cannot bear uniform stress, such as... Figure 12 As shown; to minimize the risk of damage to the top containment deck 11, such as Figure 13 As shown, a buffer pad 32 can be installed at the lower part of the refueling guide rail 31 (the buffer pad material can be a highly elastic polymer material such as rubber, and the thickness is not less than 5 times the flatness of the deck). After the buffer pad 32 is installed, the load borne by the top deck 11 of the containment approaches the uniformly distributed load 42, such as... Figure 14 As shown.

[0054] Meanwhile, because the top deck 11 of the containment vessel and the bottom plate of the loading / unloading container 2 cannot be guaranteed to be absolutely flat, gaps exist at the contact surfaces between them. During loading / unloading operations, when the material exchange channel is opened, radioactive materials will leak from these gaps into the external environment. Figure 15 The leakage path is shown in 43.

[0055] After the buffer pad is installed, the buffer pad, which is pressed down by the loading and unloading box 2, will fill the gap between the loading and unloading box 2 and the top deck 11 of the containment vessel, thus preventing the leakage of radioactive materials.

[0056] A method for installing a guide rail for a loading and unloading container on a nuclear-powered ship includes the following steps:

[0057] Step 1: During the shipbuilding phase, estimate the loading and unloading range in advance, strengthen the area that can support the guide rail (such as increasing the structural size and setting the support top support 15), and set a permanent cover plate 14 as the welding base plate of the guide rail support 34 to provide a basis for subsequent support design and installation.

[0058] Step 2: Before loading and unloading operations, arrange the guide rails 31 according to the actual shape and size of the loading and unloading box 2 provided by the base, and design the guide rail supports 34.

[0059] Step 3: Weld the designed guide rail supports 34 and material changing guide rails 31 onto each permanent cover plate 14.

[0060] Step 4: Make a simulation box that is exactly the same size as loading and unloading box 2 (the simulation box can be made of wood).

[0061] Step 5: Conduct a hoisting test using a simulation box to ensure the accurate arrangement of the material changing guide rail 31.

[0062] Step 6: Hoist the loading / unloading box 2 to the area defined by the flared opening 33.

[0063] Step 7: Hoist the loading / unloading box 2 into the area defined by the material changing guide rail 31.

[0064] Step 8: After the loading and unloading box 2 is placed in the designated position, take necessary measures to secure it (not limited to binding, anchoring, etc.).

[0065] Step 9: After the loading and unloading operation is completed, remove the material replacement guide rail 31 and guide rail support 34;

[0066] Step 10: Sand the permanent composite panel 14 smooth and apply paint to prevent corrosion.

Claims

1. A method for installing a guide rail for a nuclear power plant fuel handling cask, said guide rail comprising a refueling guide rail, said refueling guide rail comprising a plurality of fuel handling cask corner guide rails, said refueling guide rail having a flared upper end, said refueling guide rail and flared upper end each being connected to a guide rail support, said guide rail support being welded to a permanent deck, said permanent deck being pre-positioned on a surface of a ship structure, said corner guide rails having an outer shape matching an outer shape of a fuel handling cask, characterized in that, The method comprises the following steps: Step 1: During the shipbuilding stage, the loading and unloading range is estimated in advance, the area capable of supporting the guide rail is reinforced, and permanent plating is provided as the welded bottom plate of the guide rail support; Step 2: Before the loading and unloading operation, the guide rail is arranged according to the actual shape and size of the loading and unloading box provided by the base, and the guide rail support is designed; Step 3: The designed guide rail support and the loading and unloading guide rail are welded on the permanent plating; Step 4: A simulation box with the same size as the loading and unloading box is made; Step 5: The simulation box is used for hoisting test to ensure the accurate arrangement of the loading and unloading guide rail; Step 6: The loading and unloading box is hoisted into the horn mouth limited area; Step 7: The loading and unloading box is hoisted into the loading and unloading guide rail limited area; Step 8: After the loading and unloading box is dropped to the designated position, it is fixed; Step 9: After the loading and unloading operation is completed, the loading and unloading guide rail and the guide rail support are removed; Step 10: The permanent plating is polished and painted to prevent corrosion.

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