Method for manufacturing a cylinder of a shielding head of a pressure vessel of a nuclear power plant and cylinder structure

Abstract

The application discloses a manufacturing method and a structure of a cylinder of a shielding top cover of a pressure container of a nuclear power plant. The manufacturing method comprises the following steps: S100, sequentially laying multiple layers of lead plates in the same position of an inner cylinder in a radial direction, closely adhering the adjacent layers of the lead plates, and sequentially setting the axial edges of the multiple layers of the lead plates from inside to outside in a staggered manner; S200, pouring lead water to fill the gaps, and waiting for the lead water to solidify to form a lead water layer; S300, laying a first heat insulation layer on the outer side of the first end of the outermost layer of the lead plates and the outer side of the second end; S400, laying an inner layer of fixing plates on the outermost layer of the lead plates and closely adhering the inner layer of the fixing plates to the outermost layer of the lead plates, and welding and fixing the two ends of the inner layer of the fixing plates to the upper flange surface and the lower flange surface; and S500, repeatedly performing steps S100-S400 along the circumference of the inner cylinder for several times to finally form multiple cylinder-shaped layers of the lead plates and the inner layer of the fixing cylinder. The manufacturing method reduces the deviation, the wrinkle, the bulge and the like in the process of wrapping the lead plates, and improves the wrapping precision of the lead plates.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear power plant pressure vessel false top cover manufacturing, and particularly relates to a nuclear power plant pressure vessel shielding top cover cylinder manufacturing method and cylinder structure. BACKGROUND

[0002] During the nuclear power plant reactor refueling overhaul, a large amount of radioactive substances in the reactor core will be leaked outwards after the reactor pressure vessel is opened. During the high water level period of the reactor pool, the boric acid water in the pool can be used for isolation and absorption, but when the water level is low, a false top cover is needed to shield the opened reactor pressure vessel so as to isolate and shield the radioactive substances to a certain extent. The false top cover uses lead plates as a shielding layer.

[0003] The lead plate is soft in texture, high in density and good in tensile property at room temperature, so that the lead plate with high purity is prone to flow under the action of gravity. During the process of wrapping the outer cylinder of a large container with lead plates, the lead plates on the whole circumference are prone to uneven arrangement due to flow, and partial areas are prone to deviation, dislocation, wrinkles or bulges.

[0004] At present, the manufacturing of the pressure vessel wrapped with multiple layers of lead plates is commonly used in equipment requiring radiation protection or special corrosion protection. The general process mainly includes: determining the size of the lead plate, fixing the single layer of lead plate, wrapping multiple layers, and finishing detail processing. The lead wrapping process is used for the lead plate wrapping of the surface of a small container, and the total effective thickness of the lead plate is generally less than or equal to 5 mm. It is not suitable for the surface of a large heavy load container with a diameter of more than 3 m and the wrapping manufacturing of the "embedded type" lead plate with a thickness of more than 10 mm. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a nuclear power plant pressure vessel shielding top cover cylinder manufacturing method and cylinder structure.

[0006] The technical scheme adopted by the present application to solve the technical problem is: a nuclear power plant pressure vessel shielding top cover cylinder manufacturing method, comprising the following steps:

[0007] S000: connecting and fixing the inner cylinder with the upper flange surface and the lower flange surface, respectively;

[0008] S100: sequentially laying multiple layers of lead plates in the radial direction at the same position of the inner cylinder, the lead plates in adjacent layers being tightly fitted, and the axial edges of the multiple layers of lead plates being sequentially arranged in a staggered manner from inside to outside;

[0009] Wherein, the inner cylinder is placed horizontally, the first end portion of the lead plate abuts against the lower flange surface, and a gap is left between the second end portion of the lead plate and the upper flange surface;

[0010] S200: Casting lead water to fill the gap between the second end of the lead plate and the upper flange surface, and waiting for the lead water to solidify to form a lead water layer;

[0011] S300: Laying a first heat insulation layer on the outer side of the first end and the outer side of the second end of the outermost layer of lead plates;

[0012] S400: Laying an inner layer fixing plate on the outermost layer of lead plates and tightly adhering to the outermost layer of lead plates, the axial edges of the outermost layer of lead plates are arranged in a staggered manner with the axial edges of the inner layer fixing plate, and the two ends of the inner layer fixing plate are respectively welded and fixed to the upper flange surface and the lower flange surface;

[0013] S500: Repeating steps S100-S400 along the circumference of the inner cylinder to finally form a plurality of cylinder-shaped lead plate layers and cylinder-shaped inner layer fixing cylinders;

[0014] S600: Laying a plurality of outer layer fixing cylinders outside the inner layer fixing cylinder.

[0015] In some embodiments, step S500 further comprises laying a second heat insulation layer at a specific position outside the outermost layer of lead plates, and sequentially welding and fixing adjacent inner layer fixing plates along the circumference of the inner cylinder;

[0016] The specific position is opposite to the axial edge of the inner layer fixing plate.

[0017] In some embodiments, one piece of the lead plate is 1 / 4 of the total laying cylinder volume of the lead plate layer, and one piece of the inner layer fixing plate is 1 / 4 of the total laying cylinder volume of the layer;

[0018] In step S500, steps S100-S400 are repeated three times along the circumference of the inner cylinder.

[0019] In some embodiments, in step S600, the number of outer layer fixing cylinders is at least two, each outer layer fixing cylinder includes the same number of outer layer fixing plates (61) as the number of inner layer fixing plates, and the axial edges of the inner layer fixing plates and the axial edges of the at least two outer layer fixing plates (61) are arranged in a staggered manner from inside to outside.

[0020] The two adjacent outer layer fixing plates (61) on the same layer of outer layer fixing cylinders are welded and fixed.

[0021] In some embodiments, step S000 further comprises polishing the surface of the inner cylinder, so that the depth of the pits on the outer surface of the inner cylinder is less than or equal to 0.25mm, and the depth of the scratches is less than or equal to 0.2mm.

[0022] In some embodiments, in step S400, the inner layer fixing plate is fixed to the lead plate by using a clamp so that the inner layer fixing plate is tightly attached to the outermost lead plate;

[0023] After welding and fixing, the weld joint between the inner layer fixing plate and the upper flange surface and the lower flange surface is polished so that the weld joint is flush with the surface of the inner layer fixing plate;

[0024] After determining that the lead plate is compacted, the clamp is removed.

[0025] In some embodiments, the axial edge of the plurality of lead plate layers is staggered by a distance greater than or equal to 50 mm; the axial edge of the outermost lead plate is staggered from the axial edge of the inner layer fixing plate by a distance greater than or equal to 50 mm.

[0026] In some embodiments, the length of the first thermal insulation layer is greater than the arc length of the lead plate, and the width of the first thermal insulation layer is greater than or equal to 100 mm;

[0027] The length of the second thermal insulation layer is greater than the axial height of the lead plate, and the width of the second thermal insulation layer is greater than or equal to 100 mm.

[0028] In some embodiments, the number of lead plate layers is four.

[0029] The application also provides a cylinder structure manufactured by the cylinder manufacturing method, which comprises an inner cylinder, an upper flange surface, a lower flange surface, a plurality of lead plate layers, an inner layer fixing cylinder, and a plurality of outer layer fixing cylinders, wherein the inner cylinder is connected and fixed to the upper flange surface and the lower flange surface; the plurality of lead plate layers are sleeved on the outer periphery of the inner cylinder and are connected and fixed to the upper flange surface and the lower flange surface; the inner layer fixing cylinder is sleeved on the outer periphery of the outermost lead plate layer and is connected and fixed to the upper flange surface and the lower flange surface; and the plurality of outer layer fixing cylinders are sleeved on the inner layer fixing cylinder and are connected and fixed to the upper flange surface and the lower flange surface.

[0030] Each of the lead plate layers comprises a plurality of lead plates, the lead plates in the same lead plate layer are connected and fixed by lead water through a gap between adjacent lead plates; the adjacent lead plates are tightly attached to each other, and the axial edges of the plurality of lead plate layers are staggered from inside to outside.

[0031] By implementing the application, the following beneficial effects are achieved:

[0032] The method for manufacturing the shell of the nuclear power plant pressure vessel shielding top cover of the present invention effectively ensures that the lead plates adhere to and wrap around the outer surface of the inner shell by sequentially laying multiple layers of lead plates and an inner fixing plate radially at the same position. By pouring molten lead to fill the gap between the second end and the upper flange surface, the axial edges of the multiple lead plates are staggered from the inside out, and the axial edges of the lead plates are also staggered with the axial edges of the inner fixing plate. This improves the uniformity of the lead plate thickness around the circumference of the inner shell, reduces deviations, wrinkles, bulges, etc., during the lead plate wrapping process, lowers the manufacturing difficulty, improves the wrapping accuracy of the lead plates, and effectively reduces the fluidity of the lead plates.

[0033] The cylindrical structure manufactured using any of the above-described cylindrical manufacturing methods of the present invention can be tightly fitted between the inner cylindrical body and the lead plate layer, adjacent lead plate layers, lead plate layers and the lead inner layer fixed cylindrical body, the inner layer fixed cylindrical body and the outer layer fixed cylindrical body, and adjacent outer layer fixed cylindrical bodies. The axial edges of the multi-layer lead plates are staggered, and the gaps between adjacent lead plates in the same layer are filled by pouring molten lead, thereby achieving splicing of each lead plate layer, improving the uniformity of the lead plates, effectively ensuring the shielding effect of the lead plates, and preventing misalignment during long-term use. Attached Figure Description

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0035] Figure 1 This is a flowchart of a method for manufacturing the cylindrical body of a nuclear power plant pressure vessel shielding top cover according to an embodiment of the present invention;

[0036] Figure 2 It is based on Figure 1 A schematic diagram of an embodiment of a cylinder manufactured by a cylinder manufacturing method;

[0037] Figure 3 yes Figure 2 Detailed installation diagram of the inner cylinder with the upper and lower flange faces;

[0038] Figure 4 Is Figure 3 A detailed structural diagram of multiple layers of lead plates wrapped at one location within the inner cylinder;

[0039] Figure 5 Is Figure 4 Detailed structural diagram of the inner layer fixing plate being wrapped at the same location on the inner cylinder;

[0040] Figure 6 yes Figure 5 An enlarged structural diagram of the I-structure, specifically a schematic diagram of the installation of the heat insulation layer on the bottom outer side of the outermost lead plate;

[0041] Figure 7 yes Figure 5A schematic diagram illustrating the actual effect of the first layer of lead plate and inner fixing plate being wrapped in the middle; the upper flange face and lower flange face are not shown.

[0042] Figure 8 Is Figure 7 A schematic diagram of the structure for a second bandaging based on the existing structure;

[0043] Figure 9 yes Figure 7 An enlarged structural diagram of the H-structure, specifically a schematic diagram of the installation of the heat insulation layer on the outside of the lead plate at the gap position of the adjacent inner fixing plates;

[0044] Figure 10 Is Figure 8 A schematic diagram of the structure for the third bandaging step;

[0045] Figure 11 Is Figure 10 A schematic diagram showing the fourth bandaging procedure based on the existing structure;

[0046] Figure 12 Is Figure 11 Detailed structural diagram of the outer fixing plate being wrapped on the basis. Detailed Implementation

[0047] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0048] It should be noted that the flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0049] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0050] In the description of the application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and does 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 of the application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0051] In the description of the application, it needs to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or chemical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood through specific circumstances.

[0052] Referring to Figure 1 and Figure 2 , one embodiment of the application discloses a manufacturing method of a cylinder of a shielding head of a pressure vessel of a nuclear power plant and a cylinder made according to the manufacturing method of the cylinder. The cylinder comprises an inner cylinder 1, an upper flange surface 2, a lower flange surface 3, a plurality of lead plate layers 4, an inner layer fixed cylinder 5 and a plurality of outer layer fixed cylinders 6. The inner cylinder 1 is connected and fixed with the upper flange surface 2 and the lower flange surface 3 respectively. The plurality of lead plate layers 4 are sleeved on the outer periphery of the inner cylinder 1 and are connected and fixed with the upper flange surface 2 and the lower flange surface 3 respectively. The inner layer fixed cylinder 5 is sleeved on the outer periphery of the outermost lead plate layer 4 and is connected and fixed with the upper flange surface 2 and the lower flange surface 3 respectively. The plurality of outer layer fixed cylinders 6 are sleeved on the inner layer fixed cylinder 5 and are connected and fixed with the upper flange surface 2 and the lower flange surface 3 respectively.

[0053] Each lead plate layer 4 comprises a plurality of lead plates 41, and the lead plates 41 adjacent to each other in the same lead plate layer 4 are left with gaps and are connected and fixed by lead water. The adjacent layers of lead plates 41 are tightly fitted, and the axial edges of the plurality of lead plates 41 are sequentially arranged in a staggered manner from inside to outside. Understandably, the plurality of lead plates 41 of each lead plate layer 4 can be lead plates 41 with the same arc length, or can be lead plates with different arc lengths.

[0054] The manufacturing method of the cylinder comprises the following steps:

[0055] Referring to Figure 3 , the inner cylinder 1 is connected and fixed with the upper flange surface 2 and the lower flange surface 3 respectively before the first wrapping. The inner cylinder 1 is welded with the upper flange surface 2 and the lower flange surface 3 respectively, and the welds on the inner cylinder 1 and the inner and outer surfaces of the upper flange surface 2 and the lower flange surface 3 should be polished to be flush with the base material. Among them, the upper flange surface 2 is stepped. Multiple steps expand outward from the inner cylinder 1, and the spacing between the outer steps and the lower flange is greater than the spacing between the adjacent inner steps and the lower flange. Preferably, the upper flange surface 2 is provided with at least three steps, which are used to install a plurality of lead plate layers 4, an inner fixed cylinder 5 and an outer fixed cylinder 6 from inside to outside of the inner cylinder 1. Among them, the axial height of the lead plate layer 4 < the axial height of the inner fixed cylinder 5 < the axial height of the outer fixed cylinder 6.

[0056] Further, the surface of the inner cylinder 1, i.e. the outer circumferential surface of the inner cylinder 1, is polished so that the depth of the pits on the outer surface of the inner cylinder 1 is less than or equal to 0.25mm, and the depth of the scratches is less than or equal to 0.2mm. Ensure that the outer surface of the inner cylinder 1 is free of oil stains and welding bumps before wrapping, so that the subsequent installation of the lead plate 41 can be completely attached to the inner cylinder 1.

[0057] Referring to Figures 4 to 7 , the first wrapping is shown, including steps S100 to S400. Among them, the inner cylinder 1 is placed horizontally on the ground before wrapping. Generally, the axial direction of the inner cylinder 1 is parallel to the ground.

[0058] As shown in Figure 4 , step S100: a plurality of layers of lead plates 41 are laid in the same position of the inner cylinder 1 in the radial direction in turn, and the adjacent layers of lead plates 41 are tightly attached, for example, the lead plates 41 are knocked to make them tightly attached by using a rubber hammer. And the axial edges of the plurality of layers of lead plates 41 are arranged in turn in a staggered manner from inside to outside, for example, in a gradually increasing form from inside to outside, or in a gradually decreasing form from inside to outside. Understandably, each lead plate 41 is provided with axial edges on both sides in the axial direction, and the gradually increasing form from inside to outside or the gradually decreasing form from inside to outside can be applied to both sides of the plurality of layers of lead plates 41 simultaneously or separately, for example, the axial edges of both sides of the plurality of layers of lead plates 41 are simultaneously in the gradually decreasing form from inside to outside; or the axial edge of one side of the plurality of layers of lead plates 41 is in the gradually increasing form from inside to outside, and the axial edge of the other side of the plurality of layers of lead plates 41 is in the gradually decreasing form from inside to outside. In this embodiment, when the first wrapping is performed, the axial edges of both sides of the plurality of layers of lead plates 41 are simultaneously in the gradually decreasing form from inside to outside.

[0059] Among them, the first end of the lead plate 41 abuts against the lower flange surface 3, and a gap is left between the second end of the lead plate 41 and the upper flange surface 2.

[0060] Further, the number of the plurality of lead plates 41 can be three, four, five, etc., i.e., the number of the lead plate layers 4 can be three, four, five, etc. The axial edges of the plurality of lead plates 41 are staggered by a distance greater than or equal to 50 mm. For example, 50 mm, 60 mm, 65 mm, etc. In order to facilitate the installation of the circumferentially adjacent lead plates 41, the lead plates 41 at the same position are sequentially contracted from the inner cylinder 1 to the outside.

[0061] For ease of illustration, the inner cylinder 1 is divided into a plurality of position regions, and the arc length of each position region of the inner cylinder 1 generally matches the arc length of the lead plate 41. For example, the plurality of position regions are divided into a, b, c, etc. by equal division, and a suitable equal division is selected according to actual needs, such as three equal divisions, four equal divisions, five equal divisions, etc. Generally, when wrapping, the uppermost position region of the inner cylinder 1 is selected, and the inner cylinder 1 can provide sufficient support force, and the lead plate 41 naturally droops under the action of gravity. For example, in the present embodiment, the a position region is at the uppermost position, and wrapping is performed on the a position region.

[0062] In some embodiments, the arc length of each of the plurality of lead plates 41 of the lead plate layer 4 is the same, and one lead plate 41 is 1 / 4 of the total laying cylinder volume of the lead plate layer 4. For ease of illustration, the inner cylinder 1 is divided into four regions a, b, c, d by four equal divisions. It can be understood that in other embodiments, one lead plate 41 can also be 1 / 3 or 1 / 5, etc. of the total laying cylinder volume of the lead plate layer 4.

[0063] Step S200: Pouring lead water to fill the gap between the second end of the lead plate 41 and the upper flange surface 2, and after the lead water solidifies, a lead water layer 7 is formed. Before the lead water solidifies, part of the lead water will also flow into the gap between the lead water and the inner cylinder 1, the lead plate 41 and the adjacent lead plate 41, and after the lead water solidifies, the lead that is higher than the base material will be removed. The tightness between the lead plate 41 and the upper flange surface 2, the lead plate 41 and the inner cylinder 1, and the lead plate 41 and the adjacent lead plate 41 can be improved, and the shielding capability of the lead plate 41 can be further improved.

[0064] As shown in Figure 6 Step S300: A first heat insulation layer 8 is laid on the outer side of the first end and the outer side of the second end of the outermost lead plate 41 to prevent the subsequent welding operation from affecting the lead plate 41. The first end of the lead plate 41 refers to the end close to the upper flange surface 2, and the second end of the lead plate 41 refers to the end close to the lower flange surface 3. Preferably, the length of the first heat insulation layer 8 is greater than the arc length of the lead plate 41, and the width of the first heat insulation layer 8 is greater than or equal to 100 mm, for example, 100 mm, 110 mm, etc. The first heat insulation layer 8 is a heat insulation cloth made of glass fiber.

[0065] As shown in Figure 5As shown, in step S400: the inner fixing plate 51 is laid on the outermost lead plate 41 and tightly fitted to the outermost lead plate 41. The axial edge of the outermost lead plate 41 is offset from the axial edge of the inner fixing plate 51. The two ends of the inner fixing plate 51 are welded and fixed to the upper flange face 2 and the lower flange face 3, respectively. Preferably, the inner fixing plate 51 is an arc-shaped steel plate made of carbon steel, and the arc length of the inner fixing plate 51 matches the arc length of the outermost lead plate 41. In this embodiment, one inner fixing plate 51 accounts for 1 / 4 of the total amount of cylinder body laid in the layer.

[0066] In some embodiments, the axial edge of the outermost lead plate 41 is offset from the axial edge of the inner fixing plate 51 by a distance greater than or equal to 50 mm, such as 50 mm, 60 mm, 65 mm, etc. Preferably, in this embodiment, the offset distance between the axial edge of the outermost lead plate 41 and the axial edge of the inner fixing plate 51 is greater than the offset distance between the axial edges of the multiple lead plates 41.

[0067] In some embodiments, clamps are used to tightly bind the inner fixing plate 51 to the lead plate 41, ensuring a close fit between the inner fixing plate 51 and the outermost lead plate 41. After welding, the weld between the inner fixing plate 51 and the upper flange face 2 and lower flange face 3 is ground until the weld is flush with the surface of the inner fixing plate 51. After confirming that the lead plate 41 is compacted, the clamps are removed. The clamps are not shown in the diagram.

[0068] like Figure 7 As shown, according to the above steps S000 to S400, the preparation before bandaging and the actual effect of the partial tube after the first bandaging are completed. Before proceeding to the next step, rotate this part of the tube 90° clockwise or counterclockwise so that the b position area or d position area is at the top, and then continue bandaging on the b position area or d position area.

[0069] See you together Figure 8, the second wrapping, the third wrapping, etc. is continued on the basis of the end of the first wrapping, i.e. steps S100-S400 are repeated several times along the circumference of the inner cylinder 1 to finally form the plurality of cylinder-shaped lead plate layers 4 and cylinder-shaped inner layer fixed cylinders 5. The number of repetitions is determined according to actual needs. In the present embodiment, one inner layer fixed plate 51 is 1 / 4 of the total cylinder volume of the layer, one inner layer fixed plate 51 is 1 / 4 of the total cylinder volume of the layer, i.e. three repetitions are required to form the plurality of cylinder-shaped lead plate layers 4 and cylinder-shaped inner layer fixed cylinders 5. In the present embodiment, the part of the cylinder is rotated counterclockwise by 90° during the second wrapping, so that the b position area is at the uppermost position, and the second wrapping is continued at the b position area. The axial edges of the plurality of layers of lead plates 41 and the inner layer fixed plates 51 close to the a position are gradually increased from inside to outside in the form of misalignment, so as to match the gradually decreasing misalignment form of the plurality of layers of lead plates 41 and the inner layer fixed plates 51 from inside to outside at the a position during the first wrapping. In order to facilitate the placement of the lead plates 41 and the inner layer fixed plates 51 at the corresponding positions by gravity, the difficulty of wrapping is reduced. At the same time, the axial edges of the plurality of layers of lead plates 41 and the inner layer fixed plates 51 away from the a position are gradually decreased from inside to outside in the form of misalignment, so as to reduce the difficulty of the next wrapping. In this way, a gap is left between the adjacent lead plates 41 along the circumferential direction of the inner cylinder 1, the gap is filled with cast lead water, and the lead protruding from the base material is removed.

[0070] See also Figure 9 , step S500, further comprising laying a second heat insulation layer 9 at a specific position outside the outermost lead plate 41, and sequentially welding and fixing the adjacent inner layer fixed plates 51 along the circumference of the inner cylinder 1. The specific position is opposite to the axial edge of the inner layer fixed plate 51. Preferably, the second heat insulation layer 9 extends along the axial direction of the inner cylinder 1, and the length is greater than the axial height of the outermost lead plate 41, and the width is >100mm, and the second heat insulation layer 9 is a glass fiber heat insulation cloth.

[0071] See also Figure 10 and Figure 11, the third and fourth wrapping are continued in turn on the basis of the end of the second wrapping, i.e. the steps S100-S400 are repeated twice along the circumferential direction of the inner cylinder 1. Before the third wrapping is continued, the part of the cylinder is continued to be rotated counterclockwise by 90° along the cylinder rotation direction before the second wrapping, so that the c position area is at the uppermost, and the third wrapping is continued in the c position area. After the third wrapping is completed, before the fourth wrapping is continued, the part of the cylinder is continued to be rotated counterclockwise by 90° along the cylinder rotation direction before the third wrapping, so that the d position area is at the uppermost, and the fourth wrapping is continued in the d position area. During the fourth wrapping, the axial edges of the multi-layer lead plate 41 and the inner fixed plate 51 on both sides are staggered in the form of gradually increasing from inside to outside, so as to match the staggered form of gradually decreasing from inside to outside of the multi-layer lead plate 41 and the inner fixed plate 51 in the a position during the first wrapping, and the staggered form of gradually decreasing from inside to outside of the multi-layer lead plate 41 and the inner fixed plate 51 in the c position during the third wrapping. Similarly, during the third and fourth wrapping, the methods of pouring lead water and laying the second heat insulation layer 9 are the same as those during the second wrapping, and will not be repeated here.

[0072] Reference is made to Figure 12 On the basis of the end of the fourth wrapping, the step S600 is continued: laying a plurality of outer fixed cylinder 6 outside the inner fixed cylinder 5. Among them, the number of outer fixed cylinder 6 can be one layer, two layers, three layers, etc., which is set according to actual needs.

[0073] In some embodiments, the number of outer fixed cylinder 6 is at least two layers, each outer fixed cylinder 6 includes the same number of outer fixed plate 61 as the inner fixed plate 51, and the axial edges of the inner fixed plate 51 and the axial edges of the at least two outer fixed plate 61 are staggered from inside to outside. The two adjacent outer fixed plates 61 on the same layer of outer fixed cylinder are welded and fixed. In this embodiment, one outer fixed plate 61 is 1 / 4 of the total laying cylinder of the layer.

[0074] Further, the staggered distance between the axial edges of the inner fixed plate 51 and the axial edges of the at least two outer fixed plate 61 is greater than or equal to 50mm, for example, 50mm, 60mm, 65mm, etc. Preferably, in this embodiment, the staggered distance between the axial edges of the inner fixed plate 51 and the axial edges of the at least two outer fixed plate 61 is greater than the staggered distance between the axial edges of the multi-layer lead plate 41.

[0075] According to the above cylinder manufacturing method, the cylinder structure of one embodiment as shown in the figure can be manufactured, and the cylinder manufacturing method and the cylinder structure of the present application have the following advantages: Figure 2

[0076] ​1. The four-section lead plate 41 is wrapped in a four-section lead plate 41, and the four-section lead plate 41 and the outer compact carbon steel plate, i.e. the inner fixed plate 51, are wrapped synchronously, effectively reducing the flowability of the lead plate 41 and reducing the construction difficulty.

[0077] 2. Each layer of lead plate 41 is staggered, and the interface of each layer of lead plate 41 is filled with lead water pouring and filling after two wrappings, and the excess lead is removed mechanically after the lead water is cooled, thereby realizing the splicing of each layer of lead plate 41, improving the uniformity of the lead plate 41, and effectively ensuring the shielding effect of the lead plate 41.

[0078] 3. The carbon steel plate, i.e. the inner fixed plate 51 and the outer fixed plate 61, are spliced by welding, and the carbon steel plate welding port is isolated from the lead plate 41 by glass fiber heat insulation cloth before welding to prevent the lead plate 41 from melting and improve the uniformity of the lead plate 41.

[0079] 4. The lead plate 41 has high adhesion to the outer wall of the inner cylinder 1 and the inner wall of the inner fixed plate 51, and the lead plate 41 is compact and not prone to dislocation during long-term use.

[0080] By implementing the present application, the following beneficial effects are achieved:

[0081] The cylinder manufacturing method of the nuclear power plant pressure vessel shielding top cover can effectively make the lead plate 41 adhere to the surface of the inner cylinder 1, improve the uniformity of the thickness of the lead plate 41 on the circumference of the inner cylinder 1, reduce the deviation, dislocation, wrinkles, bulges and other conditions during the wrapping process of the lead plate 41, reduce the manufacturing and construction difficulty, improve the wrapping precision of the lead plate 41, and effectively reduce the flowability of the lead plate 41.

[0082] The inner cylinder of the cylinder structure can be tightly adhered to the lead plate layer, the adjacent lead plate layer, the lead plate layer and the lead inner fixed cylinder, the inner fixed cylinder and the outer fixed cylinder, and the adjacent outer fixed cylinder, the axial edge of the multi-layer lead plate is arranged in dislocation, the gap between the adjacent lead plates in the same layer is filled by pouring lead water, the splicing of each lead plate layer is realized, the uniformity of the lead plate is improved, and the shielding effect of the lead plate is effectively ensured, and the lead plate is not prone to dislocation during long-term use.

[0083] It can be understood that the above embodiments only express the preferred embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present application; it should be noted that for ordinary skilled persons in the art, the above embodiments or technical features can be freely combined without departing from the concept of the present application, and a number of modifications and improvements can be made, which all belong to the protection scope of the present application, i.e. the embodiments described in "in some embodiments" can be freely combined with any of the above and below embodiments; therefore, any equivalent transformation and modification within the scope of the claims of the present application shall belong to the scope of the claims of the present application.

Claims

1. A method of manufacturing a cylinder of a containment vessel shield head of a nuclear power plant, characterized by, The method comprises the following steps: S000: connecting and fixing the inner cylinder (1) with the upper flange surface (2) and the lower flange surface (3) respectively; S100: sequentially laying multiple layers of lead plates (41) in the same position of the inner cylinder (1) in the radial direction, the adjacent layers of lead plates (41) being tightly fitted, and the axial edges of the multiple layers of lead plates (41) being sequentially misaligned from inside to outside; Wherein, the inner cylinder (1) is placed transversely, the first end of the lead plate (41) abuts against the lower flange surface (3), and the second end of the lead plate (41) leaves a gap with the upper flange surface (2); S200: pouring lead water to fill the gap, and waiting for the lead water to solidify to form a lead water layer (7); S300: laying a first heat insulation layer (8) on the outer side of the first end and the outer side of the second end of the outermost layer of lead plates (41); S400: laying an inner layer fixing plate (51) on the outermost layer of lead plates (41) and tightly fitting the inner layer fixing plate (51) with the outermost layer of lead plates (41), the axial edges of the outermost layer of lead plates (41) being misaligned with the axial edges of the inner layer fixing plate (51), and the two ends of the inner layer fixing plate (51) being welded and fixed with the upper flange surface (2) and the lower flange surface (3) respectively; S500: repeating steps S100-S400 along the circumference of the inner cylinder (1) several times to finally form multiple cylinder-shaped lead plate layers (4) and cylinder-shaped inner layer fixing cylinders (5); S600: laying several layers of outer layer fixing cylinders (6) outside the inner layer fixing cylinder (5).

2. The method of manufacturing a cylinder of a nuclear power plant pressure vessel shield head according to claim 1, characterized in that, Step S500 further comprises laying a second heat insulation layer (9) at a specific position outside the outermost layer of lead plates (41), and sequentially welding and fixing adjacent inner layer fixing plates (51) along the circumference of the inner cylinder (1); The specific position is opposite to the axial edge of the inner layer fixing plate (51).

3. The method of manufacturing a cylinder of a nuclear power plant pressure vessel shield head according to claim 1, characterized in that, One piece of the lead plate (41) is 1 / 4 of the total cylinder volume of the lead plate layer (4), and one piece of the inner layer fixing plate (51) is 1 / 4 of the total cylinder volume of the layer; In step S500, steps S100-S400 are repeated three times along the circumference of the inner cylinder.

4. The method of manufacturing a cylinder of a nuclear power plant pressure vessel shield head according to claim 1, characterized in that, In step S600, the number of outer layer fixing cylinders (6) is at least two, each outer layer fixing cylinder (6) comprises the same number of outer layer fixing plates (61) as the inner layer fixing plates (51), and the axial edges of the inner layer fixing plates (51) and the axial edges of the outer layer fixing plates (61) of at least two layers are sequentially misaligned from inside to outside; The two outer layer fixing plates (61) on the same layer of the outer layer fixing cylinder are welded and fixed.

5. The method of manufacturing a cylinder of a nuclear power plant pressure vessel shield head according to claim 1, characterized in that, In step S000, the surface of the inner cylinder (1) is polished so that the depth of the pits on the outer surface of the inner cylinder (1) is less than or equal to 0.25mm, and the depth of the scratches is less than or equal to 0.2mm.

6. The method of manufacturing a cylinder of a containment vessel shield head of a nuclear power plant according to any one of claims 1 to 5, characterized in that, In step S400, the inner layer fixing plate (51) is tightly held with the lead plate (41) by using a hoop so that the inner layer fixing plate (51) is tightly fitted with the outermost layer of lead plates (41); After welding and fixing, the weld between the inner layer fixing plate (51) and the upper flange surface (2) and the lower flange surface (3) is polished so that the weld is flush with the surface of the inner layer fixing plate (51); After determining that the lead plate (41) is compacted, the hoop is removed.

7. The method of manufacturing a cylinder of a containment vessel shield head of a nuclear power plant according to any one of claims 1 to 5, characterized in that, The axial edge of the outermost lead plate (41) is offset from the axial edge of the inner layer fixing plate (51) by a distance greater than or equal to 50 mm.

8. The method of manufacturing a cylinder of a nuclear power plant pressure vessel shield head according to claim 2, characterized in that, The length of the first heat insulation layer (8) is greater than the arc length of the lead plate (41), and the width of the first heat insulation layer (8) is greater than or equal to 100 mm. The length of the second heat insulation layer (9) is greater than the axial height of the lead plate (41), and the width of the second heat insulation layer (9) is greater than or equal to 100 mm.

9. The method of manufacturing a cylinder of a containment vessel shield head of a nuclear power plant according to any one of claims 1 to 5, characterized in that, The number of lead plate layers (4) is four.

10. A cylinder structure manufactured using the cylinder manufacturing method according to any one of claims 1 to 9, characterized by It comprises an inner cylinder (1), an upper flange surface (2), a lower flange surface (3), a plurality of lead plate layers (4), an inner layer fixing cylinder (5) and a plurality of outer layer fixing cylinders (6), the inner cylinder (1) is connected and fixed with the upper flange surface (2) and the lower flange surface (3) respectively; a plurality of lead plate layers (4) are sleeved on the outer periphery of the inner cylinder (1) and are connected and fixed with the upper flange surface (2) and the lower flange surface (3) respectively; the inner layer fixing cylinder (5) is sleeved on the outer periphery of the outermost lead plate layer (4) and is connected and fixed with the upper flange surface (2) and the lower flange surface (3) respectively; a plurality of outer layer fixing cylinders (6) are sleeved on the inner layer fixing cylinder (5) and are connected and fixed with the upper flange surface (2) and the lower flange surface (3) respectively; Each of the lead plate layers (4) comprises a plurality of lead plates (41), the lead plates (41) adjacent to each other in the same lead plate layer (4) are connected and fixed by lead water through a gap; the adjacent stacked lead plates (41) are tightly fitted, and the axial edges of the plurality of lead plates (41) are sequentially offset from inside to outside.

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