A method for installing lower embedded parts of a nuclear power plant and a hoisting platform

Abstract

The present invention relates to the technical field of nuclear power plants, and particularly relates to an installation method for lower embedded parts of a nuclear power plant and a hoisting platform. An installation method for lower embedded parts of a nuclear power plant provided by the present invention includes respectively assembling the lower embedded parts and the hoisting platform; installing anchoring steel bars on the lower embedded parts, hoisting the lower embedded parts onto the hoisting platform, and placing them on the supporting members on the hoisting platform; assembling the steel structure frame at the top of the hoisting platform, and binding the civil engineering steel bars to the anchoring steel bars; hoisting the lower embedded parts and the hoisting platform together to the elevation position in the reactor core shaft, and then connecting the lower embedded parts with the main body of the civil engineering steel bars in the reactor core shaft. This installation construction method advances the binding work of the civil engineering steel bars to the module assembly stage, greatly reduces the occupation of the main line construction period, does not constitute cross-construction, improves the construction efficiency, reduces the cross-construction period of civil engineering installation, and reduces the safety risk.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power plants, and in particular to a method for installing lower embedded parts of a nuclear power plant and a hoisting platform. Background Art

[0002] The VVER-1200 nuclear reactor is a revolutionary development of the VVER-1000 nuclear power unit and is currently in use at numerous nuclear power plants in China. Compared to the "traditional" VVER-1000 AES-2006 unit, the VVER-1200 offers significant improvements in cost-effectiveness and safety. First, the unit's electrical output is increased by 20%. Second, the lifespan of key equipment—including the reactor pressure vessel and steam generator—has been extended from 30 years to 60 years. The high degree of automation and the use of new technologies have significantly reduced the number of operating personnel required for the unit, by 25% to 30% compared to the VVER-1000 unit.

[0003] The lower embedded parts of the support truss are an important component of the core shaft unique to the VVER reactor type. Their main function is to support the pressure vessel and reactor equipment. The current existing VVER reactor lower embedded parts and steel bar installation methods at home and abroad are:

[0004] 1. After the lower embedded parts arrive, they are prefabricated and assembled at the assembly site outside the nuclear island at the construction site. After assembly, the lower embedded parts are hoisted to the civil foundation in the nuclear island;

[0005] 2. In order from top to bottom, first complete the welding of 60 transverse anchor steel bars in the first layer, then tie several civil engineering ring bars and vertical bars on the first layer of transverse anchor steel bars, and then weld 60 transverse anchor steel bars in the second layer, then tie several civil engineering ring bars on the second layer of transverse anchor steel bars again, and tie the vertical bars to the second layer of transverse anchor steel bars, and so on until the transverse anchor welding of the tenth layer is completed.

[0006] Due to the limited space in the core shaft, installation can only be carried out by a cross-construction method. This has a long construction period, low construction efficiency, high difficulty in quality control, and occupies a long construction period of the main line of the nuclear island plant and has high labor costs. Summary of the Invention

[0007] (1) The problem to be solved by the present invention is that due to the limited space in the core shaft, the installation method of sequential cross-construction has a long construction period, low construction efficiency, high difficulty in quality control, and occupies a long construction period of the main line of the nuclear island plant and has high labor costs.

[0008] (2) Technical solution

[0009] A method for installing lower embedded parts of a nuclear power plant, comprising assembling the lower embedded parts and a hoisting platform separately;

[0010] Install the anchoring steel bars on the lower embedded part, hoist the lower embedded part onto the hoisting platform, and place it on the support on the hoisting platform;

[0011] Assemble the steel structure frame at the top of the hoisting platform, and tie the civil engineering steel bars to the anchoring steel bars;

[0012] Hoist the lower embedded part and the hoisting platform together to the elevation position in the core shaft, and then connect the lower embedded part to the main body of the civil engineering steel bars in the core shaft;

[0013] Install the embedded parts on the main body of the civil engineering steel bars in the core shaft, and weld the embedded parts to the lower embedded part;

[0014] Formwork and grout, remove the support on the hoisting platform, and hoist the hoisting platform out of the core shaft.

[0015] According to an embodiment of the present invention, the method for assembling the hoisting platform is to first group-weld the main frame and then weld the supports on the main frame;

[0016] The main frame is in a ring shape and includes multiple main rods. Multiple cross beams are welded between adjacent main rods. The supports are welded on the main rods and are perpendicular to the main rods.

[0017] According to an embodiment of the present invention, installing the anchoring steel bars on the lower embedded part includes: S1: Weld a circle of anchoring steel bars at a set height on the outer side wall of the lower embedded part;

[0018] S2: Move down or up by a fixed height and then weld another circle of anchoring steel bars;

[0019] S3: Repeat step S2 until all the anchoring steel bars are welded.

[0020] According to an embodiment of the present invention, the civil engineering steel bars include ring bars and vertical bars. According to the diameter from small to large, the ring bars are divided into four specifications, namely the first ring bar, the second ring bar, the third ring bar, and the fourth ring bar; the vertical bars are also divided into four specifications corresponding to the ring bars, namely the first vertical bar, the second vertical bar, the third vertical bar, and the fourth vertical bar;

[0021] Tying the civil engineering steel bars to the anchoring steel bars includes first tying the first ring bars layer by layer, then tying the first vertical bars on each column of anchoring steel bars, then tying the second ring bars and the second vertical bars layer by layer, and so on until the fourth ring bars and the fourth vertical bars are tied up.

[0022] According to an embodiment of the present invention, hoisting the lower embedded part and the hoisting platform together to the elevation position in the core shaft includes welding a plurality of lifting members on the top of the hoisting platform, hooking the lifting members on the top of the hoisting platform with a crane, and then hoisting the hoisting platform to the elevation position in the core shaft.

[0023] According to an embodiment of the present invention, before installing the embedded part, it further includes connecting the hoisting platform to the wall surface of the core shaft using stay cables to reinforce the hoisting platform.

[0024] According to an embodiment of the present invention, installing the embedded part on the civil engineering steel bar main body in the core shaft and welding the embedded part to the lower embedded part includes installing three embedded parts on the civil engineering steel bar main body, ensuring that the embedded parts are in contact with the bottom supporting surface of the lower embedded part, and then welding the embedded parts to the bottom supporting surface of the lower embedded part.

[0025] A hoisting platform for the above-mentioned method of installing the lower embedded part of a nuclear power plant includes a plurality of main rods, a plurality of cross beams, a plurality of support members and a steel structure frame;

[0026] The plurality of main rods are arranged along the circumferential direction to form a tubular frame, a plurality of cross beams are installed between adjacent two main rods, at least one support member is installed on each main rod, and the support member is perpendicular to the main rod;

[0027] The steel structure frame is an annular frame, the outer diameter of the annular frame is larger than the diameter of the tubular frame, the steel structure frame is installed on the top of the main rod, and the plurality of main rods are all connected to the steel structure frame.

[0028] According to an embodiment of the present invention, four cross beams are sequentially installed between adjacent two main rods, namely the first cross beam, the second cross beam, the third cross beam and the fourth cross beam. The first cross beam is close to the bottom end of the main rod, the fourth cross beam is located at the top end of the main rod, the support member is located on the upper surface of the second cross beam and is fixed to the second cross beam.

[0029] According to an embodiment of the present invention, the steel structure frame includes a plurality of connecting rods, a plurality of diagonal rods, a plurality of extension rods and a plurality of reinforcing rods;

[0030] One extension rod and one diagonal rod are vertically installed on each main rod. The diagonal rod is located above the extension rod. One end of the diagonal rod is fixed to the main rod, and the other end of the diagonal rod is fixed to the free end of the extension rod. A triangular support structure is formed among the extension rod, the diagonal rod and the main rod;

[0031] At least one connecting rod is fixedly connected between adjacent two extension rods, and the connecting rod has the same height as the fourth cross beam.

[0032] Advantages of the present invention:

[0033] An installation method for the lower embedded parts of a nuclear power plant provided by the present invention includes separately assembling the lower embedded parts and the hoisting platform; installing anchor bars on the lower embedded parts, hoisting the lower embedded parts onto the hoisting platform, and placing them on the support members on the hoisting platform; assembling the steel structure frame at the top of the hoisting platform, and binding the civil engineering steel bars to the anchor bars; hoisting the lower embedded parts and the hoisting platform together to the elevation position in the reactor core shaft, and then connecting the lower embedded parts to the main body of the civil engineering steel bars in the reactor core shaft; installing embedded parts on the main body of the civil engineering steel bars in the reactor core shaft, and welding the embedded parts to the lower embedded parts; formwork support and grouting, removing the support members on the hoisting platform, and hoisting the hoisting platform out of the reactor core shaft.

[0034] This installation construction method advances the binding work of the civil engineering steel bars to the module assembly stage, greatly reducing the occupation of the main line construction period. And compared with the complex construction environment in the reactor core shaft, the binding of the anchor bars and the civil engineering steel bars can be independently completed separately at the assembly site, without cross-construction, improving the construction efficiency, reducing the cross-construction period of civil engineering installation, reducing the safety risk, improving the construction quality, shortening the main line construction period of the nuclear island building, and reducing the construction labor cost. Description of the Drawings

[0035] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is an assembly drawing of the hoisting platform, the lower embedded parts and the civil engineering steel bars provided by the embodiment of the present invention;

[0037] Figure 2 It is a front view of the hoisting platform, the lower embedded parts and the civil engineering steel bars provided by the embodiment of the present invention;

[0038] Figure 3 It is a structural diagram of the lower embedded parts and the civil engineering steel bars provided by the embodiment of the present invention;

[0039] Figure 4 It is a front view of the lower embedded parts and the civil engineering steel bars provided by the embodiment of the present invention;

[0040] Figure 5 It is a three-dimensional view of the hoisting platform provided by the embodiment of the present invention;

[0041] Figure 6The front view of the hoisting platform provided by the embodiment of the present invention;

[0042] Figure 7 The top view of the hoisting platform provided by the embodiment of the present invention.

[0043] Icon: 1 - Lower embedded part; 2 - Hoisting platform; 201 - Main rod; 202 - First cross beam; 203 - Second cross beam; 204 - Third cross beam; 205 - Fourth cross beam; 206 - Hoisting member; 207 - Support member; 208 - Extension rod; 209 - Connecting rod; 210 - Diagonal rod; 211 - Reinforcing rod; 3 - Ring reinforcement; 4 - Vertical reinforcement; 5 - Anchor reinforcement. Specific embodiments

[0044] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0045] Embodiment 1:

[0046] As Figures 1 - 7 shown, an embodiment 1 of the present invention provides a method for installing the lower embedded part of a nuclear power plant, including separately assembling the lower embedded part 1 and the hoisting platform 2;

[0047] Install the anchor reinforcement 5 on the lower embedded part 1, hoist the lower embedded part 1 onto the hoisting platform 2, and place it on the support member 207 on the hoisting platform 2;

[0048] Assemble the steel structure frame at the top of the hoisting platform 2, and tie the civil engineering steel bars to the anchor reinforcement 5;

[0049] Hoist the lower embedded part 1 and the hoisting platform 2 together to the elevation position in the core shaft, and then connect the lower embedded part 1 to the main body of the civil engineering steel bars in the core shaft;

[0050] Install the embedded part on the main body of the civil engineering steel bars in the core shaft, and weld the embedded part to the lower embedded part 1;

[0051] Formwork and grouting, remove the support member 207 on the hoisting platform 2, and hoist the hoisting platform 2 out of the core shaft.

[0052] The implementation process of the present invention is divided into five stages, namely module assembly, overall hoisting, connection and reinforcement of the module in place with the civil engineering foundation steel bars, formwork support and grouting, and lifting away the hoisting platform 2. Compared with the original construction process, after the lower embedded part 1 is hoisted in place to the reactor core shaft, the welding of 600 anchor steel bars 5 in total for the 1st to 10th floors and the binding of several civil engineering steel bars with the anchor steel bars 5 of the lower embedded part 1 are carried out layer by layer. This installation construction method advances the binding work of the civil engineering steel bars to the module assembly stage, greatly reducing the occupation of the main line construction period. And compared with the complex construction environment in the reactor core shaft, the binding of the anchor steel bars 5 and the binding of the civil engineering steel bars can be independently completed at the assembly site respectively, without cross construction, improving the construction efficiency, reducing the cross construction period of civil engineering installation, reducing the safety risk, improving the construction quality, shortening the main line construction period of the nuclear island plant building, and reducing the construction labor cost.

[0053] The following is a detailed description of the above five stages. Specifically, the module assembly includes the following steps: assembly of the lower embedded part 1, fabrication of the hoisting platform 2, welding of the anchor steel bars 5, pre-installation of the hoisting platform 2 and the lower embedded part 1, binding of the civil engineering steel bars, and installation of the steel structure frame.

[0054] The assembly of the lower embedded part 1 is carried out on a platform built at the construction site. The assembly of the lower embedded part 1 can be carried out according to the existing assembly method, and the assembly method will not be described in detail here.

[0055] It should be noted that flanges are respectively provided at the top of the lower embedded part 1, and a support surface is formed at its bottom.

[0056] The fabrication of the hoisting platform 2 is also carried out at the construction site. As Figure 5 shown, the fabrication of the hoisting platform 2 specifically includes: first, a plurality of main rods 201 are vertically arranged in sequence at the construction site, and the main rods 201 are arranged in a circular ring frame in sequence around the circumferential direction. Then, a first cross beam 202, a second cross beam 203, a third cross beam 204 and a fourth cross beam 205 are welded in sequence between two adjacent main rods 201. Among them, the first cross beam 202 is close to the bottom end of the main rod 201, the fourth cross beam 205 is located at the top of the main rod 201, the third cross beam 204 is close to the fourth cross beam 205, and the second cross beam 203 is located between the third cross beam 204 and the first cross beam 202. Then, a lifting member 206 is welded to the top of each main rod 201 for subsequent hoisting of the hoisting platform 2, and two support members 207 are welded to both sides of each main rod 201 respectively. At the same time, the support members 207 are placed on the upper surface of the second cross beam 203, and the support members 207 are welded to the second cross beam 203.

[0057] It should be noted that the support member 207 is a support plate. One end of the support plate is welded to the main rod 201, and the other end thereof points in a direction away from the axis of the annular frame, that is, the projection of the free end of the support member 207 on the ground falls outside the annular frame.

[0058] It should be noted that the main structure of the hoisting platform 2 has not been completed yet, and a steel structure frame needs to be installed later. This is because when installing the lower embedded part 1, if the steel structure frame is erected first, it will hinder the positioning of the lower embedded part 1, resulting in the lower embedded part 1 being unable to be hoisted onto the hoisting platform 2.

[0059] In addition, the assembly of the lower embedded part 1 and the fabrication of the hoisting platform 2 can be carried out synchronously, or the lower embedded part 1 can be assembled first and then the hoisting platform 2, or the hoisting platform 2 can be assembled first and then the lower embedded part 1.

[0060] Next, the welding of the anchor bars 5 is carried out. Specifically, 600 anchor bars 5 are welded layer by layer to the outer side wall of the lower embedded part 1, with a total of ten layers, and each layer has 60 anchor bars 5.

[0061] It should be noted that the first anchor bar 5 of the first layer and the first anchor bars 5 of the remaining nine layers are in the same column.

[0062] Next, a pre-installation of the hoisting platform 2 and the lower embedded part 1 is carried out. Specifically, a crane is used to hoist the lower embedded part 1 onto the hoisting platform 2, so that the lower embedded part 1 penetrates from the top of the hoisting platform 2 into the hoisting platform 2. Subsequently, as the lower embedded part 1 moves downward, the bottom support surface of the lower embedded part 1 will fall on the support member 207, and the support member 207 thus supports the lower embedded part 1.

[0063] Finally, the binding of the civil engineering steel bars is carried out. The civil engineering steel bars include the ring bars 3 and the vertical bars 4, as Figure 3 and Figure 4 shown. The ring bars 3 are annular bars, and the ring bars 3 are divided into four specifications, and the diameters of each specification are different. The diameters of the four specifications of ring bars 3 increase in sequence, but the diameter of the smallest specification of ring bars 3 is still larger than the diameter of the lower embedded part 1 to ensure that the ring bars 3 of the smallest specification can also be placed on the anchor bars 5.

[0064] In the order of increasing diameter from small to large, the ring bars are divided into four specifications, namely the first ring bar, the second ring bar, the third ring bar, and the fourth ring bar.

[0065] Specifically, the vertical bars 4 are U-shaped, and the vertical bars 4 are also divided into four specifications, namely the first vertical bar, the second vertical bar, the third vertical bar, and the fourth vertical bar. The widths between the left and right of the four specifications of vertical bars 4 are different, and four vertical bars 4 are bound to each column of anchor bars 5.

[0066] When binding the ring bars 3 and vertical bars 4, as Figure 3 shown, in the installation order from top to bottom, first bind the first ring bar to the first layer of anchor bars 5, then bind the first ring bar to the second layer of anchor bars 5 until it is bound to the anchor bars 5 of the tenth layer. Immediately, bind a first vertical bar at the anchor bars 5 of each column, bind the first vertical bar to the first ring bar and the anchor bars 5 of this column. After all the first vertical bars are bound, then layer by layer bind the second ring bar to the anchor bars 5, and then bind a second vertical bar at the anchor bars 5 of each column, bind the second vertical bar to the second ring bar and the anchor bars 5 of this column. Follow this binding step until the fourth ring bar and the fourth vertical bar are bound.

[0067] Among them, as Figure 2 shown, the lowest ends of the four specifications of vertical bars 4 are all lower than the anchor bars 5 of the tenth layer to ensure that both the anchor bars 5 and the ring bars 3 of the tenth layer can be bound to the vertical bars 4.

[0068] Since the installation work of the anchor bars 5, ring bars 3 and vertical bars 4 is all completed at the construction site outside the reactor cavity shaft and there is no need to carry out it inside the reactor cavity shaft, the construction difficulty is reduced, the safety hazard of the operators inside the nuclear island is reduced, the labor cost is saved, the amount of scaffolding erection and the use cost of tower cranes are reduced.

[0069] After the equipment is in place, since welding the anchor bars 5 and binding the steel bars inside the reactor cavity shaft will cause the displacement of the lower embedded parts 1, while in this embodiment, completing the above work at the construction site outside the reactor cavity shaft can avoid the displacement problem of the lower embedded parts 1.

[0070] Preferably, after the civil engineering steel bars are bound, the installation of the steel structure frame is carried out next.

[0071] As Figure 1 and Figure 2 shown, in order to facilitate the hoisting of the lifting platform 2, a steel structure frame needs to be installed on the top of the lifting platform 2 before hoisting, so that the lifting equipment is connected to the steel structure frame, and then the lifting platform 2 is hoisted.

[0072] Combined with Figure 1 、 Figure 2 、 Figure 5 、 Figure 6 and Figure 7, the installation of the steel structure frame is described in detail. Specifically, an extension rod 208 is welded to each main rod 201. One end of the extension rod 208 is welded to the main rod 201. The extension rod 208 is perpendicular to the main rod 201 and has the same height as the third cross beam 204. The projection of the free end of the extension rod 208 on the ground does not fall inside the lifting platform 2. Then, an inclined rod 210 is welded to each extension rod 208. One end of the inclined rod 210 is welded to the free end of the extension rod 208, and the other end is welded to the top end of the main rod 201. In this way, a triangular structure is formed among the extension rod 208, the inclined rod 210, and the main rod 201.

[0073] Then, a connecting rod 209 is welded between two adjacent extension rods 208. The connecting rod 209 is parallel to the third cross beam 204. The first end of the connecting rod 209 is welded to the free end of one extension rod 208, and the other end is welded to the free end of the other extension rod 208.

[0074] Finally, several reinforcing rods 211 are welded between the third cross beam 204 and the connecting rod 209. Preferably, one reinforcing rod 211 is installed.

[0075] In this way, the bottom support surface of the lower embedded part 1 is placed on the support member 207 of the lifting platform 2, and the top flange surface of the lower embedded part 1 is in contact with the lower surface of the extension rod 208 and the lower surface of the reinforcing rod 211. In this way, the lower embedded part 1 is limited between the support member 207 and the steel structure frame, improving the stability of the lower embedded part 1 and enabling the lower embedded part 1 to remain stable during the lifting process.

[0076] Preferably, after the installation of the steel structure frame, at this time, the vertical bars 4 and the circular bars 3 are both pressed on the anchor bars 5. In order to reduce the burden on the anchor bars 5, slings or suspension tools are installed on the connecting rod 209 and the extension rod 208 of the steel structure frame. The slings or suspension tools are connected to the vertical bars 4, thereby pulling the vertical bars 4 so that the weight of the vertical bars 4 does not all press on the anchor bars 5, thus reducing the burden on the anchor bars 5 and avoiding the deformation of the anchor bars 5.

[0077] The second stage is the overall lifting stage, the purpose of which is to lift the lower embedded part 1 and the lifting platform 2 together to the internal elevation position of the reactor core shaft. Specifically, a lifting device is used for lifting.

[0078] During lifting, multiple slings or ropes are added to the hook of the lifting device, and then the other ends of the multiple slings or ropes are respectively tied to the lifting parts 206 at the top of the main rod 201, and then it can be lifted to the elevation position inside the reactor core shaft.

[0079] Preferably, the number of slings is the same as that of the main rod 201 to ensure the safety and stability of lifting and make the force more uniform.

[0080] The third stage is the connection and reinforcement with the civil engineering foundation steel bars after the module is in place.

[0081] Specifically, it includes the following steps:

[0082] First, connect the lower embedded part 1 and the civil engineering steel bars with the main body of the civil engineering steel bars in the reactor core shaft, and then install stay cables and inclined supports on the inner wall of the reactor core shaft. Both the stay cables and the inclined supports are located below the bottom of the hoisting platform 2. Connect the stay cables and the inclined supports to the bottom and top positions of the hoisting platform 2. Then, use sleeves to connect between the vertical steel bars 4 and the main body of the civil engineering steel bars. Finally, install three embedded parts on the main body of the civil engineering steel bars to ensure that the embedded parts are in contact with the bottom support surface of the lower embedded part 1, and then weld the embedded parts to the bottom support surface of the lower embedded part 1 to support the lower embedded part 1 through the embedded parts.

[0083] The fourth stage is formwork support and grouting. Specifically, formwork support is carried out at the elevation position, and then grouting is carried out to integrate the lower embedded part 1, the civil engineering steel bars and the main body of the civil engineering steel bars in the reactor core shaft.

[0084] Formwork support and grouting are part of the existing construction procedures, so they will not be described in detail here.

[0085] The fifth stage is to lift away the hoisting platform 2, which specifically includes the following steps: first, remove the stay cables and the inclined supports, then remove the support members 207 on the hoisting platform 2, then use the hoisting equipment to lift the hoisting platform 2, and the hoisting platform 2 is pulled out from the lower embedded part 1. Finally, the hoisting equipment lifts the hoisting platform 2 out of the reactor core shaft and places it on the construction site.

[0086] Constructing according to this method eliminates the problem of long cycle caused by cross-construction of the lower embedded part 1 and the civil engineering steel bars during the installation construction process, reduces the construction safety risk, and reduces the difficulty of quality control.

[0087] This embodiment changes the construction thinking to a certain extent, enables in-depth cooperation between civil engineering and installation, eliminates the boundary, unifies the construction benchmark, effectively reduces the interfaces, directly improves the construction quality and construction safety, indirectly improves the construction efficiency, and reduces the construction cost.

[0088] Embodiment 2:

[0089] As Figure 5 and Figure 7 shown, Embodiment 2 of the present invention provides a hoisting platform, which includes a plurality of main rods 201, a plurality of cross beams, a plurality of support members 207 and a steel structure frame;

[0090] A plurality of main rods 201 are arranged along the circumferential direction to form a tubular frame. A plurality of cross beams are installed between two adjacent main rods 201. At least one support member 207 is installed on each main rod 201, and the support member 207 is perpendicular to the main rod 201;

[0091] The steel structure frame is an annular frame. The outer diameter of the annular frame is larger than the diameter of the tubular frame. The steel structure frame is installed on the top of the main rod 201, and all the plurality of main rods 201 are connected to the steel structure frame.

[0092] Preferably, ten main rods 201 are provided. The specifications of the ten main rods 201 are the same. The ten main rods 201 are arranged in sequence to form a tubular frame.

[0093] Preferably, four cross beams are sequentially installed between two adjacent main rods 201, which are the first cross beam 202, the second cross beam 203, the third cross beam 204 and the fourth cross beam 205 from bottom to top. The first cross beam 202 is close to the bottom end of the main rod 201, and the fourth cross beam 205 is located at the top end of the main rod 201. Among them, the first cross beam 202 and the fourth cross beam 205 mainly play the role of connecting the main rods 201 to ensure the stability of the platform.

[0094] Furthermore, the support member 207 is a rod body or a plate body. A support member 207 is welded on each side of each main rod 201, and the support member 207 is located on the upper surface of the second cross beam 203. The support member 207 is fixedly welded to the second cross beam 203. In addition to connecting the main rods 201, the second cross beam 203 can also play the role of supporting the support member 207, thereby improving the bearing capacity of the support member 207 and ensuring that the lower embedded part 1 can be stably placed on the support member 207.

[0095] Optionally, the support member 207 is connected to the main rod 201 by bolts, and the support member 207 is also connected to the second cross beam 203 by bolts.

[0096] Preferably, as Figure 5 shown, the steel structure frame includes ten connecting rods 209, ten diagonal rods 210, ten extension rods 208 and a plurality of reinforcing rods 211;

[0097] Specifically, an extension rod 208 is welded on each main rod 201. One end of the extension rod 208 is welded to the main rod 201. The extension rod 208 is perpendicular to the main rod 201. The extension rod 208 has the same height as the third cross beam 204. The projection of the free end of the extension rod 208 on the ground does not fall into the interior of the hoisting platform 2.

[0098] Weld a diagonal rod 210 on each extension rod 208. One end of the diagonal rod 210 is welded to the free end of the extension rod 208, and the other end is welded to the top end of the main rod 201. In this way, a triangular structure will be formed among the extension rod 208, the diagonal rod 210 and the main rod 201. The diagonal rod 210 pulls the extension rod 208 to improve the stability of the steel structure frame.

[0099] Preferably, a connecting rod 209 is welded between every two adjacent extension rods 208. The connecting rod 209 is parallel to the third cross beam 204. The first end of the connecting rod 209 is welded to the free end of one extension rod 208, and the other end is welded to the free end of another extension rod 208. The bottom end of the diagonal rod 210 is also welded to the connecting rod 209.

[0100] Furthermore, a reinforcing rod 211 is welded between the third cross beam 204 and the connecting rod 209. The number of the reinforcing rods 211 can be selected according to the actual situation. For example, three or five reinforcing rods can be welded.

[0101] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0102] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the connection inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. In addition, in the description of the present invention, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0103] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for installing lower embedded parts of a nuclear power plant, characterized in that, Including separately assembling the lower embedded parts and the hoisting platform; Installing anchor bars on the lower embedded parts, hoisting the lower embedded parts onto the hoisting platform, and placing them on the supports on the hoisting platform; Assembling the steel structure frame at the top of the hoisting platform and tying the civil engineering steel bars to the anchor bars; Hoisting the lower embedded parts and the hoisting platform together to the elevation position in the reactor core shaft, and then connecting the lower embedded parts to the main body of the civil engineering steel bars in the reactor core shaft; Installing embedded parts on the main body of the civil engineering steel bars in the reactor core shaft and welding the embedded parts to the lower embedded parts; Formwork support and grouting, removing the supports on the hoisting platform, and hoisting the hoisting platform out of the reactor core shaft.

2. The installation method of the lower embedded parts of a nuclear power plant according to claim 1, characterized in that, The method for assembling the hoisting platform is to first weld and assemble the main frame, and then weld the supports on the main frame; The main frame is a ring-shaped frame, the main frame includes multiple main rods, and multiple cross beams are welded between two adjacent main rods. The supports are welded on the main rods and are perpendicular to the main rods.

3. A method for installing the lower embedded parts of a nuclear power plant according to claim 2, characterized in that, Installing anchor bars on the lower embedded parts includes: S1: Welding a circle of anchor bars at a set height on the outer side wall of the lower embedded parts; S2: Moving down or up a fixed height and then welding another circle of anchor bars; S3: Repeating step S2 until all anchor bars are welded.

4. A method for installing the lower embedded parts of a nuclear power plant according to claim 3, characterized in that, The civil engineering steel bars include hoop bars and vertical bars. According to the diameter from small to large, the hoop bars are divided into four specifications, namely the first hoop bar, the second hoop bar, the third hoop bar, and the fourth hoop bar; the vertical bars are also divided into four specifications corresponding to the hoop bars, namely the first vertical bar, the second vertical bar, the third vertical bar, and the fourth vertical bar; Tying the civil engineering steel bars to the anchor bars includes: First, tying the first hoop bar layer by layer, then tying the first vertical bar on each column of anchor bars, then tying the second hoop bar and the second vertical bar layer by layer, and so on until the fourth hoop bar and the fourth vertical bar are tied up.

5. A method for installing lower embedded parts of a nuclear power plant according to claim 1, characterized in that, Hoisting the lower embedded parts and the hoisting platform together to the elevation position in the reactor core shaft includes: Multiple lifting parts are welded on the top of the hoisting platform. Using a crane to hook the lifting parts on the top of the hoisting platform, and then hoisting the hoisting platform to the elevation position in the reactor core shaft.

6. A method for installing lower embedded parts of a nuclear power plant according to claim 1, characterized in that, Before installing the embedded parts, it also includes using stay cables to connect the hoisting platform to the wall of the reactor core shaft to reinforce the hoisting platform.

7. A method for installing lower embedded parts of a nuclear power plant according to claim 1, characterized in that, Installing the embedded parts on the main body of the civil engineering steel bars in the reactor core shaft and welding the embedded parts to the lower embedded parts includes: Installing three embedded parts on the main body of the civil engineering steel bars, ensuring that the embedded parts are in contact with the bottom support surface of the lower embedded parts, and then welding the embedded parts to the bottom support surface of the lower embedded parts.

8. A hoisting platform for use in the method for installing the lower embedded parts of a nuclear power plant according to any one of claims 1-7, characterized in that, Including multiple main rods, multiple cross beams, multiple supports, and a steel structure frame; The multiple main rods are arranged along the circumferential direction to form a tubular frame. Multiple cross beams are installed between two adjacent main rods. At least one support is installed on each main rod, and the support is perpendicular to the main rod; The steel structure frame is a ring-shaped frame. The outer diameter of the ring-shaped frame is larger than the diameter of the tubular frame. The steel structure frame is installed on the top of the main rods, and all the multiple main rods are connected to the steel structure frame.

9. The lifting platform according to claim 8, wherein, Four crossbeams, namely the first crossbeam, the second crossbeam, the third crossbeam and the fourth crossbeam, are successively installed between two adjacent main poles. The first crossbeam is close to the bottom end of the main pole, the fourth crossbeam is located at the top end of the main pole, and the support is located on the upper surface of the second crossbeam and is fixed to the second crossbeam.

10. A hoisting platform according to claim 9, characterized in that, The steel structure frame includes a plurality of connecting rods, a plurality of diagonal rods, a plurality of extension rods and a plurality of reinforcing rods; One extension rod and one diagonal rod are vertically installed on each main pole. The diagonal rod is located above the extension rod. One end of the diagonal rod is fixed to the main pole, and the other end of the diagonal rod is fixed to the free end of the extension rod. A triangular support structure is formed among the extension rod, the diagonal rod and the main pole; At least one connecting rod is fixedly connected between two adjacent extension rods, and the connecting rod is at the same height as the fourth crossbeam.

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