Nuclear power station large-scale equipment modular transfer platform and installation method thereof

Abstract

The invention discloses a nuclear power station large-scale equipment modular transfer platform and an installation method thereof, and the platform comprises an installation platform which is suitable for containing nuclear power station large-scale equipment; the supporting structure is arranged below the mounting platform and is used for supporting the mounting platform; the climbing structure is arranged on the supporting structure; and the working platform is arranged on the supporting structure, and the climbing structure penetrates through the working platform, so that an operator can conveniently move to the working platform through the climbing structure to work. The working platform is integrated on the supporting structure, and the climbing structure is designed to penetrate through the working platform, so that a special bolt mounting / dismounting operation space is provided for operators. Scaffolds do not need to be erected, time consumption and material consumption caused by layer-by-layer erecting of the scaffolds are avoided, and the material turnover cost is remarkably reduced. An operator can directly reach the working platform through the climbing structure and does not need to work on a high-altitude adjacent scaffold, so that the high-altitude falling accident rate can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of large-scale equipment installation in nuclear power plants, and in particular to a modular transfer platform for large-scale equipment in nuclear power plants and an installation method thereof. Background Art

[0002] During the equipment installation phase of a certain third-generation nuclear power unit, oversized equipment, such as steam generators (approximately 500 tons) and reactor pressure vessels, required high-altitude transport via a transfer platform. Conventional technology utilizes a transfer platform consisting of steel columns, main beams, and supporting structures. After heavy-load or light-load transport vehicles are hoisted to the 17.5-meter-high platform via a gantry crane, operators must then install or remove bolts between the steel columns and the bridge, and between the column groups.

[0003] Traditional transfer platforms have the following technical defects:

[0004] 1. Lack of working space: Dedicated working platforms were not provided at the joints between the steel columns and the bridge frame, or at the connections between the column supports and the steel columns. Workers had to erect 15-20m-high scaffolding to reach their work locations. The scaffolding had to be built layer by layer, and a single set of scaffolding took approximately three days to erect. It also required approximately 200 steel pipes and 50 scaffolding boards, resulting in high material turnover costs.

[0005] 2. Significant safety risks: Scaffolding operations involve working at height and near edges. Statistics show that the incidence of falls from height is 4-6 times higher than that of ground-based operations. Furthermore, there is a risk of falling components during scaffolding erection, posing a safety threat to equipment and personnel below. Furthermore, the scaffolding lacks a rigid connection to the main structure of the transfer platform, making it prone to shaking in winds exceeding force 6, necessitating complex safety measures.

[0006] 3. Inefficient construction: Scaffolding erection, dismantling, and safety inspection processes consume 25%-30% of the total construction period. For example, on a nuclear power project, scaffolding work on a single transfer platform consumed 60 man-hours and was significantly affected by weather (work had to be suspended on rainy days), resulting in delays on the critical path.

[0007] 4. Structural interference issues: The existing platform's workspace does not reserve inter-column support installation channels, requiring operators to operate within narrow gaps. The bolt tightening torque error reaches ±15%, which easily leads to the risk of connection failure. At the same time, traditional platforms mainly use welding as the connection method, and the fatigue damage rate of components after a single disassembly and assembly is as high as 10%, resulting in a low reuse rate.

[0008] Existing technologies address these issues primarily by adding temporary protective measures or optimizing scaffolding structures, but they fail to address the core issue of aerial work relying on external infrastructure within the transfer platform itself. Therefore, a modular transfer platform with integrated operational functions is urgently needed to enable efficient and safe bolting operations. Summary of the Invention

[0009] In view of this, the present invention provides a modular transfer platform for large equipment in nuclear power plants and an installation method thereof to solve the problem of high-altitude operations relying on external facilities, so that bolt installation, removal and other operations can be carried out inside the transfer platform without the need for manual scaffolding, thereby reducing construction costs, shortening construction period, and improving construction safety and efficiency.

[0010] In a first aspect, the present invention provides a modular transport platform for large-scale equipment in a nuclear power plant, comprising:

[0011] An installation platform, wherein the installation platform is suitable for holding large equipment in a nuclear power plant;

[0012] a supporting structure, the supporting structure being arranged below the mounting platform and supporting the mounting platform;

[0013] a climbing structure, the climbing structure being arranged on the supporting structure;

[0014] A working platform is provided on the supporting structure, and the climbing structure passes through the working platform so that workers can move to the working platform through the climbing structure to perform work.

[0015] The beneficial effects of the modular transfer platform for large nuclear power plant equipment are as follows:

[0016] By integrating a work platform onto the supporting structure and designing a climbing structure through the work platform, workers are provided with a dedicated space for bolt installation and removal. This eliminates the need for scaffolding, avoids the time-consuming and material-intensive layer-by-layer scaffolding construction, and significantly reduces material turnover costs.

[0017] The working platform is rigidly connected to the main structure of the transfer platform, which is different from the non-rigid connection of traditional scaffolding, avoiding the risk of shaking in strong winds; at the same time, workers can directly reach the working platform through the climbing structure, without having to work on the scaffolding at high altitude, which can effectively reduce the incidence of high-altitude fall accidents and reduce the safety threats to the equipment and personnel below caused by falling components during the scaffolding erection process.

[0018] The scaffolding erection, dismantling and safety acceptance processes are eliminated. Taking a nuclear power project as an example, 60 man-hours of scaffolding-related work can be reduced, and the impact of weather on the work is significantly reduced, avoiding delays in the critical path construction period.

[0019] The integrated design of the work platform reserves a dedicated channel for the installation of inter-column supports, preventing operators from operating in narrow gaps and reducing bolt tightening torque errors. At the same time, the work platform adopts a modular structure to reduce fatigue damage to components after a single disassembly and assembly, thereby increasing reuse rate.

[0020] In an optional embodiment, the support structure includes:

[0021] A steel beam platform, comprising a plurality of steel beams;

[0022] A plurality of steel columns are supported at the bottom end of the steel beam platform.

[0023] In an optional embodiment, the climbing structure includes:

[0024] A plurality of ladders are arranged on the outer wall surface of the steel column along the height direction of the steel column.

[0025] In an optional embodiment, a plurality of the working platforms are provided, and each of the working platforms is provided on the side wall of the steel column close to the steel beam platform.

[0026] In an optional embodiment, a rest platform is further provided on the side wall of the steel column, and the rest platform is located below the working platform. The climbing structure passes through the rest platform, so that the workers can move to the rest platform through the climbing structure to rest.

[0027] In an optional embodiment, an inter-column support is provided between two adjacent steel columns, and the inter-column supports are arranged obliquely and crosswise;

[0028] The working platform is an annular structure, and the circumferential size of the working platform completely covers the connection area between the steel column and the bridge frame and the inter-column support.

[0029] In an optional embodiment, the installation platform includes a first main beam and a second main beam, the first main beam and the second main beam are arranged in parallel and spaced apart, and the first main beam and the second main beam are both arranged on a steel beam platform;

[0030] The first main beam and the steel beam, the second main beam and the steel beam, and the steel beam and the steel column are all connected by high-strength bolts.

[0031] In an optional embodiment, an intelligent calibration system is further included, and the intelligent calibration system includes:

[0032] A sensor assembly is provided on the supporting structure, and includes a laser rangefinder and an inclination sensor. The laser rangefinder is suitable for real-time monitoring of the verticality of the supporting structure, and the inclination sensor is suitable for real-time monitoring of the horizontal displacement of the supporting structure.

[0033] an adjustment structure, the adjustment structure being disposed at the bottom end of the support structure and being adapted to adjust the verticality of the support structure;

[0034] A total station controls an adjustment structure based on a transmission signal from a sensor assembly.

[0035] In an optional embodiment, the adjustment structure includes:

[0036] An inclined washer is provided at the bottom end of the supporting structure;

[0037] The pushing component is connected to the inclined washer and can push the inclined washer to move so as to adjust the inclination of the supporting structure.

[0038] The beneficial effects of the above technical solution are: the steel column inclination data is collected in real time by sensors, the total station analyzes and issues instructions, and the driving component pushes the inclined pads to adjust the bottom support height of the steel column, ultimately realizing automated and high-precision adjustment of the inclination of the support structure, avoiding the errors and inefficiencies of traditional manual calibration.

[0039] In a second aspect, the present invention provides a method for installing a modular transfer platform for large-scale equipment in a nuclear power plant, comprising the following steps:

[0040] foundation construction;

[0041] Use a crane to lift the support structure and install the support structure;

[0042] Install the mounting platform on top of the supporting structure;

[0043] The installation of working platforms and climbing structures is carried out on the sides of the supporting structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 This is a structural schematic diagram of a modular transfer platform for large equipment in a nuclear power plant provided by the present invention.

[0046] Description of reference numerals:

[0047] 1. First main beam, 2. Second main beam, 3. First steel beam, 4. Second steel beam, 5. Third steel beam, 6. First steel column, 7. Second steel column, 8. Third steel column, 9. Fourth steel column, 10. First support, 11. Second support, 12. First platform column support, 13. Second platform column support, 14. Third platform column support, 15. Ladder, 16. Rest platform, 17. Working platform, 18. Installation platform. DETAILED DESCRIPTION

[0048] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0049] The specific embodiments of the present invention are described in detail below in conjunction with the modular transfer platform for large-scale equipment in nuclear power plants according to the first aspect of the present invention and the installation method of the modular transfer platform for large-scale equipment in nuclear power plants according to the second aspect of the present invention.

[0050] According to an embodiment of the present invention, a first aspect provides a modular transport platform for large equipment in a nuclear power plant, Figure 1 As shown, the system includes an installation platform 18, a support structure, a climbing structure, and a working platform 17. The installation platform is suitable for accommodating large nuclear power plant equipment. The support structure is positioned below and supports the installation platform. The climbing structure is positioned on the support structure. The working platform 17 is positioned on the support structure and passes through the working platform 17, allowing operators to climb the climbing structure to access the working platform 17 for work.

[0051] The modular transfer platform for large nuclear power plant equipment integrates a work platform 17 on the supporting structure and features a climbing structure that passes through the work platform, providing workers with a dedicated space for bolt installation and removal. This eliminates the need for scaffolding, avoiding the time-consuming and material-intensive layer-by-layer scaffolding construction and significantly reducing material turnover costs.

[0052] The working platform 17 is rigidly connected to the main structure of the transfer platform, which is different from the non-rigid connection of traditional scaffolding, avoiding the risk of shaking in strong winds; at the same time, workers can directly reach the working platform 17 through the climbing structure, without having to work on the scaffolding at high altitude, which can effectively reduce the incidence of high-altitude fall accidents and reduce the safety threats to the equipment and personnel below caused by falling components during the scaffolding erection process.

[0053] The scaffolding erection, dismantling and safety acceptance processes are eliminated. Taking a nuclear power project as an example, 60 man-hours of scaffolding-related work can be reduced, and the impact of weather on the work is significantly reduced, avoiding delays in the critical path construction period.

[0054] The integrated design of work platform 17 reserves a dedicated channel for the installation of inter-column supports, preventing operators from operating in narrow gaps and reducing bolt tightening torque errors. At the same time, work platform 17 adopts a modular structure to reduce fatigue damage to components after a single disassembly and assembly, thereby increasing reuse rate.

[0055] In some embodiments, the support structure includes a steel beam platform and steel columns.

[0056] The steel beam platform includes a plurality of steel beams. As a preferred embodiment, Figure 1 As shown, the steel beam platform is formed by five steel beams, namely the first steel beam 3, the second steel beam 4, the third steel beam 5, the fourth steel beam, and the fifth steel beam. The first steel beam 3 and the fourth steel beam are arranged horizontally and parallel to each other, while the second steel beam 4, the third steel beam 5, and the fifth steel beam are arranged horizontally and parallel to each other.

[0057] There are multiple steel columns, and the steel column supports are set at the bottom end of the steel beam platform. As a preferred embodiment, Figure 1 As shown, there are six steel columns, namely the first steel column 6, the second steel column 7, the third steel column 8, the fourth steel column 9, the fifth steel column and the sixth steel column, and the six steel columns are respectively arranged at the bottom end of the steel beam platform.

[0058] In some embodiments, the climbing structure includes multiple ladders 15, each of which is a double ladder, arranged on the outer wall of the steel column along the height direction of the steel column. The ladders 15 on the two opposing steel columns are arranged symmetrically. The ladders 15 are made of steel structure, and the steps are also made of non-slip patterned steel plates. The inclination angle of the ladder 15 is 60°-70°, and the step spacing is 300-350mm to facilitate climbing for operators. Guardrails are set on both sides of the ladder 15, with a railing height of 1.2m and a crossbar spacing of no more than 0.3m.

[0059] In some embodiments, a resting platform 16 is provided on the sidewall of the steel column, located below the working platform 17. A climbing structure extends through a through-hole in the platform 16, allowing workers to climb up to the platform 16 for rest. The platform 16 is positioned at an appropriate height above the steel column, providing a resting area for workers. Its dimensions are ergonomically designed, with a length of no less than 2 meters and a width of no less than 1.5 meters, and a load capacity of no less than 150 kg / m2.

[0060] In some embodiments, inter-column supports are provided between two adjacent steel columns, and the inter-column supports are arranged diagonally and crosswise. A first support 10 and a second support 11 can be provided between two steel columns distributed along the length direction, and the first and second supports 10 and 11 are arranged diagonally and crosswise and connected by a connection node. A first platform inter-column support 12, a second platform inter-column support 13, and a third platform inter-column support 14 can be provided between two steel columns distributed along the width direction, and the first and second platform inter-column supports 12 and 13 are arranged diagonally and crosswise, and the third platform inter-column support 14 is arranged horizontally between the two steel columns.

[0061] In some embodiments, a plurality of working platforms 17 are provided, and each working platform 17 is respectively provided on the side wall of the steel column near the steel beam platform. The working platform 17 is an annular structure, and its circumferential dimension completely covers the connection area between the steel column and the bridge frame and the inter-column support, and does not interfere with the inter-column support, ensuring that the operators have sufficient operating space. The load-bearing capacity of the working platform 17 is not less than 200kg / ㎡, and it can accommodate multiple operators and the tools they carry to work at the same time. The surface of the platform is made of anti-slip patterned steel plate with an anti-slip pattern depth of not less than 3mm and a friction coefficient of not less than 0.6 to ensure the walking safety of the operators.

[0062] In some embodiments, the installation platform includes a first main beam 1 and a second main beam 2. The first main beam 1 and the second main beam 2 are arranged in parallel and spaced apart. The first main beam 1 and the second main beam 2 are both set on the steel beam platform.

[0063] In some embodiments, the first main beam 1 and the steel beam, the second main beam 2 and the steel beam, and the steel beam and the steel column are all connected by high-strength bolts. This connection method is not only convenient for disassembly and reuse, but also effectively improves the disassembly and assembly efficiency.

[0064] Depending on the load conditions, high-strength bolts of M24 and M30 sizes are used. The tightening torque for M24 bolts is 500 N·m, and the tightening torque for M30 bolts is 800 N·m. The tightening torque must be strictly controlled in accordance with GB / T 1228 to ensure connection reliability and fatigue resistance.

[0065] Fatigue-resistant design: Special washers and nuts are used in bolt connections to reduce loosening and fatigue damage caused by long-term vibration and load. Furthermore, the steel surface at the connection is treated to enhance corrosion and fatigue resistance. Testing has shown that the fatigue damage rate of components after a single disassembly and assembly can be reduced to less than 5%, significantly increasing reuse rates.

[0066] In some embodiments, to ensure installation accuracy and stability of the transfer platform, the modular transfer platform for large nuclear power plant equipment also includes an intelligent calibration system, which includes a sensor assembly, an adjustment structure, and a total station. This system integrates a laser rangefinder with an inclination sensor to automatically calibrate the verticality of steel columns.

[0067] The sensor assembly, mounted on the support structure, includes a laser rangefinder and an inclination sensor. The laser rangefinder is used to monitor the verticality of the support structure in real time, while the inclination sensor is used to monitor the horizontal displacement of the support structure in real time. More specifically, a laser rangefinder and inclination sensor are installed at the top and bottom of each steel column to monitor its verticality and horizontal displacement in real time.

[0068] The adjustment structure is disposed at the bottom of the support structure and is suitable for adjusting the verticality of the support structure. The adjustment structure includes a tilted shim and a push assembly. The tilted shim is disposed at the bottom of the support structure. More specifically, three tilted shims can be disposed at the bottom of the steel column. The push assembly is an electric jack. The three tilted shims are typically arranged in a triangular pattern at the bottom of the steel column. By varying the relative positions of the tilted shims, the height difference of the support at the bottom of the steel column can be adjusted, thereby correcting the inclination angle of the steel column.

[0069] The pusher assembly is connected to the inclined shims and can move them to adjust the inclination of the supporting structure. After receiving control signals from the total station, the pusher assembly pushes the shims at specific locations in the desired direction. By adjusting the insertion depth or horizontal position of the shims, the height of each support point at the bottom of the steel column is changed, gradually reducing verticality errors.

[0070] The total station controls the adjustment structure based on the transmission signal of the sensor component. The signal output end of the sensor component is connected to the signal input end of the total station, and the controlled end of the driving component is connected to the output end of the total station.

[0071] Calibration principle and accuracy: The signal output end of the sensor assembly is connected to the total station. After receiving the real-time monitoring data, the total station uses a built-in algorithm to analyze whether the verticality and horizontal displacement of the steel column exceed the allowable range:

[0072] When the verticality error is less than or equal to the set range and the horizontal displacement is within the safe range, the system remains stable.

[0073] When the sensor detects that the verticality error of the steel column exceeds the allowable range (the error does not exceed H / 1000, where H is the height of the steel column), the system automatically sounds an alarm and automatically adjusts the shims using electric jacks to restore the verticality of the steel column to the allowable range. During the calibration process, the system uses a total station (with an accuracy of ±2") for real-time monitoring to ensure calibration accuracy.

[0074] In some embodiments, tool cabinets and material racks, such as bolt storage boxes and small power tool charging areas, are added to the work platform 17 or the rest platform 16 to avoid workers from frequently climbing up and down to retrieve objects, thereby reducing waste of work time.

[0075] Add windshields, local lighting, and ventilation devices to the aerial work platform to improve working comfort. The ventilation device can be a small axial flow fan to improve air circulation in confined spaces.

[0076] Power interfaces or small energy storage devices are reserved at key locations on the platform to provide local power supply for tools such as electric wrenches and bolt tighteners, avoiding safety hazards caused by long-distance dragging cables.

[0077] This modular transfer platform for large nuclear power plant equipment utilizes a modular, integrated design concept. Each steel column is equipped with a work platform 17, a resting platform 16, and a ladder 15. These components together form a fully enclosed workspace, enabling operations to be completed without the need for external scaffolding. This platform is suitable for the transfer of oversized equipment such as steam generators (weighing up to 500 tons) and reactor pressure vessels in third-generation nuclear power units. Through its modular, integrated work platform, fatigue-resistant connection structure, and intelligent calibration system, it addresses the technical challenges of traditional scaffolding solutions, including low efficiency, high risk, and operational blind spots.

[0078] The modular transfer platform for large nuclear power plant equipment has the following beneficial effects:

[0079] 1. Eliminate scaffolding dependence and significantly reduce construction costs and safety risks

[0080] This embodiment completely replaces the traditional 15-20m high-altitude scaffolding by integrating the working platform 17 and the rest platform 16 on the steel columns. A single platform can reduce the consumption of scaffolding materials (200 steel pipes / set, 50 scaffolding boards) and labor input (60 man-hours / set). According to calculations, the construction cost of a single project can be reduced by more than 60% (including material procurement, transportation, construction and dismantling costs).

[0081] Workers do not need to be exposed to the edge of the scaffolding. The platform is equipped with 1.2m high protective railings (compliant with GB 4053.3 standard), anti-slip pedals (friction coefficient ≥ 0.6) and double ladder safety passages, which reduce the risk of falling from heights from 4-6 times the safety hazards of traditional solutions to the equivalent ground operation risk. The incidence of safety accidents is expected to be reduced by 80%.

[0082] 2. Modular design enables efficient disassembly and assembly, shortening construction period by more than 40%.

[0083] Fast assembly and disassembly: The fully bolted structure (M24 / M30 high-strength bolts, tightening torque 500-800N·m) reduces the assembly and disassembly time of a single platform from 72 hours for a traditional welded structure to 40 hours, and the component reuse rate is ≥95% (the fatigue damage rate of a single assembly and disassembly is <5%), significantly reducing on-site construction waiting time.

[0084] Process optimization: The work platform 17 covers the entire working area of the steel columns, bridge frames, and inter-column supports (operating distance ≥ 500mm), avoiding the lengthy process of "scaffolding construction → aerial work → scaffolding dismantling" in traditional solutions. The critical path construction period can be shortened by 3-5 days per set, making it particularly suitable for parallel construction scenarios of multiple units.

[0085] 3. Precise structural design ensures operation quality and platform stability

[0086] Improved operating space and precision: The circular working platform (bearing capacity ≥ 200kg / ㎡) provides a working surface with no dead angles. Operators can directly tighten bolts with torque around the steel columns (error ≤ ±5%). Compared with the narrow space operation of traditional scaffolding, the working precision is improved by 3 times, and the hidden danger of "missed or under-tightened connection nodes" is completely eliminated.

[0087] Intelligent calibration and fatigue resistance: If equipped with an intelligent calibration system (laser rangefinder + inclination sensor), the verticality error of the steel column can be controlled within H / 1000 (H is the column height), which is four times more accurate than manual measurement (error ±20mm); the fatigue-resistant bolt connection design extends the overall life of the platform by 20%, meeting the high reliability requirements of long-term operation and maintenance of nuclear power plants.

[0088] 4. Green construction and sustainability

[0089] Bolted connections replace welding processes, reducing welding slag and exhaust emissions at the construction site, and complying with green construction standards for nuclear power projects;

[0090] Modular components can be prefabricated in a standardized manner and processed in factories. The on-site assembly error is ≤±3mm, reducing the material waste rate to below 5%, saving 30% of resources compared to traditional cast-in-place operations.

[0091] Technical Effect Comparison Table

[0092]

[0093] Through the three-dimensional innovation of "integrated working platform + modular connection structure + intelligent calibration system", this invention fundamentally solves the technical bottleneck of traditional transfer platforms relying on external scaffolding, and achieves systematic improvement in cost, efficiency, safety and reliability. It is particularly suitable for the transfer of oversized equipment of third-generation nuclear power units, and has significant engineering application value and industry promotion significance.

[0094] According to an embodiment of the present invention, in a second aspect, a method for installing a modular transfer platform for large equipment in a nuclear power plant is provided, comprising the following steps:

[0095] 1. Preparation before construction

[0096] 1. Site Preparation

[0097] Site selection requirements: Select a flat area with a geological bearing capacity ≥150kPa, use a total station to measure the site elevation, control the flatness error within ±5mm, and use a C30 concrete leveling layer to handle local height differences.

[0098] Safety isolation: A 1.8m high protective fence is set up around the site, a "No entry for high-altitude work" warning sign is hung, and a red warning light is set at night.

[0099] 2. Material and component inspection

[0100] Steel inspection:

[0101] The main beams and steel columns are made of Q345B steel with a yield strength of ≥345MPa and a tensile test elongation of ≥22%;

[0102] Section size inspection: Steel column section size deviation ±2mm, main beam height deviation ±3mm, use vernier caliper to select one inspection point every 2m;

[0103] Surface quality: no cracks, heavy skin, ultrasonic testing to detect internal defects.

[0104] Platform and ladder components:

[0105] The anti-slip steel plate of the working platform 17 is 6mm thick, with a texture depth of 3.5mm and a friction coefficient of ≥0.65 (GB / T 3960 test method).

[0106] Welding strength between ladder treads and ladder beams: Magnetic particle inspection is used to detect welds, and there are no cold welds or leaks. The bearing capacity of a single tread is ≥300kg (static load test);

[0107] The height of the guardrail is 1200±5mm, and the spacing between the horizontal bars is 300±10mm (GB 4053.3 standard).

[0108] Connector inspection:

[0109] High-strength bolts (M24, M30) have a tensile strength of ≥1000MPa and a torque coefficient of 0.11-0.15 (GB / T1231 standard). 10% of each batch is sampled for pre-tension testing.

[0110] Bolt hole accuracy: The diameter deviation of the bolt hole in the steel column connecting plate is ±0.5mm, and it is 100% inspected using a gauge.

[0111] 3. Preparation of construction equipment

[0112] Lifting equipment: 50t truck crane (jib length 50m, rated lifting capacity meets the maximum weight of steel column 25t), 25t truck crane (auxiliary lifting platform component), equipped with torque limiter (accuracy ±3%);

[0113] Measuring instruments: total station (Leica TS60, positioning accuracy ±2mm), level (DS1, accuracy ±1mm / km), laser rangefinder (accuracy ±1mm), all calibrated by the Institute of Metrology (within the validity period);

[0114] Power tools: torque wrench (0-1000 N·m, calibration error ±2%), electric welding machine (current stability ±5A).

[0115] 2. Platform Installation Process

[0116] 1. Foundation construction

[0117] Positioning and pay-off:

[0118] Use a total station to lay out according to the design drawings, with a foundation axis deviation of ±3mm, and set permanent control piles (concrete protection piers, depth 1.5m);

[0119] Pre-embedded anchor bolts: bolt center spacing deviation ±2mm, verticality deviation ≤1 / 1000, fixed with a fixed template.

[0120] Concrete pouring:

[0121] Cushion: 100mm thick C15 concrete, vibrated and compacted before leveling, flatness deviation ±3mm;

[0122] Foundation: C30 concrete is poured in layers (300mm per layer), with an insert vibrator vibrating for 20-30s / point, and standard curing test blocks are left (every 50m 3 a group);

[0123] Maintenance: Cover with plastic film + geotextile, maintain moisture for 14 days, no insulation is required when the daily average temperature is ≥5℃.

[0124] 2.Steel column installation

[0125] Positioning and initial adjustment:

[0126] Use a 50t crane to hoist the steel column. Align the anchor bolt holes at the bottom of the column with the embedded bolts. Install three groups of inclined washers (three pieces per group). Initially adjust the verticality to ≤H / 1000 (H is the column height. For example, an 18m steel column allows an 18mm deviation).

[0127] Dual theodolites (90° to each other) monitor the offset of the centerline of the column top, and a laser rangefinder measures the column base elevation (design value ± 2mm).

[0128] Smart calibration and fixing:

[0129] Start the intelligent calibration system: the inclination sensor provides real-time feedback on the steel column's tilt angle, and the electric jack (50mm stroke, 0.1mm accuracy) automatically adjusts the shims until the verticality is ≤H / 2000 (better than the design requirement);

[0130] Grouting: Use CGM-380 high-strength non-shrinkage grouting material (compressive strength ≥ 80MPa), wet the foundation surface before grouting, the grouting layer thickness is 30-50mm, and it can be unloaded only after the strength reaches 75% after 24 hours.

[0131] 3. Installation of main beam and steel beam

[0132] Main beam hoisting:

[0133] First install the first and second main beams, and temporarily fix them to the connecting plates at the top of the steel columns with M30 bolts (initial tightening torque 300N·m). Use a level to measure the mid-span deflection to be ≤L / 1000 (L is the main beam length, e.g., a 20m beam allows for a deflection of 20mm).

[0134] Final tightening: According to the "symmetrical tightening" principle, use a torque wrench to tighten twice (initial tightening 50%, final tightening 100%). The final tightening torque of M30 bolts is 800N·m. Mark the bolt number and tightening status.

[0135] Steel beam installation:

[0136] Install the first, second, third, fourth, and fifth steel beams in sequence, and connect them to the main beam using bolt welding: flange plate welding (groove angle 60°, weld height 8mm), web bolt connection (M24 bolts, torque 500N·m);

[0137] Spacing check: Use a steel tape measure to measure the center distance between adjacent steel beams, with a deviation of ±5mm and a diagonal difference of ≤10mm.

[0138] 4. Platform and ladder installation

[0139] Working platform 17 installation:

[0140] The platform is prefabricated in 4 pieces (each piece weighs ≤ 2t), hoisted to the 12m elevation of the steel column by a 25t crane, and connected to the steel column bracket with M20 bolts. The levelness of the platform is checked by a spirit level to be ≤ 3mm / m;

[0141] Railing installation: The distance between the vertical poles is 900mm, and after welding with the platform, anti-corrosion treatment is performed (epoxy zinc-rich primer 2 times and topcoat 1 time).

[0142] Ladder 15 installation:

[0143] The ladder is assembled in sections (3m per section), bolted to the side of the steel column, with an inclination angle of 65°±2°, a pedal spacing of 330mm±5mm, and a 1.5m high anti-fall net at the bottom.

[0144] 5. Support installation

[0145] Column support installation:

[0146] Lift and support at the designed angle (45°±1°), and weld both ends to the steel columns and main beam connection plates (weld quality grade 2), or connect with M24 bolts (pre-tension 155kN);

[0147] Length adjustment: Set a basket bolt in the middle of the support to adjust the support length to the design value ±2mm to eliminate installation stress.

[0148] 3. Post-installation commissioning and acceptance

[0149] 1. No-load debugging

[0150] Structural inspection:

[0151] The bolt tightening rate is 100%. Check with a 0.3kg hammer and there should be no looseness or abnormal sound.

[0152] Re-measurement of steel column verticality: total station detection ≤H / 2000, main beam horizontality ≤L / 1500.

[0153] Functional testing:

[0154] Ladder sway test: 2 people climbing at the same time, the displacement of the ladder top is ≤10mm;

[0155] Platform vibration test: 5 people jumping on the platform, amplitude ≤ 5mm, no structural abnormal sound.

[0156] 2. Load debugging

[0157] Hierarchical loading:

[0158] Load the design load (200kg / ㎡) in steps of 25% (50kg / ㎡), 50% (100kg / ㎡), 75% (150kg / ㎡), and 100% (200kg / ㎡), with each step holding for 15 minutes.

[0159] Monitoring indicators:

[0160] Platform settlement: The settlement difference of the four corners measured by the level instrument is ≤3mm;

[0161] Stress and strain: bonded resistance strain gauge (accuracy ±1%), key node stress ≤ 180MPa (Q345B allowable stress);

[0162] Deformation: The horizontal displacement of the top of the steel column measured by the laser rangefinder is ≤H / 1000.

[0163] 3. Acceptance criteria

[0164] Document acceptance: material quality assurance certificate, welding flaw detection report, bolt torque inspection record;

[0165] Physical acceptance: The construction, construction, design and supervision parties jointly accept the project and sign the "Transfer Platform Installation Acceptance Report". The project can only be put into use after the defects are rectified.

[0166] Example verification: In a nuclear power project, the transfer platform of the present invention was used to complete the transfer of a 500-ton steam generator:

[0167] Comparison of construction periods: Single platform installation time is 42 hours (traditional solution 75 hours), scaffolding-related processes are completely eliminated, and the total construction period is shortened by 12 days;

[0168] Cost comparison: A single platform saves 180,000 yuan in scaffolding costs and 72,000 yuan in labor costs;

[0169] Safety record: Achieved zero accidents during high-altitude operations, improving safety performance by three levels compared to similar projects.

[0170] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A modular transport platform for large equipment in nuclear power plants, characterized in that: include: An installation platform, wherein the installation platform is suitable for holding large equipment in a nuclear power plant; a supporting structure, the supporting structure being arranged below the mounting platform and supporting the mounting platform; a climbing structure, the climbing structure being arranged on the supporting structure; A working platform (17) is provided on the supporting structure, and the climbing structure passes through the working platform (17), so that workers can move to the working platform (17) through the climbing structure to perform work.

2. The modular transport platform for large equipment in nuclear power plants according to claim 1, characterized in that: The support structure comprises: A steel beam platform, comprising a plurality of steel beams; A plurality of steel columns are supported at the bottom end of the steel beam platform.

3. The modular transport platform for large equipment in nuclear power plants according to claim 2, characterized in that: The climbing structure comprises: A plurality of ladders (15) are arranged on the outer wall surface of the steel column along the height direction of the steel column.

4. The modular transport platform for large equipment in nuclear power plants according to claim 2, characterized in that: There are multiple working platforms (17), and each working platform (17) is respectively arranged on the side wall of the steel column close to the steel beam platform.

5. The modular transport platform for large equipment in nuclear power plants according to claim 2, characterized in that: A resting platform (16) is also provided on the side wall of the steel column. The resting platform (16) is located below the working platform (17). The climbing structure passes through the resting platform (16) so that workers can move to the resting platform (16) through the climbing structure to rest.

6. The modular transport platform for large equipment in nuclear power plants according to claim 2, characterized in that: An inter-column support is provided between two adjacent steel columns, and the inter-column supports are arranged obliquely and crosswise; The working platform (17) is an annular structure, and the circumferential dimension of the working platform (17) completely covers the connection area between the steel column and the bridge frame and the inter-column support.

7. The modular transport platform for large equipment in nuclear power plants according to claim 2, characterized in that: The installation platform comprises a first main beam (1) and a second main beam (2), the first main beam (1) and the second main beam (2) are arranged in parallel and spaced apart, and the first main beam (1) and the second main beam (2) are both arranged on a steel beam platform; The first main beam (1) and the steel beam, the second main beam (2) and the steel beam, and the steel beam and the steel column are all connected by high-strength bolts.

8. The modular transport platform for large equipment in nuclear power plants according to any one of claims 1 to 7, characterized in that: Also included is an intelligent calibration system, the intelligent calibration system comprising: A sensor assembly is provided on the supporting structure, and includes a laser rangefinder and an inclination sensor. The laser rangefinder is suitable for real-time monitoring of the verticality of the supporting structure, and the inclination sensor is suitable for real-time monitoring of the horizontal displacement of the supporting structure. an adjustment structure, the adjustment structure being disposed at the bottom end of the support structure and being adapted to adjust the verticality of the support structure; A total station controls an adjustment structure based on a transmission signal from a sensor assembly.

9. The modular transport platform for large equipment in nuclear power plants according to claim 8, characterized in that: The adjustment structure includes: An inclined washer is provided at the bottom end of the supporting structure; The pushing component is connected to the inclined washer and can push the inclined washer to move so as to adjust the inclination of the supporting structure.

10. A method for installing a modular transfer platform for large equipment in a nuclear power plant, characterized in that: The method is a method for installing a modular transfer platform for large-scale equipment in a nuclear power plant according to any one of claims 1 to 9. The following steps are involved: foundation construction; Use a crane to lift the support structure and install the support structure; Install the mounting platform on top of the supporting structure; The installation of the working platform (17) and the climbing structure is carried out on the side of the supporting structure.

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