Anti-twist hoisting method for multi-stage reference controlled ultra-supercritical boiler spiral water-cooled wall

Abstract

The application relates to the field of boiler equipment construction, and discloses a multi-stage reference control anti-twisting hoisting method for a supercritical boiler spiral water-cooled wall, which comprises the following steps: demarcating a first-stage reference according to the column position of a boiler steel frame, and demarcating three-stage references on a spiral water-cooled wall module; hoisting a rigid beam into position, aligning the rigid beam according to the first-stage reference, and demarcating a second-stage reference on the surface of the rigid beam; hoisting the spiral water-cooled wall module into a field and suspending the spiral water-cooled wall module on the side of the rigid beam; applying a transverse traction force to the spiral water-cooled wall module through an operating chain fall, so that the spiral water-cooled wall module approaches the rigid beam until the three-stage reference and the second-stage reference meet preset alignment requirements; implementing temporary welding to fix the spiral water-cooled wall module and the rigid beam, and repeatedly executing the assembling steps in the height direction layer by layer. The application utilizes deformation absorption to cut off the physical path of the error transmission to high altitude, prevents the module from being twisted, and improves the assembling precision of the heating surface.

Description

Technical Field

[0001] This invention relates to the field of boiler equipment construction, specifically to a method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control. Background Technology

[0002] Ultra-supercritical boilers are the core equipment of large thermal power plants. The lower part of their furnace generally adopts a spiral water-cooled wall structure to ensure the stability of hydrodynamic circulation. The spiral heating surface is formed by welding together inclined metal tubes. As the capacity of generator sets continues to increase, the overall size of the boiler continues to increase, and the volume and weight of the single spiral water-cooled wall module pre-assembled on the ground also increase significantly.

[0003] Because the spiral water-cooled wall tube bank has a specific helix angle, the module as a whole exhibits the characteristics of long span and low physical stiffness. During the process of lifting and transferring the assembled tube bank module to the high-altitude installation position, the module is prone to uneven local stress under its own weight, which in turn causes spatial distortion and deformation, resulting in a deviation from the theoretical helix angle required by the design. Conventional hoisting and alignment processes usually rely on a full-height through-line benchmark laid on the furnace top or ground for positioning. However, in the open working environment at heights of tens or even hundreds of meters, long-distance lines are easily affected by on-site wind loads, and the measurement accuracy of spatial three-dimensional coordinates is difficult to guarantee.

[0004] Furthermore, traditional continuous bottom-up, layer-by-layer stacking assembly methods lack effective mechanisms for eliminating staged errors. Minor dimensional deviations in the manufacturing and assembly of lower-level components accumulate and amplify at higher altitudes as the hoisting height increases. When these cascaded errors extend to transition sections or interfaces with other heating surface systems, they often lead to misalignment of pipe connections and excessive weld gaps. Construction workers must then forcefully pull and assemble these components, increasing the difficulty and risk of high-altitude operations. This also generates high residual stress within the tube bundle, affecting the long-term reliability of pressure-bearing components under high-temperature and high-pressure operating conditions. Therefore, this invention proposes a multi-level reference control method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler to address the shortcomings of existing technologies. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-level reference control method for anti-torsion hoisting of spiral water-cooled walls in ultra-supercritical boilers. This method solves the problems of low spatial positioning accuracy caused by wind load interference in long-distance high-altitude wire measurement, easy spatial torsion deformation of spiral water-cooled wall modules when suspended under their own weight, and the accumulation and amplification of bottom-level installation errors in the high-altitude area as the hoisting height increases, resulting in residual assembly stress.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a multi-level reference control method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler, comprising the following steps:

[0008] Establish a multi-level spatial reference. Based on the column position of the boiler steel frame, define the first-level reference and define the third-level reference corresponding to the helix angle on the spiral water-cooled wall module in the ground assembly area.

[0009] The rigid beam is lifted and positioned onto the temporary suspension device. The elevation and center position of the rigid beam are aligned according to the primary reference. A secondary reference is marked on the upper surface of the rigid beam. Then, the spiral water-cooled wall module is hoisted into the site and suspended in the working space to the side of the rigid beam.

[0010] The chain hoist is used to apply a lateral traction force to the spiral water-cooled wall module. The lateral traction force is adjusted to bring the spiral water-cooled wall module closer to the rigid beam until the third-level reference on the spiral water-cooled wall module and the second-level reference on the rigid beam reach the preset alignment tolerance requirement in the spatial projection relative position.

[0011] With the third-level datum and the second-level datum within the alignment tolerance requirements, the spiral water-cooled wall module is connected to the rigid beam according to the temporary welding fixing point. The steps of establishing multi-level spatial datums to the temporary welding fixing point are repeated layer by layer in the height direction until the assembly of the entire furnace spiral water-cooled wall is completed.

[0012] Preferably, the primary benchmark determined based on the column positions of the boiler steel frame specifically includes:

[0013] Select the outer load-bearing columns corresponding to the two ends of the longitudinal axis and the transverse axis of the boiler steel frame as reference columns, measure and establish the foundation elevation plane on the reference columns, and delineate the foundation horizontal reference plane in the internal space of the boiler steel frame.

[0014] Steel wire positioning lines are laid on the basic horizontal reference plane and the basic elevation plane to form intersecting absolute longitudinal center lines and absolute transverse center lines. The rectangular coordinate system constructed by the absolute longitudinal center lines and the absolute transverse center lines is established as the primary reference.

[0015] Preferably, marking the three-level reference corresponding to the helix angle on the helical water-cooled wall module in the ground assembly area specifically includes:

[0016] A calibration platform is built in the ground assembly area, and multiple individual heated surface tube panels are hoisted onto the calibration platform and assembled into the spiral water-cooled wall module.

[0017] After verifying that the helix angle parameters and overall geometric dimensions of the spiral water-cooled wall module are qualified, permanent marks are applied to the physical entity of the spiral water-cooled wall module to establish the third-level reference. The physical line segments of the permanent marks are parallel to the theoretical helix angle centerline marked on the design drawings.

[0018] Preferably, the process of aligning the elevation and center position of the rigid beam based on the primary datum, and marking the secondary datum on the upper surface of the rigid beam, specifically includes:

[0019] The primary reference is projected vertically upwards to the elevation position of the high-altitude working layer. Based on the spatial coordinates of the primary reference obtained by the projection, the rigid beam is mechanically fine-tuned for its levelness, elevation deviation, and the center distance deviation between the rigid beam and the spiral water-cooled wall module, and then locked.

[0020] After locking, the theoretical center line of the boiler and the assembly interface mark line of the spiral water-cooled wall module at the current elevation are engraved on the upper surface of the steel structure of the rigid beam. The theoretical center line of the boiler and the assembly interface mark line engraved on the surface of the rigid beam together constitute the secondary reference.

[0021] Preferably, before lifting the rigid beam into position on the temporary suspension device, the process further includes:

[0022] The space between two adjacent rigid beams is defined as an independent vertical hoisting level. The lower support boundary of the independent vertical hoisting level is provided by the lower load-bearing structure that has been positioned and fixed, and the upper alignment boundary of the independent vertical hoisting level is provided by the rigid beam of this level to be installed.

[0023] The horizontal splicing weld seam between the spiral water-cooled wall modules of adjacent upper and lower layers is located in an area that avoids the center line of the rigid beam by a set distance.

[0024] Preferably, the operation of the chain hoist to apply a lateral traction force to the spiral water-cooled wall module, and adjusting the lateral traction force to bring the spiral water-cooled wall module closer to the rigid beam, specifically includes:

[0025] The chain hoist is horizontally mounted between the rigid beam and the spiral water-cooled wall module. The hooks at both ends of the chain hoist are respectively set on the temporary pulling lugs on the rigid beam and the temporary pulling lugs on the spiral water-cooled wall module.

[0026] The chain hoists are tightened alternately in stages, generating a horizontal lateral traction force that forces the spiral water-cooled wall module to deform within the elastic yield limit of the metal pipe and move closer to the rigid beam.

[0027] Preferably, the alignment tolerance requirement until the third-level datum on the spiral water-cooled wall module and the second-level datum on the rigid beam reach the preset alignment tolerance in spatial projection specifically includes:

[0028] At least three points are uniformly selected along the length direction on the third-level reference of the spiral water-cooled wall module as measurement control points;

[0029] A taut thin steel wire is pulled and fixed along the secondary reference on the surface of the rigid beam;

[0030] The spatial vertical distance and horizontal spacing between the third-level reference for measuring the position of the measurement control point and the thin steel wire are measured.

[0031] Calculate the lateral spacing difference between the measurement control points located at both ends of the third-level datum, and use the quotient of the lateral spacing difference and the length distance between the measurement control points along the third-level datum to perform trigonometric function conversion to obtain the actual deflection angle.

[0032] When the absolute value of the difference between the horizontal spacing and the actual deflection angle are within the tolerance threshold range corresponding to the preset alignment tolerance requirement, the judgment conclusion that the third-level datum and the second-level datum are collinear is output.

[0033] Preferably, after connecting the spiral water-cooled wall module to the rigid beam according to the temporary welding fixing point, the method further includes:

[0034] Initiate formal welding between the suspension load-bearing component of the spiral water-cooled wall module and the suspension clamp of the rigid beam, monitor the interpass temperature of the formal welding operation, and implement slow cooling treatment after the welding operation is completed.

[0035] Maintain the chain hoist tension until all rigid weld joints formed by the formal welding operation cool naturally to ambient temperature.

[0036] The unloading sequence involves symmetrically releasing the chain tension of the chain hoist from the middle of the spiral water-cooled wall module towards both sides, until the supporting chain of the chain hoist is completely relaxed and the chain hoist is removed.

[0037] Preferably, the process further includes, until the carrier chain of the chain hoist is completely relaxed and the chain hoist is removed:

[0038] Perform pipe butt welding between the spiral water-cooled wall module described in this layer and the spiral water-cooled wall module already installed in the lower layer, leaving a gap for welding heat shrinkage;

[0039] By utilizing the physical flexibility of the spiral water-cooled wall module in the suspended span between two adjacent rigid beams, the local axial shrinkage caused by the cooling of the butt weld formed during the butt welding process is naturally absorbed and compensated.

[0040] Preferably, the step of repeatedly establishing multi-level spatial references layer by layer along the height direction to the temporary welding fixing point to complete the assembly of the entire furnace spiral water-cooled wall specifically includes:

[0041] An independent vertical hoisting level is defined between the two adjacent rigid beams. Within the independent vertical hoisting level, the secondary benchmark of the current floor is generated by the independent vertical projection of the primary benchmark at the bottom floor. The spiral water-cooled wall module is forced to deform and align with the secondary benchmark under the action of the lateral traction force. The mechanical elastic deformation absorbs the manufacturing dimensional deviations of the spiral water-cooled wall module itself and the installation deviations remaining during the hoisting and assembly process, cutting off the physical path of the installation error at the bottom floor to be cascaded into the high-altitude space.

[0042] In summary, the present invention has at least one of the following beneficial technical effects:

[0043] 1. This invention establishes a primary benchmark based on the column positions of the boiler steel frame, projects this primary benchmark vertically upwards to the elevation of the high-altitude working layer, and establishes a secondary benchmark on the upper surface of the rigid beam. Simultaneously, a tertiary benchmark is established on the spiral water-cooled wall module in the ground assembly area. Operators only need to align the tertiary benchmark on the spiral water-cooled wall module with the secondary benchmark on the rigid beam in physical space. The multi-level benchmark combination structure transforms the spatial three-dimensional anti-torsion positioning of the long-span spiral heating surface into a straight-line alignment step on the local joint surface of the rigid beam and the spiral water-cooled wall module, reducing the difficulty of high-altitude complex space measurement and improving the assembly position accuracy of the entire furnace spiral water-cooled wall.

[0044] 2. This invention uses a chain hoist to laterally hang between a horizontally arranged rigid beam with a high flexural section modulus and a vertically suspended thin-walled flexible spiral water-cooled wall module. The chain hoist is tightened in stages to generate a horizontal traction force. The lateral traction force forces the spiral water-cooled wall module to deform within the elastic yield limit of the metal tube and move towards the rigid beam. The stress structure uses a high-rigidity component to limit the displacement of the low-rigidity component, which overcomes the torsional deformation caused by the eccentricity of the spiral water-cooled wall module due to its own weight and the deviation of the original manufacturing dimensions, and avoids structural instability and torsion of the spiral water-cooled wall module in a suspended state.

[0045] 3. This invention defines the space between two adjacent rigid beams as an independent vertical hoisting level. Within this independent vertical hoisting level, a secondary reference for the elevation of the current layer is generated by independently projecting the primary reference of the bottom layer vertically upwards. Under the action of lateral traction, the spiral water-cooled wall module is forced to deform and align with the secondary reference, which has absolute coordinate properties. The construction structure utilizes the mechanical elastic deformation of the spiral water-cooled wall module to absorb the residual installation deviation of the spiral water-cooled wall module, so that the spiral water-cooled wall module completes the position positioning closed loop with the single-layer construction elevation as the boundary. This cuts off the physical path of the installation error of the bottom layer to be cascaded into the upper space, ensuring the verticality and dimensional stability of the overall heating surface assembly of the boiler. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0047] Figure 2 This is a schematic diagram illustrating the spatial pose adjustment and motion decomposition of the spiral water-cooled wall module of the present invention;

[0048] Figure 3 This is a schematic diagram of the overall method flow of the present invention;

[0049] Figure 4 This is a schematic diagram of the multi-level benchmark establishment process of the present invention;

[0050] Figure 5 This is a schematic diagram of the spatial definition process of the present invention;

[0051] Figure 6 This is a schematic diagram of the geometric collinearity determination process of the present invention;

[0052] Figure 7 This is a schematic diagram of the layer-by-layer assembly process of the present invention.

[0053] The components include: 1. Boiler steel frame; 2. Rigid beam; 3. Spiral water-cooled wall module; 4. Temporary hanging device; 5. Chain hoist; and 6. Temporary welding fixing point. Detailed Implementation

[0054] The following is in conjunction with the appendix Figure 1 -Appendix Figure 7 The present invention will be further described in detail below.

[0055] Please see Figure 1This invention provides a multi-level reference control anti-torsion hoisting device for the spiral water-cooled wall of an ultra-supercritical boiler, comprising a boiler steel frame 1, a rigid beam 2, a spiral water-cooled wall module 3, a temporary hanging device 4, a chain hoist 5, and a temporary welding fixing point 6. The boiler steel frame 1 is erected on a ground foundation. One end of the temporary hanging device 4 is installed at a designated elevation on the boiler steel frame 1, and the other end extends outward. The rigid beam 2 is suspended below the temporary hanging device 4. The spiral water-cooled wall module 3 is placed in the working space to the side of the rigid beam 2. Both ends of the chain hoist 5 are hooked and connected to the rigid beam 2 and the spiral water-cooled wall module 3, respectively. The temporary welding fixing point 6 is set at the contact joint between the rigid beam 2 and the spiral water-cooled wall module 3.

[0056] See attached document Figure 1 To be continued Figure 3 This invention provides a multi-level reference control method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler, comprising the following steps:

[0057] Establish a multi-level spatial reference. Based on the column position of the boiler steel frame 1, a first-level reference is defined, and a third-level reference with the corresponding helical rise angle is defined on the spiral water-cooled wall module 3 in the ground assembly area.

[0058] The rigid beam 2 is lifted and positioned on the temporary hanging device 4. The elevation and center position of the rigid beam 2 are aligned according to the primary benchmark. The secondary benchmark is marked on the upper surface of the rigid beam 2. Then the spiral water-cooled wall module 3 is hoisted into the site and suspended to the side of the rigid beam 2.

[0059] Operate the chain hoist 5 to apply a lateral traction force to the spiral water-cooled wall module 3, and adjust the traction force to make the spiral water-cooled wall module 3 move closer to the rigid beam 2 until the third-level datum on the spiral water-cooled wall module 3 and the second-level datum on the rigid beam 2 reach the preset alignment tolerance requirements in the spatial projection relative position.

[0060] With the third-level datum and the second-level datum within the alignment tolerance range, temporary welding fixing point 6 is used to connect the spiral water-cooled wall module 3 to the rigid beam 2. The above steps are repeated layer by layer in the height direction to complete the assembly of the spiral water-cooled wall of the entire furnace.

[0061] See attached document Figure 1 To be continued Figure 4The reference column of boiler steel frame 1 was determined as the origin of the measurement reference system. Boiler steel frame 1 was installed on the ground foundation, and the reference was set after confirming that the verticality of boiler steel frame 1 was completed and the settlement observation was stable. The array of load-bearing columns of boiler steel frame 1 presents a rectangular outline on the horizontal projection plane. According to the installation coordinate origin specified in the overall boiler design drawings, the outer load-bearing columns corresponding to the two ends of the longitudinal axis and the transverse axis of boiler steel frame 1 were selected as reference columns. Since the main steel frame at the bottom of the boiler has extremely high rigidity and structural stability, using it as a measurement reference system can effectively avoid the interference of structural swaying caused by high-altitude wind load on the reference. Therefore, the reference column provides a fixed spatial support for subsequent spatial elevation measurement.

[0062] Measure and establish the foundation elevation plane on the reference column. Use measuring instruments to determine and mark the horizontal elevation point 1 meter above the ground foundation on the outer surface of the vertical steel structure of the reference column. Here, 1 meter is a commonly used construction reference elevation on the engineering site. Its purpose is mainly to avoid debris on the ground foundation and meet the line of sight of construction personnel. In specific implementation, this height value can be adjusted up and down according to the zero elevation position set in the boiler drawings. Connect the horizontal elevation points on multiple reference columns by drawing lines or marking locally. Define the foundation horizontal reference plane in the internal space of the boiler steel frame 1. The foundation horizontal reference plane serves as the bottom reference plane for vertically upward measurement of the entire furnace installation position.

[0063] Establish a primary benchmark by marking absolute longitudinal and transverse center lines on the basic horizontal reference plane. Based on the geometric center coordinates of the furnace given in the overall boiler design drawings, make metal punches on the surface of the reference columns corresponding to the basic horizontal reference plane. Stretch steel wire positioning lines between the metal punches of the spatially opposite reference columns and use a tensioning device to mechanically tighten the steel wire positioning lines to prevent sagging, forming intersecting absolute longitudinal and transverse center lines. Since the mutually perpendicular cross lines can uniquely determine the coordinate positions of the longitudinal and transverse axes in a two-dimensional horizontal plane, the skew error that may be caused by unilateral positioning is eliminated. The absolute longitudinal and transverse center lines construct a fixed rectangular coordinate system on the basic horizontal reference plane. The rectangular coordinate system constructed by the absolute longitudinal and transverse center lines is established as the primary benchmark for controlling the anti-torsion installation positioning of the boiler at all heights. The primary benchmark remains fixed during the subsequent hoisting construction period and is used as the absolute coordinate reference base for the placement of high-altitude components.

[0064] See attached document Figure 2 To be continued Figure 4 Before the spiral water-cooled wall module 3 is lifted into the high-altitude work area, a local coordinate system needs to be established for it in the ground assembly area so that it can move with the component. Specifically, the ground pre-assembly and marking binding operations are carried out through the following steps.

[0065] A dedicated pipe alignment platform is constructed in the ground assembly area. A level is used to align the support structure of the alignment platform. After alignment, the pipe panel layout outline, consistent with the design drawings, is marked on the surface of the alignment platform. The alignment platform provides a flat structural support surface to eliminate the interference caused by uneven ground on the pipe panel size measurement. Multiple individual heated surface pipe panels in their factory state are hoisted onto the alignment platform and pre-assembled according to the layout outline and the splicing sequence specified in the design drawings. The individual heated surface pipe panels are spliced ​​into a spiral water-cooled wall module 3 for overall hoisting. The spiral water-cooled wall module 3 consists of multiple pipes with spiral inclination angles and connecting fins between the pipes.

[0066] The spiral helix angle parameters and overall geometric dimensions of the spiral water-cooled wall module 3 were verified using the calibration platform. The spiral helix angle is the angle formed between the spiral heating surface tube bundle and the horizontal section. During the verification operation, the inspectors used engineering surveying tools such as steel tape measures, universal squares, or total stations to measure the overall diagonal length, tube width, and tilt angle of the spiral water-cooled wall module 3. The spatial curvature of the spiral water-cooled wall is formed by assembling and splicing planar tube panels with spiral helix angles around the furnace. Since the rigid beam 2, the high-altitude load-bearing component, is in a horizontal arrangement and has pre-welded fixed-space suspension plates on it, the inclined spiral water-cooled wall module 3 must eliminate angle processing tolerances on the ground and control diagonal dimension errors to prevent rhomboid distortion of the planar tube panel itself. When the tube panel's external dimensions are distorted, the load-bearing connectors on the spiral water-cooled wall module 3 will not correspond spatially with the pre-reserved installation interfaces on the rigid beam 2, resulting in mechanical interference caused by misalignment of the connector positions.

[0067] After the geometric dimensions are verified to be qualified, permanent markings are applied to the physical entity of the spiral water-cooled wall module 3 to establish a three-level reference. Construction workers use metal scribers to make engraved lines or use marking paint to paint solid lines on the surface of the steel fins on the upper edge, lower edge, and sides of the spiral water-cooled wall module 3. The marked physical lines are parallel to the theoretical spiral helix angle center line indicated on the design drawings within the allowable parallelism tolerance range of the project. The project number for assembly alignment is marked on the side fins. The physical lines attached to the surface of the spiral water-cooled wall module 3 are set as the three-level reference of this anti-torsion method. The three-level reference essentially gives the spiral water-cooled wall module 3 an independent relative coordinate reference. When the crane lifts the spiral water-cooled wall module 3 and removes it from the ground, the three-level reference moves spatially synchronously with the spiral water-cooled wall module 3. In the subsequent free state, the three-level reference acts as a visual and physical target marker for the spiral water-cooled wall module 3 to be pulled and aligned by external force.

[0068] See attached document Figure 1 Appendix Figure 3 With appendix Figure 5After completing the calibration of the first-level and third-level benchmarks, the absolute coordinates of the bottom layer need to be projected onto the high-altitude operation layer to establish the second-level benchmark.

[0069] The rigid beam 2, which has already been mounted and positioned, provides a positioning support surface. The lower heating surface structure, including the transition section header and the lower vertical pipe panel, is installed and aligned. After the lifting machinery lifts the rigid beam 2 at this elevation to the corresponding temporary hanging device 4 and completes the mounting and positioning, the rigid beam 2, with its large structural stiffness and bending section modulus, can form a stable planar rigid constraint, providing a mechanical positioning support surface for the subsequent establishment of a high-altitude secondary benchmark and for the flexible spiral water-cooled wall module 3.

[0070] Based on the primary benchmark, the rigid beam 2 is spatially aligned. Using optical instruments such as plumb bobs or total stations, surveyors project the primary benchmark on the ground foundation horizontal benchmark surface vertically upwards to the elevation position of the high-altitude working layer. Based on the spatial coordinates of the primary benchmark obtained by projection, surveyors use fine-tuning mechanisms such as turnbuckles on the temporary hanging device 4 to mechanically fine-tune the levelness, elevation deviation, and center distance deviation between the rigid beam 2 and the heated surface pipe. During the project implementation, the elevation deviation and center distance deviation of the rigid beam 2 must be controlled within the preset mechanical tolerance limits. For example, according to the relevant regulations for the acceptance of power construction quality and the installation instructions of the boiler equipment manufacturer, the elevation deviation should be controlled within ±5 mm to meet the overall assembly accuracy requirements.

[0071] A secondary benchmark is established on the rigid beam 2 entity after it is aligned and locked. After the rigid beam 2 reaches the required spatial position accuracy and is completely locked by installing a limit baffle or performing temporary spot welding, the surveyor marks the theoretical center line of the boiler at this elevation on the upper surface of the steel structure of the rigid beam 2 (e.g., at the flange surface or web of the rigid beam 2 at the designated measurement plane). At the same time, according to the assembly dimensions of the spiral water-cooled wall module 3, the surveyor uses a scribing tool to mark the tube panel assembly interface marking line near the position of the pre-welded suspension clamp of the rigid beam 2. The center line marked on the surface of the rigid beam 2 and the tube panel assembly interface marking line together constitute the secondary benchmark.

[0072] By establishing a secondary datum to define a spatial positioning reference body, the spiral water-cooled wall module 3, being a flexible thin-walled tube bundle structure, cannot independently resist the torsional moment generated by high-altitude wind loads and self-weight eccentricity when suspended in mid-air. By defining a secondary datum on the rigid beam 2, the rigid beam 2 directly transforms into a bearing reference surface that provides positional constraints in physical space. The rigid beam 2, which has completed absolute position alignment in advance and has a secondary datum, can replace the traditional positioning mode that relies solely on total station spatial measurement. This provides a clear and stable three-dimensional alignment reference line for the spiral water-cooled wall module 3, which is subsequently hoisted into the furnace space. By using high-rigidity components to limit the displacement of low-rigidity components, the complex overall spatial anti-torsion problem is transformed into a straight-line alignment step between the rigid beam 2 and the local connection surface of the tube panel. This avoids the manufacturing tolerances accumulated by the flexible components affecting the overall furnace installation position.

[0073] To prevent uncontrollable deformation of large-area flexible tube screens during suspended installation, it is necessary to develop a strategy for defining the physical boundaries of vertical installation levels based on stiffness characteristics.

[0074] Obtain the rated lifting capacity parameters, operating radius, and unit length weight data of the spiral water-cooled wall module 3 of the hoisting machinery at the construction site, as well as the length dimensions of the loose parts supplied by the manufacturer. The total height of the boiler's spiral heating surface is large. The spiral water-cooled wall module 3 is spliced ​​from thin-walled tubes and has obvious flexibility. Large-span flexible components are prone to bending deformation or even instability under their own weight and high-altitude wind loads. It is necessary to divide the continuous spiral heating surface into multiple independent vertical hoisting levels along the boiler height direction. Through vertical segmentation, the free cantilever length of the flexible heating surface in the vertical direction can be effectively shortened. Segmented control can be used to improve the local structural stiffness, thereby reducing the initial torsional deformation caused by the eccentricity of the component due to its own weight.

[0075] Establish physical boundary definition rules for vertical hoisting levels. Based on the installation elevation data of each layer of rigid beam 2 in the boiler design drawings, define the space between two adjacent layers of rigid beam 2 as an independent vertical hoisting level. The lower support boundary of each vertical hoisting level is provided by the lower load-bearing structure that has completed the positioning and fixing operation. The lower load-bearing structure includes the lower ash hopper section water-cooled wall or the lower rigid beam 2 that has been installed in place. The upper alignment boundary of each vertical hoisting level is provided by the rigid beam 2 of this layer to be installed. When defining the physical boundary, in order to avoid mechanical interference between the welding operation of the spiral water-cooled wall module 3 and the physical structure of the rigid beam 2, the horizontal splicing weld position between the upper and lower spiral water-cooled wall modules 3 should be set in an area that avoids the center line of the rigid beam 2 by a set distance. The set distance is determined according to the actual operating space requirements of the on-site welding personnel, and the value range is set to be between 300 mm and 500 mm away from the center line of the rigid beam 2.

[0076] Within the vertical hoisting level, the geometric dimensions of the spiral water-cooled wall module 3 are controlled. Based on the span distance between two adjacent rigid beams 2, combined with the rated lifting capacity parameters of the hoisting machinery and the length-to-width ratio stiffness limit of the component, the length and weight of the individual spiral water-cooled wall module 3 after division are determined. This ensures that the weight of the divided spiral water-cooled wall module 3 does not exceed the rated lifting capacity of the hoisting machinery, and that the spiral water-cooled wall module 3 will not undergo deformation exceeding the structural yield limit within the suspended span between the two rigid beams 2. By establishing the physical boundary of the vertical hoisting level, the spiral water-cooled wall module 3 is forced to immediately match the rigid beam 2 at the corresponding elevation after being hoisted into the site.

[0077] See attached document Figure 1 Appendix Figure 3 With appendix Figure 5 After establishing the physical boundaries of the vertical hoisting levels, construction was carried out according to the installation sequence of rigid beam 2 being hoisted and positioned before spiral water-cooled wall module 3, eliminating spatial physical interference and establishing anti-torsion rigid support.

[0078] The lifting and positioning operation of rigid beam 2 is carried out. The lifting machinery lifts rigid beam 2 to the installation elevation specified in the design drawings. Rigid beam 2 is arranged on the outer side of spiral water-cooled wall module 3. The rigid beam 2 is equipped with metal connecting parts such as suspension clamps and guide devices that extend horizontally into the furnace. If the construction sequence is changed and spiral water-cooled wall module 3 is lifted first, spiral water-cooled wall module 3 will close the outer surface of the furnace in advance. When the large-volume rigid beam 2 is lifted in later, the lifting equipment of the lifting machinery and the metal connecting parts extending inward of the rigid beam 2 will not be able to pass over the already positioned spiral water-cooled wall module 3, resulting in mechanical interference. Lifting rigid beam 2 first can reserve a descending channel for subsequent components and avoid physical collisions between components in the high-altitude operation area.

[0079] A torsion-resistant support is constructed using rigid beam 2. After rigid beam 2 is hoisted into place, construction workers operate temporary hoisting device 4 to align the spatial coordinates of rigid beam 2. Limiting baffles are welded or limiting bolts are tightened at the connection between rigid beam 2 and temporary hoisting device 4 for mechanical fixation to restrict the positional movement of rigid beam 2. Rigid beam 2 is manufactured by welding H-beams or double-channel steel and other structural steel materials. Rigid beam 2 has a large moment of inertia and bending section modulus in both the horizontal and vertical planes. Spiral water-cooled wall module 3 is a thin-walled flexible structure with low stiffness to resist out-of-plane bending and torsional deformation. High-stiffness components can effectively limit the displacement deformation of low-stiffness components. The high bending stiffness of rigid beam 2 absorbs and resists the torsional stress generated by the self-weight and asymmetrical force of spiral water-cooled wall module 3. The pre-fixed rigid beam 2 constitutes the physical boundary that prevents spiral water-cooled wall module 3 from torsion, providing a rigid support surface to withstand reaction forces for subsequent traction operations.

[0080] The delayed lifting and hovering operation of the spiral water-cooled wall module 3 was carried out. After confirming that the spatial position of the rigid beam 2 was completely fixed and that the secondary reference on the rigid beam 2 was marked, the crane lifted the corresponding spiral water-cooled wall module 3 into the site. The operator guided the spiral water-cooled wall module 3 to descend to the working elevation area where the rigid beam 2 was located. At this time, the spiral water-cooled wall module 3 was in a hovering state inside the rigid beam 2. In order to prevent the component from swinging and impacting due to high-altitude wind load, the set safe hovering distance was maintained between the spiral water-cooled wall module 3 and the rigid beam 2. Combining the space requirements for manual operation by construction personnel and the requirement to avoid friction between metal parts, the safe hovering distance was set to be between 100 mm and 200 mm. The spiral water-cooled wall module 3 only relied on the hook of the crane to maintain the vertical gravity balance. The spiral water-cooled wall module 3 was not constrained in the horizontal direction. The spiral water-cooled wall module 3 had not yet made physical contact with the rigid beam 2. By prioritizing the placement of the rigid beam 2, the spiral water-cooled wall module 3 had a fixed spatial reference surface before being placed, creating the physical conditions for mechanical traction.

[0081] See attached document Figure 1 Appendix Figure 3 With appendix Figure 6 After the spiral water-cooled wall module 3 is suspended inside the rigid beam 2, a force-applying mechanism needs to be arranged to perform high-altitude forced traction in order to overcome component deformation and achieve collinear alignment of multi-level references.

[0082] To establish a physical connection for the horizontal force application mechanism, construction workers horizontally hang a chain hoist 5 between the rigid beam 2 and the spiral water-cooled wall module 3. In order to ensure uniform traction force and prevent excessive local stress on the tube screen and tearing, temporary traction lugs are pre-welded to the side fins of the spiral water-cooled wall module 3 and the corresponding positions of the rigid beam 2. Before welding, the surveyor needs to use a spirit level or level to re-measure the docking position and confirm that the temporary traction lugs on the rigid beam 2 side and the spiral water-cooled wall module 3 side are on the same absolute elevation plane. This ensures that the chain hoist 5 generates only a purely horizontal tension after being stressed, preventing the vertical parasitic force that could damage the vertical spatial position of the component due to tilting traction. When welding the temporary traction lugs on the spiral water-cooled wall module 3 side, a metal pad to increase the stress area is used, or a full welding operation is performed at a node with greater stiffness where the fins meet the water-cooled wall pipes, to avoid the lateral traction force tearing the thin-walled metal. The hooks at both ends of the chain hoist 5 are connected to the temporary traction lugs on the rigid beam 2 and the spiral water-cooled wall module 3, respectively. The arrangement spacing of the temporary traction lugs is set according to the width of the spiral water-cooled wall module 3 and the rated load of the chain hoist 5. Usually, the spacing between adjacent temporary traction lugs is set to between 2 and 3 meters.

[0083] The horizontal degree of freedom of the spiral water-cooled wall module 3 is restricted. When the spiral water-cooled wall module 3 is lifted into the site, it is only subjected to the upward vertical tension of the lifting machinery. By horizontally mounting multiple sets of chain hoists 5, the chain hoists 5 establish a lateral constraint on the spiral water-cooled wall module 3 in the horizontal direction. After mounting the chain hoists 5 and applying an initial preload to eliminate the physical sag of the chains, the spiral water-cooled wall module 3 changes from a unidirectional force state in the vertical direction to a bidirectional force state in both the vertical and horizontal directions. The horizontal physical connection eliminates the movement space of the spiral water-cooled wall module 3 in the horizontal plane, limiting the swing amplitude of the spiral water-cooled wall module 3 under the action of high-altitude lateral wind load.

[0084] Mechanical forced traction was implemented to overcome flexible deformation. Workers alternately tightened multiple sets of chain hoists 5 positioned between the rigid beam 2 and the spiral water-cooled wall module 3 in stages. During the traction process, to prevent uneven force distribution at each traction point from causing secondary torsional distortion of the spiral water-cooled wall module 3, a dedicated supervisor was assigned to the site. The supervisor issued unified operating commands via walkie-talkie or fixed whistle, directing workers at each traction point to maintain the same pulling rhythm and tightening stroke. The chain hoists 5 generated horizontal traction force. Under the action of this traction force, the spiral water-cooled wall module 3 overcame the torsional deformation caused by its own weight eccentricity and the elastic bending resistance of the metal pipe itself. The resistance moves towards the solid side of the rigid beam 2, and the mechanical force amplification effect of the chain hoist 5 generates local lateral tension. Taking advantage of the material property that the metal tube deforms during the elastic stress stage and can return to its original shape after the external force is removed, the flexible spiral water-cooled wall module 3 is forced to deform within the elastic yield limit of the metal material. This forces the overall contour of the spiral water-cooled wall module 3 to adapt to the positional constraint of the high-rigidity rigid beam 2. In order to prevent the water-cooled wall tube from undergoing irreversible plastic deformation due to excessive traction force, the operator monitors the resistance of the chain hoist 5 or connects a tension gauge in series with the stressed chain to ensure that the single-point traction force is always lower than the safe threshold of the yield strength of the metal tube.

[0085] The multi-level reference collinear alignment and locking operation was performed. While applying lateral traction force, the surveyors observed the relative position distance between the tertiary reference on the spiral water-cooled wall module 3 and the secondary reference on the rigid beam 2 in real time. The operators continuously adjusted the tension of each chain hoist 5 until the tertiary reference marking line on the surface of the spiral water-cooled wall module 3 and the center line of the secondary reference on the surface of the rigid beam 2 were aligned in physical space. According to the requirements of the overall boiler assembly and acceptance specifications, the alignment deviation between the tertiary and secondary references was controlled within the threshold range of ±2 mm. The collinear coincidence of the tertiary and secondary references indicates that the spiral water-cooled wall module 3 has been accurately positioned. Located in the three-dimensional coordinate system formed by projecting upwards from the bottom-level reference, after confirming that the reference alignment meets the standards, the construction workers immediately use U-bolts or temporary welded metal limit blocks to mechanically solidify and lock the suspension force-bearing component of the spiral water-cooled wall module 3 to the suspension clamp of the rigid beam 2. This mechanical locking operation can establish a long-term support anchor point, resist the elastic rebound force accumulated by the water-cooled wall pipe, and maintain the aligned spatial coordinates unchanged. The multi-level reference collinear alignment operation transforms the spatial anti-torsion positioning of the long-span spiral heating surface into straight line alignment on the local joint surface, completing the elimination of positioning interference and the final alignment of spatial pose.

[0086] See attached document Figure 1 Appendix Figure 3 With appendix Figure 6 During the mechanical forced traction operation, a geometric judgment step needs to be established to confirm whether the spatial relative positional relationship between the spiral water-cooled wall module 3 and the rigid beam 2 meets the assembly requirements of the design drawings.

[0087] Establish target reference lines for geometric determination. These target reference lines include a secondary reference attached to the surface of the rigid beam 2 and a tertiary reference attached to the surface of the spiral water-cooled wall module 3. The secondary and tertiary references are physically represented as solid lines or painted line segments of a certain length. As the spiral water-cooled wall module 3 moves closer to the rigid beam 2, the secondary and tertiary references appear as two skew lines that are constantly approaching each other in three-dimensional space. The core operation of geometric determination is to convert the spatial relative position of the two skew lines into measurable engineering dimensional data.

[0088] For setting up geometric determination measurement control points, since the joint surface between the rigid beam 2 and the spiral water-cooled wall module 3 has a large length span, single-point measurement can only prove that the two baselines intersect in space at a certain location, and cannot truly reflect the overall fit of the components. Only when the spacing of multiple distributed points on the entire baseline simultaneously meets the design tolerance requirements can it be proven that the flexible components are not only aligned in spatial coordinates, but also that the accumulated torsional deformation inside the components has been completely flattened by the traction force. Therefore, the inspectors uniformly select at least three points along the length direction on the third-level baseline segment of the spiral water-cooled wall module 3 as measurement control points. The measurement control points include the upper end point, midpoint, and lower end point of the line segment. Through the multi-point distributed measurement control points, the flexural deformation or uneven torsion of the spiral water-cooled wall module 3 in local areas can be effectively identified.

[0089] During the physical measurement and data acquisition operations, since the secondary and tertiary benchmarks are distributed on different structural surfaces with depth differences, in order to establish an intuitive measurement reference, the inspectors pulled and fixed a taut thin steel wire along the secondary benchmark line on the surface of the rigid beam 2 as a measurement auxiliary entity. At the selected measurement control point, the inspectors used a steel ruler, vernier caliper, or a special limiting template prefabricated according to the design spacing to measure the spatial vertical distance and horizontal distance between the tertiary benchmark of the spiral water-cooled wall module 3 and the thin steel wire.

[0090] Based on the tolerance threshold, the collinearity judgment result is output. Machining tolerances and measurement errors are unavoidable during engineering manufacturing and hoisting. Collinearity is constrained by the preset tolerance threshold. Based on the boiler steel structure and heating surface installation acceptance standards, a tolerance threshold for datum alignment is set. Combined with the assembly requirements of the construction site, the absolute value of the lateral spacing deviation between the third-level and second-level datums is set to be less than or equal to 2 mm. For angular deviation control, inspectors calculate the lateral spacing difference at the measurement control points at both ends of the datum line segment, divide the spacing difference by the length distance between the two measurement control points, and use trigonometric functions to calculate the actual deflection angle. The absolute value of the included angle deviation between the third-level and second-level datums is set to be less than or equal to 0.5 degrees. When the spacing and angle data obtained by inspectors at all deployed measurement control points are within the preset tolerance threshold range, inspectors confirm and output the judgment conclusion that the third-level and second-level datums are collinear and qualified.

[0091] Based on the geometric judgment conclusion, the position is solidified or adjusted. If the output judgment conclusion is non-overlapping, the inspector will feed back the deviation data to the traction operator and guide the traction operator to adjust the traction force of the chain hoist 5 at the specific position. Continue to carry out local deformation fine-tuning of the spiral water-cooled wall module 3. If the output judgment conclusion is collinearity qualified, it indicates that the torsional deformation of the spiral water-cooled wall module 3 has been completely overcome and the spatial orientation of the spiral water-cooled wall module 3 has reached the design standard. Based on the collinearity qualified judgment conclusion, the construction operator will immediately start the formal welding operation or high-strength bolt tightening operation of the fixed connection between the spiral water-cooled wall module 3 and the rigid beam 2 to complete the final physical solidification of the spatial position of the heated surface tube screen.

[0092] See attached document Figure 1 Appendix Figure 3 With appendix Figure 7 After completing the multi-level collinear alignment of the spiral water-cooled wall module 3 and the rigid beam 2, as well as the temporary mechanical locking, it is necessary to implement thermal curing, stress control, and establish a cumulative error cutoff mechanism to ensure the dimensional stability of the overall heating surface assembly of the boiler.

[0093] After confirming that the third-level and second-level reference datums are within the preset alignment tolerance range, the construction workers will begin the formal welding operation between the suspension load-bearing components of the spiral water-cooled wall module 3 and the suspension clamps of the rigid beam 2. Considering that the rigid beam 2 is usually made of carbon structural steel and the suspension load-bearing components of the spiral water-cooled wall module 3 are usually made of heat-resistant alloy steel, the connection between the two is a dissimilar metal welding, which has a significant tendency to cold crack. Before welding, the construction workers need to preheat the welding base material area with a flame heater or electric heating plate. In order to prevent excessive local heat input during the welding process from causing thermal expansion distortion and secondary torsion of the spiral water-cooled wall module 3, the construction workers adopt a symmetrical welding and segmented back welding construction process.

[0094] Meanwhile, inspectors used temperature measuring instruments to monitor the interpass temperature of the welding area. In accordance with the requirements of the welding procedure qualification guide for metal materials, the interpass temperature was strictly controlled within the threshold range of 150℃ to 250℃. After the welding operation was completed, the construction workers immediately wrapped and covered the weld area with heat-insulating aluminum silicate refractory fiber felt to implement slow cooling treatment. Through the physical process of metal fusion, a permanent metal load-bearing structure was established between the rigid beam 2 and the spiral water-cooled wall module 3.

[0095] Stress control and temporary traction constraint removal operations were implemented. During the mechanical forced traction stage, elastic rebound stress resisting lateral displacement accumulated inside the spiral water-cooled wall module 3. During the hot solidification stage, local welding thermal stress was generated in the connection area. A reasonable stress control procedure was necessary to prevent the spiral water-cooled wall module 3 from bouncing in space when the external force constraint was removed. The construction workers kept the chain hoists 5 taut until all rigid connection welds cooled naturally to the ambient temperature. After the welds cooled, the metal in the connection area reached the yield strength at room temperature. The high bending section stiffness of the rigid beam 2 fully took over and absorbed the residual stress accumulated inside the spiral water-cooled wall module 3. After confirming that the weld temperature had reached the room temperature standard, the construction workers used walkie-talkies to issue unified commands to loosen and remove the multiple chain hoists 5 arranged between the rigid beam 2 and the spiral water-cooled wall module 3.

[0096] During the dismantling of chain hoist 5, in order to prevent the new weld from bearing excessive transverse shear stress due to sudden changes in local traction force, the operators adopted a symmetrical and step-by-step unloading sequence from the middle position of the spiral water-cooled wall module 3 to both sides of the edge. Each release operation loosened only one or two links of chain hoist 5 until the load-bearing chain of chain hoist 5 was completely relaxed. At this time, the spiral water-cooled wall module 3 was locked by the rigid beam 2, and the spiral water-cooled wall module 3 no longer had the freedom to twist in three-dimensional space.

[0097] The pipe butt welding operation of the spiral water-cooled wall module 3 was carried out. After the main structure of the spiral water-cooled wall module 3 was constrained by the rigid beam 2 and its position was fixed, the construction workers carried out the pipe butt welding work between the spiral water-cooled wall module 3 of this layer and the water-cooled wall tube bank installed in the lower layer. The overall outline and spatial coordinates of the spiral water-cooled wall module 3 were restricted by the rigid beam 2. In order to prevent the huge internal stress caused by the thermal shrinkage of the pipe butt welding from cracking the metal tube, the construction workers reserved a welding thermal shrinkage gap of 2 mm to 4 mm according to the process specifications when assembling the pipe butts. During the actual welding process, the cooling of the butt weld of the water-cooled wall tube section produced a local axial shrinkage. Utilizing the physical flexibility of the water-cooled wall tube in the suspended span between the two layers of rigid beam 2, the shrinkage at the end of the tube section was naturally absorbed and compensated. The operation sequence of fixing the main coordinates first and then connecting the local pipe butts prevented the overall distortion of the large-area thin-walled tube screen caused by the thermal shrinkage of the tube bundle splicing.

[0098] By utilizing layered independent projection to establish a cumulative error cutoff mechanism, the traditional bottom-up continuous stacking installation mode of boiler heating surfaces leads to the continuous accumulation of manufacturing tolerances and installation deviations of the bottom components along the boiler height direction, eventually causing assembly misalignment at the high-altitude working level that cannot be eliminated by conventional means. The embodiments disclosed in this invention divide the continuous spiral water-cooled wall modules 3 into independent vertical hoisting levels, and within each vertical hoisting level, a secondary reference for the elevation of the current level is generated by independently projecting the absolute reference of the bottom layer vertically upwards. The spiral water-cooled wall modules 3 are forced to undergo deformation alignment to the secondary reference of the absolute standard.

[0099] The cumulative error truncation mechanism utilizes the long-span cantilever characteristic of the flexible tube bank between two layers of rigid beams 2. When lateral traction is applied to the chain hoist 5, the manufacturing dimensional deviations of the spiral water-cooled wall module 3 itself and the millimeter-level installation deviations remaining in the previous layer are all forcibly distributed by the lateral traction force and transformed into small elastic bending of the water-cooled wall metal tubes in the vertical span. Through mechanical elastic deformation absorption, the rigid physical dimensional interference between the tube bank's physical structures is eliminated. Based on this method, the spiral water-cooled wall module 3 achieves a closed-loop mechanical position positioning with the single-layer construction elevation as the boundary. The forced constraint positioning of the single-layer closed loop cuts off the physical path of the bottom layer installation error cascading to the upper space, thus realizing the cumulative error truncation mechanism in the macroscopic structure. The cumulative error truncation mechanism ensures that the verticality and flatness of the spiral water-cooled wall of the ultra-supercritical boiler in the overall height direction meet the design accuracy specifications.

Claims

1. A method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control, characterized in that, Includes the following steps: Establish a multi-level spatial reference. Based on the column position of the boiler steel frame (1), a first-level reference is defined, and a third-level reference with the corresponding spiral helix angle is defined on the spiral water-cooled wall module (3) in the ground assembly area. The rigid beam (2) is lifted and positioned on the temporary hanging device (4). The elevation and center position of the rigid beam (2) are aligned according to the first-level reference. The second-level reference is marked on the upper surface of the rigid beam (2). Then the spiral water-cooled wall module (3) is hoisted into the site and suspended in the working space on the side of the rigid beam (2). The chain hoist (5) is used to apply a lateral traction force to the spiral water-cooled wall module (3). The lateral traction force is adjusted to bring the spiral water-cooled wall module (3) closer to the rigid beam (2) until the third-level reference on the spiral water-cooled wall module (3) and the second-level reference on the rigid beam (2) reach the preset alignment tolerance requirements in the spatial projection relative position. With the third-level reference and the second-level reference within the alignment tolerance requirements, the spiral water-cooled wall module (3) is connected to the rigid beam (2) according to the temporary welding fixing point (6). The steps of establishing multi-level spatial references to the temporary welding fixing point (6) are repeated layer by layer in the height direction until the assembly of the entire furnace spiral water-cooled wall is completed.

2. The method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control according to claim 1, characterized in that, The primary benchmark is determined based on the column positions of the boiler steel frame (1), specifically including: Select the outer load-bearing columns corresponding to the two ends of the longitudinal axis and the transverse axis of the boiler steel frame (1) as the reference columns, measure and establish the foundation elevation plane on the reference columns, and delineate the foundation horizontal reference plane in the internal space of the boiler steel frame (1); Steel wire positioning lines are laid on the basic horizontal reference plane and the basic elevation plane to form intersecting absolute longitudinal center lines and absolute transverse center lines. The rectangular coordinate system constructed by the absolute longitudinal center lines and the absolute transverse center lines is established as the primary reference.

3. The method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control according to claim 1, characterized in that, The three-level reference for the corresponding helix angle is marked on the helical water-cooled wall module (3) in the ground assembly area, specifically including: A calibration platform is built in the ground assembly area, and multiple individual heat-receiving surface tube panels are suspended on the calibration platform and spliced ​​into the spiral water-cooled wall module (3). After verifying that the spiral helix angle parameters and overall geometric dimensions of the spiral water-cooled wall module (3) are qualified, permanent marks are applied to the entity of the spiral water-cooled wall module (3) to establish the third-level reference. The physical line segments of the permanent marks are parallel to the theoretical spiral helix angle centerline marked on the design drawings.

4. The method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control according to claim 1, characterized in that, The elevation and center position of the rigid beam (2) are aligned according to the primary datum, and the secondary datum is marked on the upper surface of the rigid beam (2). Specifically, this includes: The primary reference is projected vertically upwards to the elevation position of the high-altitude working layer. Based on the spatial coordinates of the primary reference obtained by the projection, the rigid beam (2) is mechanically fine-tuned for its levelness, elevation deviation, and center distance deviation between the rigid beam (2) and the spiral water-cooled wall module (3), and then locked. After locking, the theoretical center line of the boiler and the assembly interface mark line of the spiral water-cooled wall module (3) at the current elevation are engraved on the upper surface of the steel structure of the rigid beam (2). The theoretical center line of the boiler and the assembly interface mark line engraved on the surface of the rigid beam (2) together constitute the secondary reference.

5. The method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control according to claim 1, characterized in that, Before lifting the rigid beam (2) into place on the temporary sling (4), the following steps are also included: The space between the two adjacent rigid beams (2) is defined as an independent vertical hoisting level. The lower support boundary of the independent vertical hoisting level is provided by the lower load-bearing structure that has been positioned and fixed. The upper alignment boundary of the independent vertical hoisting level is provided by the rigid beam (2) of this level to be installed. The horizontal splicing weld between the spiral water-cooled wall modules (3) of the upper and lower adjacent layers is set in an area that avoids the center line of the rigid beam (2) by a set distance.

6. The method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control according to claim 1, characterized in that, Operating the chain hoist (5) to apply a lateral traction force to the spiral water-cooled wall module (3), and adjusting the lateral traction force to bring the spiral water-cooled wall module (3) closer to the rigid beam (2) specifically includes: The chain hoist (5) is horizontally mounted between the rigid beam (2) and the spiral water-cooled wall module (3). The hooks at both ends of the chain hoist (5) are respectively set on the temporary pulling lugs on the rigid beam (2) and the temporary pulling lugs on the spiral water-cooled wall module (3). The chain hoists (5) are tightened in alternating steps, generating a horizontal lateral traction force that forces the spiral water-cooled wall module (3) to deform within the elastic yield limit of the metal pipe and move closer to the rigid beam (2).

7. The method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control according to claim 1, characterized in that, Until the third-level datum on the spiral water-cooled wall module (3) and the second-level datum on the rigid beam (2) reach the preset alignment tolerance requirements in spatial projection relative position, specifically including: At least three points are uniformly selected along the length direction on the third-level reference of the spiral water-cooled wall module (3) as measurement control points; A taut thin steel wire is pulled and fixed along the secondary reference on the surface of the rigid beam (2); The spatial vertical distance and horizontal spacing between the third-level reference for measuring the position of the measurement control point and the thin steel wire are measured. Calculate the lateral spacing difference between the measurement control points located at both ends of the third-level datum, and use the quotient of the lateral spacing difference and the length distance between the measurement control points along the third-level datum to perform trigonometric function conversion to obtain the actual deflection angle. When the absolute value of the difference between the horizontal spacing and the actual deflection angle are within the tolerance threshold range corresponding to the preset alignment tolerance requirement, the judgment conclusion that the third-level datum and the second-level datum are collinear is output.

8. The method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control according to claim 1, characterized in that, After connecting the spiral water-cooled wall module (3) to the rigid beam (2) according to the temporary welding fixing point (6), the process further includes: Initiate formal welding between the suspension load-bearing component of the spiral water-cooled wall module (3) and the suspension clamp of the rigid beam (2), monitor the interpass temperature of the formal welding operation, and implement slow cooling treatment after the welding operation is completed. Maintain the tension of the chain hoist (5) until all rigid connection welds formed by the formal welding operation naturally cool to ambient temperature. The unloading sequence is adopted, in which the chain tension of the chain hoist (5) is released symmetrically from the middle position of the spiral water-cooled wall module (3) to both sides, until the carrying chain of the chain hoist (5) is completely relaxed and the chain hoist (5) is removed.

9. The method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control according to claim 8, characterized in that, The process continues until the carrying chain of the chain hoist (5) is completely relaxed and the chain hoist (5) is removed: Carry out the pipe butt welding work between the spiral water-cooled wall module (3) described in this layer and the spiral water-cooled wall module (3) installed in the lower layer, and reserve the welding heat shrinkage gap; Utilizing the physical flexibility of the spiral water-cooled wall module (3) in the suspended span between two adjacent rigid beams (2), it naturally absorbs and compensates for the local axial shrinkage caused by the cooling of the butt weld formed during the butt welding work.

10. The method for anti-torsion hoisting of the spiral water-cooled wall of an ultra-supercritical boiler with multi-level reference control according to claim 1, characterized in that, The steps of repeatedly establishing multi-level spatial references layer by layer along the height direction to the temporary welding fixing point (6) to complete the assembly of the entire furnace spiral water-cooled wall specifically include: Independent vertical hoisting levels are defined between the two adjacent rigid beams (2). Within the independent vertical hoisting levels, the secondary reference for the elevation of this layer is generated by the independent vertical projection of the primary reference at the bottom layer. The spiral water-cooled wall module (3) is forced to deform and align with the secondary reference under the action of the lateral traction force. The mechanical elastic deformation absorbs the manufacturing size deviation of the spiral water-cooled wall module (3) itself and the installation deviation remaining during the hoisting and assembly process, cutting off the physical path of the installation error at the bottom layer to be cascaded and transmitted to the high-altitude space.

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