A construction method for modularizing and integrating photovoltaic panels on existing industrial plant roofs.

Abstract

This invention discloses a construction method for modularizing and integrating photovoltaic (PV) panels on existing industrial plant roofs, relating to the field of PV panel construction technology. The method includes the following specific steps: Step 1: Modular prefabrication of materials; Step 2: BIM collaborative verification; Step 3: Construction of purlin brackets and purlins; Step 4: Removal of skylights and podiums; Step 5: Roof panel installation; Step 6: Modular PV installation. This method for modularizing and integrating PV panels on existing industrial plant roofs reduces on-site assembly steps through prefabricated modular components, increasing construction speed by 30%-50%. It is particularly suitable for rapid deployment on commercial and industrial rooftops or large power plants, simplifying the process and reducing reliance on skilled workers, thus decreasing labor requirements by 20%-30%. It supports "Lego-style" expansion of PV systems, eliminating the need to modify the original structure when adding capacity; and the modular design allows for rapid replacement of faulty units.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic panel construction technology, specifically a construction method for modularizing and integrating photovoltaic panels onto existing industrial plant building facades. Background Technology

[0002] As high-energy-consuming structures, industrial plants require optimization of their energy structure as a key aspect of carbon reduction.

[0004] Although the total rooftop area of ​​industrial plants nationwide exceeds 1 billion square meters, the current photovoltaic utilization rate is less than 5%, indicating that there is still enormous untapped potential and a large amount of space has not yet been converted into a source of clean energy. The main pain points of traditional photovoltaic retrofitting are: (1) Poor structural adaptability: The old factory buildings did not take into account the photovoltaic load in terms of load-bearing, waterproofing, and wind resistance. When designing, too many factors need to be considered, which increases costs and poses a series of safety hazards. (2) Complex construction: Traditional photovoltaics require customized design and have a long construction period (usually 2-6 months). Production cannot be stopped during the renovation period, nor can it affect the normal production of enterprises, which increases the difficulty of construction.

[0005] Furthermore, the coordination challenges arising from multidisciplinary construction significantly increase management costs. Due to the collaboration involved in building structure reinforcement, electrical system grid connection, and roof waterproofing, conflicts and rework frequently occur on-site. Particularly in high-altitude operations, the installation of photovoltaic modules conflicts with the protection of existing production equipment, necessitating frequent adjustments to construction plans. Industry research data shows that unplanned downtime for such renovation projects accounts for an average of 15% to 20% of the project duration, indirectly leading to a 25% or more increase in construction costs. Simultaneously, the significant differences in building age and structural form among factories in different regions make it difficult to establish a standardized construction system, further increasing the complexity of technical briefings and on-site management. This dual pressure of high time and economic costs extends the investment recovery period to 8 to 10 years, severely weakening the enthusiasm of industrial enterprises to implement photovoltaic renovations. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a construction method for modularizing and integrating photovoltaic panels on existing industrial plant roofs, thus solving the problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a construction method for modularizing and integrating photovoltaic panels on existing industrial plant roofs, comprising the following specific steps: Step 1: Modular prefabrication of materials, using digital pre-assembly technology, to prefabricate the four major modules of purlin brackets, purlin strips, roof panels and photovoltaic modules in the factory; ensuring timely supply of products for on-site construction; Step 2: BIM Collaborative Verification; Establish a 3D model that includes building structural loads (live load ≥ 0.5 kN / m²), wind pressure parameters (basic wind pressure 0.45 kN / m²), and equipment parameters; Step 3: Construction of the purlin brackets and purlins; Step Four: Demolition of the skylights and podium, as detailed below: (1) Preparations before construction; (2) Segmented demolition operation; (3) Node processing; (4) Safety protection; Step 5: Roof panel installation, details as follows: (1) Construction preparation: Use BIM technology to simulate three-dimensional slab layout, optimize the roof panel laying sequence, and ensure that the longitudinal overlap length is ≥250mm and the transverse joint misalignment is ≥300mm; use a total station to check the purlin installation accuracy, the height difference between the top surfaces of adjacent purlins is ≤3mm, and the longitudinal straightness deviation is ≤5mm / 30m; prepare a special seam locking machine (processing speed ≥8m / min) and anti-slip handling clamps; (2) Roof panel laying: lay from the low point of the roof to the high point against the wind. The positioning deviation of the first panel is ≤2mm. It is temporarily fixed with ST5.5×25mm stainless steel self-tapping screws. After every 3 panels are laid, the axis offset is checked with a theodolite. The cumulative deviation is controlled to be ≤10mm. The standing seam is formed continuously by a hydraulic seam machine. The interlocking height is ≥35mm. After interlocking, it is tightened manually with a rubber hammer. (3) Node treatment: 360° interlocking waterproof membrane is installed at the gutter, with an overlap length of ≥150mm. Polyurethane sealant is applied to the joint (thickness ≥3mm after curing); Z-shaped edge trim is installed at the gable, with a bending angle of 72°±1°, and fixed with double-row ST4.8×19mm screws (spacing 200mm); Adjustable ventilator is installed at the ridge, with an adjustment range of ±15°, and its wind resistance performance has been verified to reach level 13 wind pressure through wind tunnel testing, which meets the roof wind resistance acceptance specifications. Step 6: Modular photovoltaic installation; (1) Construction of photovoltaic guide rails and cable trays; A. Photovoltaic guide rail installation: 6063-T5 aluminum alloy guide rails (section size 40×40mm, wall thickness 2.5mm) are used. 3D layout is performed according to the BIM detailed drawings. A laser level is used to project the installation baseline onto the roof panel, with longitudinal spacing deviation controlled within ±1.5mm / m. The guide rail support base uses 304 stainless steel clamps (bolt torque value 22N·m±10%), with one set every 0.47m. Silicone structural sealant (displacement capacity ±25%) is injected at the engagement point between the base and the upright locking edge. The guide rail connection adopts a bidirectional plug-in structure, with joint gap ≤0.5mm and overall straightness deviation ≤3mm / 10m. After verification with a total station, a final tightening torque of 25N·m is applied. B. Cable tray system installation: Hot-dip galvanized cable trays (200×100mm, coating thickness ≥86μm) are laid along the roof slope, with support and hanger spacing ≤1.8m and turning radius ≥6 times the cable tray width; modular quick-assembly connectors are used to connect sections (ensuring contact resistance is not greater than 50 microohms), and conductive copper strips (with a cross-sectional area of ​​not less than 16mm²) are firmly pressed into the joints. 2 The cable tray grounding system is equipped with a galvanized flat steel bar (40mm×4mm) every 30 meters, which is reliably connected to the roof lightning protection network to ensure that the grounding resistance value does not exceed 1Ω. (2) Photovoltaic module hoisting: Install the hoisting equipment correctly on the photovoltaic module. Select the appropriate hoisting point according to the structural characteristics of the module and the hoisting requirements. For rectangular photovoltaic modules, use the four-point hoisting method. Fix the wire rope or sling to the four corners of the module to ensure that the module is subjected to uniform force during the hoisting process and avoid deformation or damage. When the component is lifted to 0.5-1m above the installation position, stop lifting; use a truck crane to move the component above the installation position, and then slowly lower the component to accurately position it. (3) Photovoltaic module installation: After the module is in place, the installer uses connectors to fix the module to the bracket. Before fixing, the connection surface should be thoroughly cleaned with non-woven cloth soaked in industrial alcohol to remove oil and oxide layer, and the flatness of the contact surface should be visually checked. The specifications and models of each bolt should be measured with vernier calipers to ensure that the bolt length and thread pitch are consistent with the design drawings. During the fixing process, the torque should be applied in three stages using a diagonal tightening method. The first pre-tightening should be to 30% of the design value, the second tightening should be to 70%, and finally, a calibrated torque wrench should be used to apply force smoothly in a clockwise direction to 100% of the design torque. A yellow waterproof marker should be used to draw continuous straight lines on the hexagonal head of the bolt and the surface of the connector to make anti-loosening marks. For critical load-bearing parts, the status should be marked with red torque marking paint 2 hours after the initial tightening, and a second tightening should be performed. During the second tightening, the wrench should be kept perpendicular to the bolt axis. Then, the installation position, verticality, and horizontality of the components should be checked and adjusted.

[0008] Optionally, the modular prefabrication process in step one is as follows: (1) Purlin module: It is made of Q355B steel by laser cutting, with a length tolerance of ±1.5mm. The preset bolt hole positions are processed by CNC punching machine, with a hole diameter deviation of ≤0.3mm; (2) Purlin module: The existing roof purlin spacing data is obtained through 3D scanning, and the processing parameters of variable cross section C-shaped steel are intelligently generated. The bending error is ≤L / 500 and ≤5mm. (3) Roof panel module: It is made of 0.6mm thick aluminum-zinc coated steel plate roll forming, with a peak height of 75±0.5mm, and is equipped with embedded slots (slot width 22±0.2mm) for quick positioning of photovoltaic guide rail; (4) Photovoltaic integrated module: pre-installed micro inverter (conversion efficiency ≥98.5%) and aluminum alloy rail (anodized film thickness ≥15μm) to form a standard unit of 3.2m×1.6m.

[0009] Optionally, in the modular prefabrication stage of step one, the material anti-corrosion treatment is completed simultaneously, the hot-dip galvanizing amount of the purlin is ≥275g / m², the salt spray resistance time of the roof panel coating is ≥1000h, and the corrosion rate is <5% within a 25-year service life.

[0010] Optionally, step two also includes a model verification operation, as follows: (1) Verify the stress value of the purlin support node (≤145MPa) through finite element analysis; (2) Simulate the effect of photovoltaic array spacing (≥300mm) on roof drainage efficiency; (3) Check the clearance between the construction equipment (such as vacuum suction cup lifting equipment) and the existing roof (≥800mm); (4) Generate construction conflict reports and optimize module installation sequence.

[0011] Optionally, step three includes purlin support positioning, purlin support installation, purlin hoisting, and purlin leveling, as detailed below: (1) Purlin positioning construction: use a laser rangefinder to position and lay out the purlin spacing marked on the design drawings, and allow the deviation to be precisely controlled within ±3mm; use a magnetic plumb line to carefully check and ensure that the verticality of the purlin installation axis and the coincidence of the center line of the steel beam web are strictly not more than 2mm; after positioning, use a marker to mark the center point of the drill hole on the lower flange of the steel beam. (2) Purlin installation: Use 2.5mm thick Q345B galvanized steel plate to prefabricate the Z-shaped purlins. Before installation, check the bending angle tolerance of ±0.5°. Tighten the anchor bolt nuts with a torque wrench, tightening them in three stages to a final torque of 85 N·m, with 2-3 threads exposed on the bolts. After installation, use a 0.02mm high-precision feeler gauge for strict inspection to ensure that the gap between the purlin and the steel beam contact surface does not exceed 0.5mm. (3) Purlin hoisting: A 25t truck crane with a special C-type lifting tool is used to hoist C250×75×20×2.5mm galvanized purlins; the hoisting angle is controlled in the range of 60°-75°, and the spacing between the hoisting points is scientifically calculated and precisely set to 0.207L to ensure the safety and stability of the hoisting process; after positioning, ST4.8×25mm self-tapping rivets are used for connection, and point fixing is performed first and then final tightening is carried out. The rivet spacing is 150mm and the allowable deviation is ±5mm. (4) Leveling the purlins: Use an electronic level to measure the straightness of the purlin installation. Set an adjustable support frame in the middle of the purlin span for fine-tuning the elevation. Ensure that the height difference between the top surfaces of adjacent purlins does not exceed 3mm. At the same time, the maximum sag of the longitudinal bending should be less than or equal to L / 500 and absolutely not exceed 10mm. After leveling, use anti-loosening shims for secondary tightening.

[0012] Optionally, the pre-construction preparations in step four are as follows: A. Using a drone equipped with a high-definition camera, perform a 3D scanning and modeling task on the skylight and ventilator to generate a BIM demolition simulation animation, so as to accurately identify and locate all connection nodes; B. Erect double-row plug-in disc-lock scaffolding, ensuring that the spacing between uprights does not exceed 1.5m and the step distance does not exceed 2m, and install U-shaped top supports at the top to support the protective netting; C. Prepare a special suction cup lifting tool (vacuum degree ≥ -90kPa) and a fall-proof cutting device.

[0013] Optionally, the segmented dismantling operation in step four is specifically as follows: A. Use a handheld laser cutting machine to separate the panels along the seams, with the cutting temperature controlled at 800-1200℃ and the cut width ≤3mm; B. Use a 4-point vacuum suction cup hanger to adsorb the skylight panel, with a lifting speed ≤0.5m / s and a single lifting area ≤2.4㎡; C. The demolition of the ventilator follows the principle of "attachments first, main structure later", prioritizing the removal of components such as rain shields and waterproof boards, while retaining the main frame as temporary support.

[0014] Optionally, the node processing in step four is as follows: A. The residual adhesive at the original connection point was thoroughly cleaned with an electric wire brush (speed ≥10000rpm) until the surface roughness reached Sa2.5 level; B. Bolt holes shall be sealed with epoxy resin mortar (compressive strength ≥60MPa) to a depth ≥50mm; C. Install temporary drainage channels (slope rate ≥ 3%) at the edge of the demolition area, and use TPO waterproof membrane to make a 300mm wide transition overlap.

[0015] Optionally, the security measures in step four are as follows: A. Install an audible and visual alarm system that automatically suspends high-altitude operations when the wind speed is ≥10.8m / s; B. Lay 3 layers of buffer netting (mesh size ≤ 20mm) under the demolition area, with a load-bearing capacity ≥ 200kg / m²; C. Workers are equipped with five-point double-hook safety belts, with a static load of ≥22kN at the anchor point.

[0016] This invention provides a construction method for modularizing and integrating photovoltaic panels onto existing industrial plant roofs, which has the following beneficial effects: This method of modularizing and integrating photovoltaic panels on existing industrial plant roofs reduces on-site assembly steps by using prefabricated modular components (such as integrated brackets and pre-connected cables), increasing construction speed by 30%-50%. It is especially suitable for rapid deployment on industrial and commercial rooftops or large power plants, simplifies the process, reduces reliance on skilled workers, and lowers labor requirements by 20%-30%. It supports "Lego-like" expansion of photovoltaic systems, eliminating the need to modify the original structure when adding capacity; and the modular design allows for quick replacement of faulty units. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the invention process. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Please see Figure 1 This invention provides a technical solution: a construction method for modularizing and integrating photovoltaic panels on existing industrial plant roofs, comprising the following specific steps: Step 1: Modular material processing. Modularize the following materials to ensure timely supply of products for on-site construction. Digital pre-assembly technology is used to prefabricate the four main modules—purlin brackets, purlins, roof panels, and photovoltaic modules—in a factory. (1) Purlin module: It is made of Q355B steel by laser cutting, with a length tolerance of ±1.5mm. The preset bolt hole positions are processed by CNC punching machine, with a hole diameter deviation of ≤0.3mm; (2) Purlin module: The existing roof purlin spacing data is obtained through 3D scanning, and the processing parameters of variable cross section C-shaped steel are intelligently generated. The bending error is ≤L / 500 and ≤5mm. (3) Roof panel module: It is made of 0.6mm thick aluminum-zinc coated steel plate roll forming, with a peak height of 75±0.5mm, and is equipped with embedded slots (slot width 22±0.2mm) for quick positioning of photovoltaic guide rail; (4) Photovoltaic integrated module: pre-installed micro inverter (conversion efficiency ≥98.5%) and aluminum alloy rail (anodized film thickness ≥15μm) to form a standard unit of 3.2m×1.6m; Serial Number Name Unit Quantity Remarks One Photovoltaic Power Generation System 1 Photovoltaic Modules pcs 10，079 Modular Product 2 String Inverter set 34 Modular Product 3 String Inverter 1 Modular Product 4 Inverter Support set 35 Modular Product 5 Inverter Nameplate set 35 Modular Product 6 Inverter Protective Cover set 35 Modular Product Two Cable 1 Photovoltaic DC Cable m 27，500 2 Photovoltaic DC Cable m 27，500 Three Cable Protection Groove Pipe 1 Aluminum Alloy Ladder-Type Straight Bridge m 860 Modular Product 2 Aluminum Alloy Ladder-Type Straight Bridge m 1，070 Modular Product 3 Aluminum Alloy Ladder-Type Straight Bridge m 1，880 Modular Product 4 Aluminum Alloy Ladder-Type Straight Bridge m 480 Modular Product 5 Aluminum Alloy Ladder-Type Straight Bridge m 80 Modular Product 6 Aluminum Alloy Ladder-Type Straight Bridge m 45 Modular Product 7 Aluminum Alloy Ladder-Type Straight Bridge m 140 Modular Product 8 Aluminum Alloy Ladder-Type Straight Bridge m 70 Modular Product 9 Conduit m 5，000 10 Auxiliary Materials item 1 Four Lightning Protection and Grounding Unit 1 Down Conductor / Lap Joint pcs 47 Modular Product 2 Horizontal Grounding Grid m 7，300 Modular Product 3 Component Grounding Wire m 3，700 Modular Product 4 Equipment Grounding Wire m 180 Modular Product 5 Other Auxiliary Materials item 1 Five Fire Protection System 1 Fire Extinguisher set 36 2 Warning Sign set 36 Six Cleaning System 1 Cleaning Gate Valve pcs 92 Modular Product 2 PPR Hot Water Pipe m 1，900 Modular Product 3 PPR Hot Water Pipe m 300 Modular Product 4 Water Meter set 2 Modular Product 5 Pressure Gauge set 2 6 Water Pump set 2 7 Check Valve pcs 2 Modular Product 8 Gate Valve pcs 2 Modular Product 9 Flexible Rubber Joint pcs 4 Modular Product 10 Expansion Joint section 40 Modular Product 11 Expansion Joint section 4 Modular Product Seven Other Auxiliary Materials 1 Photovoltaic Connector MC4 pairs 3，000 Modular Product 2 [[ID=M122]]Operation and Maintenance Passage m 1，900 Modular Product 3 Water Guide Clip pcs 20，158 Modular Product 4 Safety Fence m 60 Modular Product Eight Roof Panel 1 Channel Support m 200000 Modular Product 2 Purlin m 10000 Modular Product 3 Roof Panel tons 400 Modular Product Step 2: BIM Collaborative Verification; A three-dimensional model was established, including building structural loads (live load ≥ 0.5 kN / m²), wind pressure parameters (basic wind pressure 0.45 kN / m²), and equipment parameters, and the following verifications were performed: A. Verify the stress value of the purlin support node (≤145MPa) through finite element analysis; B. The impact of simulated photovoltaic array spacing (≥300mm) on roof drainage efficiency; C. Check the clearance between construction equipment (such as vacuum suction cup lifting equipment) and the existing roof (≥800mm); D. Generate a construction conflict report and optimize the module installation sequence; Note: During the modular prefabrication stage, material anti-corrosion treatment is completed simultaneously. The hot-dip galvanizing amount of purlins is ≥275g / m², and the salt spray resistance time of the roof panel coating is ≥1000h, ensuring that the corrosion rate is <5% during the 25-year service life. Step 3: Construction of the purlin brackets and purlins; (1) Purlin positioning construction: use a laser rangefinder to position and lay out the purlin spacing marked on the design drawings, and allow the deviation to be precisely controlled within ±3mm; use a magnetic plumb line to carefully check and ensure that the verticality of the purlin installation axis and the coincidence of the center line of the steel beam web are strictly not more than 2mm; after positioning, use a marker to mark the center point of the drill hole on the lower flange of the steel beam. (2) Purlin installation: 2.5mm thick Q345B galvanized steel plate is used to prefabricate the Z-shaped purlins. Before installation, check the bending angle tolerance of ±0.5°. Tighten the anchor bolt nuts with a torque wrench, tightening them in three stages to a final torque of 85 N·m, with 2-3 threads exposed on the bolt. After installation, use a 0.02mm high-precision feeler gauge for strict inspection to ensure that the gap between the purlin and the steel beam contact surface does not exceed 0.5mm. (3) Purlin hoisting: A 25t truck crane with a special C-type lifting tool is used to hoist C250×75×20×2.5mm galvanized purlins; the hoisting angle is controlled in the range of 60°-75°, and the spacing between the hoisting points is scientifically calculated and precisely set to 0.207L to ensure the safety and stability of the hoisting process; after positioning, ST4.8×25mm self-tapping rivets are used for connection, and point fixing is performed first and then final tightening is carried out. The rivet spacing is 150mm and the allowable deviation is ±5mm. (4) Leveling the purlins: Use an electronic level to measure the straightness of the purlin installation. Set an adjustable support frame in the middle of the purlin span for fine-tuning the elevation. Ensure that the height difference between the top surfaces of adjacent purlins does not exceed 3mm. At the same time, the maximum sag of the longitudinal bending should be less than or equal to L / 500 and absolutely not exceed 10mm. After leveling, use anti-loosening shims for secondary tightening. Step 4: Demolition of skylights and podium; (1) Preparations before construction; A. Using a drone equipped with a high-definition camera, perform a 3D scanning and modeling task on the skylight and ventilator to generate a BIM demolition simulation animation, so as to accurately identify and locate all connection nodes; B. Erect double-row plug-in disc-lock scaffolding, ensuring that the spacing between uprights does not exceed 1.5 meters and the step distance does not exceed 2 meters, and install U-shaped top supports to support the protective netting; C. Prepare a special suction cup lifting tool (vacuum degree ≥ -90kPa) and a fall-proof cutting device; (2) Segmented demolition operation; A. Use a handheld laser cutting machine to separate the panels along the seams, with the cutting temperature controlled at 800-1200℃ and the cut width ≤3mm; B. Use a 4-point vacuum suction cup hanger to adsorb the skylight panel, with a lifting speed ≤0.5m / s and a single lifting area ≤2.4m²; C. The demolition of the ventilator follows the principle of "attachments first, main structure second", prioritizing the removal of components such as rain shields and waterproof boards, while retaining the main frame as temporary support; (3) Node processing; A. The residual adhesive at the original connection point was thoroughly cleaned with an electric wire brush (speed ≥10000rpm) until the surface roughness reached Sa2.5 level; B. Bolt holes shall be sealed with epoxy resin mortar (compressive strength ≥60MPa) to a depth ≥50mm; C. Install temporary drainage channels (slope rate ≥ 3%) at the edge of the demolition area, and use TPO waterproof membrane to make a 300mm wide transition overlap; (4) Safety protection; A. Install an audible and visual alarm system that automatically suspends high-altitude operations when the wind speed is ≥10.8m / s; B. Lay 3 layers of buffer netting (mesh size ≤ 20mm) under the demolition area, with a load-bearing capacity ≥ 200kg / m²; C. Workers are equipped with five-point double-hook safety belts, with a static load of ≥22kN at the anchor point; Note: The construction process shall strictly comply with the "Technical Specification for Safety of High-Altitude Operations in Building Construction" (JGJ80) and the "Standard for Acceptance of Construction Quality of Steel Structures" (GB50205). Each process shall be inspected and approved by three parties before proceeding to the next process. Step 5: Roof panel installation; (1) Construction preparation; A. Use BIM technology to simulate three-dimensional slab layout, optimize the roof panel laying sequence, and ensure that the longitudinal overlap length is ≥250mm and the transverse joint misalignment is ≥300mm. B. Use a total station to verify the installation accuracy of the purlins. The height difference between the top surfaces of adjacent purlins should be ≤3mm, and the longitudinal straightness deviation should be ≤5mm / 30m. C. Prepare a dedicated overlock machine (processing speed ≥ 8m / min) and anti-slip handling fixtures; (2) Roof panel installation; A. Lay the boards against the wind from the lowest point of the roof to the highest point. The positioning deviation of the first board should be ≤2mm. Use ST5.5×25mm stainless steel self-tapping screws for temporary fixing. B. After every 3 boards are laid, the axis offset is checked with a theodolite, and the cumulative deviation is controlled to be ≤10mm; C. The upright seam is formed continuously using a hydraulic seam machine, with a seaming height ≥35mm. After seaming, it is manually tightened a second time with a rubber hammer. (3) Node processing; A. Install 360° interlocking waterproof membrane in the gutter area, with an overlap length of ≥150mm, and apply polyurethane sealant to the joints (thickness ≥3mm after curing). B. Z-shaped edge trim is installed on the gable wall, with a bending angle of 72°±1°, and fixed with double rows of ST4.8×19mm screws (200mm spacing). C. The adjustable ventilator installed at the ridge has an adjustment range of ±15° and its wind resistance performance has been verified through wind tunnel testing to reach level 13 wind pressure, which meets the roof wind resistance acceptance specifications. Step Six: Modular Installation of Photovoltaic Units; (1) Construction of photovoltaic guide rails, cable trays, etc.; A. Photovoltaic guide rail installation: 6063-T5 aluminum alloy guide rails (section size 40×40mm, wall thickness 2.5mm) are used. 3D layout is performed according to the BIM detailed drawings. A laser level is used to project the installation baseline onto the roof panel, with longitudinal spacing deviation controlled within ±1.5mm / m. The guide rail support base uses 304 stainless steel clamps (bolt torque value 22N·m±10%), with one set every 0.47m. Silicone structural sealant (displacement capacity ±25%) is injected at the engagement point between the base and the upright locking edge. The guide rail connection adopts a bidirectional plug-in structure, with joint gap ≤0.5mm and overall straightness deviation ≤3mm / 10m. After verification with a total station, a final tightening torque of 25N·m is applied. B. Cable tray system installation: Hot-dip galvanized cable trays (200×100mm, coating thickness ≥86μm) are laid along the roof slope, with support spacing ≤1.8m and turning radius ≥6 times the cable tray width; modular quick-assembly connectors (ensuring contact resistance is not greater than 50 microohms) are used to connect sections, and conductive copper strips (with a cross-sectional area of ​​not less than 16 square mm) are firmly pressed into the joints; a galvanized flat steel strip (40mm×4mm) is configured every 30 meters in the cable tray grounding system, and reliably connected to the roof lightning protection network to ensure that the grounding resistance value does not exceed 1Ω (testing procedure follows GB50169 standard). (2) Photovoltaic module hoisting: Install the hoisting equipment correctly on the photovoltaic module. Select the appropriate hoisting point according to the structural characteristics of the module and the hoisting requirements. Generally, for rectangular photovoltaic modules, a four-point hoisting method can be used. Fix the wire rope or sling to the four corners of the module to ensure that the module is subjected to uniform force during the hoisting process and avoid deformation or damage. After the hoisting supervisor confirms that the lifting equipment is securely installed and the components are reliably tied, the hoisting signal is given. The truck crane operator slowly lifts the components according to the command signal. The lifting speed should be uniform and stable to avoid the components swaying or colliding in the air. Throughout the entire process of lifting the components, the hoisting supervisor and all workers must closely monitor the status of the components. If any abnormality is found, a stop operation signal must be given immediately. When the component is lifted to a certain height above the installation position (generally 0.5-1m), the lifting is stopped; the component is moved above the installation position by operating the truck crane's luffing and slewing functions, and then the component is slowly lowered to accurately position it; during the descent of the component, the installation workers should guide and assist at the installation position to ensure that the component is installed in the correct direction and in the correct position; (3) After the photovoltaic modules are in place, the installers should immediately use bolts, nuts and other fasteners to fix the modules to the brackets. Before fixing, the connecting surfaces should be thoroughly cleaned with non-woven cloth soaked in industrial alcohol to remove oil and oxide layers, and the flatness of the contact surfaces should be visually checked. The specifications and models of each bolt should be measured with a vernier caliper to ensure that the bolt length and thread pitch are completely consistent with the "Fasteners List" in the design drawings. During the fixing process, the torque should be applied in three stages using a diagonal tightening method: the first pre-tightening to 30% of the design value, the second tightening to 70%, and finally using a calibrated torque wrench to apply force smoothly in a clockwise direction to 100% of the design torque. The design value should be set according to the torque standard value marked on the construction drawings. Before construction, the "High Strength" standard should be consulted. Appendix C of the "Technical Specification for Bolted Connections" provides a comparison table to confirm the torque coefficients of bolts made of different materials (e.g., grade 8.8 / 10.9). These standard values ​​will vary depending on factors such as the bolt's mechanical properties, thread diameter, and surface treatment process (Dacromet / hot-dip galvanizing). Finally, use a yellow waterproof marker to draw continuous straight lines on the hexagonal head of the bolt and the surface of the connector to mark against loosening and ensure the reliability of the connection. For critical load-bearing parts, a red torque marking paint should be used to mark the status 2 hours after initial tightening, followed by a second tightening. During the second tightening, the wrench must be kept perpendicular to the bolt axis. After completion, the initial / final tightening time, operator, and inspection stamp information in the "Bolt Tightening Record Sheet" should be updated simultaneously. After confirmation by the quality inspector, the record should be scanned and uploaded to the project cloud drive for archiving and future reference. The installation position, verticality, and horizontality of the components should be checked and adjusted. The construction team should be equipped with calibrated and valid measuring tools such as a Leica TS60 theodolite, a Sokkia SDL30X digital level, and a Faro S150 laser level. Measurements should be conducted according to the "three-inspection system": after the lead surveyor completes the adjustments, the lead surveyor should use an explosion-proof walkie-talkie to notify the verification personnel to conduct a second measurement. The interval between the two measurements should be controlled within 15 minutes to ensure consistent environmental conditions. Finally, the quality engineer should conduct a random inspection of no less than 20% using an independently sealed Topcon OS-103 total station. According to the mandatory provisions of Article 6.2.8 of the "Code for Acceptance of Construction Quality of Masonry Works" GB50203,... When the verticality deviation exceeds ±1.5‰, a set of 0.1mm precision stainless steel wedge shims should be used for fine adjustment. The thickness of the shim assembly should not exceed 3mm and it should be spot-welded for fixation. When the horizontal deviation exceeds ±2mm, it can be corrected by adjusting the M24 leveling bolts at the bottom of the bracket with a 0.02mm precision digital feeler gauge. Each adjustment should not exceed 0.5mm. All adjustment data must be entered into the quality control module of the project management APP in real time through an explosion-proof PDA. The system will automatically associate the BIM model coordinate data and generate an "Installation Accuracy Inspection Report" with a three-dimensional deviation vector. The inspection results will be synchronized to the digital construction platform of the owner, supervisor and general contractor in real time through blockchain technology.

[0022] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A construction method for modularizing and integrating photovoltaic panels onto existing industrial plant roofs, characterized in that, The specific steps include the following: Step 1: Modular prefabrication of materials, using digital pre-assembly technology, to prefabricate the four major modules of purlin brackets, purlin strips, roof panels and photovoltaic modules in the factory; ensuring timely supply of products for on-site construction; Step 2: BIM Collaborative Verification; Establish a 3D model that includes building structural loads (live load ≥ 0.5 kN / m²), wind pressure parameters (basic wind pressure 0.45 kN / m²), and equipment parameters; Step 3: Construction of the purlin brackets and purlins; Step Four: Demolition of the skylights and podium, as detailed below: (1) Preparations before construction; (2) Segmented demolition operation; (3) Node processing; (4) Safety protection; Step 5: Roof panel installation, details as follows: (1) Construction preparation: Use BIM technology to simulate three-dimensional slab layout, optimize the roof panel laying sequence, and ensure that the longitudinal overlap length is ≥250mm and the transverse joint misalignment is ≥300mm; use a total station to check the purlin installation accuracy, the height difference between the top surfaces of adjacent purlins is ≤3mm, and the longitudinal straightness deviation is ≤5mm / 30m; prepare a special seam locking machine (processing speed ≥8m / min) and anti-slip handling clamps; (2) Roof panel laying: lay from the low point of the roof to the high point against the wind. The positioning deviation of the first panel is ≤2mm. It is temporarily fixed with ST5.5×25mm stainless steel self-tapping screws. After every 3 panels are laid, the axis offset is checked with a theodolite. The cumulative deviation is controlled to be ≤10mm. The standing seam is formed continuously by a hydraulic seam machine. The interlocking height is ≥35mm. After interlocking, it is tightened manually with a rubber hammer. (3) Node treatment: 360° interlocking waterproof membrane is installed at the gutter, with an overlap length of ≥150mm. Polyurethane sealant is applied to the joint (thickness ≥3mm after curing); Z-shaped edge trim is installed at the gable, with a bending angle of 72°±1°, and fixed with double-row ST4.8×19mm screws (spacing 200mm); Adjustable ventilator is installed at the ridge, with an adjustment range of ±15°, and its wind resistance performance has been verified to reach level 13 wind pressure through wind tunnel testing, which meets the roof wind resistance acceptance specifications. Step 6: Modular photovoltaic installation; (1) Construction of photovoltaic guide rails and cable trays; A. Photovoltaic guide rail installation: 6063-T5 aluminum alloy guide rails (section size 40×40mm, wall thickness 2.5mm) are used. 3D layout is performed according to the BIM detailed drawings. A laser level is used to project the installation baseline onto the roof panel, with longitudinal spacing deviation controlled within ±1.5mm / m. The guide rail support base uses 304 stainless steel clamps (bolt torque value 22N·m±10%), with one set every 0.47m. Silicone structural sealant (displacement capacity ±25%) is injected at the engagement point between the base and the upright locking edge. The guide rail connection adopts a bidirectional plug-in structure, with joint gap ≤0.5mm and overall straightness deviation ≤3mm / 10m. After verification with a total station, a final tightening torque of 25N·m is applied. B. Cable tray system installation: Hot-dip galvanized cable trays (200×100mm, coating thickness ≥86μm) are laid along the roof slope, with support and hanger spacing ≤1.8m and turning radius ≥6 times the cable tray width; modular quick-assembly connectors are used to connect sections (ensuring contact resistance is not greater than 50 microohms), and conductive copper strips (with a cross-sectional area of ​​not less than 16mm²) are firmly pressed into the joints. 2 The cable tray grounding system is equipped with a galvanized flat steel bar (40mm×4mm) every 30 meters, which is reliably connected to the roof lightning protection network to ensure that the grounding resistance value does not exceed 1Ω. (2) Photovoltaic module hoisting: Install the hoisting equipment correctly on the photovoltaic module. Select the appropriate hoisting point according to the structural characteristics of the module and the hoisting requirements. For rectangular photovoltaic modules, use the four-point hoisting method. Fix the wire rope or sling to the four corners of the module to ensure that the module is subjected to uniform force during the hoisting process and avoid deformation or damage. When the component is lifted to 0.5-1m above the installation position, stop lifting; use a truck crane to move the component above the installation position, and then slowly lower the component to accurately position it. (3) Photovoltaic module installation: After the module is in place, the installer uses connectors to fix the module to the bracket. Before fixing, the connection surface should be thoroughly cleaned with non-woven cloth soaked in industrial alcohol to remove oil and oxide layer, and the flatness of the contact surface should be visually checked. The specifications and models of each bolt should be measured with vernier calipers to ensure that the bolt length and thread pitch are consistent with the design drawings. During the fixing process, the torque should be applied in three stages using a diagonal tightening method. The first pre-tightening should be to 30% of the design value, the second tightening should be to 70%, and finally, a calibrated torque wrench should be used to apply force smoothly in a clockwise direction to 100% of the design torque. A yellow waterproof marker should be used to draw continuous straight lines on the hexagonal head of the bolt and the surface of the connector to make anti-loosening marks. For critical load-bearing parts, the status should be marked with red torque marking paint 2 hours after the initial tightening, and a second tightening should be performed. During the second tightening, the wrench should be kept perpendicular to the bolt axis. Then, the installation position, verticality, and horizontality of the components should be checked and adjusted.

2. The construction method for modular and integrated installation of photovoltaic panels on existing industrial plant building facades according to claim 1, characterized in that: The modular prefabrication process in step one is as follows: (1) Purlin module: It is made of Q355B steel by laser cutting, with a length tolerance of ±1.5mm. The preset bolt hole positions are processed by CNC punching machine, with a hole diameter deviation of ≤0.3mm; (2) Purlin module: The existing roof purlin spacing data is obtained through 3D scanning, and the processing parameters of variable cross section C-shaped steel are intelligently generated. The bending error is ≤L / 500 and ≤5mm. (3) Roof panel module: It is made of 0.6mm thick aluminum-zinc coated steel plate roll forming, with a peak height of 75±0.5mm, and is equipped with embedded slots (slot width 22±0.2mm) for quick positioning of photovoltaic guide rail; (4) Photovoltaic integrated module: pre-installed micro inverter (conversion efficiency ≥98.5%) and aluminum alloy rail (anodized film thickness ≥15μm) to form a standard unit of 3.2m×1.6m.

3. The construction method for modularizing and integrating photovoltaic panels on existing industrial plant buildings according to claim 1, characterized in that: In step one, the material anti-corrosion treatment is completed simultaneously during the modular prefabrication stage. The hot-dip galvanizing amount of the purlin is ≥275g / m², and the salt spray resistance time of the roof panel coating is ≥1000h, ensuring that the corrosion rate is <5% within a 25-year service life.

4. The construction method for modularizing and integrating photovoltaic panels on existing industrial plant building facades according to claim 1, characterized in that: Step two also includes a model verification operation, as detailed below: (1) Verify the stress value of the purlin support node (≤145MPa) through finite element analysis; (2) Simulate the effect of photovoltaic array spacing (≥300mm) on roof drainage efficiency; (3) Check the clearance between the construction equipment (such as vacuum suction cup lifting equipment) and the existing roof (≥800mm); (4) Generate construction conflict reports and optimize module installation sequence.

5. The construction method for modularizing and integrating photovoltaic panels on existing industrial plant buildings according to claim 1, characterized in that: Step three includes purlin support positioning, purlin support installation, purlin hoisting, and purlin leveling, as detailed below: (1) Purlin positioning construction: use a laser rangefinder to position and lay out the purlin spacing marked on the design drawings, and allow the deviation to be precisely controlled within ±3mm; use a magnetic plumb line to carefully check and ensure that the verticality of the purlin installation axis and the coincidence of the center line of the steel beam web are strictly not more than 2mm; after positioning, use a marker to mark the center point of the drill hole on the lower flange of the steel beam. (2) Purlin installation: Use 2.5mm thick Q345B galvanized steel plate to prefabricate the Z-shaped purlins. Before installation, check the bending angle tolerance of ±0.5°. Tighten the anchor bolt nuts with a torque wrench, tightening them in three stages to a final torque of 85 N·m, with 2-3 threads exposed on the bolts. After installation, use a 0.02mm high-precision feeler gauge for strict inspection to ensure that the gap between the purlin and the steel beam contact surface does not exceed 0.5mm. (3) Purlin hoisting: A 25t truck crane with a special C-type lifting tool is used to hoist C250×75×20×2.5mm galvanized purlins; the hoisting angle is controlled in the range of 60°-75°, and the spacing between the hoisting points is scientifically calculated and precisely set to 0.207L to ensure the safety and stability of the hoisting process; after positioning, ST4.8×25mm self-tapping rivets are used for connection, and point fixing is performed first and then final tightening is carried out. The rivet spacing is 150mm and the allowable deviation is ±5mm. (4) Leveling the purlins: Use an electronic level to measure the straightness of the purlin installation. Set an adjustable support frame in the middle of the purlin span for fine-tuning the elevation. Ensure that the height difference between the top surfaces of adjacent purlins does not exceed 3mm. At the same time, the maximum sag of the longitudinal bending should be less than or equal to L / 500 and absolutely not exceed 10mm. After leveling, use anti-loosening shims for secondary tightening.

6. The construction method for modular and integrated installation of photovoltaic panels on existing industrial plant building facades according to claim 1, characterized in that: The pre-construction preparations in step four are as follows: A. Using a drone equipped with a high-definition camera, perform a 3D scanning and modeling task on the skylight and louver, thereby generating a BIM demolition simulation animation to accurately identify and locate all connection nodes; B. Erect double-row plug-in disc-lock scaffolding, ensuring that the spacing between uprights does not exceed 1.5m and the step distance does not exceed 2m, and install U-shaped top supports at the top to support the protective netting; C. Prepare a special suction cup lifting tool (vacuum degree ≥ -90kPa) and a fall-proof cutting device.

7. The construction method for modular and integrated installation of photovoltaic panels on existing industrial plant building facades according to claim 1, characterized in that: The segmented dismantling operation in step four is as follows: A. Use a handheld laser cutting machine to separate the panels along the seams. The cutting temperature should be controlled between 800-1200℃ and the kerf width should be ≤3mm. B. Use a 4-point vacuum suction cup hanger to adsorb the skylight panel, with a lifting speed ≤0.5m / s and a single lifting area ≤2.4㎡; C. The demolition of the ventilator follows the principle of "attachments first, main structure later", prioritizing the removal of components such as rain shields and waterproof boards, while retaining the main frame as temporary support.

8. The construction method for modular and integrated installation of photovoltaic panels on existing industrial plant building facades according to claim 1, characterized in that: The node processing in step four is as follows: A. The residual adhesive at the original connection point was thoroughly cleaned with an electric wire brush (speed ≥10000rpm) until the surface roughness reached Sa2.5 level; B. Bolt holes shall be sealed with epoxy resin mortar (compressive strength ≥60MPa) to a depth ≥50mm; C. Install temporary drainage channels (slope rate ≥ 3%) at the edge of the demolition area, and use TPO waterproof membrane to make a 300mm wide transition overlap.

9. The construction method for modularizing and integrating photovoltaic panels on existing industrial plant buildings according to claim 1, characterized in that: The security measures in step four are as follows: A. Install an audible and visual alarm system that automatically suspends high-altitude operations when the wind speed is ≥10.8m / s; B. Lay 3 layers of buffer netting (mesh size ≤ 20mm) under the demolition area, with a load-bearing capacity ≥ 200kg / m²; C. Workers are equipped with five-point double-hook safety belts, with a static load of ≥22kN at the anchor point.

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