An external steel skeleton type modular offshore floating photovoltaic platform

Abstract

The application belongs to the technical field of offshore renewable energy utilization, and discloses an external steel skeleton type modular offshore floating photovoltaic platform, which comprises a steel structure bearing frame, a buoyancy unit, a photovoltaic power generation assembly and a mooring system; the inner cavity of the steel structure bearing frame is divided into a plurality of grid units by longitudinal and transverse reinforcing beams, and a structural stiffening knee plate is arranged at the node; the buoyancy unit is inlaid in each grid unit, and the buoyancy unit is connected with the buoyancy body connecting lug plate and the buoyancy body fixed lock pin in the inner side of the grid unit through the buoyancy body; the upper surface of the steel structure bearing frame is provided with a photovoltaic assembly support bracket for installing a photovoltaic power generation panel, and a structural counterweight block is installed; the outer periphery of the steel structure bearing frame is provided with the mooring system, and the mooring system comprises a fixed base and a mooring connecting assembly, and the fixed base mainly comprises two parallel lug plates. The application overcomes the defects of insufficient structural strength of the traditional floating platform, greatly reduces the probability of damage of the hollow buoyancy body due to collision, and greatly reduces the operation and maintenance cost and downtime.

Description

Technical Field

[0001] This invention belongs to the field of marine renewable energy utilization technology, specifically a modular marine floating photovoltaic platform with an external steel frame. Background Technology

[0002] With the accelerated transformation of the global energy structure, photovoltaic power generation, as an important component of clean and renewable energy, has seen its installed capacity continue to expand. However, land resources for onshore photovoltaic power generation are becoming increasingly scarce. Offshore floating photovoltaic systems, due to their advantages such as not occupying land resources, abundant solar radiation, low module operating temperature, and high power generation efficiency, are gradually becoming an important development direction in the photovoltaic power generation field.

[0003] Most mainstream floating photovoltaic platforms are currently constructed from high-density polyethylene (HDPE) floating modules, which support the photovoltaic modules through the floating module's own structure or an internal frame. While these platforms have proven successful in calm waters such as inland lakes and reservoirs, they face several challenges when applied to marine environments: First, insufficient structural strength and poor overall platform rigidity make them vulnerable to strong winds, waves, and swells, posing a significant risk of deformation and even damage. Second, the exposed lightweight floating materials are susceptible to external collisions, impacts from floating objects, and mechanical damage, leading to water ingress and affecting the platform's buoyancy and safety. Third, the fixed connection between the floating modules and the supporting structure necessitates the disassembly and replacement of a large number of components after a single module is damaged, resulting in significant maintenance workload and high costs.

[0004] The relevant reference CN120646166A discloses a floating offshore photovoltaic platform module, in which the floating body component is connected to the main steel frame through a flexible connector. The floating body component and the main steel frame are flexibly decoupled. Under wind and waves, the main steel frame is prone to twisting and bending, and the photovoltaic panel module is squeezed, collided, tilted and misaligned, resulting in damage and detachment of the photovoltaic panel module. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a modular offshore floating photovoltaic platform with an external steel frame that overcomes the defects of insufficient structural strength of traditional floating platforms, greatly reduces the probability of hollow buoyancy body being damaged by collision, and significantly reduces operation and maintenance costs and downtime.

[0006] To address the above technical problems, this invention provides an external steel frame modular floating photovoltaic platform for offshore use, comprising a steel structure load-bearing frame, buoyancy units, photovoltaic power generation components, and a mooring system; The steel structure load-bearing frame is divided into several grid units by longitudinal and transverse reinforcing beams, and structural stiffening elbows are set at the nodes; Each grid cell contains embedded buoyancy units, which are integrally formed hollow buoyancy bodies. The hollow buoyancy bodies have buoyancy body connecting lugs on their sides, and each grid cell has a buoyancy body fixing pin on its inner side. The buoyancy body connecting lugs and the buoyancy body fixing pins are connected in conjunction. Directly above the buoyancy unit, photovoltaic panels are installed on the upper surface of the steel structure bearing frame via photovoltaic module support brackets, and structural counterweights are also installed on the upper surface of the steel structure bearing frame. A mooring system is installed around the outer perimeter of the steel structure load-bearing frame. The mooring system includes a fixed base and mooring connection components. The mooring connection components are installed on the fixed base. The fixed base is located on the side of the steel structure load-bearing frame and is mainly composed of two parallel ear plates.

[0007] By adopting the above technical solution, the internal cavity of the external steel structure load-bearing frame is divided into several grid units by longitudinal and transverse reinforcing beams. The hollow buoyancy body is completely surrounded within the grid unit, providing buoyancy for the steel structure load-bearing frame. The probability of the hollow buoyancy body being damaged by collision is greatly reduced. In conjunction with the structural stiffening elbow plates at the nodes, a high-rigidity spatial frame system is formed, which effectively disperses the stress points and can effectively resist the impact of sea waves, strong wind loads and complex sea conditions. It is suitable for harsh offshore operating environments, overcomes the defects of insufficient structural strength of traditional floating platforms, improves the structural stability of the steel structure load-bearing frame under wind and waves, and greatly reduces the probability of damage and detachment of photovoltaic power generation modules 3.

[0008] Preferably, the hollow buoyancy body is made of high-density polyethylene.

[0009] By adopting the above technical solution, high-density polyethylene hollow buoyancy bodies are used to provide buoyancy. The material is lightweight, corrosion-resistant, and has low construction and transportation costs. The steel structure load-bearing frame encloses the buoyancy unit on the inside, protecting it from external mechanical damage and extending the service life of the hollow buoyancy body.

[0010] Preferably, the lateral projection width of the photovoltaic panel does not exceed the net width of the corresponding grid unit.

[0011] By adopting the above technical solution, the lateral projection width of the photovoltaic panel does not exceed the net width of the corresponding grid unit, so as to ensure that the load of the photovoltaic panel can be effectively transferred to the longitudinal and transverse reinforcing beam nodes and avoid excessive cantilever causing local bending moment concentration.

[0012] Preferably, the volume of the hollow buoyancy body is 50%-75% of the volume of the grid cell.

[0013] By adopting the above technical solutions, we can avoid the problem of insufficient buoyancy or swaying of the hollow buoyant body due to its small size, or installation difficulties due to its large size.

[0014] Preferably, the structural counterweight is a concrete block or a cast iron block.

[0015] By adopting the above technical solution, the materials are readily available and the manufacturing is convenient, effectively reducing the overall center of gravity of the platform and enhancing its anti-overturning ability.

[0016] Preferably, the two steel structure load-bearing frames are assembled together by mooring connection components.

[0017] By adopting the above technical solutions, the platform can be flexibly expanded through mooring connection components to meet the needs of offshore photovoltaic projects of different scales.

[0018] Preferably, the mooring connection assembly is mainly composed of a shackle and a mooring chain. The inner end of the shackle passes between two lugs and is hinged to the lugs via a first pin. The outer end of the shackle is connected to the end link of the mooring chain via a second pin.

[0019] By adopting the above technical solution, the mooring connection component can serve as both a mooring node for a floating photovoltaic platform and a flexible connection node between adjacent modules. The mooring connection component achieves a flexible transition through a hinged structure, which can fully absorb and buffer the angle changes caused by the undulation of water waves, effectively avoiding structural tearing or fatigue damage that may be caused by rigid connections, and has both high reliability and versatility applicable to multiple scenarios.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The external steel structure bearing frame of this invention is divided into several grid units by longitudinal and transverse reinforcing beams. The hollow buoyancy body is completely surrounded within the grid unit, providing buoyancy for the steel structure bearing frame. The probability of the hollow buoyancy body being damaged by collision is greatly reduced. Combined with the structural stiffening elbow plates at the nodes, a high-rigidity spatial frame system is formed, which effectively disperses the stress points and can effectively resist the impact of sea waves, strong wind loads and complex sea conditions. It is suitable for harsh marine operating environments, overcomes the defects of insufficient structural strength of traditional floating platforms, improves the structural stability of the steel structure bearing frame under wind and waves, and greatly reduces the probability of damage and detachment of photovoltaic power generation modules.

[0021] 2. This invention uses a high-density polyethylene hollow buoyancy body to provide buoyancy. The material is lightweight, corrosion-resistant, and has low construction and transportation costs. The steel structure load-bearing frame encloses the buoyancy unit on the inside, protecting it from external mechanical damage and extending the service life of the hollow buoyancy body.

[0022] 3. The buoyancy unit of this invention is independently connected to the inner side of the frame by the buoyancy body connecting ear plate and the buoyancy body fixing locking pin. Any single hollow buoyancy body can be unlocked and removed for replacement if damaged, without disassembling other components of the platform. This greatly reduces operation and maintenance costs and downtime, realizes true modular operation and maintenance, and reduces operation and maintenance costs. Attached Figure Description

[0023] Figure 1 This is a structural diagram of the present invention; Figure 2 This is a schematic diagram of the steel structure load-bearing frame of the present invention; Figure 3 This is a schematic diagram of the buoyancy unit structure of the present invention; Figure 4 This is a schematic diagram of the mooring connection component structure of the present invention.

[0024] Drawing No.: 1. Steel structure load-bearing frame; 1-1. Longitudinal and transverse reinforcing beams; 1-2. Fixed base; 1-2-1. Ear plate; 1-3. Structural stiffening elbow plate; 1-4. Float body fixing pin; 2. Buoyancy unit; 2-1. Hollow buoyancy body; 2-2. Buoyancy body connecting ear plate; 3. Photovoltaic power generation module; 3-1. Photovoltaic module support bracket; 3-2. Photovoltaic power generation panel; 3-3. Structural counterweight block; 4. Mooring system; 4-1. Mooring connection component; 4-1-1. Shackle; 4-1-2. Mooring chain; 4-2. Mooring anchor chain. Detailed Implementation

[0025] like Figure 1 As shown, a modular offshore floating photovoltaic platform with an external steel frame includes a steel structure load-bearing frame 1, a buoyancy unit 2, photovoltaic power generation modules 3, and a mooring system 4. The steel structure load-bearing frame 1 is welded from high-strength steel and is placed on the outermost side of the platform to form an integral rigid frame that directly bears external loads such as wave impact, wind load, and mooring tension.

[0026] like Figure 2 As shown, the internal cavity of the steel structure load-bearing frame 1 is divided into several grid units by longitudinal and transverse reinforcing beams 1-1, and structural stiffening elbow plates 1-3 are set at the nodes to further improve the overall rigidity and deformation resistance of the frame. The external steel structure load-bearing frame 1 also surrounds the internal buoyancy unit, protecting the lightweight floating material from external collisions and mechanical damage, and has the dual function of load-bearing and floating body protection, fundamentally solving the problems of insufficient structural strength and easy damage to the floating body in traditional floating platforms. A mooring system 4 is set around the outer perimeter of the steel structure load-bearing frame 1.

[0027] like Figure 3 As shown, each grid cell is embedded with a buoyancy unit 2. The buoyancy unit 2 is a hollow buoyancy body 2-1 formed in one piece. The hollow buoyancy body 2-1 is provided with a buoyancy body connecting lug 2-2 on its side. Each grid cell is provided with a buoyancy body fixing pin 1-4 on its inner side. The buoyancy body connecting lug 2-2 and the buoyancy body fixing pin 1-4 are connected in cooperation.

[0028] Directly above buoyancy unit 2, photovoltaic panels 3-2 are mounted on the upper surface of the steel structure support frame 1 via photovoltaic module support brackets 3-1. Structural counterweights 3-3 are also installed on the upper surface of the steel structure support frame 1. The photovoltaic panels 3-2 are mounted on the upper surface of the platform via the photovoltaic module support brackets 3-1, with the installation tilt angle set according to the latitude of the project location to optimize power generation efficiency. Since the concentrated arrangement of the photovoltaic modules 3 causes a shift in the platform's center of gravity, structural counterweights 3-3 are placed at appropriate locations to level the overall center of gravity, ensuring the platform's stability on the water surface. The generated electrical energy is collected and transmitted to the onshore grid-connected system via submarine cables.

[0029] The mooring system 4 includes a fixed base 1-2 and a mooring connection assembly 4-1, which is mounted on the fixed base 1-2. The fixed base 1-2 is located on the side of the steel structure load-bearing frame 1 and mainly consists of two parallel lug plates 1-2-1. The inner ends of the lug plates 1-2-1 are welded to the steel structure load-bearing frame 1, and triangular reinforcing ribs (or elbow plates) are symmetrically welded to the outer sides of the lug plates 1-2-1 at the junction with the steel structure load-bearing frame 1.

[0030] The internal cavity of the external steel structure load-bearing frame 1 is divided into several grid units by longitudinal and transverse reinforcing beams 1-1. The hollow buoyancy body 2-1 is completely surrounded within the grid units, providing buoyancy for the steel structure load-bearing frame 1. The probability of the hollow buoyancy body 2-1 being damaged by collision is greatly reduced. Together with the structural stiffening elbow plates 1-3 at the nodes, a high-rigidity spatial frame system is formed, which effectively disperses the stress points and can effectively resist the impact of sea waves, strong wind loads and complex sea conditions. It is suitable for harsh offshore operating environments, overcomes the defects of insufficient structural strength of traditional floating platforms, improves the structural stability of the steel structure load-bearing frame 1 under wind and waves, and greatly reduces the probability of damage and detachment of photovoltaic power generation modules 3.

[0031] The buoyancy unit 2 is a sealed hollow structure integrally molded from high-density polyethylene material, embedded within each grid unit of the steel structure load-bearing frame 1. It is locked in place by the side buoyancy connecting lugs 2-2 of the hollow buoyancy body 2-1 engaging with the inner buoyancy fixing pins 1-4 of the frame. This connection method is detachable; each buoyancy unit 2 is independent. If any single unit is damaged, it can be removed and replaced simply by releasing the corresponding locking pin, without disassembling surrounding components. This achieves true modular operation and maintenance, reducing maintenance costs.

[0032] The photovoltaic panels 3-2 are installed on the upper surface of the platform at a certain angle (facing the sunlight), causing a lateral shift in the platform's center of gravity relative to its center of buoyancy. Without counterweight compensation, the platform will tilt longitudinally, affecting power generation efficiency and increasing structural stress. The function of the structural counterweights 3-3 is to apply balancing weight to the corresponding upward tilting position of the steel structure support frame 1 on the back side of the photovoltaic panels 3-2, restoring the platform to a horizontal buoyancy. The installation position and number of structural counterweights 3-3 can be flexibly adjusted according to counterweight requirements to adapt to different photovoltaic module 3 arrangement schemes and installation tilt angles. The structural counterweights 3-3 installed on the steel structure support frame 1 allow for flexible adjustment of the platform's center of gravity, ensuring the stability of the platform's attitude on the water surface.

[0033] The hollow buoyancy body 2-1 is made of high-density polyethylene, which is lightweight, corrosion-resistant, and has low construction and transportation costs. The steel structure load-bearing frame encloses the buoyancy unit inside, protecting it from external mechanical damage and extending the service life of the hollow buoyancy body 2-1.

[0034] The lateral projection width of photovoltaic panel 3-2 shall not exceed the net width of the corresponding grid unit. This is to ensure that the load of photovoltaic panel 3-2 can be effectively transferred to the nodes of longitudinal and transverse reinforcing beams 1-1, and to avoid local bending moment concentration caused by excessive cantilever.

[0035] The volume of the hollow buoyancy body 2-1 is 50%-75% of the volume of the grid cell. This avoids the hollow buoyancy body 2-1 being too small, which would result in insufficient buoyancy or swaying of the buoyancy body, or too large, which would result in installation difficulties.

[0036] The structural counterweight 3-3 is a concrete block or cast iron block. The material is readily available and easy to manufacture. It effectively lowers the overall center of gravity of the platform and enhances its anti-overturning ability.

[0037] The two steel structural load-bearing frames 1 are assembled together by mooring connection components 4-1. The platform can be flexibly expanded by splicing the mooring connection components 4-1 to meet the needs of offshore photovoltaic projects of different sizes.

[0038] like Figure 4As shown, the mooring connection assembly 4-1 is mainly composed of a shackle 4-1-1 and a mooring chain 4-1-2. The inner end of the shackle 4-1-1 passes between two lugs 1-2-1 and is hinged to the lugs 1-2-1 via a first pin, forming a single-degree-of-freedom movable joint. The outer end of the shackle 4-1-1 is connected to the end link of the mooring chain 4-1-2 via a second pin. The mooring chain 4-1-2 extends outward to connect to the underwater anchoring system or other platform modules. The mooring connection assembly 4-1 can serve as a mooring node for a floating photovoltaic platform or as a flexible connection node between adjacent modules. The mooring connection assembly 4-1 achieves a flexible transition through its hinged structure, which can fully absorb and buffer the angle changes caused by the undulation of water waves, effectively avoiding structural tearing or fatigue damage that may be caused by rigid connections, and possessing both high reliability and versatility applicable to multiple scenarios.

[0039] The mooring system 4, via fixed bases 1-2 arranged around the steel structure support frame 1 and connected to anchor chains via mooring connection components 4-1, anchors the platform to the seabed foundation, restricting the platform's horizontal drift under the influence of wind, waves, and currents, while allowing the platform to rise and fall freely with tides. The mooring arrangement and anchor chain specifications are specifically designed according to the extreme environmental conditions of the sea area. Multiple platform units can be spliced ​​together via mooring connection components 4-1 to form a large-scale floating photovoltaic array. Example 1

[0040] This embodiment provides a specific implementation plan for an external steel frame modular offshore floating photovoltaic platform.

[0041] The steel structure load-bearing frame 1 is assembled by welding a perimeter frame and longitudinal and transverse reinforcing beams 1-1, forming sixteen rectangular grid units in four columns × four rows. Stiffening elbow plates 1-3 are welded at the frame nodes. Twelve fixed bases 1-2 are installed on each side of the steel structure load-bearing frame 1. Float fixing pins 1-4 are installed at corresponding positions on the inner side of each grid unit, with four float fixing pins 1-4 distributed at the four corners of each grid unit. All steel components undergo hot-dip galvanizing for corrosion protection after welding to meet the durability requirements of marine corrosive environments.

[0042] The buoyancy unit 2 consists of twelve pieces, integrally molded from high-density polyethylene, with a sealed hollow cavity inside. Each of the four corners of the hollow buoyancy unit 2-1 has a buoyancy connecting lug 2-2. During installation, each buoyancy unit 2 is embedded into its corresponding grid unit, and the buoyancy connecting lug 2-2 is locked in place with the inner buoyancy fixing pins 1-4 of the steel structure support frame 1. If any buoyancy unit 2 is damaged, it can be removed and replaced simply by releasing the corresponding four buoyancy fixing pins 1-4, without affecting adjacent buoyancy units 2 or the overall platform structure.

[0043] The photovoltaic power generation module 3 comprises sixteen photovoltaic panels 3-2, which are fixed to the upper chord of the steel structure load-bearing frame 1 via aluminum alloy photovoltaic module support brackets 3-1. The installation tilt angle is determined based on the latitude of the project location. The platform's center of gravity is calculated based on the arrangement of the buoyancy unit 2 and the photovoltaic power generation module 3. Structural counterweights 3-3 are installed at appropriate positions on the unbalanced side to adjust the platform's attitude on the water surface. The electrical wiring of each photovoltaic panel 3-2 is routed along the frame beam via cable trays, converges into a waterproof junction box on the side of the platform, and then is led to the onshore grid connection system via submarine cables.

[0044] In mooring system 4, shackle 4-1-1 connects the fixed base 1-2 on the steel structure bearing frame 1 to the mooring anchor chain 4-2, which extends to the seabed anchoring foundation. The mooring arrangement and anchor chain specifications are designed according to the combined extreme working conditions of once-in-a-century wind, wave, and current conditions in the sea area where the project is located. When it is necessary to expand the installed capacity, multiple unit platforms can remove the mooring anchor chain 4-2 so that the mooring connection component 4-1 can be directly connected to the fixed base 1-2 of another unit platform to form a large floating photovoltaic array.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular floating photovoltaic platform with an external steel frame, comprising a steel structure load-bearing frame (1), a buoyancy unit (2), photovoltaic power generation components (3), and a mooring system (4); characterized in that: The steel structure load-bearing frame (1) divides the internal cavity into several grid units through longitudinal and transverse reinforcing beams (1-1), and structural stiffening elbows (1-3) are set at the nodes. Each grid unit is inlaid with a buoyancy unit (2), which is a hollow buoyancy body (2-1) formed in one piece. The hollow buoyancy body (2-1) is provided with a buoyancy body connecting lug (2-2) on the side. Each grid unit is provided with a buoyancy body fixing pin (1-4) on the inside. The buoyancy body connecting lug (2-2) and the buoyancy body fixing pin (1-4) are connected in cooperation. Directly above the buoyancy unit (2), a photovoltaic power generation panel (3-2) is installed on the upper surface of the steel structure bearing frame (1) through a photovoltaic module support bracket (3-1), and a structural counterweight block (3-3) is also installed on the upper surface of the steel structure bearing frame (1). A mooring system (4) is set around the outer perimeter of the steel structure load-bearing frame (1). The mooring system (4) includes a fixed base (1-2) and a mooring connection assembly (4-1). The mooring connection assembly (4-1) is installed on the fixed base (1-2). The fixed base (1-2) is set on the side of the steel structure load-bearing frame (1) and is mainly composed of two parallel ear plates (1-2-1).

2. A modular offshore floating photovoltaic platform with an external steel frame as described in claim 1, characterized in that: The hollow buoyancy body (2-1) is made of high-density polyethylene.

3. A modular offshore floating photovoltaic platform with an external steel frame as described in claim 1, characterized in that: The lateral projection width of the photovoltaic panel (3-2) does not exceed the net width of the corresponding grid unit.

4. A modular offshore floating photovoltaic platform with an external steel frame as described in claim 1, characterized in that: The volume of the hollow buoyancy body (2-1) is 50%-75% of the volume of the grid cell.

5. A modular offshore floating photovoltaic platform with an external steel frame as described in claim 1, characterized in that: The structural counterweight (3-3) is a concrete block or a cast iron block.

6. A modular offshore floating photovoltaic platform with an external steel frame as described in claim 1, characterized in that: Two steel structure load-bearing frames (1) are assembled together by mooring connection components (4-1).

7. A modular offshore floating photovoltaic platform with an external steel frame as described in claim 1, characterized in that: The mooring connection assembly (4-1) is mainly composed of a shackle (4-1-1) and a mooring chain (4-1-2). The inner end of the shackle (4-1-1) passes between two ear plates (1-2-1) and is hinged to the ear plates (1-2-1) by a first pin. The outer end of the shackle (4-1-1) is connected to the end link of the mooring chain (4-1-2) by a second pin.

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