Offshore floating type photovoltaic power station buoyancy tank

Abstract

The invention discloses an offshore floating type photovoltaic power station buoyancy tank which comprises a plurality of rectangular BFRP buoyancy tank single bodies, the rectangular BFRP buoyancy tank single bodies are sequentially connected through adhesive layers to form a cuboid buoyancy tank body, and a plurality of shear connectors and a plurality of cabin connectors are arranged on the surface of the buoyancy tank body; the shear connectors are transversely glued on the surfaces of the BFRP buoyancy tank monomers through glue layers; the cabin connecting piece is longitudinally glued on the surfaces of two adjacent buoyancy tank single bodies through a glue layer; uHPC concrete plates are poured on the outer side of the buoyancy tank body, and the shear connectors and the cabin connectors are wrapped in the UHPC concrete plates. The buoyancy tank has the characteristics of corrosion resistance, light weight, high strength and tear resistance, can provide enough bearing capacity for a floating photovoltaic structure in a marine environment, and can resist the coupling effect of wind, wave and flow loads.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power stations, and in particular to a buoyancy box of an offshore floating photovoltaic power station. Background Art

[0002] Photovoltaic power generation includes land photovoltaic power generation and water photovoltaic power generation. Among them, water photovoltaic power generation usually uses pontoons to support photovoltaic modules. The pontoons can float on the water to prevent the photovoltaic modules from getting wet. Commonly used pontoon structures are stainless steel metal pontoons, HDPE pontoons and HSCC-FB pontoons. When the existing pontoon structures are used in marine environments, the HDPE pontoons are resistant to seawater corrosion, but there are problems such as weak force at the connection earrings, low overall strength of the pontoons, and easy to be torn by wind and waves, and the durability of HDPE materials is insufficient; the high-performance concrete pontoon HSCC-FB has high strength, but has the disadvantages of heavy weight and poor corrosion resistance; therefore, the existing pontoon structures cannot adapt well to the marine environment with high salt and strong winds and waves.

[0003] Basalt fiber reinforced polymers (BFRP) have the advantages of high tensile strength, corrosion resistance, green and pollution-free, but also have the disadvantage of low elastic modulus. The application of BFRP materials in pontoon structure design can effectively improve the durability of pontoons, but there are problems of poor structural stiffness and unsatisfactory dynamic response. Ultra-high performance concrete (UHPC) has the performance characteristics of high strength, high stiffness and low permeability. However, the use of UHPC for offshore pontoon structure design has the problem of heavy weight. If UHPC and BFRP materials can be organically combined and optimized, and the performance advantages of the two materials can be fully utilized, it will be of great significance to this field. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a floating pontoon for an offshore floating photovoltaic power station.

[0005] The technical solution adopted by the present invention is: A pontoon for an offshore floating photovoltaic power station comprises a plurality of rectangular BFRP pontoon monomers, wherein the plurality of rectangular BFRP pontoon monomers are sequentially connected by adhesive layers to form a rectangular pontoon body, wherein the surface of the pontoon body is provided with a plurality of shear connectors and a plurality of cabin connectors; the shear connectors are transversely bonded to the surface of the BFRP pontoon monomers by adhesive layers; the cabin connectors are longitudinally bonded to the surfaces of two adjacent pontoon monomers by adhesive layers; a UHPC concrete slab is cast on the outer side of the pontoon body, and the shear connectors and the cabin connectors are wrapped in the UHPC concrete slab.

[0006] Furthermore, the compartment of the rectangular BFRP pontoon monomer is filled with dry inert gas to enhance the buoyancy of the pontoon.

[0007] Furthermore, the adhesive layer is a milled fiber reinforced resin, wherein the milled fiber can be milled glass fiber, milled basalt fiber or milled carbon fiber, and the volume fraction of the milled fiber is 20% to 40%.

[0008] By adopting the above technical solution, the shear strength and shear modulus of the adhesive layer can be improved, thereby improving the bonding strength between adjacent cabins and the overall structural rigidity of the pontoon.

[0009] Furthermore, the rectangular BFRP pontoon monomer is formed by wet winding of a multi-axial basalt fiber cloth, and the fiber arrangement angles of the multi-axial basalt fiber cloth are 0°, 45°, 90° and 135°, wherein the 0° and 90° fibers have the same proportion, and the volume fraction of the two is 55% to 75% of the total fibers, and the 45° and 135° fibers have the same proportion, and the volume fraction of the two is 25% to 45% of the total fibers.

[0010] By adopting the above technical solution, fibers with different arrangement angles are mixed to improve the shear resistance and lateral stiffness of the buoyancy chamber.

[0011] Furthermore, the cabin connector is flat and is made of multi-axial basalt fiber cloth by wet winding, with a tensile strength of 551-710 MPa, a tensile modulus of 26.8-33.2 GPa, and a shear strength of 48.5-69.1 MPa; the fiber arrangement angles of the multi-axial basalt fiber cloth are 0°, 45°, 90° and 135°, wherein the 0° and 90° fibers account for the same proportion, and the total volume fraction of the two is 55%-75%, and the 45° and 135° fibers account for the same proportion, and the total volume fraction of the two is 25%-45%.

[0012] By adopting the above technical solution, the connection strength and overall structural rigidity of the pontoon unit are further enhanced, thereby improving the overall strength of the pontoon.

[0013] Furthermore, the shear-resistant connector includes a first connector and a second connector, both of which have L-shaped cross-sections and the same structure, and the two connectors are connected back to back by a glue layer; the shear-resistant connector is made of multi-axial basalt fiber cloth through a molding process, and the fiber arrangement angles of the multi-axial basalt fiber cloth are 0°, 45°, 90° and 135°, wherein the 0° and 90° fibers have the same proportion, and the volume fraction of the two is 55% to 75% of the total fibers, and the 45° and 135° fibers have the same proportion, and the volume fraction of the two is 25% to 45% of the total fibers.

[0014] By adopting the above technical solution, the shear resistance and overall structural rigidity of the pontoon are further enhanced, and the performance of the pontoon in resisting wind, wave and current loads is improved.

[0015] Furthermore, the UHPC concrete slab has a thickness of 5 cm to 15 cm, a compressive strength of ≥120 MPa, and an expansion of not less than 220 mm. The raw material composition of the UHPC concrete slab is, in parts by weight: 800-1000 parts of cement; Silica fume 150-250 parts; 900-110 parts of sea sand; 150-250 parts of quartz powder; 150-180 parts of sea water; 20-30 parts of polycarboxylic acid type high efficiency water reducing agent; 40-90 parts of chopped basalt fiber.

[0016] By adopting the above technical solution, the corrosion resistance of the pontoon is further improved, the connection strength between the concrete and the BFRP pontoon is enhanced, and the tear resistance of the pontoon is improved.

[0017] Furthermore, the chopped basalt fiber is made by mixing continuous basalt fibers with twists of 40 to 100 and 160 to 800 tex with epoxy resin in proportion, forming them through a pultrusion process, and then cutting them, wherein the volume content of the basalt fiber is 50 to 70%, the fiber length after cutting is 10 to 25 mm, and the tensile strength of the obtained chopped basalt fiber is not less than 1000 MPa, and the elastic modulus is not less than 40 GPa.

[0018] The adoption of the above technical solution can improve the long-term performance of seawater and sea sand UHPC and extend the service life of the pontoon structure.

[0019] The method for preparing any one of the above-mentioned floating boxes of offshore floating photovoltaic power stations comprises the following steps connected in sequence: (1) Prepare a BFRP pontoon monomer and fill the compartment of the pontoon monomer with dry inert gas; (2) Several BFRP pontoon monomers are glued together in sequence through the glue layer to form a rectangular pontoon body; (3) Bonding shear connectors and cabin connectors on the outer surface of the pontoon body; (4) Arrange BFRP mesh cloth and bottom formwork on the bottom surface of the pontoon body, and cast the UHPC concrete slab on the bottom surface of the pontoon; (5) After the bottom surface is poured, BFRP mesh cloth and side and top formwork are arranged on the side and top surfaces of the pontoon body, and the UHPC concrete slabs on the side and top surfaces of the pontoon are poured; (6) After pouring, a certain period of curing is carried out to allow the UHPC concrete layer to achieve the expected performance and produce the pontoon of the offshore floating photovoltaic power station.

[0020] By adopting the above technical solution, the pontoon can be prepared through an assembly process, and a large number of components can be prefabricated, which can effectively shorten the construction period of the pontoon preparation and reduce the construction cost.

[0021] Furthermore, the BFRP mesh cloth is made by mixing continuous basalt fibers with twists of 40 to 100 and 2000 to 3800 tex with epoxy resin in proportion, forming them through a pultrusion process, and then molding them. The volume content of the basalt fiber is 40 to 50%. The single branch width of the molded BFRP mesh cloth is 10 mm, the thickness is 5 mm, the mesh is square, and the side length is 50 mm to 100 mm; the tensile strength is not less than 750 MPa, and the elastic modulus is not less than 30 GPa.

[0022] Using the above technical solution, the BFRP grid is arranged in the center of the UHPC concrete slab and acts as a UHPC reinforcement material, playing a role in crack control and toughness improvement.

[0023] Beneficial effects of the present invention: The pontoon made by the present invention, which is made by combining an embedded BFRP cabin with a seawater and sea sand UHPC concrete slab, has the characteristics of corrosion resistance, light weight, high strength and tear resistance. It can provide sufficient bearing capacity for the floating photovoltaic structure in the marine environment and resist the coupling effects of wind, wave and current loads.

[0024] The present invention adopts BFRP material to prepare embedded cabins and uses fiber-reinforced resin layers as adhesive layers to connect the cabins and shear connectors and cabin connector components, overcoming the problems of poor rigidity and low interface connection performance of traditional FRP-constructed composite structures, and achieving high rigidity and reliable connection of the pontoon structure.

[0025] The buoyancy box of the present invention can be prepared by an assembly process, and a large number of components can be prefabricated components, which can effectively shorten the on-site construction period and reduce the on-site construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a three-dimensional structural diagram of a floating pontoon of an offshore floating photovoltaic power station.

[0027] Figure 2 for Figure 1 A partial cross-sectional view of .

[0028] Figure 3 for Figure 1 Longitudinal section of .

[0029] Figure 4 for Figure 1 Horizontal cross-section of .

[0030] Figure 5 for Figure 1 Schematic diagram of the connection structure between the shear connector and the pontoon body.

[0031] In the figure: 1. BFRP pontoon monomer, 2. cabin connector, 3. shear connector, 4. adhesive layer, 5. top UHPC concrete slab, 6. side UHPC concrete slab, 7. BFRP grid, 8. bottom UHPC concrete slab, 9. first connector. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and a preferred implementation manner. Example 1

[0034] See also Figure 1-Figure 5 A floating photovoltaic power station pontoon at sea comprises three rectangular BFRP pontoon monomers 1, which are connected in sequence by a glue layer 4 to form a rectangular pontoon body, and a plurality of shear connectors 3 and a plurality of cabin connectors 2 are arranged on the surface of the pontoon body; the shear connectors 3 are laterally bonded to the four surfaces of the BFRP pontoon monomers 1 by the glue layer 4; the cabin connectors 2 are longitudinally bonded to the surfaces of two adjacent pontoon monomers 1 by the glue layer 4; a UHPC concrete slab is cast on the outer side of the pontoon body, and the shear connectors 3 and the cabin connectors 2 are wrapped in the UHPC concrete slab.

[0035] The rectangular BFRP pontoon monomer 1 is formed by a multi-axial basalt fiber cloth through an existing wet winding process. The fiber arrangement angles of the multi-axial basalt fiber cloth are 0°, 45°, 90° and 135°, wherein the 0° and 90° fibers account for the same proportion, preferably the volume fraction of the total fiber is 55% to 75%, and the 45° and 135° fibers account for the same proportion, preferably the volume fraction of the total fiber is 25% to 45%. The preferred rectangular BFRP pontoon monomer 1 has a box size of 1 to 1.2 m long, 0.8 to 0.9 m wide, 0.8 to 0.9 m high, 10 to 20 mm thick, and a chamfer with a radius of 5 to 10 mm at the corners. In this embodiment, the box size is 1 m long, 0.8 m wide, 0.8 m high, 10 mm thick, and a chamfer with a radius of 5 mm at the corners. The volume fraction of 0° and 90° fibers accounts for 75% of the total fibers, and the volume fraction of 45° and 135° fibers accounts for 25% of the total fibers.

[0036] The adhesive layer 4 is of the prior art, preferably a milled fiber reinforced resin, wherein the milled fiber can be milled glass fiber, milled basalt fiber or milled carbon fiber, and the volume fraction of the milled fiber is 20% to 40%. In this embodiment, the milled fiber is milled basalt fiber, and the volume fraction is 20%.

[0037] The cabin connector 2 is flat, and preferably has a single size of 50 to 80 cm in length, 10 to 20 cm in width, and 5 to 10 mm in thickness. In specific implementation, the number and spacing are selected according to the surface size of the pontoon monomer. For example, in this embodiment, two cabin connectors 2 are bonded to the surface of each pontoon monomer, and the two cabin connectors 2 are evenly distributed. The size of the cabin connector 2 is 50 cm in length, 10 cm in width, and 5 mm in thickness.

[0038] The cabin connector is made of multi-axial basalt fiber cloth through the existing wet winding process, with a tensile strength of 551-710MPa, a tensile modulus of 26.8-33.2GPa, and a shear strength of 48.5-69.1MPa; the fiber arrangement angles of the multi-axial basalt fiber cloth are 0°, 45°, 90°, and 135°, of which 0° and 90° fibers account for the same proportion, and the total volume fraction of the two is 55%-75%, and 45° and 135° fibers account for the same proportion, and the total volume fraction of the two is 25%-45%. In this embodiment, the volume fraction of 0° and 90° fibers accounts for 75% of the total fibers, and the volume fraction of 45° and 135° fibers accounts for 25% of the total fibers.

[0039] See also Figure 5 The shear-resistant connector 4 includes two first connectors 9 and second connectors, both of which are L-shaped in cross section and have the same structure. The two connectors are connected back to back to form a T shape through the adhesive layer 4. Figure 1 As shown, four T-shaped shear connectors 4 are connected end to end and bonded to the four surfaces of the pontoon through the adhesive layer 4. In specific implementation, the number and spacing are selected according to the length of the pontoon. For example, in this embodiment, two shear connectors 4 are bonded to the surface of the first pontoon monomer, and the two shear connectors 4 are located on one side of the cabin connector 2. One shear connector 4 is bonded to the surface of the second pontoon monomer, and one shear connector 4 is located in the middle of the two cabin connectors 2. Two shear connectors 4 are bonded to the surface of the third pontoon monomer, and the two shear connectors 4 are located on one side of the cabin connector 2. Preferably, the size of a single connector is: thickness 20mm ~ 30mm, and the length of both sides is equal, both 40mm ~ 60mm. In this embodiment, the size of a single connector is: thickness 20mm, and the length of both sides is 60mm.

[0040] The first connector 9 and the second connector are both made of multi-axial basalt fiber cloth through the existing molding process. The tensile strength of a single connector is 551MPa~710MPa, the tensile modulus is 26.8GPa~33.2GPa, and the shear strength is 48.5MPa~69.1MPa. The fiber arrangement angles of the multi-axial basalt fiber cloth are 0°, 45°, 90° and 135°, wherein the 0° and 90° fibers have the same proportion, and the volume fraction of the two is 55%~75% of the total fibers, and the 45° and 135° fibers have the same proportion, and the volume fraction of the two is 25%~45% of the total fibers. In this embodiment, the volume fraction of the 0° and 90° fibers is 75% of the total fibers, and the volume fraction of the 45° and 135° fibers is 25% of the total fibers.

[0041] The thickness of the UHPC concrete slab is 5 cm to 15 cm, the compressive strength is ≥ 120 MPa, and the expansion is not less than 220 mm. In this embodiment, the thickness of the UHPC concrete slab is 5 cm, and the raw material composition of the UHPC concrete slab is calculated by weight: 800 parts of cement; 150 parts of silica fume; Sea sand 110 parts; 150 parts of quartz powder; 150 parts of sea water; 20 parts of polycarboxylic acid type high efficiency water reducing agent; Chopped basalt fiber 40 parts.

[0042] The chopped basalt fibers are prepared by mixing continuous basalt fibers with twists of 40-100 and 160-800 tex with epoxy resin in proportion, forming the fibers through a pultrusion process, and then cutting the fibers. The volume content of the basalt fibers is 50-70%, and the length of the fibers after cutting is 10-25 mm. The tensile strength of the obtained chopped basalt fibers is not less than 1000 MPa, and the elastic modulus is not less than 40 GPa.

[0043] The method for preparing the buoyancy chamber comprises the following steps which are connected in sequence: (1) preparing a BFRP pontoon monomer 1, and filling a compartment of the pontoon monomer with dry inert gas; (2) The three BFRP pontoon monomers are sequentially bonded together through the adhesive layer 4 to form a rectangular pontoon body; (3) bonding the shear connector 3 and the cabin connector 4 to the outer surface of the buoyancy tank body; (4) Arrange BFRP mesh cloth 7 and bottom formwork on the bottom surface of the pontoon body, and cast the bottom UHPC concrete slab 8; (5) After the bottom surface is poured, BFRP mesh cloth and side and top surface formwork are arranged on the side and top surfaces of the pontoon body, and the top surface UHPC concrete slab 5 and four side surface UHPC concrete slabs 4 are poured; (6) After pouring, a certain period of curing is carried out to allow the UHPC concrete layer to achieve the expected performance and produce the pontoon of the offshore floating photovoltaic power station.

[0044] The BFRP mesh cloth is made of continuous basalt fibers with a twist of 40-100 and 2000-3800 tex and epoxy resin, which are mixed in proportion and then formed by a pultrusion process and then molded, wherein the volume content of the basalt fiber is 40-50%, and the single branch width of the formed BFRP mesh cloth is 10mm, the thickness is 5mm, the mesh is square, and the side length is 50mm-100mm; the tensile strength is not less than 750MPa, and the elastic modulus is not less than 30GPa. In this embodiment, the volume content of the basalt fiber is 45%, the mesh is square, and the side length is 50mm. Example 2

[0045] This embodiment is basically the same as Embodiment 1, except that: The volume fraction of the multi-axial basalt fiber cloth made of the rectangular BFRP pontoon monomer 1 is 55% for the 0° and 90° fibers of the total fibers, and the volume fraction of the 45° and 135° fibers of the total fibers is 45%.

[0046] The ground fibers used to make the adhesive layer 4 are ground carbon fibers, with a volume fraction of 40%.

[0047] The volume fraction of the multi-axial basalt fiber cloth used to make the cabin connector 2 is 55% for the 0° and 90° fibers and 45° and 135° fibers, respectively.

[0048] The volume fraction of the multi-axial basalt fiber cloth used to make the shear-resistant connector 4 is 55% for the 0° and 90° fibers and 45% for the 135° fibers.

[0049] The raw material composition of the UHPC concrete slab is as follows in parts by weight: Cement 1000 parts; Silica fume 250 parts; 900 parts of sea sand; Quartz powder 250 parts; Seawater 180 parts; 30 parts of polycarboxylic acid type high efficiency water reducing agent; Chopped basalt fiber 90 parts. Example 3

[0050] This embodiment is basically the same as Embodiment 2, except that: The raw material composition of the UHPC concrete slab is as follows in parts by weight: Cement 900 parts; Silica fume 200 parts; 500 parts of sea sand; Quartz powder 200 parts; Seawater 180 parts; 25 parts of polycarboxylic acid type high efficiency water reducing agent; Chopped basalt fiber 60 parts.

[0051] Comparative Example 1 The pontoon of comparative example 1 has the same external dimensions as that of example 1, but the pontoon structure material is reinforced concrete designed according to the "equal rigidity method" to replace BFRP-seawater sand UHPC as the outer wall of the pontoon. Among them, C60 concrete is used for concrete, HRB400 steel bars are used for steel bars, the reinforcement ratio is 0.42%, and the outer wall thickness is 68 mm.

[0052] The deadweight of the pontoon structure was measured and calculated, and the dynamic response analysis of Examples 1-3 and Comparative Example 1 was performed using the software ANSYS. The results are shown in Table 1.

[0053]

[0054] It can be seen from Table 1 that, compared with the traditional reinforced concrete pontoon structure, the pontoon structure using the embodiment of the present invention has a larger buoyancy ratio and a smaller wave-excited vibration amplitude, indicating that the pontoon structure of the present invention shows a significant improvement in material utilization and dynamic response under waves.

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications are also within the protection scope of the present invention.

Claims

1. A floating photovoltaic power station pontoon, characterized in that: The invention comprises a plurality of rectangular BFRP pontoon monomers (1), wherein the plurality of rectangular BFRP pontoon monomers (1) are connected in sequence through an adhesive layer (4) to form a rectangular parallelepiped pontoon body, and a plurality of shear connectors (3) and a plurality of cabin connectors (2) are arranged on the surface of the pontoon body; the shear connectors (3) are transversely bonded to the surface of the BFRP pontoon monomer (1) through the adhesive layer (4); the cabin connectors (2) are longitudinally bonded to the surfaces of two adjacent pontoon monomers (1) through the adhesive layer (4); and a UHPC concrete slab (8) is cast on the outer side of the pontoon body, and the shear connectors (3) and the cabin connectors (2) are wrapped in the UHPC concrete slab (8).

2. The floating photovoltaic power station buoy according to claim 1, characterized in that: The compartment of the rectangular BFRP pontoon monomer (1) is filled with dry inert gas.

3. The floating photovoltaic power station pontoon according to claim 1, characterized in that: The adhesive layer (4) is a milled fiber reinforced resin, wherein the milled fiber can be milled glass fiber, milled basalt fiber or milled carbon fiber, and the volume fraction of the milled fiber is 20% to 40%.

4. The offshore floating photovoltaic power station buoy according to claim 1, characterized in that: The rectangular BFRP pontoon monomer (1) is formed by wet winding of a multi-axial basalt fiber cloth, wherein the fiber arrangement angles of the multi-axial basalt fiber cloth are 0°, 45°, 90° and 135°, wherein the 0° and 90° fibers have the same proportion, and the volume fraction of the two in the total fibers is 55% to 75%, and the 45° and 135° fibers have the same proportion, and the volume fraction of the two in the total fibers is 25% to 45%.

5. The offshore floating photovoltaic power station buoy according to claim 1, characterized in that: The cabin connector (2) is in the form of a flat plate and is made of multi-axial basalt fiber cloth by wet winding, and has a tensile strength of 551 to 710 MPa, a tensile modulus of 26.8 to 33.2 GPa, and a shear strength of 48.5 to 69.1 MPa. The fiber arrangement angles of the multi-axial basalt fiber cloth are 0°, 45°, 90°, and 135°, wherein the 0° and 90° fibers account for the same proportion, and the total volume fraction of the two is 55% to 75%, and the 45° and 135° fibers account for the same proportion, and the total volume fraction of the two is 25% to 45%.

6. The offshore floating photovoltaic power station buoy according to claim 1, characterized in that: The shear-resistant connector (3) comprises a first connector and a second connector, both of which are L-shaped in cross section and have the same structure, and the two connectors are connected back to back via a glue layer (4); the shear-resistant connector (3) is made of multi-axial basalt fiber cloth through a molding process, and the fiber arrangement angles of the multi-axial basalt fiber cloth are 0°, 45°, 90° and 135°, wherein the 0° and 90° fibers have the same proportion, and the volume fraction of the two is 55% to 75% of the total fibers, and the 45° and 135° fibers have the same proportion, and the volume fraction of the two is 25% to 45% of the total fibers.

7. The offshore floating photovoltaic power station buoy according to claim 1, characterized in that: The UHPC concrete slab (8) has a thickness of 5 cm to 15 cm, a compressive strength of ≥120 MPa, and an expansion of not less than 220 mm; the raw material composition of the UHPC concrete slab (8) is, in parts by weight: 800-1000 parts of cement; Silica fume 150-250 parts; 900-110 parts of sea sand; 150-250 parts of quartz powder; 150-180 parts of sea water; 20-30 parts of polycarboxylic acid type high efficiency water reducing agent; 40-90 parts of chopped basalt fiber.

8. The floating photovoltaic power station pontoon according to claim 7, characterized in that: The chopped basalt fibers are prepared by mixing continuous basalt fibers with twists of 40 to 100 and 160 to 800 tex with epoxy resin in proportion, forming the fibers through a pultrusion process, and then cutting the fibers. The volume content of the basalt fibers is 50 to 70%, and the length of the fibers after cutting is 10 to 25 mm. The tensile strength of the obtained chopped basalt fibers is not less than 1000 MPa, and the elastic modulus is not less than 40 GPa.

9. A method for preparing a pontoon for an offshore floating photovoltaic power station according to any one of claims 1 to 8, characterized in that: The following steps are connected in sequence: (1) preparing a BFRP pontoon monomer (1), and filling a compartment of the pontoon monomer with dry inert gas; (2) bonding a plurality of BFRP pontoon monomers (1) together in sequence through a glue layer (4) to form a rectangular pontoon body; (3) bonding the shear connector (3) and the cabin connector (2) to the outer surface of the buoyancy tank body; (4) Arrange the BFRP mesh cloth (7) and the bottom formwork on the bottom surface of the pontoon body, and cast the UHPC concrete slab on the bottom surface of the pontoon; (5) After the bottom surface is poured, BFRP mesh cloth (7) and side and top surface formwork are arranged on the side and top surfaces of the pontoon body, and the UHPC concrete slabs on the side and top surfaces of the pontoon are poured; (6) After pouring, a certain period of curing is carried out to allow the UHPC concrete layer to achieve the expected performance and produce the pontoon of the offshore floating photovoltaic power station.

10. The method for preparing a pontoon for an offshore floating photovoltaic power station according to claim 9, characterized in that: The BFRP mesh cloth (7) is made by mixing continuous basalt fibers with a twist of 40 to 100 and 2000 to 3800 tex with epoxy resin in a certain proportion, forming the fibers through a pultrusion process, and then molding them. The volume content of the basalt fibers is 40 to 50%. The molded BFRP mesh cloth (7) has a single-branch width of 10 mm and a thickness of 5 mm. The mesh is square and has a side length of 50 mm to 100 mm. The tensile strength is not less than 750 MPa, and the elastic modulus is not less than 30 GPa.

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