Light high-strength corrosion-resistant composite material photovoltaic support

Abstract

The invention discloses a light-weight high-strength corrosion-resistant composite material photovoltaic support, and relates to the technical field of new materials and new energy, the light-weight high-strength corrosion-resistant composite material photovoltaic support comprises a front stand column and a rear stand column, the front stand column and the rear stand column are pre-buried in a concrete pile to be fixed, the top end is provided with an oblique beam, the oblique beam and the stand columns adopt triangular connecting pieces with partition plate sleeves, and a plurality of purlines are arranged on the oblique beam in parallel; the purlins are fixed to the oblique beams through purlin supports. In order to improve the stability of the support, a front inclined strut and a rear inclined strut are additionally arranged between the stand column and the oblique beam, the inclined struts and the stand column as well as the inclined struts and the oblique beam are connected through triangular connecting pieces with partition plate sleeves, gaskets are additionally arranged at the connecting positions of the stand column, and the triangular connecting pieces for connecting the inclined struts and the oblique beam and purlin supports share a pair of long holes penetrating through the oblique beam. The triangular connecting piece with the partition plate sleeve and the gasket is utilized, so that the pressure-bearing contact surfaces of components such as the stand column and the inclined strut are changed from bolt holes to end total sections, and the pressure-resisting axial force of the inclined beam, the stand column and the inclined strut is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy, and particularly relates to a lightweight, high-strength and corrosion-resistant composite photovoltaic support. Background Art

[0002] A photovoltaic support is a structure for supporting photovoltaic modules, which needs to bear wind and snow loads of different magnitudes and the self-weight load of the modules during use. Currently, the photovoltaic supports used in solar power generation projects are mainly ordinary steel supports, hot-dip galvanized steel supports, stainless steel supports and aluminum alloy supports. The cost of aluminum alloy supports is high, while the photovoltaic supports made of traditional steel have a high self-weight, are inconvenient to install and have a high transportation cost. In terms of application scenarios, areas such as deserts and near-shore tidal flats have become new important areas for large-scale development of photovoltaic power generation due to their flat terrain and high light intensity. However, due to the high content of Cl - , SO4 2- etc. in the soil of tidal flats and near-shore areas, and the supports are usually installed outdoors and need to withstand long-term sun exposure and rain, resulting in that traditional steel structure photovoltaic supports are extremely easy to be corroded and difficult to meet the requirements of the service life and safety of photovoltaic power stations. Therefore, the corrosion resistance and lightweight of photovoltaic supports are the development trends of the future photovoltaic industry.

[0003] In recent years, the characteristics of fiber-reinforced composites such as lightweight, high-strength, corrosion-resistant, aging-resistant and good electrical insulation have been widely recognized. In various industries, fiber-reinforced composites have been gradually used to replace traditional steel. There have been various materials such as fiber-reinforced composite photovoltaic frames and fiber composite bars promoted and applied in engineering projects.

[0004] It can be seen that fiber-reinforced composite photovoltaic brackets can become a new choice in the field of solar power generation. For example, the authorized invention patent CN201610727939.7 discloses a high-strength composite photovoltaic bracket, the main material of which is a square tube of glass fiber reinforced composite material; the authorized utility model patent CN202320987816.2 discloses a single-pile photovoltaic bracket using basalt fiber composite materials, and proposes that the fiber composite photovoltaic bracket can have a profile with reinforcing ribs; the public invention CN202111667311.X proposes a double-pile photovoltaic bracket made of basalt fiber composite materials, and sets shear braces between the columns to improve the bearing capacity of the bracket. Although fiber-reinforced composite materials are a bit prominent, their shortcomings are also obvious: the material is anisotropic, not only has a low elastic model, low stiffness, and poor resistance to deformation, but also its mechanical performance parameters in the 90-degree direction are significantly lower than those in the 0° direction. When mechanical connection is used, the material is easy to break along the 0° direction at the opening stress concentration position. Based on the contents of existing patent inventions, the current fiber-reinforced composite photovoltaic brackets have the following urgent problems to be solved: when drilling holes in the profile, if the low stiffness at the hole position is considered, there are often problems such as difficulty in drilling holes in the profile and low production efficiency, making it difficult to promote and apply fiber-reinforced composite materials in large-scale centralized photovoltaic projects. Summary of the invention

[0005] In view of the deficiencies in the prior art, an object of the present invention is to provide a lightweight, high-strength, corrosion-resistant composite photovoltaic bracket.

[0006] The technical solution adopted by the present invention is:

[0007] A lightweight, high-strength, corrosion-resistant composite photovoltaic support, comprising a front column and a rear column, the front column and the rear column are pre-buried and fixed in a pile foundation, an inclined beam is provided at the top end of the front column and the rear column, the inclined beam is connected to the front column and the rear column by a triangular connector, the triangular connector is provided with a sleeve with a partition, a plurality of purlins are arranged in parallel on the inclined beam for connecting photovoltaic components, the purlins are fixed to the inclined beam by purlin supports, a front diagonal brace and a rear diagonal brace are added between the front column, the rear column and the diagonal beam to improve the stability of the support, the front diagonal brace and the front column are connected by the triangular connector, the rear diagonal brace and the rear column are also connected by the triangular connector, and the front diagonal brace and the rear diagonal brace are also connected to the diagonal beam by the triangular connector.

[0008] By adopting the above technical solutions, the compressive strength of the photovoltaic support can be improved, and the service life of the photovoltaic support can be extended. The front column and the rear column are used to support the photovoltaic modules, and a front diagonal brace is arranged between the front column and the inclined beam, and a rear diagonal brace is arranged between the rear column and the inclined beam, so as to improve the support strength of the column, so that after snow accumulates on the photovoltaic modules, the front diagonal brace and the rear diagonal brace can be used for auxiliary support. Through the setting of the triangular connecting piece, the connection between the front diagonal brace and the front column, and the rear diagonal brace and the rear column is made more stable.

[0009] Preferably, the front column, the rear column, the inclined beam, the purlin, the front diagonal brace, and the rear diagonal brace are all fiber-reinforced composite materials produced by pultrusion process. The reinforcing fiber material can be any one of basalt fiber, glass fiber, and carbon fiber, and the matrix material can be any one of epoxy resin, unsaturated polyester resin, vinyl resin, and polyurethane.

[0010] By adopting the above technical solutions, making use of the reinforced composite materials enables the entire support to be able to cope with more severe weather conditions after assembly.

[0011] Preferably, the pile foundation can be a reinforced concrete independent foundation or a bored cast-in-place pile foundation, and the pile foundation form can be a circular pile foundation or a rectangular pile foundation.

[0012] By adopting the above technical solutions, the pile foundation form can be changed according to the actual situation to adapt to more installation and construction environments.

[0013] Preferably, the size, depth, and reinforcement ratio of the pile foundation can be determined according to the snow load intensity and geotechnical conditions at the support usage location. The concrete strength grade of the pile body is at least C25, and the pile body protrudes about 50-200 mm above the ground surface.

[0014] By adopting the above technical solutions, it is ensured that the pile body concrete has high strength and durability, can resist erosion and wear in the natural environment, and extends the service life of the pile foundation.

[0015] Preferably, the length of the front column and the rear column embedded in the pile foundation should meet the uplift force requirements, and the distance between the bottom of the front column and the rear column and the bottom of the pile foundation is greater than 1.5 times the column width.

[0016] By adopting the above technical solutions, it can be ensured that when the column is subjected to external forces, excessive bending moment and shear force will not occur at its bottom, thereby improving the bearing capacity of the column.

[0017] Preferably, before using the triangular connecting piece to connect the inclined beam, the front column, and the rear column, 2 holes are drilled in the inclined beam, and at least 1 hole is drilled at the top of the front column and the rear column respectively.

[0018] By adopting the above technical solution, pre-drilling holes in the inclined beam, front column and rear column can ensure that the triangular connecting piece can be quickly and accurately positioned during installation. This not only improves the installation efficiency but also reduces the rework and repair work caused by inaccurate positioning.

[0019] Preferably, the center of the triangular connecting piece connecting the inclined beam and the front column and connecting the inclined beam and the rear column is 100 - 500 mm away from both ends of the inclined beam.

[0020] By adopting the above technical solution, it can be ensured that the connection point is located in the effective stress-bearing area of the inclined beam, avoiding stress concentration and connection failure caused by the connection being too close to the end point.

[0021] Preferably, the height and width of the purlin connecting piece are 5 - 10 mm larger than the purlin, at least 4 holes are opened on the upper and lower two surfaces, and at least 2 holes are opened on the left and right sides, and they are respectively connected to two sections of purlins by bolts.

[0022] By adopting the above technical solution, the connecting piece can be applicable to purlins of different sizes. When it is necessary to replace or upgrade the purlins, there is no need to replace the connecting piece, reducing the maintenance cost.

[0023] Preferably, the photovoltaic module adopts a pressing block, and the pressing block and the purlin are fixed by a U-shaped clamp with a fixing plate. The hole spacing of the pressing block is at least 5 - 10 mm larger than the width of the purlin.

[0024] By adopting the above technical solution, the design of the hole spacing of the pressing block enables the pressing block to be applicable to purlins of different widths, and there is no need to customize special pressing blocks for each size of purlin, reducing the material cost and procurement difficulty.

[0025] A lightweight, high-strength and corrosion-resistant composite material photovoltaic support includes the following design steps:

[0026] Step S1, according to the topographic and geological characteristics of the project site area, light resource conditions, components, component installation directions, etc., initially select the structural form of the photovoltaic support, including support inclination angle, single-array support length, number of pile foundations, span, column spacing, etc.;

[0027] Step S2, initially select the cross-sectional form, size parameters and installation methods of each component of the photovoltaic support. The cross-sectional form is one or a combination of C-shaped cross-section, rectangular cross-section, circular cross-section, and special-shaped cross-section;

[0028] Step S3, based on the photovoltaic support design standard, determine the force and deformation requirements of the purlins, inclined beams, front columns, rear columns, front diagonal braces, and rear diagonal braces of the photovoltaic support according to the initially selected component size parameters and material parameters;

[0029] Step S4: Calculate the load acting on the purlin according to the wind and snow loads in the project site area, the types of photovoltaic modules, and the dimensions of the support members based on the specifications.

[0030] Step S5: Using numerical calculation software, based on the initially selected support structure form and dimensional parameters, establish a calculation model for the force and deformation of the photovoltaic support. Assign the corresponding physical and mechanical parameters to the composite material photovoltaic support according to the data from the composite material laboratory. At the same time, apply the load calculated in S4 to the purlin to simulate the force and deformation of the photovoltaic support under wind and snow loads and the self-weight of the modules.

[0031] Step S6: Compare the calculation results in Step S5 with the requirements for the force and deformation of each component in Step S4.

[0032] Step S7: When the force and deformation of the photovoltaic support structure are both smaller than the parameters mentioned in Step S4, the initially selected parameters can be used as the design scheme for the lightweight, high-strength, corrosion-resistant composite material photovoltaic support structure. If the requirements of Step S4 are not met, reselect the dimensional parameters of the photovoltaic support components, recalculate according to Step S5, and make a judgment according to Step S6 until the force and deformation of the photovoltaic support structure meet the requirements of Step S4. Take the parameters that meet the requirements of force and deformation as the design scheme for the lightweight, high-strength, corrosion-resistant composite material photovoltaic support structure.

[0033] By adopting the above technical solutions, the installation form and support angle of the support are designed and selected according to the actual situation, and appropriate support materials are selected for lapping, so that the support can cope with different environments.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] The present invention proposes a design method for a lightweight, high-strength, corrosion-resistant composite material photovoltaic support, which takes into account the defect of the lower stiffness of the composite material. Using the proposed design method, the force and deformation characteristics of each component of the support under the wind and snow load conditions in the project location can be fully considered throughout the process, effectively ensuring the stability and safety of the support during use. It is a truly high-strength composite material photovoltaic support.

[0036] The present invention uses triangular connectors to connect the front column, rear column and diagonal beam, the front column and the front diagonal brace, and the front diagonal brace and the diagonal beam. And the installation points of the purlin - diagonal beam - diagonal brace / column are designed together, and the overhanging lengths at both ends of the diagonal beam are small, which can greatly reduce the number of holes in the diagonal beam, avoid stress concentration in the diagonal beam, improve the deformation resistance and bearing capacity of the diagonal beam, and greatly improve the stability of the support under wind and snow load conditions.

[0037] The present invention adopts triangular connectors with partition sleeves, which improves the bearing capacity of the fiber-reinforced composite material in the 0° direction. It can fully ensure that the axial force of the support under different wind and snow load conditions is less than the design value, ensuring that the support will not undergo instability failure along the 0° direction during use.

[0038] All the photovoltaic brackets proposed by the present invention are fiber-reinforced composite materials integrally formed by pultrusion process, without structures such as stiffeners. The pultrusion production efficiency is high, and an opening production line can be set up after the pultrusion line. The opening efficiency is high, which is convenient for popularization and application in large-scale centralized photovoltaic projects.

[0039] The mass of the composite material photovoltaic bracket proposed by the present invention is only 50-60% of the mass of the traditional steel bracket, acid and alkali resistant, corrosion resistant, and no additional maintenance is required during long-term use in a strong corrosion environment. Description of the Drawings

[0040] Figure 1 It is a schematic diagram of the bracket installation of the present invention;

[0041] Figure 2 It is of the present invention Figure 1 Schematic diagram of the enlarged structure at A in

[0042] Figure 3 It is of the present invention Figure 1 Schematic diagram of the enlarged structure at B in

[0043] Figure 4 It is a schematic diagram of the splicing structure of the triangular connecting piece of the present invention.

[0044] In the figure: 1. Front column; 2. Rear column; 3. Pile foundation; 4. Inclined beam; 5. Triangular connecting piece; 6. Sleeve with partition; 7. Steel gasket; 8. Purlin; 9. Photovoltaic module; 10. Purlin support; 11. Front inclined brace; 12. Rear inclined brace; 13. Pressing block; 14. U-shaped clamp. Detailed Embodiments

[0045] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0046] The purpose of the present invention is to provide a lightweight, high-strength and corrosion-resistant composite material photovoltaic bracket to replace the traditional steel bracket, reduce the weight of the bracket, avoid the corrosion problem of the bracket, and ensure stability and safety under wind and snow loads at the same time.

[0047] To make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0048] Embodiment 1

[0049] Refer to Figures 1-4, a lightweight, high-strength and corrosion-resistant composite photovoltaic support, including columns. The columns include a front column 1 and a rear column 2. The front column 1 and the rear column 2 are pre-embedded and fixed in the pile foundation 3. At the top of the front column 1 and the rear column 2, there is an inclined beam 4. The inclined beam 4 is connected to the front column 1 and the rear column 2 by a triangular connecting piece 5. The triangular connecting piece 5 is provided with a sleeve with a partition 6. On the inclined beam 4, multiple purlins 8 are arranged in parallel for connecting the photovoltaic modules 9. The purlins 8 are fixed to the inclined beam 4 by purlin brackets 10. Front diagonal braces 11 and rear diagonal braces 12 are added between the front column 1, the rear column 2 and the inclined beam 4 to improve the stability of the support. The front diagonal brace 11 is connected to the front column 1 by a triangular connecting piece 5, and the rear diagonal brace 12 is also connected to the rear column 2 by a triangular connecting piece 5. The front diagonal brace 11 and the rear diagonal brace 12 are also connected to the inclined beam 4 by a triangular connecting piece 5.

[0050] For the convenience of transportation and installation, one purlin 8 in an array can be divided into multiple sections, and the multiple sections of purlins 8 are connected by purlin connecting pieces. The photovoltaic modules 9 are fixed by middle clamping blocks and edge clamping blocks. The middle clamping blocks and the edge clamping blocks are fixed to the purlins 8 by U-shaped cards 14 with fixed plates.

[0051] The front column 1, the rear column 2, the inclined beam 4, the purlins 8, the front diagonal braces 11, the rear diagonal braces 12 and the purlin connecting pieces are all fiber-reinforced composites produced by pultrusion process. The reinforcing fiber material can be any one of basalt fiber, glass fiber and carbon fiber, and the matrix material can be any one of epoxy resin, unsaturated polyester resin, vinyl resin and polyurethane.

[0052] Furthermore, the height and width of the purlin connecting piece are 5 - 10 mm larger than those of the purlin 8. At least 4 holes are opened on the upper and lower two surfaces, and at least 2 holes are opened on the left and right sides. The purlin connecting piece is connected to the two sections of purlins 8 respectively by bolts. The opening positions of the clamping blocks 13 should be adapted to the width of the purlin 8, and the hole spacing is at least 5 - 10 mm larger than the width of the purlin 8. The width of the U-shaped card 14 should be 5 - 10 mm larger than the width of the purlin 8, and the length should be able to meet the requirements of fastening and installation.

[0053] Preferably, the pile foundation 3 can be a reinforced concrete independent foundation or a bored cast-in-place pile foundation 3. The form of the pile foundation 3 can be a circular pile foundation 3 or a rectangular pile foundation 3. The size, depth and reinforcement ratio of the pile foundation 3 can be determined according to the wind and snow load intensity and the geotechnical conditions at the location where the support is used. The concrete strength grade of the pile body is at least C25, and the pile body protrudes about 50 - 200 mm above the ground surface.

[0054] It should be noted that the length of the front column 1 and the rear column 2 pre-embedded in the pile foundation 3 should meet the uplift force requirements, and the distance between the bottom of the front column 1 and the rear column 2 and the bottom of the pile foundation 3 is about 1 - 2 times the column width.

[0055] When the on-site construction conditions are restricted or the construction accuracy is low, the front column 1 and the rear column 2 embedded in the pile foundation 3 can be replaced with embedded steel parts. The embedded steel parts and the columns above the ground are firmly connected by limit bolts and through bolts, and a waterproof sealing ring is set. The size and shape of the embedded steel parts should be adapted to the installation size of the columns above the ground.

[0056] Furthermore, when using the triangular connecting piece 5 to connect the inclined beam 4 with the front column 1 and the rear column 2, 2 holes are opened on the inclined beam 4, and at least 1 hole is opened at the top of the front column 1 and the rear column 2 respectively. When using the triangular connecting piece 5 to connect the inclined beam 4 with the front inclined brace 11 and the rear inclined brace 12, 2 holes are opened on the inclined beam 4, and at least 1 hole is opened at the top of the front inclined brace 11 and the rear inclined brace 12 respectively.

[0057] It should be noted that, in order to reduce the number of holes in the inclined beam 4, reduce the stress concentration at the hole-opening position of the inclined beam 4, and ensure that the mechanical properties of the inclined beam 4 are not reduced, the purlin bracket 10 for fixing the purlin 8 on the inclined beam 4 and the triangular connecting piece 5 for connecting the inclined beam 4 with the front column 1 and connecting the inclined beam 4 with the rear column 2 share 2 holes; the purlin bracket 10 for fixing the purlin 8 on the inclined beam 4 and the triangular connecting piece 5 for connecting the inclined beam 4 and the front inclined brace 11 and connecting the inclined beam 4 and the rear inclined brace 12 share 2 holes.

[0058] In order to reduce the deformation amount at both ends of the inclined beam 4 under extreme wind and snow loads, the distance from the center of the triangular connecting piece 5 connecting the inclined beam 4 and the front column 1 and connecting the inclined beam 4 and the rear column 2 to both ends of the inclined beam 4 should be controlled to be 100 - 500 mm.

[0059] When using the triangular connecting piece 5 to connect the front column 1 and the front inclined brace 11 and connect the rear column 2 and the rear inclined brace 12, 2 holes are opened on the front column 1 and the rear column 2, and at least 1 hole is opened on the front inclined brace 11 and the rear inclined brace 12.

[0060] It should be noted that when using the triangular connecting piece 5 to connect the front column 1 with the front inclined brace 11 and the rear column 2 with the rear inclined brace 12 respectively, a steel gasket 7 is provided on each of the front column 1 and the rear column 2, and the gasket is installed on the opposite side of the triangular connecting piece 5. The length of the steel gasket 7 is equivalent to that of the triangular connecting piece 5, the width is equivalent to the width of the column at the installation position, and the thickness is 1 - 3 mm. Through holes are opened on the steel gasket, and the hole-opening position is the same as that of the triangular connecting piece 5.

[0061] Embodiment 2

[0062] This embodiment uses specific examples to elaborate in detail on a lightweight, high-strength, corrosion-resistant composite material photovoltaic support provided in Embodiment 1.

[0063] The site elevation of a certain agricultural PV power station is about 700 - 1500 m, the natural slope is 0° - 30°, the basic wind pressure with a return period R = 50 years in the field area is 0.30 kN / m², and the basic snow pressure with a return period R = 50 years is: 0.30 kN / m². The solar energy resources in the project construction area reach the "abundant" level. According to the project's solar energy resource situation and the mainstream and locally promoted PV modules9 products in the current market, the project plans to adopt 560Wp (N-type) monocrystalline silicon double-sided double-glass modules (module specifications: 2278×1134×30 mm). And according to the requirements of the PV power station and agricultural land, the fixed support adopts a transverse purlin8 and longitudinal support layout scheme, and the lowest height of the PV support from the ground is not less than 1.5 m.

[0064] A design method proposed based on a lightweight, high-strength and corrosion-resistant composite material PV support:

[0065] Step S1, according to the topographic and geological characteristics, light resource conditions, modules, module installation directions, etc. of the project field area, initially select the structural form of the PV support, including support inclination angle, single-array support length, number of pile foundations3, span, column spacing, etc.

[0066] According to the topographic and geological characteristics, light resource conditions, modules, and module installation directions of the project field area, it is initially determined that the PV support adopts a double-pile PV support, with a support inclination angle of 31°, one array using 7 frames of supports, 8 groups of pile foundations3, and a pile foundation3 span of 4.0 m. According to the module specifications and support inclination angle, the single-array support length is 30.134 m, and the distance between the front column1 and the rear is 3.17 m. Each single module has 4 contact points with the purlin8, and 4 purlins8 are set for the single-array support.

[0067] Step S2, according to design experience, initially select the cross-sectional types, dimension parameters and installation methods of each component of the PV support. The cross-sectional form can be various forms and combinations such as C-shaped cross-section, rectangular cross-section, circular cross-section, special-shaped cross-section, etc.

[0068] Based on the design experience of a large number of PV power stations, the cross-sections of the front column1, rear column2, inclined beam4, purlin8, front diagonal brace11, rear diagonal brace12 and purlin connection piece of the PV support are initially designed as rectangular cross-sections, and the height and width of the purlin connection piece are 5 - 10 mm larger than those of the purlin8.

[0069] The front column1 and rear column2 are inserted into the cast-in-site concrete pile foundations3. The columns must be located at the center of the pile foundations3, with a concentricity of 0.5. A triangular connection piece5 with a partition sleeve6 is used to connect the top of the front column1 and rear column2 and the inclined beam4, and it is fastened with an M14×100 external hexagonal bolt group.

[0070] Step S3, based on the PV support design standard, determine the force and deformation requirements of the purlin8, inclined beam4, column, and diagonal brace of the PV support according to the initially selected component dimension parameters and material parameters.

[0071] For the deflection requirements of the purlins 8 and inclined beams 4 of the photovoltaic support, and the column top displacement requirements of the front and rear columns 2, see formula (1). For the buckling analysis requirements of the overall support structure, the first-order eigenvalue f > 1.

[0072] z < (l1 / 250, l2 / 250, l3 / 60). (1)

[0073] In the formula: z < (z1, z2, z3) are the deflections of the purlin 8, the inclined beam 4, and the column top deformation respectively, with the unit of mm, and l < (l1, l2, l3) are the lengths of the purlin 8, the inclined beam 4, and the column respectively, with the unit of mm.

[0074] The purlin 8 and the inclined beam 4 consider the flexural bearing capacity M c , and the main tension and compression axial forces N of the columns and diagonal braces c , including the bearing capacity of material failure, overall stability bearing capacity, and local stability bearing capacity. For the detailed requirements, see formulas (2) to (4).

[0075] M ≤ M c , N ≤ N c (2)

[0076] M c = min(M r , M cr1 , M cr2 ) (3)

[0077] N c = min(N s , N cr1 , N cr2 ) (4)

[0078]

[0079] In the formula: M r ——The design value of the flexural bearing capacity when the member undergoes material failure, MPa;

[0080] M cr1 ——The standard value of the overall stability flexural bearing capacity when the pultruded profile bends around the strong axis, MPa;

[0081] M cr1 ——The standard value of the local stability flexural bearing capacity when the flange or web undergoes local buckling, MPa;

[0082] f L,d ——The longitudinal strength design value of the member, MPa;

[0083] I y ——The moment of inertia about the weak axis, N·mm 2 ;

[0084] y —— Distance from the neutral axis to the edge fiber of the member, mm;

[0085] C b —— Moment correction factor for a member with supports at both ends and unrestrained within the span;

[0086] —— Longitudinal compressive elastic modulus, MPa;

[0087] D J —— Torsional stiffness of a rectangular section;

[0088] L b —— Length between lateral restraint points of the compression flange or length between two adjacent supports that restrain the torsional of the cross-section, mm;

[0089] f cr —— Design value of the critical buckling stress, MPa;

[0090] N s —— Design value of the ultimate bearing capacity for the failure of the compressive material of the entire cross-section of the member, N;

[0091] N cr1 —— Ultimate bearing capacity of the overall stability of the member, N;

[0092] N cr2 —— Ultimate bearing capacity of the local stability of the member, N;

[0093] A n —— Net cross-sectional area of the member, mm 2 ;

[0094] —— Design value of the longitudinal compressive strength, mm 2 ;

[0095] λ —— Effective slenderness ratio;

[0096] A g —— Total cross-sectional area of the member, mm 2 ;

[0097] —— Transverse compressive elastic modulus, MPa;

[0098] υ LT —— In-plane Poisson's ratio;

[0099] G LT —— In-plane shear modulus, MPa;

[0100] β w —— Ratio of width to thickness.

[0101] Step S4: Calculate the load acting on purlin 8 according to the wind and snow loads in the project site area, the types of photovoltaic modules, and the dimensions of the support members in accordance with the specifications.

[0102] Calculate the load acting on purlin 8 according to the wind and snow loads in a certain project site area, the types of photovoltaic modules, and the dimensions of the support members in accordance with the specifications.

[0103] Step S5: Use numerical calculation software to establish a calculation model for the stress and deformation of the photovoltaic support based on the initially selected support structure form and dimensional parameters. Assign the corresponding physical and mechanical parameters to the composite material photovoltaic support according to the data from the composite material laboratory. At the same time, apply the load calculated in S4 to purlin 8 to simulate the stress and deformation of the photovoltaic support under wind and snow loads and the self-weight of the modules.

[0104] Use numerical calculation software to establish a solid element calculation model for the stress and deformation of the photovoltaic support based on the initially selected support structure form and dimensional parameters. For the convenience of calculation, only the support of the span with the largest deformation (the outermost span) is selected for calculation in this model. Apply the calculated load to purlin 8 to simulate the stress and deformation of the photovoltaic support under wind and snow loads and the self-weight of the modules.

[0105] Step S6: Compare the calculation results in Step S5 with the stress and deformation requirements of each component in Step S4.

[0106] Based on the calculation model established in Step S5, obtain the overall deformation of a lightweight, high-strength, and corrosion-resistant composite material photovoltaic support, as well as the bending moment and axial force of each component of the support.

[0107] According to the calculation results, count the deformation data of diagonal beam 4, purlin 8, front column 1, and rear column 2.

[0108] According to the calculation results, count the bending moment and axial force borne by diagonal beam 4, purlin 8, bracing, and columns.

[0109] Step S7: When the stress and deformation of the photovoltaic support structure are both smaller than the parameters mentioned in Step S4, the initially selected parameters can be used as the structural design scheme for the lightweight, high-strength, and corrosion-resistant composite material photovoltaic support. If the requirements of Step S4 are not met, re-select the dimensional parameters of the photovoltaic support components, recalculate according to Step S5, and make a judgment according to Step S6 until the stress and deformation of the photovoltaic support structure meet the requirements of Step S4. Take the parameters that meet the stress and deformation requirements as the structural design scheme for the lightweight, high-strength, and corrosion-resistant composite material photovoltaic support.

[0110] According to the allowable deformation value of a lightweight, high-strength, and corrosion-resistant composite material photovoltaic support calculated in Step 4, under the load in Step S4, the support structure designed according to the support parameters selected in Step S1 and Step S2.

[0111] It should be noted that when the construction conditions at the project site are restricted or the construction accuracy is low, the front column 1 and the rear column 2 embedded in the pile foundation 3 can be replaced with embedded steel parts. The embedded steel parts and the columns above the ground are tightly connected by limit bolts and through bolts, and waterproof sealing rings are set. The size and shape of the embedded steel parts should be adapted to the installation size of the columns above the ground.

Claims

1. A lightweight, high-strength and corrosion-resistant composite material photovoltaic support, characterized in that: It includes a front column (1) and a rear column (2), characterized in that the front column (1) and the rear column (2) are embedded and fixed in a pile foundation (3), the top ends of the front column (1) and the rear column (2) are provided with a diagonal beam (4), the diagonal beam (4) is connected to the front column (1) and the rear column (2) by a triangular connecting piece (5), the triangular connecting piece (5) is provided with a partition sleeve (6), multiple purlins (8) are arranged in parallel on the diagonal beam (4) for connecting photovoltaic modules (9), the purlins (8) are fixed to the diagonal beam (4) by purlin supports (10), a front diagonal brace (11) and a rear diagonal brace (12) are added between the front column (1), the rear column (2) and the diagonal beam (4) to improve the stability of the support, the front diagonal brace (11) and the front column (1) are connected by the triangular connecting piece (5), the rear diagonal brace (12) and the rear column (2) are also connected by the triangular connecting piece (5), and the front diagonal brace (11) and the rear diagonal brace (12) are also connected to the diagonal beam (4) by the triangular connecting piece (5).

2. The lightweight, high-strength and corrosion-resistant composite material photovoltaic support according to claim 1, wherein: The front column (1), rear column (2), diagonal beam (4), purlin (8), front diagonal brace (11), and rear diagonal brace (12) are all fiber-reinforced composite materials produced by the pultrusion process.

3. A lightweight, high-strength and corrosion-resistant composite material photovoltaic support according to claim 1, characterized in that: The pile foundation (3) can be a reinforced concrete independent foundation or a drilled cast-in-place pile foundation (3), and the form of the pile foundation (3) can be a circular pile foundation (3) or a rectangular pile foundation (3).

4. The lightweight, high-strength and corrosion-resistant composite material photovoltaic bracket according to claim 3, wherein The size, depth, and reinforcement ratio of the pile foundation (3) can be determined according to the snow and wind load intensity and geotechnical conditions at the support use location. The concrete strength grade of the pile body is at least C25, and the pile body protrudes about 50 - 200 mm above the ground surface.

5. The lightweight, high-strength and corrosion-resistant composite material photovoltaic support according to claim 1, characterized in that, The length of the front column (1) and the rear column (2) embedded in the pile foundation (3) should meet the uplift force requirements, and the distance between the bottom of the front column (1) and the rear column (2) and the bottom of the pile foundation (3) is greater than 1.5 times the column width.

6. The lightweight, high-strength and corrosion-resistant composite material photovoltaic support according to claim 1, wherein Before connecting the diagonal beam (4), the front column (1), and the rear column (2) with the triangular connecting piece (5), two holes are opened on the diagonal beam (4), and at least 1 hole is opened at the top of the front column (1) and the rear column (2) respectively.

7. The lightweight, high-strength and corrosion-resistant composite photovoltaic support according to claim 1, characterized in that, The distance from the center of the triangular connecting piece (5) connecting the diagonal beam (4) and the front column (1) and the distance from the center of the triangular connecting piece (5) connecting the diagonal beam (4) and the rear column (2) to both ends of the diagonal beam (4) are 100 - 500 mm.

8. A lightweight, high-strength and corrosion-resistant composite material photovoltaic support according to claim 7, characterized in that, The height and width of the connecting piece for connecting the purlin (8) are 5 - 10 mm larger than the purlin (8), at least 4 holes are opened on the upper and lower two surfaces, and at least 2 holes are opened on the left and right sides, and are connected to two sections of purlins (8) by bolts respectively.

9. The lightweight, high-strength and corrosion-resistant composite material photovoltaic support according to claim 1, characterized in that The photovoltaic module (9) uses a pressing block (13), and the pressing block (13) and the purlin (8) are fixed by a U-shaped card (14) with a fixed plate. The hole spacing of the pressing block (13) is at least 5 - 10 mm larger than the width of the purlin (8).

10. Specifically applied to the photovoltaic support according to claims 1-9, characterized in that, It includes the following design steps: Step S1: According to the topographic and geological characteristics of the project site area, light resource conditions, components, component installation directions, etc., preliminarily select the structural form of the photovoltaic support, including support inclination angle, single-array support length, number of pile foundations (3), span, column spacing, etc.; Step S2: Preliminarily select the cross-sectional form, dimension parameters and installation methods of each component of the photovoltaic support. The cross-sectional form is one or a combination of C-shaped cross-section, rectangular cross-section, circular cross-section, and special-shaped cross-section; Step S3: Based on the design standards of the photovoltaic support, determine the stress and deformation requirements of the purlins (8), inclined beams (4), columns, and diagonal braces of the photovoltaic support according to the preliminarily selected component dimension parameters and material parameters; Step S4: According to the wind and snow loads in the project site area, the model of the photovoltaic module (9) and the dimensions of the support components, calculate the loads acting on the purlins (8) according to the specifications; Step S5: Use numerical calculation software to establish a stress and deformation calculation model of the photovoltaic support based on the preliminarily selected support structural form and dimension parameters, assign corresponding physical and mechanical parameters to the composite material photovoltaic support according to the composite material laboratory data, and at the same time apply the loads calculated in S4 to the purlins (8) to simulate the stress and deformation of the photovoltaic support under wind and snow loads and the self-weight of the components; Step S6: Compare the calculation results in Step S5 with the stress and deformation requirements of each component in Step S4; Step S7: When the stress and deformation of the photovoltaic support structure are both smaller than the parameters mentioned in Step S4, the preliminarily selected parameters can be used as the structural design scheme of the lightweight, high-strength and corrosion-resistant composite material photovoltaic support. If the requirements of Step S4 are not met, re-select the dimension parameters of the photovoltaic support components, recalculate according to Step S5, and make a judgment according to Step S6 until the stress and deformation of the photovoltaic support structure meet the requirements of Step S4. Take the parameters that meet the requirements of stress and deformation as the structural design scheme of the lightweight, high-strength and corrosion-resistant composite material photovoltaic support.

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