Numerical wind tunnel analysis method for a mid-span flexible photovoltaic support with adjustable tilt angle

Abstract

An embodiment of the present application provides a numerical wind tunnel analysis method for a mid-span flexible photovoltaic bracket with adjustable tilt, which relates to the field of photovoltaic power generation technology. The present application establishes a first wind field model to conduct a numerical wind tunnel test on a single-body structure three-dimensional model to perform strength verification on the mid-span flexible photovoltaic bracket with adjustable tilt, and establishes a second wind field model to conduct a numerical wind tunnel test on a multi-body uniformly distributed array three-dimensional model to perform resonance monitoring on the mid-span flexible photovoltaic bracket with adjustable tilt. Not only does the numerical wind tunnel test take a single target as the test object, but the influence of the interaction between multiple targets on the test results is also taken into account, thereby improving the accuracy of the numerical wind tunnel test results.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of photovoltaic power generation technology, and in particular to a numerical wind tunnel analysis method for a mid-span, tilt-adjustable flexible photovoltaic bracket. Background Art

[0002] The increasing adoption of flexible photovoltaic brackets has significantly improved the adaptability of these brackets for various installation scenarios. However, the supporting strength and rigidity of these brackets for photovoltaic modules have been significantly reduced. Traditional static wind load calculation methods cannot account for wind-induced vibrations, necessitating the introduction of dynamic wind load analysis methods. However, there are currently no reference standards for this.

[0003] At the same time, because traditional brackets cannot automatically level under extreme wind speeds, flexible brackets with adjustable inclination angles have emerged on the market. Since the module's windward angle varies with the sun's altitude, determining the shape factor for wind load calculations becomes more difficult. Traditional empirical data from load analysis is no longer applicable.

[0004] Furthermore, wind tunnel testing is a traditional method for dynamic wind load analysis. However, because the specimens being tested are too large for the wind tunnel dimensions, they must be scaled down. This scaled-down specimen can lead to significant deviations in fluid dynamics properties. For example, the natural frequency of flexible supports and the torque values ​​of fasteners cannot be accurately determined. Therefore, wind tunnel test results can only be used as a guide.

[0005] In summary, a numerical wind tunnel analysis method for flexible photovoltaic supports with adjustable tilt angles is urgently needed to address the problems of the lack of dynamic wind load analysis standards for flexible supports, the inapplicability of traditional value standards such as the shape coefficient due to the adjustable tilt angle, and the inaccurate results of scaled wind tunnel tests. Summary of the Invention

[0006] In view of the above problems, an embodiment of the present application provides a numerical wind tunnel analysis method for a mid-span flexible photovoltaic bracket with adjustable tilt angle, so as to overcome the above problems or at least partially solve the above problems.

[0007] A first aspect of an embodiment of the present application provides a wind tunnel test method for a mid-span, tilt-adjustable flexible photovoltaic support, the method comprising:

[0008] S1. Obtain the design parameters of the mid-span adjustable tilt flexible photovoltaic support;

[0009] S2. Establishing a three-dimensional model of the monomer structure of the mid-span adjustable tilt flexible photovoltaic support with the tilt angle of the photovoltaic module as a first initial angle according to the design parameters;

[0010] S3. Establishing a first wind field model based on the three-dimensional model of the monomer structure, wherein the angle between the inlet of the first wind field model and the windward surface of the three-dimensional model of the monomer structure is a second initial angle;

[0011] S4. Based on the first wind field model, perform strength verification on the mid-span adjustable tilt flexible photovoltaic support;

[0012] S5, evenly arranging the plurality of said monomer structure three-dimensional models to establish a multi-body evenly distributed array three-dimensional model;

[0013] S6. Establish a second wind field model based on the multi-body uniformly distributed array three-dimensional model, where the angle between the inlet of the second wind field model and the windward surface of the uniformly distributed array three-dimensional model is the second initial angle;

[0014] S7. Based on the second wind field model, performing resonance monitoring on the mid-span adjustable tilt flexible photovoltaic support;

[0015] S8, adjusting the first initial angle according to a first preset interval angle, and repeating steps S1-S7;

[0016] S9. Adjust the second initial angle according to a second preset interval angle, and repeat steps S1-S8.

[0017] Optionally, step S4 includes:

[0018] S4.1. In the first wind field model, select a first preset turbulence model;

[0019] S4.2. Set a first boundary condition for the first wind field model, where the first boundary condition includes: a first initial pressure and a first initial velocity;

[0020] S4.3. Based on the first preset turbulence model and the first boundary condition, perform numerical wind tunnel calculations using finite element analysis software to determine wind pressure parameters distributed on the photovoltaic panels of the three-dimensional model of the single structure;

[0021] S4.4 determining a shape coefficient of the three-dimensional model of the single structure and a gust coefficient of the wind load in the first wind field model based on the wind pressure parameter;

[0022] S4.5. Based on the shape coefficient and the gust coefficient, perform strength verification on the photovoltaic bracket of the single-body three-dimensional model using the wind load statics equation.

[0023] Optionally, the strength check of the photovoltaic support of the single-structure three-dimensional model by using a wind load statics equation includes:

[0024] Obtaining the structural strength of the photovoltaic support of the single-body three-dimensional model;

[0025] Calculating the intensity of the wind load acting on the photovoltaic support in the first wind field model using the wind load statics equation;

[0026] Based on the structural strength of the photovoltaic support and the strength of the wind load acting on the photovoltaic support, the photovoltaic support of the single-body three-dimensional model is strength-checked.

[0027] Optionally, step S4 further includes:

[0028] S4.6. When the structural strength of the photovoltaic support in the three-dimensional model of the single structure is lower than the strength of the wind load acting on the photovoltaic support, strengthen the structural strength of the photovoltaic support in the three-dimensional model of the single structure.

[0029] Optionally, step S7 includes:

[0030] S7.1. In the second wind field model, select a second preset turbulence model;

[0031] S7.2. Set a second boundary condition for the second wind field model, where the second boundary condition includes: a second initial pressure and a second initial velocity;

[0032] S7.3. Based on the second preset turbulence model and the second boundary condition, perform numerical wind tunnel calculations using finite element analysis software to determine the transition flow characteristics between any two adjacent three-dimensional models of the single-body structure in the multi-body uniformly distributed array three-dimensional model;

[0033] S7.4. Determine whether resonance occurs between any two adjacent three-dimensional models of the monomer structure according to the transition flow characteristics.

[0034] Optionally, determining whether resonance occurs between any two adjacent three-dimensional models of the monomer structure according to the transition flow characteristics includes:

[0035] determining an oscillation frequency of the transition flow according to the transition flow characteristics;

[0036] Performing modal analysis on any two adjacent three-dimensional models of the monomer structure in the multi-body uniformly distributed array three-dimensional model using finite element analysis software to determine the vibration frequency corresponding to the free vibration mode of any two adjacent three-dimensional models of the monomer structure;

[0037] In a case where the oscillation frequency of the transitional flow is the same as the vibration frequency corresponding to the free vibration mode, it is determined that resonance occurs between any two adjacent three-dimensional models of the monomer structure.

[0038] Optionally, step S7 further includes:

[0039] S7.5. When it is determined that resonance occurs between any two adjacent three-dimensional models of the monomer structure, modify the structural parameters of the photovoltaic support of the two adjacent three-dimensional models of the monomer structure.

[0040] Optionally, the step S3 of establishing a first wind field model according to the three-dimensional model of the monomer structure includes:

[0041] Taking the monomer structure three-dimensional model as a reference, the entrance of the first wind field model is established at a first preset distance from the windward side of the monomer structure three-dimensional model, the exit of the first wind field model is established at a second preset distance from the leeward side of the monomer structure three-dimensional model, and the boundaries of the first wind field model are established at third preset distances from both sides and above the monomer structure three-dimensional model.

[0042] Optionally, the step S6 of establishing a second wind field model according to the multi-body uniformly distributed array three-dimensional model includes:

[0043] Taking the multi-body evenly distributed array three-dimensional model as a reference, the entrance of the second wind field model is established at a first preset distance from the windward side of the multi-body evenly distributed array three-dimensional model, the exit of the second wind field model is established at a second preset distance from the leeward side of the multi-body evenly distributed array three-dimensional model, and the boundaries of the second wind field model are established at third preset distances from both sides and above the multi-body evenly distributed array three-dimensional model.

[0044] Optionally, the first initial angle is 5 degrees, the first preset interval angle is 5 degrees, and adjusting the first initial angle according to the first preset interval angle includes:

[0045] Taking the first initial angle of 5 degrees as a reference, and according to the first preset interval angle of 5 degrees, the first initial angle is adjusted to 10 degrees, 15 degrees, 20 degrees, 25 degrees, and 30 degrees respectively.

[0046] Optionally, the second initial angle is 0 degrees, the second preset interval angle is 15 degrees, and adjusting the second initial angle according to the second preset interval angle includes:

[0047] Taking the second initial angle of 0 degrees as a reference, and according to the second preset interval angle of 15 degrees, the second initial angle is adjusted to 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees, 90 degrees, 105 degrees, 120 degrees, 135 degrees, 150 degrees, 165 degrees, and 180 degrees respectively.

[0048] This application has the following advantages:

[0049] The embodiment of the present application provides a numerical wind tunnel analysis method for a medium-span flexible photovoltaic bracket with adjustable tilt, the method comprising: S1, obtaining design parameters of the medium-span flexible photovoltaic bracket with adjustable tilt; S2, establishing a three-dimensional model of a single structure of the medium-span flexible photovoltaic bracket with adjustable tilt based on the design parameters and taking the tilt angle of the photovoltaic module as a first initial angle; S3, establishing a first wind field model based on the three-dimensional model of the single structure, wherein the angle between the inlet of the first wind field model and the windward surface of the three-dimensional model of the single structure is a second initial angle; S4, performing a strong wind tunnel analysis on the medium-span flexible photovoltaic bracket based on the first wind field model. Degree verification; S5, evenly arrange multiple three-dimensional models of the single structure to establish a multi-body evenly distributed array three-dimensional model; S6, establish a second wind field model based on the multi-body evenly distributed array three-dimensional model, and the angle between the inlet of the second wind field model and the windward surface of the evenly distributed array three-dimensional model is the second initial angle; S7, based on the second wind field model, perform resonance monitoring on the mid-span adjustable tilt flexible photovoltaic bracket; S8, adjust the first initial angle according to the first preset interval angle, and repeat steps S1-S7; S9, adjust the second initial angle according to the second preset interval angle, and repeat steps S1-S8. This application establishes a first wind field model to conduct numerical wind tunnel tests on a single-body structure three-dimensional model to perform strength verification on a mid-span flexible photovoltaic bracket with adjustable tilt, and establishes a second wind field model to conduct numerical wind tunnel tests on a multi-body uniformly distributed array three-dimensional model to perform resonance monitoring on the mid-span flexible photovoltaic bracket with adjustable tilt. Not only does the numerical wind tunnel test take a single target as the test object, but the influence of the interaction between multiple targets on the test results is also taken into account, thereby improving the accuracy of the numerical wind tunnel test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0051] Figure 1 This is a schematic flow chart of the steps of a numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic bracket provided in an embodiment of the present application;

[0052] Figure 2 This is a schematic diagram of a three-dimensional model of a single structure of a mid-span, tilt-adjustable flexible photovoltaic support provided in an embodiment of the present application;

[0053] Figure 3 This is a schematic diagram of a three-dimensional model of a multi-body uniformly distributed array of a mid-span adjustable tilt flexible photovoltaic support provided in an embodiment of the present application;

[0054] Figure 4 This is a schematic diagram of a curve showing the relationship between frequency and amplitude of a mid-span, tilt-adjustable flexible photovoltaic bracket provided in an embodiment of the present application;

[0055] Figure 5 This is a schematic structural diagram of a first wind field model and an edge space of a single structure three-dimensional model provided in an embodiment of the present application;

[0056] Figure 6 This is a schematic diagram of the component inclination angle of a mid-span adjustable inclination flexible photovoltaic bracket provided in an embodiment of the present application;

[0057] Figure 7 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 0 degrees;

[0058] Figure 8 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 15 degrees;

[0059] Figure 9 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 30 degrees;

[0060] Figure 10 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 45 degrees;

[0061] Figure 11 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 60 degrees;

[0062] Figure 12 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model and a wind field model provided in an embodiment of the present application when the relative position angle is 75 degrees;

[0063] Figure 13 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 90 degrees;

[0064] Figure 14 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 105 degrees;

[0065] Figure 15 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 120 degrees;

[0066] Figure 16 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 135 degrees;

[0067] Figure 17 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 150 degrees;

[0068] Figure 18 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model when the relative position angle is 165 degrees;

[0069] Figure 19 This is a schematic diagram of a multi-body uniformly distributed array three-dimensional model provided in an embodiment of the present application and a second wind field model where the relative position angle is 180 degrees. DETAILED DESCRIPTION

[0070] The exemplary embodiments of the present application will be described in more detail below in conjunction with the accompanying drawings in the embodiments of the present application. Although the accompanying drawings show exemplary embodiments of the present application, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0071] In a first aspect of the embodiment of the present application, a numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic bracket is provided, such as Figure 1 As shown, the method includes:

[0072] S1. Obtain the design parameters of the mid-span adjustable tilt flexible photovoltaic support;

[0073] S2. Establishing a three-dimensional model of the monomer structure of the mid-span adjustable tilt flexible photovoltaic support with the tilt angle of the photovoltaic module as a first initial angle according to the design parameters;

[0074] S3. Establishing a first wind field model based on the three-dimensional model of the monomer structure, wherein the angle between the inlet of the first wind field model and the windward surface of the three-dimensional model of the monomer structure is a second initial angle;

[0075] S4. Based on the first wind field model, perform strength verification on the mid-span adjustable tilt flexible photovoltaic support;

[0076] S5, evenly arranging the plurality of said monomer structure three-dimensional models to establish a multi-body evenly distributed array three-dimensional model;

[0077] S6. Establish a second wind field model based on the multi-body uniformly distributed array three-dimensional model, where the angle between the inlet of the second wind field model and the windward surface of the uniformly distributed array three-dimensional model is the second initial angle;

[0078] S7. Based on the second wind field model, performing resonance monitoring on the mid-span adjustable tilt flexible photovoltaic support;

[0079] S8, adjusting the first initial angle according to a first preset interval angle, and repeating steps S1-S7;

[0080] S9. Adjust the second initial angle according to a second preset interval angle, and repeat steps S1-S8.

[0081] Specifically, in this embodiment, it is first necessary to obtain the key parameters of the mid-span adjustable tilt flexible photovoltaic bracket in the current project. The key parameters of the mid-span adjustable tilt flexible photovoltaic bracket can be the size, material, etc. of the bracket. Based on the key parameters of the mid-span adjustable tilt flexible photovoltaic bracket obtained, the following is made: Figure 2 The three-dimensional single-body structure model of a mid-span, adjustable-tilt flexible photovoltaic support is shown. For this model, the inclination angle of the photovoltaic modules is preset to a first initial angle. Next, based on the three-dimensional single-body structure model, a first wind field model corresponding to the three-dimensional single-body structure model is established. The angle between the first wind field model and the windward surface of the three-dimensional single-body structure model is preset to a second initial angle. Finally, the strength of the mid-span, adjustable-tilt flexible photovoltaic support is verified using the first wind field model.

[0082] Furthermore, multiple single-unit structural three-dimensional models of mid-span, tilt-adjustable flexible photovoltaic supports are established, and these single-unit structural three-dimensional models are evenly distributed to form a multi-unit evenly distributed array three-dimensional model. It should be noted that the tilt angle of the photovoltaic components in each single-unit structural three-dimensional model in this multi-unit evenly distributed array three-dimensional model is preset to a first initial angle. Next, based on the multi-unit evenly distributed array three-dimensional model, a second wind field model corresponding to the multi-unit evenly distributed array three-dimensional model is established, and the angle between the second wind field model and the windward surface of the multi-unit evenly distributed array three-dimensional model is preset to a second initial angle. Finally, resonance monitoring of the mid-span, tilt-adjustable flexible photovoltaic support is performed using the second wind field model.

[0083] In the present application, the design parameters of the mid-span adjustable tilt flexible photovoltaic bracket are obtained; a single-body structure three-dimensional model and a multi-body uniformly distributed array three-dimensional model of the mid-span adjustable tilt flexible photovoltaic bracket are established according to the design parameters; a first wind field model corresponding to the single-body structure three-dimensional model and a second wind field model corresponding to the multi-body uniformly distributed array three-dimensional model are established according to the single-body structure three-dimensional model and the multi-body uniformly distributed array three-dimensional model; based on the first wind field model, the mid-span adjustable tilt flexible photovoltaic bracket is strength checked; based on the second wind field model, the mid-span adjustable tilt flexible photovoltaic bracket is resonance monitored. In this embodiment, a first wind field model is established to conduct numerical wind tunnel tests on a three-dimensional model of a single structure to perform strength verification on a mid-span flexible photovoltaic bracket with adjustable tilt, and a second wind field model is established to conduct numerical wind tunnel tests on a three-dimensional model of a multi-body uniformly distributed array to perform resonance monitoring on a mid-span flexible photovoltaic bracket with adjustable tilt. Not only is a single target used as a test object for the numerical wind tunnel test, but the influence of the interaction between multiple targets on the test results is also taken into account, thereby improving the accuracy of the numerical wind tunnel test results.

[0084] In a preferred embodiment of the present application, step S4 performs strength verification on the mid-span adjustable tilt flexible photovoltaic support based on the first wind field model, specifically comprising:

[0085] S4.1. In the first wind field model, select a first preset turbulence model;

[0086] S4.2. Set a first boundary condition for the first wind field model, where the first boundary condition includes: a first initial pressure and a first initial velocity;

[0087] S4.3. Based on the first preset turbulence model and the first boundary condition, perform numerical wind tunnel calculations using finite element analysis software to determine wind pressure parameters distributed on the photovoltaic panels of the three-dimensional model of the single structure;

[0088] S4.4 determining a shape coefficient of the three-dimensional model of the single structure and a gust coefficient of the wind load in the first wind field model based on the wind pressure parameter;

[0089] S4.5. Based on the shape coefficient and the gust coefficient, perform strength verification on the photovoltaic bracket of the single-body three-dimensional model using the wind load statics equation.

[0090] Specifically, in this embodiment, a first preset turbulence model is selected in the first wind field model; a first boundary condition of the first wind field model is set, wherein the first boundary condition includes: a first initial pressure and a first initial velocity; based on the first preset turbulence model and the first boundary condition, numerical wind tunnel calculation is performed using finite element analysis software to determine the wind pressure parameters distributed on the photovoltaic panels of the single-structure three-dimensional model; based on the wind pressure parameters, the body coefficient of the single-structure three-dimensional model and the gust coefficient of the wind load in the first wind field model are determined; based on the body coefficient and the gust coefficient, the photovoltaic bracket of the single-structure three-dimensional model is strength-checked using the wind load statics equation. This embodiment simulates a real wind field in reality by selecting a pre-set first turbulence model in the first wind field model, wherein, after selecting the first turbulence model, the first boundary condition of the first wind field model, i.e., the initial condition applied to the first turbulence model in the first wind field model, is further determined: a first initial pressure and a first initial velocity. Furthermore, based on the first turbulence model and the first boundary condition applied to the first turbulence model, numerical wind tunnel calculations were performed using finite element analysis software to determine the wind pressure parameters distributed on the photovoltaic panels of the monolithic three-dimensional model when the first turbulence model in the first wind field model applied a wind load to the monolithic three-dimensional model at a first initial pressure and a first initial velocity. Based on the wind pressure parameters, the shape coefficient of the monolithic three-dimensional model and the gust coefficient of the wind load in the first wind field model were determined. The strength of the photovoltaic support of the monolithic three-dimensional model was then verified based on the shape coefficient and the gust coefficient using existing static equations for wind loads.

[0091] In a preferred embodiment of the present application, the strength verification of the photovoltaic bracket of the single-body structure three-dimensional model through the wind load statics equation includes: obtaining the structural strength of the photovoltaic bracket of the single-body structure three-dimensional model; calculating the strength of the wind load acting on the photovoltaic bracket in the first wind field model through the wind load statics equation; and performing strength verification of the photovoltaic bracket of the single-body structure three-dimensional model based on the structural strength of the photovoltaic bracket and the strength of the wind load acting on the photovoltaic bracket.

[0092] Specifically, in this embodiment of the present application, the structural strength of the photovoltaic bracket of the single-structure three-dimensional model is obtained; the strength of the wind load acting on the photovoltaic bracket in the first wind field model is calculated by the wind load statics equation; based on the structural strength of the photovoltaic bracket and the strength of the wind load acting on the photovoltaic bracket, the strength of the photovoltaic bracket of the single-structure three-dimensional model is checked. In this embodiment, it is first necessary to determine the structural strength of the photovoltaic bracket based on the design parameters of the photovoltaic bracket in the single-structure three-dimensional model, and the maximum load that the photovoltaic bracket can withstand can be determined by the structural strength. Through the wind load statics equation, based on the shape coefficient and the gust coefficient, the strength of the wind load acting on the photovoltaic bracket in the first wind field model is calculated, that is, the thrust of the wind load on the photovoltaic bracket in the first wind field model is obtained. Finally, the structural strength of the photovoltaic bracket is compared with the strength of the wind load, that is, the maximum load that the photovoltaic bracket can withstand and the thrust of the wind load on the photovoltaic bracket are compared, so as to check the strength of the photovoltaic bracket of the single-structure three-dimensional model.

[0093] In a preferred embodiment of the present application, step S4 further includes:

[0094] S4.6. When the structural strength of the photovoltaic support in the three-dimensional model of the single structure is lower than the strength of the wind load acting on the photovoltaic support, strengthen the structural strength of the photovoltaic support in the three-dimensional model of the single structure.

[0095] Specifically, by checking the strength of the photovoltaic bracket of the single-body structure three-dimensional model, it can be determined whether the photovoltaic bracket can withstand the wind load in the first wind field model. If the structural strength of the photovoltaic bracket of the single-body structure three-dimensional model is lower than the strength of the wind load acting on the photovoltaic bracket, the structural strength of the photovoltaic bracket needs to be adjusted. In actual applications, the structural strength of the photovoltaic bracket can be improved by selecting higher strength materials or increasing the thickness of the bracket. This application does not make specific restrictions here.

[0096] In a preferred embodiment of the present application, step S7 performs resonance monitoring on the mid-span adjustable tilt flexible photovoltaic support based on the second wind field model, specifically comprising the following steps:

[0097] S7.1. In the second wind field model, select a second preset turbulence model;

[0098] S7.2. Set a second boundary condition for the second wind field model, where the second boundary condition includes: a second initial pressure and a second initial velocity;

[0099] S7.3. Based on the second preset turbulence model and the second boundary condition, perform numerical wind tunnel calculations using finite element analysis software to determine the transition flow characteristics between any two adjacent three-dimensional models of the single-body structure in the multi-body uniformly distributed array three-dimensional model;

[0100] S7.4. Determine whether resonance occurs between any two adjacent three-dimensional models of the monomer structure according to the transition flow characteristics.

[0101] Specifically, in this embodiment, a second preset turbulence model is selected in the second wind field model; second boundary conditions for the second wind field model are set, wherein the second boundary conditions include: a second initial pressure and a second initial velocity; based on the second preset turbulence model and the second boundary conditions, numerical wind tunnel calculations are performed using finite element analysis software to determine the transition flow characteristics between any two adjacent single-structure three-dimensional models in the multi-body uniformly distributed array three-dimensional model; and based on the transition flow characteristics, whether resonance occurs between any two adjacent single-structure three-dimensional models is determined. This embodiment simulates a real wind field in reality by selecting a pre-set second turbulence model in the second wind field model. After selecting the second turbulence model, second boundary conditions for the second wind field model, i.e., starting conditions applied to the second turbulence model in the second wind field model, are further determined: a second initial pressure and a second initial velocity. Furthermore, based on the second turbulence model and the second boundary conditions applied to the second turbulence model, numerical wind tunnel calculations are performed using finite element analysis software to determine the transition flow characteristics between any two adjacent single-structure three-dimensional models in the multi-body uniformly distributed array three-dimensional model. Based on the information about the transition flow characteristics, whether resonance occurs between two adjacent brackets can be determined. It’s important to note that resonance occurs when the bracket vibrates at a frequency that matches the wind’s frequency, potentially causing damage or destruction. This step allows us to identify potential resonance issues and take steps to prevent them.

[0102] In a preferred embodiment of the present application, determining whether resonance occurs between any two adjacent three-dimensional models of the monomer structure based on the transition flow characteristics includes: determining the oscillation frequency of the transition flow based on the transition flow characteristics; performing modal analysis on any two adjacent three-dimensional models of the monomer structure in the multi-body uniformly distributed array three-dimensional model using finite element analysis software to determine the vibration frequency corresponding to the free vibration mode of any two adjacent three-dimensional models of the monomer structure; and determining that resonance occurs between any two adjacent three-dimensional models of the monomer structure when the oscillation frequency of the transition flow is the same as the vibration frequency corresponding to the free vibration mode.

[0103] Specifically, in this embodiment, based on the transition flow characteristics, the oscillation frequency of the transition flow is determined; finite element analysis software is used to perform modal analysis on any two adjacent monomer structure three-dimensional models in the multi-body uniformly distributed array three-dimensional model to determine the vibration frequency corresponding to the free vibration mode of any two adjacent monomer structure three-dimensional models; when the oscillation frequency of the transition flow is the same as the vibration frequency corresponding to the free vibration mode, it is determined that resonance occurs between the any two adjacent monomer structure three-dimensional models. In this embodiment, a pre-set second turbulence model is selected in the second wind field model to simulate a real wind field in reality, and a wind load is applied to the multi-body uniformly distributed array three-dimensional model by determining the second boundary conditions of the second wind field model, that is, the initial conditions of the second turbulence model applied to the second wind field model: a second initial pressure and a second initial velocity, and the simulation results are observed to determine the characteristics of the transition flow, thereby determining the oscillation frequency of the transition flow based on the characteristics of the transition flow. The oscillation frequency of the transition flow refers to the frequency at which the wind swings between the supports, that is, the oscillation frequency of the wind flow in space. Furthermore, finite element analysis software is used to perform modal analysis on any two adjacent three-dimensional monomeric structures, thereby determining the vibration frequency between the photovoltaic brackets of any two adjacent three-dimensional monomeric structures in the free vibration mode, wherein the vibration frequency under the free vibration mode characterizes the free vibration characteristics of the photovoltaic bracket when not subjected to external forces. Then, the oscillation frequency of the transition flow is compared with the vibration frequency corresponding to the free vibration mode of the photovoltaic brackets of any two adjacent three-dimensional monomeric structures. If the oscillation frequency of the transition flow and the vibration frequency corresponding to the free vibration mode are the same, it can be determined that resonance occurs between the two adjacent three-dimensional monomeric structures, that is, resonance occurs between the photovoltaic brackets of the two adjacent three-dimensional monomeric structures.

[0104] In an exemplary embodiment, the above-mentioned multi-body uniformly distributed array three-dimensional model can also be placed in the finite element analysis software, and the swing frequency and amplitude of the transition flow are used as the initial simulation boundary conditions. The finite element analysis software is run to observe whether the amplitude of the photovoltaic bracket changes suddenly. During this period, the swing frequency of the initial simulation boundary conditions can be continuously changed, and the changes in the amplitude of the photovoltaic bracket can be continuously observed. If the amplitude of the photovoltaic bracket suddenly increases when the swing frequency is adjusted near a certain position, it is judged that the frequency is the resonant frequency of the photovoltaic bracket. Specifically, Figure 4 The diagram of the relationship curve between the frequency and amplitude of the mid-span adjustable tilt flexible photovoltaic bracket shown is as follows. When the resonant frequency is adjusted to 150HZ-250HZ, the amplitude suddenly increases, and it can be determined that the resonant frequency of the photovoltaic bracket is 150HZ-250HZ.

[0105] In a preferred embodiment of the present application, step S7 performs resonance monitoring on the mid-span adjustable tilt flexible photovoltaic support based on the second wind field model, and further includes:

[0106] S7.5. When it is determined that resonance occurs between any two adjacent three-dimensional models of the monomer structure, modify the structural parameters of the photovoltaic support of the two adjacent three-dimensional models of the monomer structure.

[0107] In this embodiment, if resonance is determined to occur between two adjacent single-body three-dimensional photovoltaic brackets, the structural parameters of the two adjacent brackets need to be modified. This can avoid the resonance phenomenon and, in turn, prevent bracket damage or performance degradation due to increased bracket vibration. In practical applications, by adjusting the structural parameters of the two brackets, such as material, shape, or size, their vibration frequency can be changed to ensure that they no longer match the swing frequency of the transitional flow in the wind farm, thereby avoiding resonance and increasing the stability and reliability of the photovoltaic bracket.

[0108] In a preferred embodiment of the present application, step S3 describes establishing a first wind field model based on the monomer structure three-dimensional model, including: taking the monomer structure three-dimensional model as a reference, establishing the entrance of the first wind field model at a first preset distance from the windward side of the monomer structure three-dimensional model, establishing the exit of the first wind field model at a second preset distance from the leeward side of the monomer structure three-dimensional model, and establishing the boundaries of the first wind field model at a third preset distance from both sides and above the monomer structure three-dimensional model.

[0109] Specifically, if Figure 5 The schematic diagram of the structure of the first wind field model and the edge space of the monomer structure three-dimensional model is shown. In this embodiment, first, taking the monomer structure three-dimensional model as a reference, starting from the windward side of the monomer structure three-dimensional model, an entrance of the first wind field model is established at a first preset distance from the windward side, and this entrance is the starting point of the first wind field model; on the leeward side of the monomer structure three-dimensional model, an exit of the first wind field model is established at a second preset distance from the leeward side, and this exit is the end point of the first wind field model; on both sides and above the monomer structure three-dimensional model, boundaries of the first wind field model are respectively established, and the distance between these boundaries and the sides and the top of the monomer structure three-dimensional model is a third preset distance. These boundaries define the boundary conditions of the first wind field model to ensure that the simulated wind field environment is as close as possible to the actual wind field conditions.

[0110] In a preferred embodiment of the present application, step S6 describes establishing a second wind field model based on the multi-body evenly distributed array three-dimensional model, including: taking the multi-body evenly distributed array three-dimensional model as a reference, establishing the entrance of the second wind field model at a first preset distance from the windward side of the multi-body evenly distributed array three-dimensional model, establishing the exit of the second wind field model at a second preset distance from the leeward side of the multi-body evenly distributed array three-dimensional model, and establishing the boundaries of the second wind field model at a third preset distance from both sides and above the multi-body evenly distributed array three-dimensional model.

[0111] Specifically, in this embodiment, first, taking the multi-body uniformly distributed array three-dimensional model as a reference, starting from the windward side of the multi-body uniformly distributed array three-dimensional model, the entrance of the second wind field model is established at a first preset distance from the windward side, and this entrance is the starting point of the second wind field model; on the leeward side of the multi-body uniformly distributed array three-dimensional model, the exit of the second wind field model is established at a position at a second preset distance from the leeward side, and this exit is the end point of the second wind field model; on both sides and above the multi-body uniformly distributed array three-dimensional model, the boundaries of the second wind field model are respectively established, and the distance between these boundaries and the sides and above of the multi-body uniformly distributed array is a third preset distance, and these boundaries define the boundary conditions of the second wind field model to ensure that the simulated wind field environment is as close to the real wind field conditions as possible.

[0112] In a preferred embodiment of the present application, the first initial angle is 5 degrees, and the first preset interval angle is 5 degrees. Adjusting the first initial angle according to the first preset interval angle includes: taking the first initial angle of 5 degrees as a reference, and adjusting the first initial angle to 10 degrees, 15 degrees, 20 degrees, 25 degrees, and 30 degrees respectively according to the first preset interval angle of 5 degrees.

[0113] Specifically, refer to Figure 6 The schematic diagram of the component inclination angle of a mid-span adjustable tilt flexible photovoltaic bracket shown in the figure takes the component inclination angle of 5 degrees as the initial angle, and then adjusts the initial angle at intervals of 5 degrees. Specifically, starting from 5 degrees, the component inclination angle is adjusted to 10 degrees, 15 degrees, 20 degrees, 25 degrees, and 30 degrees in sequence, so as to conduct tests at a series of angles. The present application analyzes the resonance between photovoltaic brackets through numerical wind tunnel tests at component inclination angles of different angles, and adjusts parameters for brackets with resonance at different angles, thereby helping to improve the stability of the photovoltaic bracket. In an embodiment of the present application, the mid-span adjustable tilt flexible photovoltaic bracket is re-calibrated for strength by adjusting the inclination angle of the photovoltaic component in the three-dimensional model of the single structure and based on the first wind field model; and / or, the inclination angle of the photovoltaic component in the three-dimensional model of the multi-body uniformly distributed array is adjusted, and based on the second wind field model, the mid-span adjustable tilt flexible photovoltaic bracket is re-monitored for resonance.

[0114] In a preferred embodiment of the present application, the second initial angle is 0 degrees, and the second preset interval angle is 15 degrees. Adjusting the second initial angle according to the second preset interval angle includes: taking the second initial angle of 0 degrees as a reference, and adjusting the second initial angle to 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees, 90 degrees, 105 degrees, 120 degrees, 135 degrees, 150 degrees, 165 degrees, and 180 degrees respectively according to the second preset interval angle of 15 degrees.

[0115] Specifically, refer to Figure 7-19 In this embodiment, under the initial condition, the second initial angle, that is, the angle between the inlet of the second wind field model and the windward surface of the multi-body uniformly distributed array three-dimensional model, is set to 0 degrees, and then the second initial angle is adjusted at intervals of 15 degrees each time to perform multi-angle simulation tests. The specific adjustment order is as follows: 0 degrees, 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees, 90 degrees, 105 degrees, 120 degrees, 135 degrees, 150 degrees, 165 degrees, and 180 degrees. This application conducts numerical wind tunnel tests at different angles between the inlet of the second wind field model and the windward surface of the multi-body uniformly distributed array three-dimensional model to analyze the resonance between photovoltaic brackets, and adjusts parameters for brackets with resonance at different angles, thereby helping to improve the stability of the photovoltaic brackets. In an embodiment of the present application, the inlet angle between the single-body structure three-dimensional model and the first wind field model is adjusted, and based on the first wind field model, the strength of the mid-span adjustable tilt flexible photovoltaic bracket is re-calibrated; and / or, the inlet angle between the multi-body uniformly distributed array three-dimensional model and the second wind field model is adjusted, and based on the second wind field model, the resonance monitoring of the mid-span adjustable tilt flexible photovoltaic bracket is re-performed.

[0116] The embodiment of the present application provides a numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic bracket, the method comprising: S1, obtaining design parameters of the mid-span adjustable tilt flexible photovoltaic bracket;

[0117] S2. According to the design parameters, a single-body structure three-dimensional model of a mid-span adjustable tilt flexible photovoltaic bracket is established with the inclination angle of the photovoltaic component as the first initial angle; S3. According to the single-body structure three-dimensional model, a first wind field model is established, and the angle between the inlet of the first wind field model and the windward surface of the single-body structure three-dimensional model is the second initial angle; S4. Based on the first wind field model, the strength of the mid-span adjustable tilt flexible photovoltaic bracket is checked; S5. Multiple single-body structure three-dimensional models are evenly arranged to establish a multi-body evenly distributed array three-dimensional model; S6. According to the multi-body evenly distributed array three-dimensional model, a second wind field model is established, and the angle between the inlet of the second wind field model and the windward surface of the evenly distributed array three-dimensional model is the second initial angle; S7. Based on the second wind field model, resonance monitoring of the mid-span adjustable tilt flexible photovoltaic bracket is performed; S8. Adjust the first initial angle according to the first preset interval angle, and repeat steps S1-S7; S9. Adjust the second initial angle according to the second preset interval angle, and repeat steps S1-S8. This application establishes a first wind field model to conduct numerical wind tunnel tests on a single-body structure three-dimensional model to perform strength verification on a mid-span flexible photovoltaic bracket with adjustable tilt, and establishes a second wind field model to conduct numerical wind tunnel tests on a multi-body uniformly distributed array three-dimensional model to perform resonance monitoring on the mid-span flexible photovoltaic bracket with adjustable tilt. Not only does the numerical wind tunnel test take a single target as the test object, but the influence of the interaction between multiple targets on the test results is also taken into account, thereby improving the accuracy of the numerical wind tunnel test results.

[0118] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0119] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0120] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "includes," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements that are inherent to such process, method, article, or terminal device. In the absence of further restrictions, an element defined by the phrase "comprises a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0121] The above is a detailed introduction to the numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic bracket provided by this application. This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method of this application and its core idea; at the same time, for general technical personnel in this field, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on this application.

Claims

1. A numerical wind tunnel analysis method for a mid-span, adjustable-tilt flexible photovoltaic support, characterized in that: The method comprises: S1. Obtain the design parameters of the mid-span adjustable tilt flexible photovoltaic support; S2. Establishing a three-dimensional model of the monomer structure of the mid-span adjustable tilt flexible photovoltaic support with the tilt angle of the photovoltaic module as a first initial angle according to the design parameters; S3. Establishing a first wind field model based on the three-dimensional model of the monomer structure, wherein the angle between the inlet of the first wind field model and the windward surface of the three-dimensional model of the monomer structure is a second initial angle; S4. Based on the first wind field model, perform strength verification on the mid-span adjustable tilt flexible photovoltaic support; S5, evenly arranging the plurality of said monomer structure three-dimensional models to establish a multi-body evenly distributed array three-dimensional model; S6. Establish a second wind field model based on the multi-body uniformly distributed array three-dimensional model, where the angle between the inlet of the second wind field model and the windward surface of the uniformly distributed array three-dimensional model is the second initial angle; S7. Based on the second wind field model, performing resonance monitoring on the mid-span adjustable tilt flexible photovoltaic support; S8, adjusting the first initial angle according to a first preset interval angle, and repeating steps S1-S7; S9, adjusting the second initial angle according to a second preset interval angle, and repeating steps S1-S8; The step of establishing a first wind field model based on the three-dimensional model of the monomer structure includes: Taking the monomer structure three-dimensional model as a reference, establishing an entrance of the first wind field model at a first preset distance from the windward side of the monomer structure three-dimensional model, establishing an exit of the first wind field model at a second preset distance from the leeward side of the monomer structure three-dimensional model, and establishing boundaries of the first wind field model at third preset distances from both sides and above the monomer structure three-dimensional model respectively; The step of establishing a second wind field model based on the multi-body uniformly distributed array three-dimensional model includes: Taking the multi-body evenly distributed array three-dimensional model as a reference, the entrance of the second wind field model is established at a first preset distance from the windward side of the multi-body evenly distributed array three-dimensional model, the exit of the second wind field model is established at a second preset distance from the leeward side of the multi-body evenly distributed array three-dimensional model, and the boundaries of the second wind field model are established at third preset distances from both sides and above the multi-body evenly distributed array three-dimensional model.

2. The numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic support according to claim 1 is characterized in that: The step S4 comprises: S4.

1. In the first wind field model, select a first preset turbulence model; S4.

2. Set a first boundary condition for the first wind field model, where the first boundary condition includes: a first initial pressure and a first initial velocity; S4.

3. Based on the first preset turbulence model and the first boundary condition, perform numerical wind tunnel calculations using finite element analysis software to determine wind pressure parameters distributed on the photovoltaic panels of the three-dimensional model of the single structure; S4.4 determining a shape coefficient of the three-dimensional model of the single structure and a gust coefficient of the wind load in the first wind field model based on the wind pressure parameter; S4.

5. Based on the shape coefficient and the gust coefficient, perform strength verification on the photovoltaic bracket of the single-body three-dimensional model using the wind load statics equation.

3. The numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic support according to claim 2 is characterized in that: The strength check of the photovoltaic support of the single-structure three-dimensional model by using the wind load statics equation includes: Obtaining the structural strength of the photovoltaic support of the single-body three-dimensional model; Calculating the intensity of the wind load acting on the photovoltaic support in the first wind field model using the wind load statics equation; Based on the structural strength of the photovoltaic support and the strength of the wind load acting on the photovoltaic support, the photovoltaic support of the single-body three-dimensional model is strength-checked.

4. The numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic support according to claim 3 is characterized in that: The step S4 further includes: S4.

6. When the structural strength of the photovoltaic support in the three-dimensional model of the single structure is lower than the strength of the wind load acting on the photovoltaic support, strengthen the structural strength of the photovoltaic support in the three-dimensional model of the single structure.

5. The numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic support according to claim 1 is characterized in that: The step S7 comprises: S7.

1. In the second wind field model, select a second preset turbulence model; S7.

2. Set a second boundary condition for the second wind field model, where the second boundary condition includes: a second initial pressure and a second initial velocity; S7.

3. Based on the second preset turbulence model and the second boundary condition, perform numerical wind tunnel calculations using finite element analysis software to determine the transition flow characteristics between any two adjacent three-dimensional models of the single-body structure in the multi-body uniformly distributed array three-dimensional model; S7.

4. Determine whether resonance occurs between any two adjacent three-dimensional models of the monomer structure according to the transition flow characteristics.

6. The numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic support according to claim 5 is characterized in that: The determining, based on the transition flow characteristics, whether resonance occurs between any two adjacent three-dimensional models of the monomer structure includes: determining an oscillation frequency of the transition flow according to the transition flow characteristics; Performing modal analysis on any two adjacent three-dimensional models of the monomer structure in the multi-body uniformly distributed array three-dimensional model using finite element analysis software to determine the vibration frequency corresponding to the free vibration mode of any two adjacent three-dimensional models of the monomer structure; In a case where the oscillation frequency of the transitional flow is the same as the vibration frequency corresponding to the free vibration mode, it is determined that resonance occurs between any two adjacent three-dimensional models of the monomer structure.

7. The numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic support according to claim 6 is characterized in that: The step S7 further includes: S7.

5. When it is determined that resonance occurs between any two adjacent three-dimensional models of the monomer structure, modify the structural parameters of the photovoltaic support of the two adjacent three-dimensional models of the monomer structure.

8. The numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic support according to claim 1 is characterized in that: The first initial angle is 5 degrees, the first preset interval angle is 5 degrees, and adjusting the first initial angle according to the first preset interval angle includes: Taking the first initial angle of 5 degrees as a reference, and according to the first preset interval angle of 5 degrees, the first initial angle is adjusted to 10 degrees, 15 degrees, 20 degrees, 25 degrees, and 30 degrees respectively.

9. The numerical wind tunnel analysis method for a mid-span adjustable tilt flexible photovoltaic support according to claim 1, characterized in that: The second initial angle is 0 degrees, the second preset interval angle is 15 degrees, and adjusting the second initial angle according to the second preset interval angle includes: Taking the second initial angle of 0 degrees as a reference, and according to the second preset interval angle of 15 degrees, the second initial angle is adjusted to 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees, 90 degrees, 105 degrees, 120 degrees, 135 degrees, 150 degrees, 165 degrees, and 180 degrees respectively.

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