A design method for constructing a uniform concentrator for a plate-shaped absorber based on planar reflective units

Abstract

This invention relates to a design method for constructing a uniform concentrator for a plate-shaped absorber based on planar reflector units, belonging to the field of solar photovoltaic and photothermal technology. The uniform concentrator of this invention includes a solar photovoltaic panel and planar reflectors. The planar reflectors are symmetrically and obliquely arranged on both sides of the solar photovoltaic panel to uniformly reflect sunlight incident on the planar reflectors and cover the entire light-receiving surface of the solar photovoltaic panel. Initial design parameters are obtained, a mathematical model of the geometric relationship of each planar reflector in the uniform concentrator is established, and the structural parameters (angle α) of each planar reflector are calculated. n Inclination angle β n and width D n Using the ray tracing software Tracepro, the landing point of light rays on a concentrator model constructed based on a mathematical model was simulated to verify the reliability of the mathematical model. Using the ray tracing software Tracepro, the energy flux density distribution on the surface of a solar photovoltaic panel was simulated under the condition of perpendicular sunlight incident at an incident angle of 0° to verify its uniformity.

Description

Technical Field

[0001] This invention relates to a design method for constructing a uniform concentrator for a plate-shaped absorber based on a planar reflective unit, belonging to the field of solar photovoltaic and photothermal technology. Background Technology

[0002] Solar concentrators increase energy flux density per unit area by focusing sunlight, which is significant for improving photovoltaic power generation efficiency, increasing photothermal conversion temperature, and reducing the cost of solar energy utilization systems. In fields such as photovoltaic / photothermal integration (PV / T), compact and easily integrated flat-plate absorbers show promising application prospects. However, traditional concentrators used with fixed flat-plate absorbers generally suffer from a key drawback: the concentrated light spot is extremely unevenly distributed on the absorber surface. This typically manifests as excessively high energy flux density in the central region and insufficient light intensity in the peripheral regions.

[0003] This unevenness in light distribution has serious consequences: For the photovoltaic component, localized hot spots cause a sharp increase in cell temperature, resulting in a significant decrease in photoelectric conversion efficiency and easily inducing the "hot spot effect," leading to permanent cell damage and safety hazards. For the photothermal or PV / T components, extremely high localized heat loads accelerate material aging, generate thermal stress, and cause component deformation or even cracking, severely impairing the long-term reliability and overall performance of the system. To avoid such damage, systems are often forced to reduce the concentration ratio or adopt complex and expensive cooling solutions, greatly limiting the optimization space for efficiency and cost.

[0004] In existing technologies, solutions such as complex curved surface concentrator designs or moving the absorber have been proposed to improve the uniformity of light concentration. However, these methods generally suffer from problems such as high processing difficulty, high manufacturing cost, complex system structure, introduction of additional optical losses, or impact on heat dissipation reliability. Therefore, developing a concentrator structure design method that can achieve a highly uniform energy flux density distribution on the surface of a flat plate absorber, while also being simple in structure and low in cost, has become a key technical problem that urgently needs to be solved in the field of solar energy utilization. Summary of the Invention

[0005] To address the shortcomings of existing technologies, such as uneven energy flux density distribution on the surface of flat plate absorbers caused by concentrators, as well as complex structures and high costs, this invention provides a design method for constructing a uniform concentrator for a plate-shaped absorber based on planar reflector units. By establishing an accurate geometric optical mathematical model, the key structural parameters of each planar reflector are determined, ensuring that vertically incident sunlight can uniformly cover the entire surface of the solar photovoltaic panel after reflection.

[0006] A design method for constructing a uniform concentrator for a plate-shaped absorber based on a planar reflector unit, wherein the uniform concentrator includes a solar photovoltaic panel 1 and a planar reflector 2. The planar reflector 2 is obliquely and symmetrically arranged on both sides of the solar photovoltaic panel 1 to uniformly reflect the sunlight incident on the planar reflector 2 to cover the entire light-receiving surface of the solar photovoltaic panel 1.

[0007] The specific steps are as follows:

[0008] S1. Obtain initial design parameters: the number of single-sided plane mirrors is N, the solar photovoltaic panel is located at the lowest end, and the nth single-sided plane mirror is numbered 1, 2...N from bottom to top. The angle α1 between the lower end of the first plane mirror and the surface of the solar photovoltaic panel, the distance L between the lower end of the first plane mirror and the starting absorption point of the solar photovoltaic panel, and the width W of the solar photovoltaic panel.

[0009] S2. Based on the initial design parameters, establish a mathematical model of the geometric relationship between each plane mirror of the uniform concentrator, and calculate the structural parameters of each plane mirror; the structural parameters include the angle α between the lower end point of the nth plane mirror and the surface of the solar photovoltaic panel. n The tilt angle β of the nth plane mirror n and the width D of the nth plane mirror n ;

[0010] S3. Using the ray tracing software Tracepro, simulate the reflection path and landing point of sunlight perpendicularly incident (i.e., incident angle 0°) on a concentrator model constructed based on a mathematical model. Compare the simulated landing point with the theoretically predicted position of the mathematical model to verify the reliability of the mathematical model.

[0011] S4. Using the ray tracing software Tracepro, simulate the energy flux density distribution in different areas of the solar photovoltaic panel surface under the condition of perpendicular sunlight incidence (i.e., incident angle 0°). By analyzing the energy flux density distribution map, verify the uniformity of the energy flux density distribution.

[0012] Preferably, the mathematical model in step S2 is:

[0013] Taking the first plane mirror (n=1) as an example (see...) Figure 12 The derivation process is as follows:

[0014] Let α1 be the angle between the lower end of the first plane mirror and the surface of the solar photovoltaic panel, L be the distance between the lower end of the mirror and the starting absorption point of the solar photovoltaic panel, and W be the width of the solar photovoltaic panel.

[0015] When sunlight is incident perpendicularly, it needs to cover the entire light-receiving surface of the solar photovoltaic panel after being reflected by the first plane mirror. Let the lower end point of the mirror be C, the upper end point be D, and the left and right ends of the photovoltaic panel be A and B, respectively. Then the rays reflected from points C and D should fall on points A and B, respectively. From geometric relationships, we can obtain:

[0016] 1. Extend DC to intersect AB at point E, and let ∠CEF = β1, which is the tilt angle of the first plane mirror;

[0017] 2. According to the law of reflection, the angle of incidence and the angle of reflection are equal, therefore the angle of reflection nCB = β1;

[0018] 3. In triangle BCE, the formula for calculating β1 can be obtained by using the complementary angle relationship and trigonometric function formulas;

[0019] 4. Translate AB to GC. In triangle CDG, given CG=W, CD=D1, ∠DGC=α1, ∠CDG=β1–α1, we can solve for the expression of D1 using the Law of Sines.

[0020] Therefore, the mathematical model formula for n=1 is obtained:

[0021] ;

[0022] In the formula, W is the width of the solar photovoltaic panel, L is the distance between the lower end of the first plane mirror and the starting absorption point of the solar photovoltaic panel, α1 is the angle between the lower end of the first plane mirror and the surface of the solar photovoltaic panel, β1 is the tilt angle of the first plane mirror, and D1 is the width of the first plane mirror.

[0023] For mirrors n=2 and the nth mirror thereafter, the exact same geometric construction and derivation method can be used:

[0024] Use the upper end point of the previous reflector as the lower end point of this reflector;

[0025] Let the angle between the lower endpoint and the surface of the photovoltaic panel be α. n ;

[0026] Using the same geometric relationship as n=1, its inclination angle β is derived. n With width D n The calculation formula.

[0027] Therefore, when n=2, β2 and D2 can be deduced by analogy; the same applies when n≥3; the structural parameters of any nth plane mirror can be obtained through recursion.

[0028] When n=1, the mathematical model is:

[0029] ;

[0030] In the formula, W is the width of the solar photovoltaic panel, L is the distance between the lower end of the first plane mirror and the starting absorption point of the solar photovoltaic panel, α1 is the angle between the lower end of the first plane mirror and the surface of the solar photovoltaic panel, β1 is the tilt angle of the first plane mirror, and D1 is the width of the first plane mirror.

[0031] When n=2, the mathematical model is:

[0032] ;

[0033] In the formula, α2 is the angle between the lower end of the second plane mirror and the surface of the solar photovoltaic panel, β2 is the tilt angle of the second plane mirror, and D2 is the width of the second plane mirror.

[0034] When 3≤n≤N, the mathematical model is:

[0035] ;

[0036] In the formula, α n Let β be the angle between the lower end of the nth plane mirror and the surface of the solar photovoltaic panel. n Let D be the tilt angle of the nth plane mirror. n Let be the width of the nth plane mirror.

[0037] Preferably, the method for verifying the reliability of the mathematical model in step S3 is as follows: using the ray tracing software Tracepro, a ray tracing simulation is performed on the uniform concentrator model constructed according to the mathematical model under the condition of an incident angle of 0°, and the landing position of each ray on the absorption surface is recorded; the simulated landing point is compared point-to-point with the theoretically predicted landing point of the mathematical model, and the root mean square error (RMSE) and the maximum deviation (e) are calculated. max If RMSE ≤ 1 mm and e max If the value is ≤2mm, the mathematical model is deemed reliable; otherwise, the model is recalculated and simulated by adjusting the tilt angle (adjustment range is ±1°) and width (adjustment range is ±2mm) of the reflector until the judgment condition is met.

[0038] Preferably, the method for verifying the uniformity of energy flux density distribution in step S4 is as follows: Simulate the concentrator model constructed according to the mathematical model in Tracepro under the condition of an incident angle of 0° to obtain the energy flux density distribution on the absorption surface; calculate the average value of the energy flux density and compare it with the energy flux density at each point; if the deviation of the energy flux density of the entire region from the average value does not exceed ±10%, then the energy flux density distribution is considered uniform; otherwise, redesign by adjusting the tilt angle (adjustment range is ±1°) and width (adjustment range is ±2mm) parameters of the reflector until the judgment condition is met.

[0039] The beneficial effects of this invention are:

[0040] (1) The energy flow distribution of the present invention is highly uniform: by designing the layout and parameters of the plane mirror through a precise mathematical model, the serious problem of uneven light spot in the traditional plane mirror focusing system can be effectively eliminated, and the uniform distribution of energy flow density on the surface of the absorber can be achieved, thus completely avoiding the extremely harmful local "hot spot" phenomenon.

[0041] (2) The present invention improves performance and reliability: the uniform energy flow distribution significantly improves the power generation efficiency and service life of photovoltaic cells (avoiding hot spot effect), while reducing the risk of material aging, thermal stress and failure caused by local overheating of photothermal or PV / T modules, and improving the long-term operational reliability and comprehensive performance of the entire system.

[0042] (3) The present invention is easy to process and low in cost: the use of a standard plane mirror to replace the complex curved mirror greatly reduces the processing difficulty and manufacturing cost, which is conducive to large-scale commercial application and promotion;

[0043] (4) The invention has a simple and compact structure: the device has a simple structure, mainly consisting of a flat photovoltaic panel and a planar reflector array on both sides, which is easy to integrate and install. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the overall structure of a uniform concentrator;

[0045] Figure 2 A schematic diagram of the initial design parameters for a uniform concentrator;

[0046] Figure 3 A schematic diagram of the geometric parameters of a uniform concentrator when n=1;

[0047] Figure 4 When n=1, the Tracepro software was used to simulate the position of the light ray to verify the schematic diagram of the model (incident angle 0°).

[0048] Figure 5 The energy flux density distribution on the surface of a solar photovoltaic panel was simulated using Tracepro software when n=1 (incident angle 0°).

[0049] Figure 6 A schematic diagram of the geometric parameters of a uniform concentrator when n=2;

[0050] Figure 7 When n=2, the location of the light ray's impact point is simulated using Tracepro software to verify the schematic diagram of the model (incident angle 0°).

[0051] Figure 8 The energy flux density distribution on the surface of a solar photovoltaic panel was simulated using Tracepro software when n=2 (incident angle 0°).

[0052] Figure 9 A schematic diagram of the geometric parameters of a uniform concentrator when n=3;

[0053] Figure 10 When n=3, the Tracepro software was used to simulate the position of the light ray to verify the schematic diagram of the model (incident angle 0°).

[0054] Figure 11 The energy flux density distribution on the surface of a solar photovoltaic panel was simulated using Tracepro software when n=3 (incident angle 0°).

[0055] Figure 12 This is a schematic diagram illustrating the derivation of the mathematical model formula. Detailed Implementation

[0056] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0057] In this embodiment of the invention, the uniform concentrator includes a solar photovoltaic panel 1 and a plane reflector 2. The plane reflector 2 is obliquely and symmetrically arranged on both sides of the solar photovoltaic panel 1 to uniformly reflect sunlight incident on the plane reflector 2 and cover the entire light-receiving surface of the solar photovoltaic panel 1 (see...). Figure 1 ).

[0058] Example 1: Taking a single-sided planar reflector (n=1) as an example, a design method for constructing a uniform concentrator for a plate-shaped absorber based on a planar reflector unit (see...) Figure 2 and 3 The specific steps are as follows:

[0059] S1. Obtain initial design parameters: the number of single-sided plane mirrors is 1, the solar photovoltaic panel is located at the lowest end, the angle α1 between the lower end of the first plane mirror and the surface of the solar photovoltaic panel is 30°, the distance L between the lower end of the first plane mirror and the starting absorption point of the solar photovoltaic panel is 2mm, and the width of the solar photovoltaic panel is W=156mm; the design irradiance of the uniform concentrator is 1000W / m². 2 ;

[0060] S2. Based on the initial design parameters, establish a mathematical model of the geometric relationship between each plane mirror of the uniform concentrator, and calculate the structural parameters of each plane mirror; the structural parameters include the angle α1 between the lower end of the first plane mirror and the surface of the solar photovoltaic panel, the tilt angle β1 of the first plane mirror, and the width D1 of the first plane mirror;

[0061] When n=1, the mathematical model is:

[0062] ;

[0063] In the formula, W is the width of the solar photovoltaic panel, L is the distance between the lower end of the first plane mirror and the starting absorption point of the solar photovoltaic panel, α1 is the angle between the lower end of the first plane mirror and the surface of the solar photovoltaic panel, β1 is the tilt angle of the first plane mirror, and D1 is the width of the first plane mirror.

[0064] Calculations show that the tilt angle β1 of the first plane mirror is 60° and the width D1 is 156mm.

[0065] Based on the initial design parameters, the tilt angle β1 (60°) and width D1 (156mm) of the first planar reflector, a uniform concentrator model was accurately constructed in the 3D modeling software.

[0066] S3. Using the ray tracing software Tracepro, ray tracing simulations were performed on the uniform concentrator model constructed according to the mathematical model at an incident angle of 0°, recording the landing position of each ray on the absorption surface (see...). Figure 4 The simulated landing point is compared point-to-point with the theoretically predicted landing point of the mathematical model, and the root mean square error RMSE (0.66 mm) and the maximum deviation e are calculated. max (1.64mm); According to the mathematical model reliability judgment method, that is, if RMSE≤1mm and e max If the error is ≤2mm, the mathematical model is considered reliable; otherwise, the model is recalculated and simulated by adjusting parameters such as the reflector tilt angle (±1° allowed) and width (±2mm allowed) until the judgment condition is met. Therefore, in this embodiment, the root mean square error RMSE (0.66mm) is ≤1mm and e max (1.64mm)≤2mm, its mathematical model is reliable;

[0067] S4. Simulate the concentrator model constructed according to the mathematical model in Tracepro under the condition of 0° incident angle to obtain the energy flux density distribution on the absorption surface (see...). Figure 5 ); calculate the average energy flux density (average energy flux density is 1.89 kW / m³). 2 And compare it with the energy flux density at each point; according to the method for judging the uniformity of energy flux density distribution, if the energy flux density of the whole area deviates from the average value by no more than ±10%, then the energy flux density distribution is considered uniform; otherwise, redesign by adjusting parameters such as the tilt angle of the reflector (allowed adjustment ±1°) and the width (allowed adjustment ±2mm) until the judgment condition is met;

[0068] In this embodiment, the energy flux density of all regions deviates from the average value by 4.8%, which is less than the threshold of 10%. Therefore, the energy flux density distribution on the absorption surface in this embodiment is uniform.

[0069] Example 2: Taking a single-sided arrangement of two planar mirrors (n=2) as an example, a design method for constructing a uniform concentrator for a plate-shaped absorber based on planar reflective units (see...) Figure 6 The specific steps are as follows:

[0070] S1. Obtain initial design parameters: the number of single-sided plane mirrors is 2, the solar photovoltaic panel is located at the lowest end, and the single-sided plane mirrors are numbered 1 and 2 from bottom to top. The angle α1 between the lower end of the first plane mirror and the surface of the solar photovoltaic panel is 34.4°, the distance L between the lower end of the first plane mirror and the starting absorption point of the solar photovoltaic panel is 2mm, and the width of the solar photovoltaic panel is W=156mm; the design irradiance of the uniform concentrator is 1000W / m². 2 ;

[0071] S2. Based on the initial design parameters, establish a mathematical model of the geometric relationship between each plane mirror of the uniform concentrator, and calculate the structural parameters of each plane mirror; the structural parameters include the angle α between the lower end point of the nth (n=1 and 2) plane mirror and the surface of the solar photovoltaic panel. n The tilt angle β of the nth plane mirror n and the width D of the nth plane mirror n ;

[0072] When n=1, the mathematical model is:

[0073] ;

[0074] In the formula, W is the width of the solar photovoltaic panel, L is the distance between the lower end of the first plane mirror and the starting absorption point of the solar photovoltaic panel, α1 is the angle between the lower end of the first plane mirror and the surface of the solar photovoltaic panel, β1 is the tilt angle of the first plane mirror, and D1 is the width of the first plane mirror.

[0075] When n=2, the mathematical model is:

[0076] ;

[0077] In the formula, α2 is the angle between the lower end of the second plane mirror and the surface of the solar photovoltaic panel, β2 is the tilt angle of the second plane mirror, and D2 is the width of the second plane mirror.

[0078] The specific values ​​of the tilt angle β1 (62.2°) and width D1 (189.3mm) of the first plane mirror were obtained through calculation. At the same time, the position of the upper end point of the first plane mirror was calculated, and the angle α2 (61.9°) between the lower end point of the second plane mirror and the surface of the solar photovoltaic panel was determined. Based on the angle α2 (61.9°) between the lower end point of the second plane mirror and the surface of the solar photovoltaic panel, the tilt angle β2 (76.0°) of the second plane mirror was calculated, and D2 was the width D2 (567.8mm) of the second plane mirror.

[0079] Based on the initial design parameters, the tilt angle β1 (62.2°) and width D1 (189.3mm) of the first plane mirror, and the angle α2 (61.9°), tilt angle β2 (76.0°), and width D2 (567.8mm) between the lower end of the second plane mirror and the surface of the solar photovoltaic panel, a uniform concentrator model was accurately constructed in the 3D modeling software.

[0080] S3. Using the ray tracing software Tracepro, a ray tracing simulation was performed on the uniform concentrator model constructed according to the mathematical model at an incident angle of 0°. The landing position of each ray on the absorption surface was recorded (see...). Figure 7 The simulated landing point is compared point-to-point with the theoretically predicted landing point of the mathematical model, and the root mean square error RMSE (0.32 mm) and the maximum deviation e are calculated. max (1.08mm); According to the mathematical model reliability judgment method, that is, if RMSE≤1mm and e max If the error is ≤2mm, the mathematical model is deemed reliable; otherwise, the model is recalculated and simulated by adjusting parameters such as the reflector tilt angle (±1° allowed) and width (±2mm allowed) until the judgment condition is met. Therefore, in this embodiment, the root mean square error RMSE (0.32mm) is ≤1mm and e max (1.08mm)≤2mm, its mathematical model is reliable;

[0081] S4. Simulate the concentrator model constructed according to the mathematical model in Tracepro under the condition of 0° incident angle to obtain the energy flux density distribution on the absorption surface (see...). Figure 8 ); calculate the average energy flux density (average energy flux density is 2.75 kW / m³). 2 And compare it with the energy flux density at each point; according to the method for judging the uniformity of energy flux density distribution, if the energy flux density of the whole area deviates from the average value by no more than ±10%, then the energy flux density distribution is considered uniform; otherwise, redesign by adjusting parameters such as the tilt angle of the reflector (allowed adjustment ±1°) and the width (allowed adjustment ±2mm) until the judgment condition is met;

[0082] In this embodiment, the energy flux density of all regions deviates from the average value by 0.4%, which is less than the threshold of 10%. Therefore, the energy flux density distribution on the absorption surface in this embodiment is uniform.

[0083] Example 3: Taking a single-sided arrangement of three planar mirrors (n=3) as an example, a design method for constructing a uniform concentrator for a plate-shaped absorber based on planar reflective units (see...) Figure 9 The specific steps are as follows:

[0084] S1. Obtain initial design parameters: the number of single-sided plane mirrors is 3, the solar photovoltaic panel is located at the lowest end, and the single-sided plane mirrors are numbered 1, 2, and 3 from bottom to top. The angle α1 between the lower end of the first plane mirror and the surface of the solar photovoltaic panel is 10°, the distance L between the lower end of the first plane mirror and the starting absorption point of the solar photovoltaic panel is 2mm, and the width of the solar photovoltaic panel is W=156mm; the design irradiance of the uniform concentrator is 1000W / m². 2 ;

[0085] S2. Based on the initial design parameters, establish a mathematical model of the geometric relationship between each plane mirror of the uniform concentrator, and calculate the structural parameters of each plane mirror; the structural parameters include the angle α between the lower end point of the nth (n=1, 2, and 3) plane mirror and the surface of the solar photovoltaic panel. n The tilt angle β of the nth plane mirror n and the width D of the nth plane mirror n ;

[0086] When n=1, the mathematical model is:

[0087] ;

[0088] In the formula, W is the width of the solar photovoltaic panel, L is the distance between the lower end of the first plane mirror and the starting absorption point of the solar photovoltaic panel, α1 is the angle between the lower end of the first plane mirror and the surface of the solar photovoltaic panel, β1 is the tilt angle of the first plane mirror, and D1 is the width of the first plane mirror.

[0089] When n=2, the mathematical model is:

[0090] ;

[0091] In the formula, α2 is the angle between the lower end of the second plane mirror and the surface of the solar photovoltaic panel, β2 is the tilt angle of the second plane mirror, and D2 is the width of the second plane mirror.

[0092] When n=3, the mathematical model is:

[0093] ;

[0094] In the formula, α3 is the angle between the lower end of the third plane mirror and the surface of the solar photovoltaic panel, β3 is the tilt angle of the third plane mirror, and D3 is the width of the third plane mirror.

[0095] Calculations yielded the specific values ​​of the tilt angle β1 (50°) and width D1 (42.14 mm) of the first plane mirror. Simultaneously, the position of the upper end of the first plane mirror was calculated, and the angle α2 (48.31°) between the lower end of the second plane mirror and the surface of the solar photovoltaic panel was determined. Based on this angle α2 (48.31°), the tilt angle β2 (69.16°) of the second plane mirror was calculated. D2 is the first... The width of the two plane mirrors is D2 (327.38 mm). At the same time, the position of the upper end of the second plane mirror is calculated, the angle α3 (66.74°) between the lower end of the third plane mirror and the surface of the solar photovoltaic panel is determined, and the tilt angle β3 (78.37°) of the third plane mirror is calculated based on the angle α3 (66.74°) between the lower end of the third plane mirror and the surface of the solar photovoltaic panel. D3 is the width of the third plane mirror D3 (711.08 mm).

[0096] Based on the initial design parameters, the tilt angle β1 (50°) and width D1 (42.14 mm) of the first plane mirror, the angle α2 (48.31°), tilt angle β2 (69.16°), and width D2 (327.38 mm) between the lower end of the second plane mirror and the surface of the solar photovoltaic panel, and the angle α3 (66.74°), tilt angle β3 (78.37°), and width D3 (711.08 mm) between the lower end of the third plane mirror and the surface of the solar photovoltaic panel, a uniform concentrator model is accurately constructed in 3D modeling software;

[0097] S3. Using the ray tracing software Tracepro, a ray tracing simulation was performed on the uniform concentrator model constructed according to the mathematical model at an incident angle of 0°. The landing position of each ray on the absorption surface was recorded (see...). Figure 10 The simulated landing point is compared point-to-point with the theoretically predicted landing point of the mathematical model, and the root mean square error RMSE (0.73 mm) and the maximum deviation e are calculated. max (1.21mm); According to the mathematical model reliability judgment method, that is, if RMSE≤1mm and e max If the error is ≤2mm, the mathematical model is considered reliable; otherwise, the model is recalculated and simulated by adjusting parameters such as the reflector tilt angle (±1° allowed) and width (±2mm allowed) until the judgment condition is met. Therefore, in this embodiment, the root mean square error RMSE (0.73mm) is ≤1mm and e max(1.21mm)≤2mm, its mathematical model is reliable;

[0098] S4. Simulate the concentrator model constructed according to the mathematical model in Tracepro under the condition of 0° incident angle to obtain the energy flux density distribution on the absorption surface (see...). Figure 11 ); Calculate the average energy flux density (average energy flux density is 4.20 kW / m³). 2 And compare it with the energy flux density at each point; according to the method for judging the uniformity of energy flux density distribution, if the energy flux density of the whole area deviates from the average value by no more than ±10%, then the energy flux density distribution is considered uniform; otherwise, redesign by adjusting parameters such as the tilt angle of the reflector (allowed adjustment ±1°) and the width (allowed adjustment ±2mm) until the judgment condition is met;

[0099] In this embodiment, the energy flux density of all regions deviates from the average value by 5.2%, which is less than the threshold of 10%. Therefore, the energy flux density distribution on the absorption surface in this embodiment is uniform.

[0100] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for designing a homogenizer for a plate-shaped absorber based on a planar reflective unit, characterized in that, The uniform concentrator comprises a solar photovoltaic panel (1) and plane mirrors (2) symmetrically arranged on both sides of the solar photovoltaic panel (1) to uniformly reflect the sunlight incident on the plane mirrors (2) to the entire light-receiving surface of the solar photovoltaic panel (1). The specific steps are as follows: S1. Obtain initial design parameters, the number of single-sided plane mirrors is N, the solar photovoltaic panel is located at the lowest end, the serial numbers of the single-sided nth plane mirror from bottom to top are 1, 2, …, N, the angle between the lower end point of the first plane mirror and the surface of the solar photovoltaic panel is α1, the distance between the lower end point of the first plane mirror and the starting absorption point of the solar photovoltaic panel is L, and the width of the solar photovoltaic panel is W; S2. Based on the initial design parameters, a mathematical model of the geometric relationship of each block plane mirror of the uniform concentrator is established, and the structure parameters of each plane mirror are calculated; the structure parameters include the included angle α between the lower end point of the nth plane mirror and the surface of the solar photovoltaic panel n , the inclination angle β of the nth plane mirror n , and the width D of the nth plane mirror n ; S3. Use the light ray tracing software Tracepro to simulate the reflection path and landing point position of the sunlight on the concentrator model constructed according to the mathematical model under the condition of vertical incidence, i.e. an incident angle of 0°, compare the simulated landing point position with the theoretically predicted position according to the mathematical model, and verify the reliability of the mathematical model; S4. Use the light ray tracing software Tracepro to simulate the energy flux density distribution of each region of the solar photovoltaic panel surface under the condition of vertical incidence, i.e. an incident angle of 0°, and verify the uniformity of the energy flux density distribution by analyzing the energy flux density distribution diagram; The mathematical model in step S2 is: When n=1, the mathematical model is: ； In the formula, W is the width of the solar photovoltaic panel, L is the distance between the lower end point of the first plane mirror and the starting absorption point of the solar photovoltaic panel, α1 is the angle between the lower end point of the first plane mirror and the surface of the solar photovoltaic panel, β1 is the inclination angle of the first plane mirror, and D1 is the width of the first plane mirror; When n=2, the mathematical model is: ； In the formula, α2 is the angle between the lower end point of the second plane mirror and the surface of the solar photovoltaic panel, β2 is the inclination angle of the second plane mirror, and D2 is the width of the second plane mirror; When 3≤n≤N, the mathematical model is: ； In the formula, α n is the angle between the lower end point of the nth flat mirror and the surface of the solar photovoltaic panel, β n is the inclination angle of the nth flat mirror, D n is the width of the nth flat mirror.

2. The method for designing a uniform condenser for a plate-shaped absorber based on a planar reflective unit according to claim 1, characterized in that: The method for verifying the reliability of the mathematical model in step S3 is: In step S3, the light ray tracing software Tracepro is used to simulate the light ray tracing of the uniform condenser model constructed according to the mathematical model under the condition that the incident angle is 0°, and the landing position of each light ray on the absorption surface is recorded; the simulated landing points are compared with the theoretically predicted landing points of the mathematical model point by point, and the root mean square error RMSE and the maximum deviation e max are calculated; if the root mean square error RMSE is less than or equal to 1 mm and the maximum deviation e max is less than or equal to 2 mm, it is determined that the mathematical model is reliable; otherwise, the mirror inclination angle and width parameters are adjusted to recalculate and simulate until the determination condition is met.

3. The method for designing a uniform condenser for a plate-shaped absorber based on a planar reflective unit according to claim 1, characterized in that: The method for verifying the uniformity of the energy flux density distribution in step S4 is: In step S4, the concentrator model constructed according to the mathematical model is simulated in Tracepro under the condition of an incident angle of 0°, the energy flux density distribution on the absorption surface is obtained, the average value of the energy flux density is calculated, and compared with the energy flux density of each point; if the deviation of the energy flux density of all regions from the average value is not more than ±10%, the energy flux density distribution is considered to be uniform; otherwise, the mirror inclination angle and width parameters are adjusted for redesign until the above determination condition is met.

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