An optimization design method for photovoltaic sunshade at the entrance of a high-speed tunnel

Abstract

The invention discloses an optimization design method for a photovoltaic awning at a high-speed tunnel entrance, which specifically relates to the field of tunnel engineering, and the specific steps are as follows: selecting tunnel entrance and exit test data; constructing a tunnel actual vehicle test and a tunnel entrance illumination change threshold function model according to the selected tunnel entrance and exit test data, and obtaining a reasonable illumination change threshold for the tunnel entrance and exit; using Ecotect Analysis to simulate the light environment model of the photovoltaic awning at the tunnel entrance and exit, and using a mathematical evaluation model to obtain the best tunnel entrance and exit photovoltaic awning design scheme; using the TOPSIS comprehensive evaluation method, and evaluating the relative advantages and disadvantages of various design schemes of the tunnel entrance and exit photovoltaic awning according to the selected evaluation indicators, and obtaining the optimal scheme.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering, and in particular to an optimization design method for a photovoltaic sunshade for a high-speed tunnel entrance. Background Art

[0002] Tunnels have the advantages of shortening mileage and improving transportation efficiency. Therefore, in the case of limited development of mountain highways, tunnel construction plans have been widely adopted. However, the frequent traffic accidents on highway tunnel (group) sections have always been a pain point in its development process. According to surveys, the drastic changes in the light environment at the tunnel entrance can easily cause visual and psychological discomfort to drivers, and easily cause drivers to make mistakes and cause traffic accidents. At present, the tunnel entrance and exit light reduction measures that are widely used in actual projects mainly include: landscape greening light reduction, positive and negative bamboo door openings, sunshades and awnings.

[0003] The traditional sunshade at the entrance of a high-speed tunnel mainly has the following disadvantages:

[0004] (1) When the driver exits the tunnel, there will be a brief period of visual blindness, i.e., the "white hole effect". When the driver enters the tunnel, there will be a "black hole effect". For example, the photovoltaic panels in document CN111648784A are laid evenly rather than evenly and gradually, which makes the sunshade effect of the awning more dependent on the light-transmitting plate, and the refraction effect of the light-transmitting plate will change with the length of use, thereby reducing the actual sunshade effect of the awning.

[0005] (2) It is unable to adapt to and alleviate sudden changes in illumination inside and outside the tunnel. Moreover, most dimming structures only consider the tunnel entrance and lack the analysis of the visual adaptation of drivers of different types of vehicles. The research on photovoltaic power supply in tunnels is relatively single-minded, and does not combine photovoltaic power generation technology with dimming structures at the tunnel entrance, nor does it consider the impact of their superposition and coupling effects on the light environment.

[0006] (3) When designing the length parameters, there are many subjective factors, and a reasonable length analysis is not conducted in combination with the dimming transition effect.

[0007] (4) There is no research on the segmentation of the light environment of the awning, so the light intensity inside the awning cannot be changed continuously and evenly, and the actual effect is poor.

[0008] (5) The geographical location of the tunnel and the angle of sunlight were not taken into consideration, resulting in excessive waste in laying photovoltaic panels, which had mediocre effects but increased the economic cost of construction. Summary of the invention

[0009] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an optimized design method for photovoltaic awnings at the entrance of a high-speed tunnel, providing the best awning design scheme to adapt to the transition between light and dark; the innovative structure of the awning solves the problem of cumbersome installation and inability to replace it in time, and the entire device is simplified, the installation process is simple, and the shading effect can be effectively improved.

[0010] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0011] An embodiment of the present invention provides a method for optimizing the design of a photovoltaic sunshade at a high-speed tunnel entrance, and the specific steps are as follows:

[0012] Select the tunnel entrance and exit test data;

[0013] According to the selected tunnel entrance and exit test data, the tunnel vehicle test and the tunnel entrance illumination change threshold function model are constructed to obtain the reasonable illumination change threshold of the tunnel entrance and exit;

[0014] Ecotect Analysis was used to simulate the light environment model of the photovoltaic sunshade at the tunnel entrance and exit, and the mathematical evaluation model was used to obtain the optimal design scheme of the photovoltaic sunshade at the tunnel entrance and exit;

[0015] The TOPSIS comprehensive evaluation method was used to evaluate the relative advantages and disadvantages of various design schemes for photovoltaic awnings at tunnel entrances and exits according to the selected evaluation indicators to obtain the optimal scheme.

[0016] As a further implementation method, the tunnel entrance and exit test data selection includes illumination data and pupil area data; illumination data collection requires repeated measurement three times at different cross-sectional positions at each data collection point, and the average value is taken as the illumination value at that location.

[0017] As a further implementation method, the tunnel entrance illumination change threshold function model is:

[0018] S=e 10.958 E -0.387

[0019]

[0020]

[0021] Where, ω is the change rate of the driver’s pupil area at time i; S i ——The pupil area of ​​the driver at time i, the rate of change of ambient illumination at time ε-i, and the ambient illumination value at time Ei-i.

[0022] As a further implementation method, the spacing distance of each steel arch frame is set, the inclination angle of the photovoltaic panel is set, the light reflectivity of the tunnel side wall, tunnel top wall and photovoltaic panel material is determined, the geographic location parameters and lamp arrangement interval data parameters are input, and the model is built according to the actual size of the tunnel at a ratio of 1:1.

[0023] As a further implementation, the mathematical evaluation model includes a tunnel entrance photovoltaic awning foundation length model, as follows:

[0024]

[0025] T=0.0204*[E out -E in ] A

[0026] Where: T—the time required for the driver’s vision to recover at the tunnel entrance, E out —Tunnel exterior illumination, E in —Tunnel interior illumination, D th — Length of tunnel entrance section, D tr — Length of tunnel transition section, V t —Tunnel design speed, A-factor, ranges from 0.5 to 0.7.

[0027] As a further implementation method, the first area ratio, second area ratio and third area ratio of the area occupied by the photovoltaic panels in the initial section of the photovoltaic awnings at the tunnel entrance and exit are respectively combined with the light transmittance of the first visor, the light transmittance of the second visor and the light transmittance of the third visor, and the light environment simulation is performed to calculate the corresponding maximum illumination change rate of each combination. When the maximum illumination change rate is within the reasonable ambient illumination change threshold, the parameter values ​​of the awning model are obtained.

[0028] As a further implementation method, the illumination uniformity coefficient k and the total length l of the photovoltaic awning are 总 , Solar equivalent radiation photovoltaic area s 光 The three-dimensional attribute indicators are used to comprehensively evaluate the scheme, find the optimal solution, and determine the photovoltaic panel area ratio σ, the visor transmittance ρ and the length l of each section of the photovoltaic awning at the tunnel entrance and exit.

[0029] As a further implementation method, before using TOPSIS to evaluate the advantages and disadvantages of various parameter design schemes of photovoltaic awnings at tunnel entrances and exits, different weights are assigned to each evaluation index according to its importance through the hierarchical analysis method.

[0030] As a further implementation method, a forward-oriented data matrix is ​​obtained through each evaluation index, and the forward-oriented data matrix is ​​standardized to obtain a standardized matrix, and the maximum and minimum values ​​of each index in the standardized matrix are used to calculate the optimal solution vector and the worst solution vector.

[0031] As a further implementation method, the optimal solution vector and the worst solution vector calculate the Euclidean distance between each evaluation scheme and the optimal solution and the worst solution, and calculate the relative closeness S of each evaluation scheme to the optimal solution through the Euclidean distance and the weight of each indicator. i , closeness S i The closer it is to 1, the better the solution.

[0032] The beneficial effects of the present invention are as follows:

[0033] (1) The optimization method of the present invention takes into account the tunnel entrance and the visual adaptability of drivers of different vehicle models; considers the segmentation of the light environment of the awning; and can achieve the design of the optimal awning that can achieve continuous and uniform changes in the light intensity at the tunnel entrance and exit, which can significantly improve the visual and psychological discomfort caused by the sudden change of the light environment at the entrance and exit of the highway tunnel.

[0034] (2) The present invention is arranged at the entrance and exit of a high-speed tunnel and can serve as a transition section between the external road and the tunnel road, so that the cross-sectional dimensions of the external road and the cross-sectional dimensions of the tunnel opening are transitioned in advance, thereby alleviating the psychological and physiological discomfort caused by the sudden change in lateral width to the driver.

[0035] (3) The present invention comprehensively considers geographical factors and the angle of sunlight exposure, uses simulation software to determine the optimal inclination position of the photovoltaic panels of the photovoltaic awning, and designs a tunnel photovoltaic awning that receives the highest solar radiation and generates the most electricity.

[0036] (4) Based on the reasonable threshold of the change in ambient light intensity and the physical model of the tunnel awning light environment simulation, the present invention designs a tunnel photovoltaic awning that satisfies the driver's visual and psychological adaptation in terms of the total length of the awning, the bottom hollow height, the number of sections, the length of each awning section, the proportion of solar photovoltaic panels in the area of ​​each awning section, and the light transmittance of each awning section. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0038] Figure 1 is a schematic diagram of the overall structure of the present invention according to one or more embodiments;

[0039] Among them, 1. Skeleton; 2. Photovoltaic panels; 3. Translucent panels; 4. Shadows; 5. Highways; 6. Mountains; 7. Tracks; 8. The sun. DETAILED DESCRIPTION

[0040] Embodiment 1:

[0041] like Figure 1 As shown, an embodiment of the present invention provides a method for optimizing the design of a photovoltaic sunshade at a high-speed tunnel entrance, and the specific steps are as follows:

[0042] Selection of real vehicle test data on driver's visual psychological adaptation at tunnel entrances and exits;

[0043] Construct tunnel vehicle test and tunnel entrance illumination change threshold function model to obtain reasonable illumination change threshold of tunnel entrance and exit;

[0044] Ecotect Analysis was used to simulate the light environment model of the photovoltaic sunshade at the tunnel entrance and exit, and the mathematical evaluation model was used to obtain the optimal design scheme of the photovoltaic sunshade at the tunnel entrance and exit;

[0045] The TOPSIS comprehensive evaluation method was used to evaluate the relative advantages and disadvantages of various design schemes for photovoltaic awnings at tunnel entrances and exits according to the selected evaluation indicators to obtain the optimal scheme.

[0046] The actual vehicle test data of the driver's visual psychological adaptation at the tunnel entrance and exit in the step 1 includes illumination data and pupil area data; the illumination data collection needs to be repeated three times at each data collection point at different cross-sectional positions, and the average value is taken as the illumination value at that location.

[0047] In the step 2, the tunnel entrance illumination change threshold function model is:

[0048] S=e 10.958 E -0.387 (Tunnel entrance)

[0049]

[0050]

[0051] Where, ω is the change rate of the driver’s pupil area at time i (%); S i ——The driver’s pupil area at time i (px), the ambient illumination change rate at time ε-i, and the ambient illumination value at time Ei-i;

[0052] When driving at the entrance of a tunnel, when the pupil area changes by 20%, the driver feels comfortable; when the pupil area changes by 20% by 40%, the driver feels nervous; when the pupil area changes by 40%, the driver feels very nervous. In addition, since 0.2s is the smallest time interval for the human eye to perceive light and dark, the illumination change rate corresponding to the pupil area change rate of 20% within 0.2s is used as the threshold of environmental illumination change that satisfies the driver's smooth transition at the entrance and exit of the tunnel.

[0053] Therefore, in this embodiment, the illumination change rate corresponding to the driver's pupil area change rate of 20% within 0.2s is used as the ambient illumination change threshold that satisfies the driver's smooth transition at the tunnel entrance and exit. It can be obtained that the ambient illumination change rate ε at the tunnel entrance does not exceed 37.5%, and the ambient illumination change rate ε at the tunnel exit does not exceed 140%.

[0054] In the step three, the photovoltaic awning light environment simulation model is constructed by first constructing a steel arch skeleton model. In this embodiment, the model is built based on the size of the Jiwei (Jinan-Weifang) high-speed tunnel group in Shandong Province, and the three-dimensional drawing function in AutoCAD is used to establish a 1:1 three-dimensional steel arch skeleton model with a limited clearance height of 5.00m and a limited clearance width of 15.25m.

[0055] Furthermore, the interval of the steel arch frame is set according to the distance that the driver travels within the shortest light and dark perception time. Specifically, the maximum speed of small passenger cars on the highway shall not exceed 120 kilometers per hour, and other motor vehicles shall not exceed 100 kilometers per hour. The minimum light and dark perception time interval of the human eye is 0.2s, and the design speed of Jiwei Expressway is 120km / h. Therefore, the distance traveled by a small car in the shortest visual stimulation time is 6.6m, and the distance traveled by a large car is 5.5m, so the interval of the steel arch frame is set to 5.5m.

[0056] The tunnel photovoltaic awning is a general awning with solar photovoltaic panels. The photovoltaic panels can absorb sunlight to reduce the illumination in the awning, and can also convert solar energy into electricity, which is then integrated through the inverter to supply the tunnel lighting, ventilation, fire protection and other systems. However, the setting angle of the photovoltaic panels on the awning will affect the light intensity of different lanes in the awning, resulting in great differences in the changing rules of light intensity in each lane. Therefore, the setting angle of the photovoltaic panels needs to be determined before establishing the tunnel photovoltaic awning model.

[0057] Since my country is located in the northern hemisphere, it is impossible for sunlight to shine vertically from above to the sunshade of the Jiwei Expressway Tunnel. Instead, it will shine from south to north. However, the incident angle (i.e., the solar altitude angle) will change with the earth's revolution throughout the year. The law of change is: as time passes from the winter solstice (sunlight directly hits the Tropic of Capricorn) to the summer solstice (sunlight directly hits the Tropic of Cancer), the incident angle of sunlight gradually increases, and as time passes from the summer solstice to the winter solstice, the incident angle of sunlight will gradually decrease. The calculation method of the solar altitude angle is:

[0058]

[0059] Where: a——sun altitude angle; ——Geographic latitude of the project location; φ——Geographic latitude of the direct sun point. Note: The formula depends on whether the project location and the direct sun point are in the same hemisphere. If so, take -, otherwise take +. For this reason, if photovoltaic panels are placed on the awning to absorb solar energy and generate electricity, the photovoltaic panels should be tilted to the south at a certain angle.

[0060] After the photovoltaic power generation system is built, the amount of light radiation received by the photovoltaic panels determines the amount of power generated. The principle followed in determining the specific angle of the photovoltaic panels to the south is to maximize the annual power generation of the photovoltaic panels arranged on the awning. Since the solar altitude angle will continue to change with the revolution of the earth, it is difficult to obtain the installation angle when the photovoltaic panels receive the maximum annual light radiation through conventional calculation methods. Therefore, professional photovoltaic system design simulation software PVsyst is needed here for simulation calculation. Before simulation, it is necessary to obtain regional meteorological and annual solar radiation data.

[0061] Due to weather and other reasons, it is difficult to determine the daily light radiation in each region. In order to reduce errors, the average value of solar radiation data from each region for many years (at least 10 years, preferably more than 20 years) should be used. This study uses the software Meteonorm to obtain relevant data.

[0062] The PVsyst photovoltaic software was used to simulate and calculate the plane radiation received by the components of the regional photovoltaic power generation system at different installation inclinations. The results show that as the inclination increases, the plane radiation received by the photovoltaic components also increases. When the inclination reaches 30, the plane radiation received by the photovoltaic system also reaches the maximum value. Therefore, the optimal installation inclination angle of the awning photovoltaic panel is selected as 30 degrees south.

[0063] In addition to the spacing distance of each steel arch frame and the inclination angle parameters of the photovoltaic panels, it is also necessary to determine the light reflectivity of the tunnel side walls, tunnel top walls and photovoltaic panel materials, geographical location parameters and lamp layout spacing data parameters, and then build a model according to the actual size of the tunnel at a 1:1 ratio.

[0064] Among them, according to the "Highway Tunnel Ventilation and Lighting Design Code" (JTJ 023.1-1999), the wall materials with a reflectivity of not less than 70% should be laid within a 2m high range on both sides of the tunnel, and considering the pollution in the tunnel, the side wall reflection coefficient is set to 0.5 in the simulation model; due to the density of automobile exhaust, the top of the tunnel is more susceptible to pollution than other areas. No matter what kind of material with high reflectivity to light is used for painting, rapid and serious pollution that cannot be handled in time will greatly reduce its reflective effect. Therefore, the reflection coefficient of the top wall material in the simulation model is taken as 0.1; the surface of the photovoltaic panel is a treated tempered glass surface rather than a mirror surface, which only has a slight diffuse reflection, and its reflectivity to light is about 5%. In this embodiment, the interval between the tunnel lighting lamps is set to 5m, and the geographical location parameters are set to the Jiwei Expressway section in Jinan area, that is, 36.6 north latitude, 117.8 east longitude, and the time zone is East 8 (Jinan area), and the model axis is set to the east-west direction (the direction of Jiwei Expressway).

[0065] Ecotect Analysis was used to simulate the light environment model of photovoltaic awnings at tunnel entrances and exits, and a mathematical evaluation model was used to obtain the optimal design scheme of photovoltaic awnings at tunnel entrances and exits. The design scheme of photovoltaic awnings at tunnel entrances and exits included the determination of the basic length of the photovoltaic awning, the number of sections n of the photovoltaic awning, the length of each section l of the photovoltaic awning, the proportion of solar photovoltaic panels in the area of ​​each section of the awning σ, and the transmittance ρ of each section of the photovoltaic awning (the part other than the photovoltaic panels).

[0066] Determination of the basic length of the photovoltaic sunshade: Through actual vehicle tests, the visual adaptation time of the driver when driving at the entrance of a tunnel with different illumination differences inside and outside the tunnel was obtained, and a relevant mathematical model was established and the calculation formula for the length of the dimming grille at the tunnel entrance was given as follows:

[0067] T=0.0204*[E out -E in ] A

[0068] Wherein A-coefficient, the value range is 0.5-0.7, in this embodiment, A is taken as 0.6031, then, substitute into the formula to get:

[0069] T=0.0204*[E out -E in ] 0.6031

[0070] Where: T is the time required for the driver to recover his vision at the entrance of the tunnel (s); E out —— Illuminance outside the tunnel (lux); E in ——Illumination inside the tunnel (lux).

[0071] Considering that the driver should complete visual adaptation within the length range of the photovoltaic awning in front of the tunnel entrance, the entrance section and the transition section, that is, the distance traveled during the vision recovery time should be the driving distance from the beginning of the increase of the pupil area to the stabilization of the pupil area. Therefore, the reasonable design length of the photovoltaic awning at the tunnel entrance should be:

[0072]

[0073] Where: D th ——Length of tunnel entrance section (m), D tr ——Length of tunnel transition section (m), V t —Tunnel design speed.

[0074] Combined with the calculation formula of the tunnel entrance section and transition section length in the "Highway Tunnel Lighting Design Detailed Rules" (JTG / T D70 / 2-01-2014), the basic length of the photovoltaic awning model at the tunnel entrance can be calculated to be 128m. For the needs of segmented simulation analysis, the basic length is set to 132m. The photovoltaic awning length of the tunnel entrance obtained by the above method is only suitable as the basic length, and the final photovoltaic awning length needs to be corrected during the simulation process.

[0075] Determination of the number of segments: In order to make the illumination in the photovoltaic awning change evenly and gradually, and not to give the driver too much visual stimulation in a short period of time, causing the driver's discomfort, the number of segments of the photovoltaic awning should be reduced as much as possible under the premise of satisfying the driver's smooth transition;

[0076] Determination of the length of each section: Divide the basic length of the photovoltaic awning into equal parts according to the number of sections and perform simulation calculations on the illumination inside the awning. If there is a section in which the illumination changes relatively slowly or even does not change, reduce the length of that section by one step (5.5m) and continue the simulation until the illumination inside the awning changes evenly. The final length of each section of the photovoltaic awning is obtained accordingly.

[0077] Determination of the overall length: Determine the actual length of the photovoltaic awning based on the determined lengths of each section.

[0078] In the specific simulation process, the area ratio of the photovoltaic panels in the initial section of the photovoltaic awning at the tunnel entrance and exit is taken as the first area ratio. Second area ratio And the third area ratio The transmittance of the first sun visor is ρ=0.9, the transmittance of the second sun visor is ρ=0.8, and the transmittance of the third sun visor is ρ=0.7. They are combined separately and the light environment simulation is performed. The corresponding maximum illumination change rate of each combination is calculated. According to the reasonable environmental illumination change threshold, when the maximum illumination change rate is within the reasonable environmental illumination change threshold, the parameter values ​​of the entire photovoltaic awning are obtained according to the principle that the proportion of the area occupied by the photovoltaic panels at the tunnel entrance increases, the transmittance of the sun visors decreases, and the proportion of the area occupied by the photovoltaic panels at the tunnel exit decreases, and the transmittance increases.

[0079] Specifically, in the process of light environment simulation, three schemes of the area ratio of photovoltaic panels at the beginning (end) of the sunshade are preliminarily set: the first area ratio Second area ratio And the third area ratio Four sunshade (except the photovoltaic panel) transmittance schemes: the first sunshade transmittance is ρ = 0.9, the second sunshade transmittance is ρ = 0.8, the third sunshade transmittance is ρ = 0.7 and the fourth sunshade transmittance is ρ = 0.6. The light environment simulation of the above schemes is carried out respectively to study the illumination change rate of adjacent feature points of each lane at the sight height of different vehicle models when the light transitions from the outside to the beginning of the sunshade.

[0080] From the simulation data, the initial section parameter combinations of the photovoltaic sunshade that meet the smooth visual transition of drivers at the tunnel entrance are as follows:

[0081]

[0082] According to the simulation data, the parameter combinations of the end section of the photovoltaic awning that can meet the smooth transition of drivers at the tunnel entrance are as follows:

[0083]

[0084]

[0085] If a one-section photovoltaic awning is to be installed at the entrance of a tunnel, it is necessary to find a combination of photovoltaic panel area ratio and visor transmittance that can satisfy the driver's smooth transition at the junction of the photovoltaic awning and the external environment, and at the junction of the tunnel entrance and the photovoltaic awning. From the simulation data, it is known that if a one-section photovoltaic awning is installed at the entrance of a tunnel, no combination of photovoltaic panel area ratio and visor transmittance can satisfy the driver's smooth transition at the entrance of the tunnel. Therefore, it is not feasible to install a one-section photovoltaic awning at the entrance of a tunnel.

[0086] If the photovoltaic awning at the entrance of the tunnel is set to a two-stage type (initial stage and final stage), the situation that is easiest to satisfy the driver's visual transition is considered first, that is, the illumination difference between the two sections of the photovoltaic awning is the smallest, and the difference between the proportion of photovoltaic panels and the transmittance of the awning is the smallest, that is, the proportion of photovoltaic panels in the two sections of the photovoltaic awning is The light transmittance of the sun visor is ρ 初 =0.8,ρ 末 =0.3. In this case, the illumination at the junction of the two sections of the photovoltaic sunshade is simulated and analyzed, and the maximum illumination change rate in the shed is 38.3%>37.5%, so it cannot meet the requirements of smooth transition of the light environment, and the number of sections n of the photovoltaic sunshade needs to be increased.

[0087] Therefore, the photovoltaic awning at the entrance of the tunnel needs to be set up in three sections (initial section, middle section, and final section). Taking into account the gradual change of light intensity in the awning, at the entrance of the tunnel, along the driving direction, the photovoltaic panels are in an inverted triangle shape, that is, the area of ​​the photovoltaic panels gradually increases, and the transmittance of the visor gradually decreases. The illumination in the awning at the junction of the initial section and the middle section and the junction of the middle section and the final section of the photovoltaic awning under various photovoltaic panel area ratios and different visor transmittances is simulated, and the maximum illumination change rate at the sight height of each lane and each vehicle type is calculated. The feasible solution is as follows:

[0088] Feasible schemes for the combination of parameters of the initial and middle sections of the photovoltaic sunshade at the tunnel entrance

[0089]

[0090]

[0091] Feasible schemes for the combination of parameters in the middle and end sections of the photovoltaic sunshade at the tunnel entrance

[0092]

[0093] If there is a gentle illumination change section in the light environment of the awning during simulation, the light-reducing material has no obvious effect on the illumination reduction in the awning, and cannot meet the requirements of a uniform and gradual light environment. The length of this section of the awning should be reduced. Therefore, the final length of the photovoltaic awning needs to be corrected based on its basic length. The basic length is divided into three equal sections, and the illumination changes at each sight height of each lane in the awning are obtained by simulation analysis of all schemes. If there are two adjacent feature points with almost no illumination change, the section of the photovoltaic awning is shortened by one step, and finally the actual length and total length of each section of the photovoltaic awning at the entrance of the tunnel can be obtained. As can be seen from the above table, there is a certain overlap in the feasible combination schemes of the parameters of the initial section and the final section of the photovoltaic awning at the tunnel exit. It can be seen that a one-section photovoltaic awning can meet the driver's smooth transition at the tunnel exit.

[0094] The photovoltaic sunshade design scheme for the tunnel entrance and exit in this embodiment is based on the Jiwei Expressway Tunnel as an example, and the tunnel entrance parameters are set as the proportion of the photovoltaic panel to the initial section area. Proportion of photovoltaic panels in the middle section area Proportion of photovoltaic panels in the area of ​​the last section Initial sun visor transmittance ρ 初 =0.9, middle section ρ 中 =0.6, the final section ρ 末 =0.3 as an example to carry out the following simulation and calculation. First, the basic length is divided into three equal sections. By simulating and analyzing all feasible solutions, the illumination changes at each sight height of each lane in the shed are obtained. If there are two adjacent feature points with almost no illumination change, the section of the photovoltaic awning is shortened by one step, and finally the actual length and total length of each section of the photovoltaic awning at the entrance of the tunnel can be obtained. Based on the above research, all feasible solutions are simulated for the light environment within the full length of the shed, and then according to the above length correction method, the actual length and total length of each section of the photovoltaic awning at the entrance and exit of the tunnel can be obtained. The following table shows the feasible solutions for the parameter combinations of the initial section, middle section, and final section of the three-section photovoltaic awning at the entrance and exit of the tunnel.

[0095] Feasible schemes for the combination of parameters of the initial section, middle section and final section of the three-section photovoltaic awning

[0096]

[0097]

[0098] Feasible scheme for various parameter combinations of one-stage photovoltaic awning at tunnel exit

[0099]

[0100] Through the illumination change uniformity coefficient k, the total length of the photovoltaic awning l 总 , Solar equivalent radiation photovoltaic area s 光 The three-dimensional attribute indicators are used to comprehensively evaluate the scheme, find the optimal solution, and determine the photovoltaic panel area ratio σ, the visor transmittance ρ and the length l of each section of the photovoltaic awning at the tunnel entrance and exit.

[0101] Selection of evaluation indicators:

[0102] The illumination change in the photovoltaic awning is not completely uniform. The illumination change at each joint is large, while the illumination change in each section of the awning is small. Therefore, the illumination change uniformity coefficient k is selected as the value standard to characterize the smoothness of the illumination change in the awning. The smaller the value, the more uniform and smooth the illumination change in the awning, and the more favorable it is for the driver to drive smoothly. The calculation formula is as follows:

[0103]

[0104] In the formula, K x - Uniform coefficient of illumination variation in the shed at each sight height of each lane, x- can be the sight height of the car in the left lane, the sight height of the car in the middle lane, the sight height of the truck in the middle lane, the sight height of the car in the right lane, and the sight height of the truck in the right lane; ε max - Maximum illumination change rate in the shed (%); ε av- Average illumination change rate in the shed (%);

[0105] The uniformity coefficient of overall illumination variation in the shed is:

[0106]

[0107] Total length of photovoltaic awning l 总 If it is too short, the illumination variation per unit time will be too large, and the light reduction effect cannot be fully achieved. If it is too long, it will cause great economic waste. 总 As one of the comprehensive evaluation indicators, all the above schemes have met the driver's visual transition requirements. 总 The smaller the value, the lower the economic cost of the solution.

[0108] According to the actual cross-sectional dimensions of the photovoltaic awning and the area ratio of the photovoltaic panels in each section of the photovoltaic awning, the solar energy equivalent radiation photovoltaic area s in each feasible solution can be calculated. 光 The larger the value is, the more photovoltaic power generation the corresponding solution will generate, and the higher the economic and environmental emission reduction benefits will be.

[0109] In this embodiment, 23 feasible schemes are designed for the parameters of the photovoltaic awning at the tunnel entrance (the feasible schemes for the combination of parameters of the initial section, the middle section, and the final section of the three-section photovoltaic awning) and 8 feasible schemes are designed for the parameters of the photovoltaic awning at the tunnel exit, including the illumination variation uniformity coefficient k, the total length l of the photovoltaic awning, and the illumination variation uniformity coefficient k of the photovoltaic awning. 总 , Solar equivalent radiation photovoltaic area S 光 The calculation results are as follows:

[0110] Calculation results of evaluation indicators of photovoltaic awning at tunnel entrance

[0111]

[0112]

[0113] Calculation results of evaluation indicators of photovoltaic awning at tunnel exit

[0114]

[0115] Program evaluation:

[0116] The AHP-TOPSIS evaluation model was used to evaluate 23 tunnel entrance photovoltaic awning design schemes and 8 tunnel exit photovoltaic awning design schemes. The calculation steps are as follows:

[0117] (1) Indicator empowerment

[0118] The hierarchical analysis method is used to assign weights and judge the importance relationship between each evaluation index. The more important the index is, the greater its contribution to the target layer. The Delphi scoring method is used to score each index according to its importance and establish a judgment matrix A.

[0119]

[0120] Each element a in the matrix ij The importance of index i relative to index j is determined by using a scale of 1-9 and its reciprocal, and the following table is selected:

[0121]

[0122] Considering that the original intention of designing photovoltaic awnings is to alleviate the sudden change of ambient illumination at the entrance and exit of the tunnel, to ensure the smooth visual transition of drivers when driving at the tunnel entrance, thereby reducing the traffic accident rate at the tunnel entrance, the illumination change uniformity coefficient k is the most important indicator for evaluating the quality of photovoltaic awnings, followed by the total length l of the photovoltaic awning. 总 The economic benefits of photovoltaic panels using solar energy to generate electricity are much less than the cost of setting up sunshades, so the indicator solar equivalent radiation photovoltaic area S 光 The priority is the lowest. Substituting into the above formula, the matrix A is:

[0123]

[0124] The largest characteristic root λ of the judgment matrix A max The corresponding eigenvectors are normalized to obtain a vector W whose sum of elements is equal to 1. The vector W is the ranking weight of the relative importance of the criterion layer to the target layer. Before determining the vector W as the weight vector (that is, the elements in the vector W are the weights of the evaluation index), the judgment matrix A needs to be checked for consistency. The consistency index is defined as:

[0125]

[0126] Where, λmax is the maximum eigenvalue of the judgment matrix A; n is the number of evaluation indicators.

[0127] The smaller the consistency index, the better the consistency of the judgment matrix A. CI = 0 means that the judgment matrix A completely satisfies the consistency, which means that the judgment matrix A basically meets the consistency. Since the relative importance of subjective evaluation indicators is somewhat vague, it is difficult to construct a judgment matrix that completely satisfies the consistency. Therefore, the judgment matrix is ​​allowed to have a certain inconsistency range. Here, the test coefficient is introduced to measure the size of the consistency index. The quantitative relationship between the two is as follows:

[0128]

[0129] In the formula, RI-random consistency index, its value is related to the number of evaluation indicators n, as shown in the following table:

[0130]

[0131] If CR < 0.1, the judgment matrix passes the consistency test, and the vector W can be used to assign weights to each evaluation index.

[0132] The consistency test of matrix A is performed, and the results are as follows:

[0133]

[0134] After weighting the evaluation indicators, TOPSIS can be used to evaluate the relative advantages and disadvantages of each solution. The main steps are as follows:

[0135] Construct an original data matrix X with n rows and m columns (n ​​evaluation schemes, m evaluation indicators). The element x in the matrix X is ij is the value of the jth evaluation indicator in the ith evaluation scheme.

[0136] Evaluation indicators are divided into positive indicators and negative indicators. Positive indicators are indicators with larger values, the better, and negative indicators are indicators with smaller values, the better. When negative indicators appear, they need to be processed positively, so that all indicators become positive indicators with larger values, the better. The positive conversion of negative indicators generally adopts the inverse method, as shown in the following formula, and finally constructs the positive data matrix X'.

[0137]

[0138] x′ ij =x ij , (i=1,2…n,j=1,2…m) (the original index is a positive index)

[0139] Where: x ij ——The element in the i-th row and j-th column in the data matrix X'.

[0140] Since the dimensions of the evaluation indicators are different and cannot be calculated at the same time, it is also necessary to standardize the data matrix X′ after the forward transformation to obtain the standardized matrix Z. The elements z in the matrix Z are ij The calculation method is as follows:

[0141]

[0142] The optimal solution vector (Z) is calculated based on the maximum and minimum values ​​of each index in the standardized matrix Z. + ) and the worst solution vector (Z - ), the formula is as follows:

[0143]

[0144]

[0145] Calculate the Euclidean distance between the i-th (i=1, 2, ...n) solution to be evaluated and the optimal solution and the worst solution, which are defined as and

[0146]

[0147]

[0148] Where: w j ——The weight of the jth evaluation indicator.

[0149] Calculate the relative closeness S between each evaluated solution and the optimal solution i , 0≤S i ≤1, S i The closer it is to 1, the better the corresponding evaluation scheme is, and the closer it is to 0, the worse the corresponding evaluation scheme is.

[0150]

[0151] The eigenvector corresponding to the maximum eigenvalue root after normalization is W = [0.7334, 0.1991, 0.0675] T, from which the weights corresponding to the uniformity coefficient of illumination change K, the total length of the photovoltaic awning ltotal and the solar equivalent radiation photovoltaic area Slight are 0.7334, 0.1991 and 0.0675 respectively.

[0152] (2) Comprehensive evaluation

[0153] Solar equivalent radiation photovoltaic area S 光 It is a positive indicator, and the illumination uniformity coefficient k and the total length l of the photovoltaic awning 总It is a reverse indicator and needs to be processed first and then standardized to obtain the standardized matrix of each design scheme of photovoltaic awning at the entrance and exit of the tunnel, and calculate the distance between each scheme and the optimal solution and the worst solution (D i+ , D i- ) and the relative closeness to the optimal solution (S i ), as shown in the following table:

[0154] Tunnel entrance photovoltaic awning scheme D i+ , D i-， S i

[0155]

[0156] Tunnel exit photovoltaic awning scheme D i+ ,Di-,S i

[0157]

[0158] According to the evaluation results, for the photovoltaic sunshade at the tunnel entrance, Scheme 2 is the closest to the optimal solution and is the best design. Compared with the design scheme corresponding to the 1 / 6 area of ​​the photovoltaic panels in the initial section, the scheme corresponding to the 1 / 5 area of ​​the photovoltaic panels is generally worse. This is because the ambient illumination at the junction between the outside and the photovoltaic sunshade and the internal junction of the photovoltaic sunshade varies greatly, the illumination in the shed varies unevenly, and the photovoltaic sunshade is overall longer, which increases the construction cost. Therefore, even if the photovoltaic panel area is larger and the power generation is higher, it cannot make up for its disadvantages.

[0159] For the photovoltaic sunshade at the tunnel exit, Scheme 5 is the optimal design. In addition, it can be found that Scheme 2 is better than Schemes 1 and 3, and Scheme 5 is better than Schemes 4 and 6. The main reason for this rule is that the sunshade transmittance of Schemes 1 and 4 is relatively high, and the illumination changes relatively drastically at the junction of the tunnel and the photovoltaic sunshade. The sunshade transmittance of Schemes 3 and 6 is relatively low, and the illumination changes greatly at the transition between the photovoltaic sunshade and the outside world, indicating that higher or lower sunshade transmittance is not the best choice, and Scheme 1 is better than Scheme 3, and Scheme 4 is better than Scheme 6. Based on this, it can also be inferred that the priority of uniform illumination change at the junction of the photovoltaic sunshade and the outside world is higher than the junction of the tunnel and the photovoltaic sunshade.

[0160] Optimal design parameters of photovoltaic awnings at tunnel entrances

[0161]

[0162] Optimal design parameters of photovoltaic awning at tunnel exit

[0163]

[0164] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A photovoltaic sunshade optimization design method for a high-speed tunnel entrance, characterized in that: The specific steps are as follows: Select the tunnel entrance and exit test data; According to the selected tunnel entrance and exit test data, the tunnel vehicle test and the tunnel entrance illumination change threshold function model are constructed to obtain the reasonable illumination change threshold of the tunnel entrance and exit; Ecotect Analysis was used to simulate the light environment model of the photovoltaic sunshade at the tunnel entrance and exit, and the mathematical evaluation model was used to obtain the optimal design scheme of the photovoltaic sunshade at the tunnel entrance and exit; The TOPSIS comprehensive evaluation method is used to evaluate the relative advantages and disadvantages of various design schemes of photovoltaic awnings at tunnel entrances and exits according to the selected evaluation indicators to obtain the optimal scheme. The selected evaluation indicators are: illumination uniformity coefficient k, total length of photovoltaic awning l 总 , Solar equivalent radiation photovoltaic area s 光 , comprehensively evaluate the scheme through three-dimensional attribute indicators, find the optimal solution, and determine the photovoltaic panel area proportion σ, the sunshade transmittance ρ and length l of each section of the photovoltaic sunshade at the entrance and exit of the tunnel; Before using TOPSIS to evaluate the advantages and disadvantages of the design schemes of various parameters of photovoltaic awnings at tunnel entrances and exits, different weights were assigned to each evaluation index according to its importance through the analytic hierarchy process; A forward-normalized data matrix is ​​obtained through each evaluation index, and the forward-normalized data matrix is ​​normalized to obtain a normalized matrix. The maximum and minimum values ​​of each index in the normalized matrix are used to calculate the optimal solution vector and the worst solution vector. According to the optimal solution vector and the worst solution vector, the Euclidean distance between each evaluation scheme and the optimal solution and the worst solution is calculated. The relative closeness S of each evaluation scheme to the optimal solution is calculated by the Euclidean distance and the weight of each indicator. i , closeness S i The closer it is to 1, the better the solution.

2. The photovoltaic sunshade optimization design method for a high-speed tunnel entrance according to claim 1, characterized in that: The tunnel entrance and exit test data include illumination data and pupil area data; illumination data collection requires repeated measurement three times at different cross-sectional positions at each data collection point, and the average value is taken as the illumination value at that location.

3. The photovoltaic sunshade optimization design method for a high-speed tunnel entrance according to claim 1, characterized in that: The threshold function model of tunnel entrance illumination change is: Where, ω is the change rate of the driver’s pupil area at time i; S i ——The driver’s pupil area at time i, the rate of change of ambient illumination at time ε-i, and the ambient illumination value at time Ei-i.

4. The photovoltaic sunshade optimization design method for a high-speed tunnel entrance according to claim 1, characterized in that: Set the spacing distance of each steel arch frame, set the inclination angle of the photovoltaic panel, determine the light reflectivity of the tunnel sidewall, tunnel top wall and photovoltaic panel materials, input the geographic location parameters and lighting layout spacing data parameters, and build a 1:1 model according to the actual size of the tunnel.

5. The method for optimizing the design of a photovoltaic sunshade for a high-speed tunnel entrance according to claim 1, characterized in that: The mathematical evaluation model includes the basic length model of the photovoltaic awning at the tunnel entrance and exit, as follows: Where: - the time it takes for the driver's vision to recover at the tunnel entrance, —Tunnel exterior illumination, —Illumination inside the tunnel, — Length of the tunnel entrance section, — Length of tunnel transition section, V t —Tunnel design speed, A-factor, ranges from 0.5 to 0.

7.

6. The photovoltaic sunshade optimization design method for a high-speed tunnel entrance according to claim 1, characterized in that: The first area ratio, second area ratio and third area ratio of the area occupied by the photovoltaic panels in the initial section of the photovoltaic awning at the tunnel entrance and exit are combined with the light transmittance of the first visor, the light transmittance of the second visor and the light transmittance of the third visor, and the light environment simulation is performed to calculate the corresponding maximum illumination change rate of each combination. When the maximum illumination change rate is within the reasonable ambient illumination change threshold, the parameter values ​​of the awning model are obtained.

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