Auxiliary calibration apparatus and method for heliostat, and photothermal power generation system

Abstract

An auxiliary calibration apparatus and method for a heliostat, and a photothermal power generation system. The auxiliary calibration apparatus for a heliostat comprises a calibration body and a detection assembly. The calibration body comprises a first optical surface and a second optical surface which are oppositely disposed. The detection assembly is provided with a first sensing surface and a second sensing surface, the first sensing surface being parallel to the second sensing surface. The detection assembly is used for detecting a second light spot position of a target point of a receiving tower on the second sensing surface after passing through the second optical surface, and detecting a first light spot position of the image of the sun in a heliostat on the first sensing surface after passing through the first optical surface, so as to adjust the angle of the heliostat on the basis of the second light spot position, such that the first light spot position and the second light spot position are symmetrical about the center of the detection assembly. By using the described solution, the adjustment precision of the heliostat can be improved.

Description

Heliostat auxiliary calibration device, method and solar thermal power generation system

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 29, 2024, with application number 202410123061.0 and invention name “Heliostat assisted calibration device, method and solar thermal power generation system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the technical field of solar thermal power generation, and in particular to a heliostat auxiliary calibration device and method, and a solar thermal power generation system. Background Art

[0003] Solar thermal power generation is an important area of ​​renewable energy utilization, primarily encompassing three types of systems: trough, tower, and dish. Tower-type solar thermal power generation systems require higher tracking complexity and precision than trough and dish systems.

[0004] A heliostat is a component of a tower-type solar thermal power generation system. Its function is to reflect sunlight beams to a fixed position on a receiving tower to generate heat, which is then converted into electricity by the receiving tower.

[0005] Because the sun's position in the sky constantly changes throughout the day, the heliostats must constantly adjust their angles to reflect sunlight onto the tower's receivers. The closer the heliostats' reflected sunlight is to the center of the receiver, the higher the power generation efficiency. Therefore, adjusting the heliostat angle is crucial to tower-type solar thermal power generation systems.

[0006] However, the existing heliostat adjustment method has limited adjustment accuracy, which affects power generation efficiency.

[0007] Summary of the Invention

[0008] The problem to be solved by the present invention is to improve the adjustment accuracy of the heliostat.

[0009] To solve the above problems, an embodiment of the present invention provides a heliostat auxiliary calibration device, the heliostat auxiliary calibration device comprising:

[0010] Calibration body, and detection components;

[0011] The calibration body includes a first optical surface and a second optical surface arranged opposite to each other;

[0012] The detection component is located on the calibration body; the detection component has a first sensing surface facing the first optical surface and a second sensing surface facing the second optical surface; the first sensing surface is parallel to the second sensing surface;

[0013] The detection assembly is configured to detect a second light spot position of a target point of the receiving tower on the second sensing surface via the second optical surface, and to detect a first light spot position of an image of the sun in the heliostat on the first sensing surface via the first optical surface, so as to adjust the angle of the heliostat based on the second light spot position so that the first light spot position and the second light spot position are symmetrical around the center of the detection assembly.

[0014] In a possible embodiment of the present invention, the calibration body includes: a light-shielding surface; the first optical surface and the second optical surface are located on both symmetrical sides of the light-shielding surface and are connected to the light-shielding surface to form a accommodating cavity; the detection component is located in the accommodating cavity.

[0015] In a possible embodiment of the present invention, the first optical surface has a first light-transmitting hole; the second optical surface has a second light-transmitting hole.

[0016] In a possible embodiment of the present invention, at least one of the first light-transmitting hole and the second light-transmitting hole is located at the center of the optical surface.

[0017] In a possible embodiment of the present invention, the first optical surface is provided by a first lens, and the second optical surface is provided by a second lens.

[0018] In a possible embodiment of the present invention, the detection assembly includes: a first detector and a second detector, the first detector being used to detect a first light spot position of the sun's image in the heliostat on the first sensing surface via the first optical surface, and the second detector being used to detect a second light spot position of a receiving tower target on the second sensing surface via the second optical surface.

[0019] In a possible embodiment of the present invention, both the first detector and the second detector are image sensors.

[0020] In a possible embodiment of the present invention, the first detector and the second detector are arranged back to back.

[0021] In a possible embodiment of the present invention, the first sensing surface and the second sensing surface are aligned along a light transmission direction.

[0022] In a possible embodiment of the present invention, the heliostat auxiliary calibration device further includes: a control component; wherein:

[0023] the control component is configured to determine whether the first light spot position and the second light spot position are symmetrical about the center of the detection component, and determine an adjustment angle of the heliostat based on the first light spot position and the second light spot position if the first light spot position and the second light spot position are not symmetrical about the center of the detection component;

[0024] The control component is connected to the heliostat bracket; the heliostat bracket is used to perform an angle adjustment operation on the heliostat under the control of the control component.

[0025] In a possible embodiment of the present invention, the heliostat auxiliary calibration device further includes: a calibration body bracket; the calibration body bracket is installed on the heliostat bracket or the mirror surface of the heliostat.

[0026] In a possible embodiment of the present invention, the control component is also used to determine whether the first sensing surface and the second sensing surface are aligned along the direction of light transmission, and when they are not aligned, determine the angle between the first coordinate system where the first sensing surface is located and the second coordinate system where the second sensing surface is located, and after performing a coordinate system conversion on any one of the first light spot position and the second light spot position based on the angle, determine whether the first light spot position and the second light spot position are symmetrical around the center of the detection component.

[0027] In a possible embodiment of the present invention, the calibration body is a cylinder.

[0028] In a possible embodiment of the present invention, the receiving tower target point is the center point of the receiver on the receiving tower.

[0029] An embodiment of the present invention further provides a heliostat auxiliary calibration method, which uses any of the above-mentioned heliostat auxiliary calibration devices to calibrate a heliostat; the method comprises:

[0030] Adjusting the position of the detection component so that the receiving tower target is located within the sensing range of the second sensing surface, and obtaining a second light spot position of the receiving tower target on the second sensing surface via the second optical surface;

[0031] Adjusting the heliostat so that the image of the sun in the heliostat is located within the sensing range of the first sensing surface, and obtaining a first spot position of the image of the sun in the heliostat on the first sensing surface via the first optical surface;

[0032] determining whether the first light spot position and the second light spot position are symmetrical around the center of the detection component;

[0033] In response to the first light spot position and the second light spot position not being symmetrical about the center of the detection assembly, determining an adjustment angle of the heliostat based on the first light spot position and the second light spot position;

[0034] Based on the determined adjustment angle of the heliostat, the heliostat is adjusted, and the first light spot position is re-detected until the second light spot position is symmetrical to the re-obtained first light spot position around the center of the detection assembly.

[0035] In a possible embodiment of the present invention, before determining whether the first light spot position and the second light spot position are symmetrical around the center of the detection component, the method further includes:

[0036] determining whether the first sensing surface and the second sensing surface are aligned along the light transmission direction;

[0037] In response to the first sensing surface and the second sensing surface being misaligned along the light transmission direction, determining an angle between a first coordinate system where the first sensing surface is located and a second coordinate system where the second sensing surface is located;

[0038] After performing coordinate system transformation on any one of the first light spot position and the second light spot position based on the included angle, it is determined whether the first light spot position and the second light spot position are symmetrical around the center of the detection component.

[0039] An embodiment of the present invention further provides a solar thermal power generation system, comprising: a heliostat, a receiving tower, and any one of the above heliostat auxiliary calibration devices, wherein the heliostat auxiliary calibration device corresponds one-to-one to the heliostat.

[0040] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0041] By applying the solution of the present invention, a detection assembly is provided. This detection assembly can detect the second spot position of the receiving tower target on the second sensing surface via the second optical surface, and can also detect the first spot position of the sun's image in the heliostat on the first sensing surface via the first optical surface. Based on the second spot position, the angle of the heliostat can be adjusted so that the first and second spot positions are symmetrical about the center of the detection assembly. Because the first sensing surface is parallel to the second sensing surface, in actual use, the sunlight reflected by the heliostat can essentially reach the receiving tower target, achieving photothermal conversion. Furthermore, by providing an additional heliostat auxiliary calibration device to calibrate the heliostat, it is only necessary to ensure that the first and second spot positions are symmetrical about the center of the detection assembly. This reduces the number of factors influencing calibration, enabling ultra-high-precision calibration and improving the power generation efficiency of the power station.

[0042] Furthermore, when an image sensor is used as a detection component, accurate detection can be achieved regardless of day or night, so the heliostat can be calibrated around the clock, which can improve the real-time performance of the calibration.

[0043] The present invention also provides a solar thermal power generation system, in which a heliostat auxiliary calibration device corresponds one-to-one to a heliostat, so that each heliostat auxiliary calibration device can calibrate a unique heliostat, preventing interference between sunlight reflected by the heliostats, thereby improving the parallelism of calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG1 is a schematic diagram of placing a camera on a receiving tower to calibrate a heliostat;

[0045] FIG2 is a schematic diagram of a ground-mounted camera for calibrating a heliostat;

[0046] 3 is a schematic diagram of calibrating a heliostat using a heliostat auxiliary calibration device according to an embodiment of the present invention;

[0047] FIG4 is a schematic diagram of a cross-sectional structure of a heliostat auxiliary calibration device according to an embodiment of the present invention;

[0048] FIG5 is a schematic diagram of the three-dimensional structure of a heliostat auxiliary calibration device according to an embodiment of the present invention;

[0049] FIG6 is a schematic diagram of the calibration principle of a heliostat auxiliary calibration device according to an embodiment of the present invention;

[0050] FIG7 is a schematic structural diagram of a heliostat auxiliary calibration device according to an embodiment of the present invention;

[0051] FIG8 is a schematic diagram showing the positions of the first sensing surface and the second sensing surface corresponding to the image when the first sensing surface and the second sensing surface are aligned;

[0052] FIG9 is a schematic diagram showing the positions of corresponding images when the first sensing surface and the second sensing surface are not aligned;

[0053] FIG10 is a flow chart of a heliostat assisted calibration method according to an embodiment of the present invention;

[0054] FIG11 is a schematic diagram showing a calibration effect of a heliostat auxiliary calibration device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] Currently, the following three methods are commonly used to adjust heliostats:

[0056] 1. Use the coordinate + astronomical calendar solution.

[0057] Specifically, each heliostat is installed on the Global Positioning System (GPS). Based on the coordinates and time of the heliostat, the complete astronomical calendar is used to calculate the angle that the heliostat should present, so that sunlight can be reflected to the receiver of the receiving tower.

[0058] The biggest problem with the above solution is its lack of accuracy. Specifically, when a heliostat power plant reaches a certain scale, the distance between the farthest heliostat and the receiving tower can reach over 2 kilometers. A deviation of 0.3 mrad in alignment accuracy will reduce power generation efficiency. This solution is limited by ground flatness, the initial installation angle, equipment aging, and atmospheric refraction of sunlight. It is impossible to achieve exceptionally high accuracy, which severely restricts the scale of ultra-large heliostat power plants and affects power generation efficiency.

[0059] 2. Solution for placing cameras on receiving towers

[0060] 1 , one or more cameras 13 are placed around a receiver 12 on a receiving tower 11. The cameras 13 are used to continuously detect the reflected light from each heliostat, thereby establishing feedback for adjusting the angle of the heliostat.

[0061] Although this solution can achieve high accuracy, because the camera can only detect light from one heliostat at a time, and the light reflected by multiple heliostats may interfere with each other, this solution cannot be used for parallel, real-time adjustments. This results in very low power generation efficiency and cannot be used to build ultra-large power plants.

[0062] 3. As shown in Figure 2, one or more cameras 21 are installed on the ground. The cameras 21 detect the position of the sun's rays 23 reflected by the heliostat 22 falling on the receiving tower 24. A computer 25 is used to establish feedback based on this position to adjust the angle of the heliostat. The receiving tower 24 is provided with a target plate 241 and a receiver 242.

[0063] This solution cannot perform parallel and real-time calibration. For example, if multiple heliostats were to illuminate the target plate simultaneously, they would interfere with each other. Therefore, this solution is neither real-time nor parallel.

[0064] To address this issue, the present invention provides a heliostat-assisted calibration device. Using this heliostat-assisted calibration device to calibrate a heliostat only requires ensuring that the positions of the first and second light spots are symmetrical around the center of the detection assembly. This device reduces the number of factors influencing calibration and enables ultra-high-precision calibration, thereby improving the power generation efficiency of the power station.

[0065] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0066] 3 , an embodiment of the present invention provides a heliostat auxiliary calibration device, which may include: a calibration body 30 and a detection component.

[0067] The calibration body 30 includes a first optical surface 34 and a second optical surface 35 disposed opposite to each other.

[0068] The detection component is located on the calibration body 30; the detection component has a first sensing surface 301 facing the first optical surface 34 and a second sensing surface 302 facing the second optical surface 35; the first sensing surface 301 is parallel to the second sensing surface 302;

[0069] The detection assembly is configured to detect a second light spot position of the target point A of the receiving tower 50 on the second sensing surface 302 via the second optical surface 35, and to detect a first light spot position of the image of the sun 40 in the heliostat 60 on the first sensing surface 301 via the first optical surface 34, so as to adjust the angle of the heliostat 60 based on the second light spot position so that the first and second light spot positions are symmetrical around the center of the detection assembly.

[0070] Because the first sensing surface 301 and the second sensing surface 302 are parallel, when the first spot position of the image of the sun 40 in the heliostat 60 on the first sensing surface 301 and the second spot position of the target A on the receiving tower 50 on the second sensing surface 302 are symmetrical about the center of the detection assembly, the sunlight reflected by the heliostat 60 can be parallel to the light that passes through the target point on the receiving tower 50 and reaches the second sensing surface 302. In this way, in actual application, the incident position of the sunlight reflected by the heliostat 60 on the receiving tower 50 is close to or coincides with the position of the target point on the receiving tower 50, so that the sunlight reflected by the heliostat 60 can be reflected onto the receiving tower 50, achieving light-to-heat conversion.

[0071] By using the heliostat auxiliary calibration device according to the embodiment of the present invention, the first spot position of the sun's image in the heliostat on the first sensing surface via the first optical surface is detected, and the second spot position of the receiving tower target on the second sensing surface via the second optical surface is detected. Ultimately, the sunlight reflected by the heliostat is parallel to the sunlight passing through the receiving tower target 50 and reaching the second sensing surface 302. This allows for high calibration accuracy, thereby improving power generation efficiency.

[0072] In a specific implementation, referring to Figure 3 , the receiving tower 50 is provided with a receiver 51 for receiving reflected sunlight during the actual photothermal conversion process. The receiving tower 50 may also be provided with a target plate 52 for calibrating the heliostat. The target plate 52 may be provided with multiple target points, and any one of these target points may be selected as the target point for calibrating the heliostat.

[0073] In a specific implementation, the target plate 52 and receiver 51 can be located in different areas of the receiving tower 50, and the corresponding receiving tower areas can partially overlap. In some embodiments, the receiving tower areas corresponding to the target plate 52 and receiver 51 can completely overlap, so that the target point for calibrating the heliostat coincides with a point on the receiver 51. In this case, the heliostat is calibrated directly using a point on the receiver 51.

[0074] In one embodiment of the present invention, to achieve higher power generation efficiency, the receiving tower target point can be set to the center of the receiver 51 on the receiving tower. This allows the calibrated heliostat to direct the sun's reflected light to or around the center of the receiver 51. The closer the sun's reflected light is to the center of the receiver, the higher the power generation efficiency.

[0075] In a specific implementation, the detection component can be implemented in a variety of ways, which are not limited here.

[0076] In one embodiment of the present invention, referring to Figures 3 and 4 , the detection assembly includes a first detector 31 and a second detector 32. The first detector 31 is used to detect the position of a first spot of the sun's image in the heliostat on the first sensing surface 301 via the first optical surface 34, and the second detector 32 is used to detect the position of a second spot of the receiving tower target point A on the second sensing surface 302 via the second optical surface 35.

[0077] In a specific implementation, at least one of the first detector 31 and the second detector 32 can be implemented as a sensor. For example, the first detector 31 can be implemented as a sensor, while the second detector 32 can be implemented as another detection device or circuit. In another example, both the first detector 31 and the second detector 32 can be implemented as sensors.

[0078] In a specific implementation, the first detector 31 and the second detector 32 can be implemented by sensors, or by different sensors. There are many types of sensors that can be used for detection, which are not limited here.

[0079] In one embodiment, an image sensor can be used as the sensor for detection. There are various types of image sensors, such as contact image sensors (CIS image sensors). Using an image sensor, the first position of the sun relative to the first sensing surface 301 can be determined by detecting the spot position of the sun's image on the first sensing surface 301. The second position of the receiving tower target relative to the second sensing surface can be determined by detecting the spot position of the receiving tower target on the second sensing surface 302. Subsequently, based on the spot position of the sun on the first sensing surface 301, it can be determined whether the sunlight L1 reflected by the heliostat is perpendicular to the first sensing surface 301. Based on the spot position of the receiving tower target on the second sensing surface 302, it can be determined whether the line connecting the receiving tower target and a specified point on the second sensing surface 302 is perpendicular to the second sensing surface 302.

[0080] By using an image sensor as the sensor for detection, accurate detection can be achieved regardless of day or night, so the heliostat can be calibrated around the clock, improving the real-time performance of the calibration.

[0081] In a specific implementation, to further improve detection accuracy, when using an image sensor for detection, a light source can be provided at the target point of the receiving tower. When the second light spot position of the tower target point on the second sensing surface is symmetrical with the first light spot position of the sun's image on the first sensing surface about the center of the detection assembly, the light generated by the light source at the target point of the receiving tower is parallel to the sunlight reflected by the heliostat. As a result, the incident position of the sunlight reflected by the heliostat on the receiving tower is close to or coincides with the position of the target point on the receiving tower. Ultimately, the sunlight reflected by the heliostat can illuminate the vicinity of or the target point of the receiving tower.

[0082] In a specific implementation, referring to FIG. 4 , the first detector 31 and the second detector 32 may be disposed back to back, thereby making it easier for the first sensing surface 301 to face the heliostat, the second sensing surface 302 to face the receiving tower, and the first sensing surface 301 to be parallel to the second sensing surface 302 .

[0083] In some embodiments, a gap may exist between the first detector 31 and the second detector 32. The specific size of the gap can be set according to actual conditions, such as the thickness of the chip package, the thickness of the chip mounting surface, and the thickness of the PCB board of the first detector 31 and the second detector 32. Other components may also be placed between the first detector 31 and the second detector 32.

[0084] In a specific implementation, the center of the detection assembly can be the center position of the detection assembly along the light transmission direction. When the detection assembly includes the first detector 31 and the second detector 32, the center of the detection assembly is the center position of the first detector 31 and the second detector 32 as a whole in the light transmission direction.

[0085] In a specific implementation, the first optical surface 34 and the second optical surface 35 can be glass cover plates made of a light-shielding material. Each of the first and second optical surfaces 34 and 35 has a specific field of view. During calibration, the position of the receiving tower target can be observed within the field of view. Adjusting the heliostat also allows for observation of the solar image. For example, the first optical surface 34 can be provided by a first lens, and the second optical surface 35 can be provided by a second lens.

[0086] In a specific implementation, the first optical surface 34 can be directly mounted on the first detector 31 , the second optical surface 35 can be directly mounted on the second detector 32 , and the first detector 31 and the second detector 32 can be connected back to back.

[0087] In one embodiment of the present invention, referring to Figures 3 and 4 , the calibration body 30 may further include a light shielding surface 33. The first optical surface 34 and the second optical surface 35 are located on either side of the light shielding surface 33 and connected to the light shielding surface 33 to form a receiving cavity; the detection component is located in the receiving cavity.

[0088] In a specific implementation, the light-shielding surface 33 can be made of a light-shielding material. The light-shielding surface 33, the first optical surface 34, and the second optical surface 35 together form a closed housing cavity. The first detector 31 and the second detector 32 are fixed within this housing cavity. This allows the housing cavity to be aligned with the receiving tower target, so that the tower target forms a light spot on the second sensing surface 302. Subsequent adjustment of the heliostat can ensure that the image of the sun forms a light spot on the first sensing surface 301.

[0089] In a specific implementation, the calibration body 30 can have a variety of shapes. For example, referring to Figure 3, the calibration body 30 can be a cylinder. In this case, the first optical surface 34 and the second optical surface 35 are equivalent to the upper and lower surfaces of the cylinder, and the shading surface 33 is equivalent to the cylindrical surface of the cylinder.

[0090] In some embodiments, the calibration body may also be in other shapes having a first optical surface and a second optical surface, such as a cuboid, a cube, etc., which is not limited here.

[0091] In a specific implementation, the first optical surface may have a first light-transmitting hole, and the second optical surface may have a second light-transmitting hole. Referring to Figure 5 , taking the calibration body as a cylinder, the image of the sun in the heliostat is formed on the first sensing surface 301 by light passing through the first light-transmitting hole. The image of the receiving tower target point A is formed on the second sensing surface 302 by light passing through the second light-transmitting hole. The image of the receiving tower target point A on the second sensing surface 302 is shown as P1. Point A' in image P1 is the imaging position of the receiving tower target point A. Based on this imaging position, the corresponding light spot position can be determined.

[0092] In a specific implementation, the positions of the first light-transmitting hole and the second light-transmitting hole on the optical surface are not limited, as long as the first light spot position of the sun's image on the first sensing surface and the second light spot position of the receiving tower target on the second sensing surface are symmetrical around the center of the detection component.

[0093] In one embodiment of the present invention, to facilitate calibration, at least one of the first light-transmitting hole and the second light-transmitting hole may be located at the center of the optical surface on which they are located. For example, the first light-transmitting hole may be located at the center of the first optical surface, and the second light-transmitting hole may be located at the center of the second optical surface.

[0094] Taking the example of a first light-transmitting hole B located at the center of the first optical surface 34 and a second light-transmitting hole C located at the center of the second optical surface 35, referring to FIG6 , the sun's image D2 is irradiated onto the first sensing surface 301 through the first light-transmitting hole B, resulting in a first light spot position D2'. The tower target point A2 is irradiated onto the first sensing surface 302 through the second light-transmitting hole C, resulting in a second light spot position A2'. The first light spot position D2' and the second light spot position A2' are symmetrical around the detection assembly center O. In actual applications, the actual irradiation position of the sun's image D1 is A3. This actual irradiation position A3 is very close to the tower target point A2, typically only a few millimeters away. Therefore, it can be assumed that the sun's image D1 irradiates the tower target point A2.

[0095] For another example, referring to Figure 6 , the sun's image D1 passes through the first light-transmitting aperture B, forming a first light spot position D1' on the first sensing surface 301. The tower target point A1 passes through the second light-transmitting aperture C, forming a second light spot position A1' on the first sensing surface 302. The first and second light spot positions D1' and A1' are symmetrical around the detection assembly center O. In this case, in practical applications, the actual illumination position of the sun's image D1 coincides with the tower target point A1, achieving the highest calibration accuracy.

[0096] In a specific implementation, the first optical surface 34 and the first detector 31 can constitute a first camera module, and the second optical surface 35 and the second detector 32 can constitute a second camera module. The first camera module and the second camera module are two back-to-back camera modules. The two camera modules can be coaxially fixed in the accommodating cavity.

[0097] In a specific implementation, based on the detection result of the detection assembly, the rotation angle of the heliostat can be manually adjusted so that the second light spot position is symmetrical to the first light spot position around the center of the detection assembly.

[0098] In one embodiment of the present invention, in order to improve the calibration efficiency and the adjustment accuracy, referring to FIG3 and FIG7 , the heliostat auxiliary calibration device may further include: a control component 36 .

[0099] The control component 36 is configured to determine whether the first light spot position and the second light spot position are symmetrical about the center of the detection component, and to determine an adjustment angle of the heliostat based on the first light spot position and the second light spot position if the first light spot position and the second light spot position are not symmetrical about the center of the detection component.

[0100] The control component 36 is in communication with the heliostat support 601 ; the heliostat support 601 is configured to perform an angle adjustment operation on the heliostat 60 under the control of the control component 36 .

[0101] In a specific implementation, the heliostat support 601 may include a drive component and a rotating shaft. The drive component may receive control signals from the control assembly 36 and thereby drive the rotating shaft to rotate horizontally or vertically, thereby adjusting the angle of the calibration body or the heliostat. The drive component may be a stepper motor or other drive components, without limitation.

[0102] In a specific implementation, referring to FIG3 , the heliostat auxiliary calibration device may further include a calibration body bracket 37. This calibration body bracket 37 may be implemented using a structure that does not allow for angle adjustment of the calibration body. In this case, only the heliostat angle can be automatically adjusted during the entire calibration process.

[0103] In a specific implementation, the calibration body bracket 371 can be independently installed on the ground, or can be installed on the support shaft of the heliostat or on the mirror surface of the heliostat, which is not limited here.

[0104] In a specific implementation, the control assembly 36 is integrated into the accommodating cavity, or integrated into the calibration body bracket 371 , and is interconnected with the calibration body bracket 371 and the heliostat bracket 372 via signal lines.

[0105] In practice, to facilitate production and debugging, the first camera module and the second camera module can be configured to have the same specifications and be placed back-to-back. This dual camera module with the same specifications and placed back-to-back is called a dual mirror.

[0106] In one embodiment, referring to FIG6 , the first sensing surface 301 and the second sensing surface 302 can be aligned along the light transmission direction X. That is, the first sensing surface 301 and the second sensing surface 302 are centrally aligned, their surfaces are parallel, and their formats overlap along the light transmission direction X. In this case, referring to FIG8 , the image P1 obtained based on the first sensing surface 301 and the image P2 obtained based on the second sensing surface 302 completely overlap along the light transmission direction X.

[0107] In some embodiments, due to limitations in process precision, the first sensing surface 301 and the second sensing surface 302 cannot be completely aligned along the light transmission direction X. In this case, referring to FIG. 9 , the image P1 obtained based on the first sensing surface 301 and the image P2 obtained based on the second sensing surface 302 cannot completely overlap along the light transmission direction X.

[0108] In order to ensure calibration accuracy, in one embodiment, the control component can also be used to determine whether the first sensing surface and the second sensing surface are aligned along the direction of light transmission, and when they are not aligned, determine the angle between the first coordinate system where the first sensing surface is located and the second coordinate system where the second sensing surface is located, and after performing coordinate system conversion on any one of the first light spot position and the second light spot position based on the angle, determine whether the first light spot position and the second light spot position are symmetrical around the center of the detection component.

[0109] Specifically, when determining the angle between the first coordinate system where the first sensing surface is located and the second coordinate system where the second sensing surface is located, the first detector and the second detector can be used to respectively capture two images of the same scene as test pattern images to obtain the coordinate system data of the two test images. Referring to Figure 9, the coordinate system data corresponding to the test image P1 obtained based on the first sensing surface 301 is P1', and the coordinate system data corresponding to the test image P2 obtained based on the second sensing surface 302 is P2'. If the coordinate axis positions of the two coordinate system data P1' and P2' do not completely coincide, the inventory can determine that the first sensing surface and the second sensing surface are not aligned along the direction of light transmission. At this time, the control component can calculate the angle between the two coordinate systems and store it.

[0110] Later in the calibration process, after obtaining the second light spot position, the coordinate system of the second light spot position can be transformed based on the coordinate system angle to obtain the position coordinates of the second light spot position in the coordinate system where the first light spot position is located, thereby determining whether the second light spot position and the first light spot position are symmetrical around the center of the detection component after the coordinate transformation.

[0111] Of course, in the subsequent calibration process, the control component can also perform a coordinate system conversion on the first light spot position based on the coordinate system angle after obtaining the first light spot position, and obtain the position coordinates of the first light spot position in the coordinate system where the second light spot position is located, thereby determining whether the first light spot position and the second light spot position are symmetrical around the center of the detection component after the coordinate conversion.

[0112] As can be seen from the foregoing, the heliostat auxiliary calibration device in the embodiment of the present invention can not only improve the adjustment accuracy of the heliostat (the adjustment accuracy can be achieved within 0.1° according to the optical solution), but also can calibrate the heliostat in the second phase. Moreover, during the calibration process, there is no need to rotate the heliostat auxiliary calibration device, only the heliostat needs to be rotated.

[0113] In addition, by providing a control component to perform alignment detection on the first sensing surface and the second sensing surface, the entire heliostat auxiliary calibration device does not require particularly high precision during the production and installation process.

[0114] When using an image sensor as a detection component, it can be in an online calibration state around the clock, improving the real-time performance of the calibration.

[0115] In order to enable those skilled in the art to better understand and implement the present invention, the method and system corresponding to the above-mentioned heliostat auxiliary calibration device are described in detail below.

[0116] 10 , an embodiment of the present invention further provides a heliostat auxiliary calibration method, wherein a heliostat is calibrated using any of the heliostat auxiliary calibration devices described in the above embodiments. Specifically, the method may include the following steps:

[0117] Step 110 , adjusting the position of the detection component so that the receiving tower target is located within the sensing range of the second sensing surface, and obtaining a second light spot position of the receiving tower target on the second sensing surface via the second optical surface.

[0118] Step 120 : Adjust the heliostat so that the image of the sun in the heliostat is located within the sensing range of the first sensing surface, and obtain a first spot position of the image of the sun in the heliostat on the first sensing surface through the first optical surface.

[0119] Step 130 : Determine whether the first light spot position and the second light spot position are symmetrical around the center of the detection component.

[0120] When the first light spot position and the second light spot position are not symmetrical around the center of the detection component, step 140 is executed.

[0121] Step 140: Determine an adjustment angle of the heliostat based on the first light spot position and the second light spot position.

[0122] After the adjustment angle of the heliostat is obtained, step 120 may be executed again until the second light spot position and the newly obtained first light spot position are symmetrical around the center of the detection assembly.

[0123] Before determining whether the first light spot position and the second light spot position are symmetrical around the center of the detection component, the method may further include:

[0124] Determine whether the first sensing surface and the second sensing surface are aligned along the direction of light transmission. When the first sensing surface and the second sensing surface are not aligned along the direction of light transmission, the angle between the first coordinate system where the first sensing surface is located and the second coordinate system where the second sensing surface is located can be determined first. Subsequently, when executing step 140, any one of the first light spot position and the second light spot position can be converted into a coordinate system based on the angle to determine whether the first light spot position and the second light spot position are symmetrical around the center of the detection component. If the first sensing surface and the second sensing surface are aligned along the direction of light transmission, then when executing step 140, whether the first light spot position and the second light spot position are symmetrical around the center of the detection component can be directly determined based on the detection result.

[0125] Referring to Figure 3 , assuming that the detection assembly includes a first detector 31 and a second detector 32, both of which are image sensors, the control assembly can first determine whether the first sensing surface 301 and the second sensing surface 302 are aligned. If they are not aligned, the angle between the first coordinate system of the first sensing surface and the second coordinate system of the second sensing surface can be calculated. If they are aligned, there is no need to calculate the angle between the first coordinate system of the first sensing surface and the second coordinate system of the second sensing surface.

[0126] During the actual calibration process, the first detector 31 can send the collected image data about the second light spot position to the control component 36. Based on the second light spot position, the control component 36 can adjust the rotation axis of the heliostat so that the image of the sun at the first light spot position and the second light spot position in the second detector are centrally symmetrical around the center point of the sensor.

[0127] For example, receiving tower target point A1 corresponds to sun image D1, and receiving tower target point A2 corresponds to sun image D2. Receiving tower target point A1 is completely perpendicular to first sensing surface 301, and the light emitted by sun image D1 is completely perpendicular to second sensing surface 302. This is a special case of three points coinciding. In this case, the sun can perfectly illuminate receiving tower target point A1.

[0128] It should be noted that, referring to FIG6 , during the actual calibration process, the image data sent by the first detector 31 to the control component 36 displays the second imaging position corresponding to the second light spot position. The image data sent by the second detector 32 to the control component 36 displays the first imaging position corresponding to the first light spot position. Because the first sensing surface 301 and the second sensing surface 302 are symmetrically located on either side of the detection component, when the first and second light spot positions are symmetrical about the center of the detection component, the coordinates of the first and second imaging positions along the X direction should be symmetrical relative to the center O of the detection component, and their coordinates along the Y direction should be identical relative to the center O of the detection component. The Y direction is perpendicular to the X direction.

[0129] In general, light is not perpendicular to a surface. For example, as shown in Figure 6, the direction of light from the receiving tower target A2 is parallel to the direction of light from the sun's image D2 after the heliostat is adjusted. Therefore, the offset between the actual illumination position A3 of the sun's image D2 and the receiving tower target A2 is negligible. This completes the real-time calibration of the heliostat, ensuring that the sun illuminates the receiving tower's target area.

[0130] If the direction of the sun's image D2 is not parallel to the direction of the light from the receiving tower target A2, the control assembly 36 can send an angle adjustment signal to the heliostat mount to fine-tune its angle. Ultimately, feedback control is used to bring the direction of the sun's image D2 parallel to the direction of the light from the receiving tower target A2.

[0131] The final state after adjustment is completed may be shown in FIG11 . At this time, the image D of the sun directly shines on the receiver 51 . The final result after calibration is that the sun directly shines on the receiver 51 .

[0132] An embodiment of the present invention further provides a solar thermal power generation system. Referring to FIG. 11 , the system may include:

[0133] Heliostat 40, receiving tower 50 and heliostat auxiliary calibration device, wherein the heliostat auxiliary calibration device corresponds to the heliostat one by one.

[0134] In a specific implementation, a heliostat auxiliary calibration device is provided corresponding to each heliostat one by one, so that each heliostat auxiliary calibration device can calibrate a unique heliostat, preventing interference between sunlight reflected by the heliostats, thereby improving calibration parallelism.

[0135] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A heliostat auxiliary calibration device, characterized in that: include: Calibration body, and detection components; The calibration body includes a first optical surface and a second optical surface arranged opposite to each other; The detection component is located on the calibration body; the detection component has a first sensing surface facing the first optical surface and a second sensing surface facing the second optical surface; The first sensing surface is parallel to the second sensing surface; The detection assembly is configured to detect a second light spot position of a target point of the receiving tower on the second sensing surface via the second optical surface, and to detect a first light spot position of an image of the sun in the heliostat on the first sensing surface via the first optical surface, so as to adjust the angle of the heliostat based on the second light spot position so that the first light spot position and the second light spot position are symmetrical around the center of the detection assembly.

2. The heliostat auxiliary calibration device according to claim 1, wherein: The calibration body includes: a light-shielding surface; the first optical surface and the second optical surface are located on two symmetrical sides of the light-shielding surface and connected with the light-shielding surface to form a receiving cavity; the detection component is located in the receiving cavity.

3. The heliostat auxiliary calibration device according to claim 1, wherein: The first optical surface has a first light-transmitting hole; the second optical surface has a second light-transmitting hole.

4. The heliostat auxiliary calibration device according to claim 3, wherein: At least one of the first light-transmitting hole and the second light-transmitting hole is located at the center of the optical surface.

5. The heliostat auxiliary calibration device according to claim 1, wherein: The first optical surface is provided by a first lens, and the second optical surface is provided by a second lens.

6. The heliostat auxiliary calibration device according to any one of claims 1 to 5, characterized in that: The detection assembly includes: a first detector and a second detector, the first detector being used to detect a first light spot position of the sun's image in the heliostat on the first sensing surface via the first optical surface, and the second detector being used to detect a second light spot position of the receiving tower target on the second sensing surface via the second optical surface.

7. The heliostat auxiliary calibration device according to claim 6, wherein: The first detector and the second detector are both image sensors.

8. The heliostat auxiliary calibration device according to claim 6, wherein: The first detector and the second detector are arranged back to back.

9. The heliostat auxiliary calibration device according to claim 6, wherein: The first sensing surface is aligned with the second sensing surface along a light transmission direction.

10. The heliostat auxiliary calibration device according to claim 1, wherein: Also includes: A control assembly; wherein: the control component is configured to determine whether the first light spot position and the second light spot position are symmetrical about the center of the detection component, and determine an adjustment angle of the heliostat based on the first light spot position and the second light spot position if the first light spot position and the second light spot position are not symmetrical about the center of the detection component; The control component is in communication connection with the heliostat support; the heliostat support is used to perform an angle adjustment operation on the heliostat under the control of the control component.

11. The heliostat auxiliary calibration device according to claim 10, wherein: Also includes: Calibration body bracket; the calibration body bracket is installed on the heliostat bracket or the mirror surface of the heliostat.

12. The heliostat auxiliary calibration device according to claim 10, wherein: The control component is also used to determine whether the first sensing surface and the second sensing surface are aligned along the direction of light transmission, and when they are not aligned, determine the angle between the first coordinate system where the first sensing surface is located and the second coordinate system where the second sensing surface is located, and after performing a coordinate system conversion on any one of the first light spot position and the second light spot position based on the angle, determine whether the first light spot position and the second light spot position are symmetrical around the center of the detection component.

13. The heliostat auxiliary calibration device according to claim 1, wherein: The calibration body is a cylinder.

14. The heliostat auxiliary calibration device according to claim 1, wherein: The receiving tower target point is the center point of the receiver on the receiving tower.

15. A heliostat assisted calibration method, characterized in that: A heliostat is calibrated using the heliostat auxiliary calibration device according to any one of claims 1 to 14; the method comprising: Adjusting the position of the detection component so that the receiving tower target is located within the sensing range of the second sensing surface, and obtaining a second light spot position of the receiving tower target on the second sensing surface via the second optical surface; Adjusting the heliostat so that the image of the sun in the heliostat is located within the sensing range of the first sensing surface, and obtaining a first spot position of the image of the sun in the heliostat on the first sensing surface via the first optical surface; determining whether the first light spot position and the second light spot position are symmetrical around the center of the detection component; In response to the first light spot position and the second light spot position not being symmetrical about the center of the detection assembly, determining an adjustment angle of the heliostat based on the first light spot position and the second light spot position; Based on the determined adjustment angle of the heliostat, the heliostat is adjusted, and the first light spot position is re-detected until the second light spot position is symmetrical to the re-obtained first light spot position around the center of the detection assembly.

16. The heliostat-assisted calibration method according to claim 15, wherein: Before determining whether the first light spot position and the second light spot position are symmetrical around the center of the detection component, the method further includes: Determine whether the first sensing surface and the second sensing surface are aligned along the light transmission direction allow; In response to the first sensing surface and the second sensing surface being misaligned along the light transmission direction, determining an angle between a first coordinate system where the first sensing surface is located and a second coordinate system where the second sensing surface is located; After performing coordinate system conversion on any one of the first light spot position and the second light spot position based on the included angle, it is determined whether the first light spot position and the second light spot position are symmetrical around the center of the detection component.

17. A solar thermal power generation system, characterized in that: include: A heliostat, a receiving tower, and the heliostat auxiliary calibration device according to any one of claims 1 to 15, wherein the heliostat auxiliary calibration device corresponds to the heliostat in a one-to-one manner.

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