Optical beam former for concentrated radiation and optical system with optical beam former

Abstract

Optical beam former (10) for concentrated radiation, comprising an outer beam former (12) which forms a beam passage (18) extending along a central axis (16) for conducting the concentrated radiation and which has a beam inlet opening (20) and a beam outlet opening (22), wherein the beam passage (18) has a radiation-reflecting inner wall (24), wherein the beam inlet opening (20) has a first maximum diameter D1 transverse to the central axis (16), and comprising an inner beam former (14) which has a radiation-reflecting outer wall (26) and is arranged coaxially to the outer beam former (12), wherein the inner beam former (14) has a second maximum diameter D2 transverse to the central axis (16), wherein D1 ≥ 1.5 D2.

Description

[0001] The present invention relates to a beam former for concentrated radiation and to an optical system comprising such an optical beam former.

[0002] Light sources such as the sun, short-arc lamps, and LEDs typically have emission zones that are round, spherical, or ellipsoidal in shape. If the light source is projected onto target surfaces using optical elements, the intensity distribution on the target surface will also exhibit a correspondingly round shape, resulting in an uneven distribution across the target surface.

[0003] When irradiating surfaces such as test areas but also areas of solar receivers or photovoltaic surfaces, a uniform intensity of the irradiation is often advantageous.

[0004] To achieve uniformity of the concentrated radiation, optical elements such as beam shapers or collimators are known, which ensure uniformity of the radiation. One such beam shaper is known from DE 10 2017 214 227 A1, owned by the applicant.

[0005] US 2006 / 0193066 A1 discloses a beam former having the features of the preamble of claim 1. Further beam formers are known from EP 0 194 820 A2 and DE 10 2008 025 820 A1.

[0006] However, it has been found that the previously known beam formers are often still unable to produce an insufficient uniformity of the intensity of the radiation incident on a test surface and, in particular, when using polygonal, especially rectangular, irradiated surfaces, the intensity distribution in the corners is insufficiently uniform.

[0007] It is therefore the object of the present invention to provide a beam former of the type mentioned at the outset which effects an improved intensity distribution of light, in particular in polygonal, irradiated surfaces, wherein preferably an adjustment option for fine adjustment and adaptation is provided.

[0008] The invention is defined by the features of claim 1.

[0009] The optical beam shaper for concentrated radiation according to the invention has an outer beam shaping part that forms a beam passage extending along a central axis for passing the concentrated radiation, and a beam inlet opening and a beam outlet opening, wherein the beam passage has a radiation-reflecting inner wall, wherein the beam inlet opening has a maximum diameter D1 transverse to the central axis. The invention is characterized by an inner beam shaping part that has a reflective outer wall and is arranged coaxially to the outer beam shaping part, wherein the inner beam shaping part has a second maximum diameter D2 transverse to the central axis, where: D1≥1.5 D2, preferably D1≥2 D2.

[0010] The inner beam shaping part reflects the high intensity of the radiation present in the center of the concentrated radiation outward through the reflective outer wall and at least partially enters the beam passage of the outer beam shaping part, where the radiation is then further reflected by the reflective inner wall of the outer beam shaping part. Because the inner beam shaping part is located on the central axis and thus in the area of ​​greatest radiation intensity, the area of ​​the radiation with the highest radiation intensity can be better distributed.Because the maximum diameter D1 of the beam inlet opening is at least twice as large as the maximum diameter D2 of the inner beam shaping part, it can be ensured that at least a large part of the beam from the reflective outer wall of the inner beam shaping part reaches the beam passage of the outer beam shaping part and is reflected there.

[0011] For the purposes of this invention, "maximum diameter" refers to the maximum extension in the diameter direction. For example, for a circular diameter, the maximum diameter corresponds to the diameter of the circle, and for a square cross-section, the maximum diameter corresponds to the diagonal.

[0012] Preferably, the outer beam shaping part has a hollow cylindrical shape, with the beam passage having a constant cross-section. Within the scope of the invention, the hollow cylindrical shape does not mean that only a circular cross-section is present; rather, other cross-sectional shapes, such as rectangular, square, polygonal, or even an elliptical cross-section, are also possible.

[0013] Alternatively, the outer beam shaping part can be provided with a hollow truncated cone shape or a hollow truncated pyramid shape, with the beam passage having a cross-section that tapers from the beam inlet opening to the beam outlet opening. This type of configuration has proven particularly advantageous because, when radiation enters through the beam inlet opening, it can, on the one hand, achieve a comparatively good homogenization of the intensity distribution and, at the same time, further concentration on, for example, a target to be irradiated.

[0014] In a further alternative embodiment, the outer beam shaping part can also have a double hollow truncated cone shape or a double hollow truncated pyramid shape, wherein the beam passage has a cross-section that initially tapers from the beam inlet opening to the beam outlet opening and then widens, or a cross-section that initially tapers from the beam inlet opening to the beam outlet opening and then widens.

[0015] The truncated pyramid shapes can be regular truncated pyramid shapes or, for example, the shapes of a truncated wedge or double truncated wedge.

[0016] The terms “reflective outer wall” or “reflective inner wall” or also with regard to all other reflective surfaces within the scope of the present invention are understood to mean surfaces which have a radiation reflectance of at least 60%, preferably at least 75%, preferably hemispherical solar (AM 1.5) reflectance of at least 60%, preferably at least 75%.

[0017] The beam inlet opening of the outer beam shaping part can have a circular, elliptical, rectangular, preferably square, or polygonal shape. The beam outlet opening of the outer beam shaping part can have a circular, elliptical, rectangular, preferably square, or polygonal shape. In principle, the beam inlet opening and the beam outlet opening can have the same shape. It is also possible for the beam inlet opening and the beam outlet opening to have different shapes. For example, it can be provided that the beam outlet opening has a shape adapted to the target, for example, a square shape, and the beam inlet opening has a polygonal, for example, octagonal shape.Such an arrangement has the advantage, for example, that the shape of the beam exit opening can correspond to the shape of the target and the beam entry opening, as an octagon, has a shape approximating a circle, which is thus adapted to a radiation source, wherein at the same time the reflective inner wall in the beam passage can consist of several flat surfaces, which simplifies the manufacture of the outer beam shaping part.

[0018] It is preferably provided that the beam inlet opening of the outer beam shaping part and the beam outlet opening of the outer beam shaping part have the same shape and the beam passage has a cross-sectional shape adapted to the beam inlet opening and the beam outlet opening.

[0019] The inner jet-forming part can have a cross-section with a circular, elliptical, rectangular, preferably square, or polygonal shape. In principle, the inner jet-forming part can have a cross-sectional shape adapted to the outer jet-forming part or a different cross-sectional shape,

[0020] Preferably, the inner beam shaping part extends at least partially into the beam passage of the outer beam shaping part. Depending on the design of a radiation source for concentrated radiation and, if applicable, the position of the focal point of the radiation, arranging the inner beam shaping part at least partially into the beam passage of the outer beam shaping part can be advantageous in order to direct a large portion of the radiation reflected by the reflective outer wall of the inner beam shaping part into the beam passage of the outer beam shaping part.

[0021] It can also be provided that the inner beam shaping part is located completely in the beam passage of the outer beam shaping part.

[0022] The inner beam shaping part can be closed in the direction of the radiation source, with the inner beam shaping part tapering as sharply as possible towards a radiation source. In principle, however, it is preferred if the inner beam shaping part forms a second beam passage extending along the central axis for conducting the concentrated radiation, and has a second beam inlet opening and a second beam outlet opening, wherein the second beam passage has a radiation-reflecting second inner wall. Thus, a portion of the radiation located in the center in the region of the central axis can be guided through the second beam passage, whereas another portion is reflected by the outer wall of the inner beam shaping part and directed towards the outer wall of the outer beam shaping part.

[0023] In particular, it can be provided that the inner beam shaping part has a hollow truncated cone shape or a hollow truncated pyramid shape, wherein the second beam passage has a cross-section widening from the second beam inlet opening to the second beam outlet opening.

[0024] The second beam entry opening is thus smaller than the second beam exit opening. This ensures that only a small portion of the radiation from the center, where the intensity is high, passes through the second beam entry opening into the second beam passage and is reflected by the second inner walls, with this radiation being distributed to the larger second beam exit opening. Another portion of the radiation from the center, which has a high intensity, is reflected outwards by the outer wall of the inner beam shaping part and evened out via the outer beam shaping part. This allows the high beam intensity in the center in particular to be advantageously distributed and thus evened out.

[0025] The second beam inlet opening of the inner beam shaping part can have a circular, elliptical, rectangular, preferably square, or polygonal shape and / or the second beam outlet opening of the inner beam shaping part can have a circular, elliptical, rectangular, preferably square, or polygonal shape.

[0026] The reflective inner wall of the outer beam shaping part, the reflective outer wall of the inner beam shaping part and / or the reflective second inner wall of the inner beam shaping part can be a mirror-coated or polished surface.

[0027] According to the invention, the inner beam shaping part is arranged so that it can be displaced relative to the outer beam shaping part in the direction of the central axis. Thus, the position of the inner beam shaping part can be adjusted relative to the outer beam shaping part, allowing adjustments to be made to achieve an improved distribution of the radiation onto a target.

[0028] Alternatively or additionally, according to the invention, the inner beam shaping part can be rotatable relative to the outer beam shaping part about the central axis. Thus, by rotating the inner beam shaping part, the position of the inner beam shaping part and thus the radiation distribution can be optimized.

[0029] In a particularly preferred embodiment of the invention, the outer beam shaping part has a square cross-section and the inner beam shaping part has a square cross-section, wherein the inner beam shaping part is rotated by 45° around the central axis relative to the outer beam shaping part. This ensures that the surfaces of the outer wall of the inner beam shaping part face the corners of the inner wall of the outer beam shaping part, so that radiation reflected by the outer wall of the inner beam shaping part can advantageously reach the corners of the outer beam shaping part, thus achieving improved radiation distribution in the corners.

[0030] In a preferred embodiment of the present invention, it is provided that the inner beam shaping part is arranged at least partially in the beam passage of the outer beam shaping part, wherein at least one holding rib extends from the reflective outer wall of the inner beam shaping part to the reflective inner wall of the outer beam shaping part for holding the inner beam shaping part, wherein the at least one holding rib has surfaces that reflect the radiation. By means of the holding rib, the inner beam shaping part can thus be advantageously held in the outer beam shaping part. In this embodiment, it can be provided, for example, that the inner beam shaping part has an octagonal cross-section of the second beam inlet opening and a square cross-section of the second beam outlet opening.The outer beam shaping part can have an octagonal cross-section beam inlet opening and a square beam outlet opening. The inner beam shaping part can be held by several, for example, eight, holding ribs, so that the second beam passage forms an inner channel and eight outer channels, through which a particularly advantageous uniformity of the radiation intensity on a target can be achieved.

[0031] The invention further relates to an optical system comprising a radiation concentrator or a radiation source, a target to be irradiated with the radiation, for example, a target surface, and a beam former according to the invention. Such a system can be used, for example, for experimental purposes for testing solar receivers. The target can also be a photovoltaic cell, for example, so that the optical system can be used to concentrate radiation onto a photovoltaic cell.

[0032] Preferably, the outer beam-shaping part is arranged so that it can be displaced relative to the target. This allows adjustments and fine adjustments to be made to the optical system. The displacement can occur, in particular, in the direction of the central axis of the optical beam shaper.

[0033] In this case, the outer beam shaping part and the inner beam shaping part can be slidably mounted on a rail via a respective bracket. Such a design allows for the outer and inner beam shaping parts to be slidably mounted on a rail with a simple construction, allowing them to be moved relative to each other and relative to the target, thus enabling simple adjustment and fine-tuning for uniform radiation of the target.

[0034] A preferably adjustable aperture can also be arranged in the beam path in front of the inner beam shaping part, via which the radiation that hits the inner beam shaping part or enters the second beam path can be adjusted.

[0035] The radiation can be light, for example, solar radiation. In principle, the radiation can encompass ranges of the electromagnetic spectrum from the X-ray range to the infrared.

[0036] The invention is explained in more detail below with reference to the following figures.

[0037] They show: Fig. 1 a first embodiment of an optical system according to the invention with an optical beam former according to the invention and Fig. 2 a second embodiment of an optical system according to the invention with an optical beam former according to the invention.

[0038] In Fig. Figure 1 schematically illustrates an optical system 100 according to the invention. The optical system 100 consists of a radiation concentrator 110, a target 120 to be irradiated with the radiation, and an optical beam shaper 10 according to the invention.

[0039] In this example, it's important to note that we want to irradiate a square area. If the target is hexagonal, the arrangement can be adjusted accordingly.

[0040] The optical beam former 10 consists of an outer beam former 12 and an inner beam former 14. The inner beam former 14 and the outer beam former 12 are arranged coaxially to one another on a central axis 16.

[0041] The inner beam shaping part 14 and the outer beam shaping part 12 are movably mounted on a rail 140 via holders 19. Thus, the inner beam shaping part 14 can be moved relative to the outer beam shaping part 12, and both beam shaping parts 12 and 14 can be moved relative to the target 120.

[0042] The outer beam shaping part 12 forms a beam passage 18 for the passage of the concentrated radiation and extends along the central axis 16. The radiation can be introduced into the beam passage 18 through a beam inlet opening 20 and the radiation leaves the outer beam shaping part 12 through a beam outlet opening 22 and reaches the target 120.

[0043] The outer beam shaping part 12 has a rectangular cross-section and tapers toward the target 120. A reflective inner wall 24 surrounds the beam passage 18.

[0044] The inner beam shaping part 14 also has a square cross-section and widens toward the outer beam shaping part 12. The inner beam shaping part 14 has a reflective outer wall 26. The inner beam shaping part 14 forms a second beam passage 28 extending along the central axis for passing the concentrated radiation and has a second beam inlet opening 30 and a second beam outlet opening 32. The second beam passage 28 has a second inner wall 34 that reflects the radiation.

[0045] In Fig. In Figure 1, the inner beam shaping part 14 is shown at a distance from the outer beam shaping part 12 for clarity. During operation, the inner beam shaping part 14 is positioned by means of the rail 140 such that the inner beam shaping part 14 is partially located within the beam passage 18 of the outer beam shaping part 12. This ensures that radiation from the concentrator 110 that strikes the reflective outer wall 26 of the inner beam shaping part 14 is reflected and strikes the reflective inner wall 24 of the outer beam shaping part 12.

[0046] The inner beam shaping part 14 is rotated by 45° relative to the outer beam shaping part 12, so that reflective surfaces of the reflective outer wall 26 face corners of the beam passage 18 of the outer beam shaping part 12, whereby during operation radiation is guided more effectively into the corners of the outer beam shaping part 12, so that on the target 120 there is an improved intensity distribution even in the corners.

[0047] Furthermore, the inner beam shaping part 14 ensures that a small portion of the high-intensity radiation in the center of the concentrated radiation, and thus located in the region of the central axis 16, passes through the second beam inlet opening 30 into the inner beam shaping part 14, whereas a large portion of the high-intensity radiation from the center region is reflected by the outer wall 26 and thus distributed. The portion of the radiation passing through the second beam inlet opening 30 into the second beam passage 28 is distributed over a larger area by the widening shape of the inner beam shaping part 14, so that an overall improved uniformity of the beam intensity on the target 120 can be achieved.

[0048] The beam inlet opening 20 of the outer beam shaping part 12 has a first maximum diameter D1 transverse to the central axis 16, which is larger than the second maximum diameter D2 of the inner beam shaping part 14 transverse to the central axis 16, where D1≥1.5 D2 applies. This ensures that the inner beam shaping part 14 can be partially located within the outer beam shaping part 12.

[0049] In Fig. 2 shows a second embodiment of an optical system 100 according to the invention. Fig. The optical system 100 shown in Figure 2 has, just like the one shown in Fig. 1, the optical system 100 comprises a radiation concentrator 110, a target 120 to be irradiated, and an optical beam former 10 according to the invention. The outer beam former part 12 of the optical beam former 10 is movably mounted on a rail 140 and is movable relative to the target 120. In the Fig. In the embodiment shown in Figure 2, the outer beam shaping part 12 is designed such that it has an octagonal beam inlet opening 20 and a square beam outlet opening 22. The inner beam shaping part 14 is arranged completely within the outer beam shaping part 12 and is held by holding ribs 36 that extend from the reflective outer wall 26 of the inner beam shaping part 14 to the reflective inner wall 24 of the outer beam shaping part 12. The inner beam shaping part 14 also has a second beam inlet opening 30 with an octagonal shape and a beam outlet opening 32 that has a square shape. Fig.The optical beam former 10 according to the invention shown in Figure 2 has the advantage that nine channels are formed for radiation guidance. The octagonal shape of the beam inlet opening 20 creates a shape that approximates a round light spot of the radiation source, and the radiation is transformed by the optical beam former 10 into a square shape that is adapted to the target 120. Furthermore, the individual channels achieve an advantageous uniformity of the light intensity. List of reference symbols 10 optical beam formers 12 outer jet forming part 14 inner jet molding 16 Central axis 18 Ray passage 19 Bracket 20 Beam entrance opening 22 Beam exit opening 23 Ray passage 24 inner wall 26 Outer wall 28 second beam pass 30 second beam entrance opening 32 second beam exit opening 34 inner wall 36 holding ribs 100 optical system 110 Concentrator 120 Target 140 rail D1 diameter D2 diameter

Claims

[1] Optical beam former (10) for concentrated radiation, comprising an outer beam former (12) which forms a beam passage (18) extending along a central axis (16) for the passage of the concentrated radiation and has a beam inlet opening (20) and a beam outlet opening (22), wherein the beam passage (18) has a radiation-reflecting inner wall (24), wherein the beam inlet opening (20) has a first maximum diameter D1 transverse to the central axis (16), wherein an inner beam shaping part (14) has a radiation-reflecting outer wall (26) and is arranged coaxially to the outer beam shaping part (12), wherein the inner beam shaping part (14) has a second maximum diameter D2 transverse to the central axis (16), where D1 ≥ 1.5 D2, characterized by , that the inner jet-forming part (14) is arranged to be displaceable in the direction of the central axis (16) relative to the outer jet-forming part (12) and / or that the inner jet shaping part (14) is rotatable about the central axis (16) relative to the outer jet shaping part (12). [2] Optical beam former according to claim 1, characterized by that the outer beam shaping part (12) has a hollow cylindrical shape, wherein the beam passage (18) preferably has a constant cross-section. [3] Optical beam former according to claim 1, characterized by that the outer beam shaping part (12) has a hollow truncated cone shape or a hollow truncated pyramid shape, wherein the beam passage (18) has a cross-section tapering from the beam inlet opening (20) to the beam outlet opening (22). [4] Optical beam former according to claim 1, characterized byin that the outer beam shaping part (12) has a double hollow truncated cone shape or a double hollow truncated pyramid shape, wherein the beam passage (18) has a cross-section which initially tapers and then widens from the beam inlet opening (20) to the beam outlet opening (22) or a cross-section which initially tapers and then widens from the beam inlet opening (20) to the beam outlet opening (22). [5] Optical beam former according to one of claims 1 to 4, characterized by that the beam inlet opening (20) of the outer beam shaping part (12) has a circular, elliptical, rectangular, preferably square, or polygonal shape and / or the beam outlet opening (22) of the outer beam shaping part (12) has a circular, elliptical, rectangular, preferably square, or polygonal shape. [6] Optical beam former according to claim 5, characterized bythat the beam inlet opening (20) of the outer beam shaping part (12) and the beam outlet opening (22) of the outer beam shaping part (12) have the same shape and the beam passage (18) has a cross-sectional shape adapted to the beam inlet opening (20) and the beam outlet opening (22). [7] Optical beam former according to one of claims 1 to 6, characterized by that the inner jet shaping part (14) has a cross-section with a circular, elliptical, rectangular, preferably square, or polygonal shape. [8] Optical beam former according to one of claims 1 to 7, characterized by that the inner beam shaping part (14) extends at least partially into the beam passage of the outer beam shaping part (12). [9] Optical beam former according to claim 8, characterized by that the inner beam shaping part (14) is arranged completely in the beam passage of the outer beam shaping part (12). [10] Optical beam former according to one of the preceding claims, characterized by in that the inner beam shaping part (14) forms a second beam passage (28) extending along the central axis (16) for passing the concentrated radiation and has a second beam inlet opening (30) and a second beam outlet opening (32), wherein the second beam passage (28) has a radiation-reflecting second inner wall (34). [11] Optical beam former according to claim 10, characterized by that the inner beam shaping part (14) has a hollow truncated cone shape or a hollow truncated pyramid shape, wherein the second beam passage has a cross-section widening from the second beam inlet opening to the second beam outlet opening. [12] Optical beam former according to one of the preceding claims, characterized bythat the reflective inner wall (24) of the outer beam shaping part (12), the reflective outer wall of the inner beam shaping part (14) and / or the reflective second inner wall of the inner beam shaping part (14) is / are a mirror-coated or polished surface. [13] Optical beam former according to one of the preceding claims, characterized by that the outer jet-forming part (12) has a rectangular cross-section and the inner jet-forming part (14) has a rectangular cross-section, wherein the inner jet-forming part (14) is rotated by 45° about the central axis (16) relative to the outer jet-forming part (12). [14] Optical beam former according to one of the preceding claims, characterized bythat the inner beam shaping part (14) is arranged at least partially in the beam passage of the outer beam shaping part (12), wherein at least one holding rib (36) extends from the reflective outer wall (26) of the inner beam shaping part (14) to the reflective inner wall (24) of the outer beam shaping part (12) for holding the inner beam shaping part (14), wherein the at least one holding rib (36) has surfaces that reflect the radiation. [15] Optical system (100) with a concentrator (110) for radiation or with a radiation source, a target (120) to be irradiated with the radiation and an optical beam former (10) according to one of claims 1 to 14. [16] Optical system according to claim 15, characterized by that the outer beam shaping part (12) is arranged displaceably relative to the target (120). [17] Optical system according to claim 16, characterized bythat the outer jet forming part (12) and the inner jet forming part (14) are each movably mounted on a rail (140) via a holder (19).

Images