Thermal solar collector arrangement for heating a fluid.

Abstract

Disclosed is a thermal solar collector arrangement (1) comprising a solar energy absorbing tube (10) for a fluid and a reflector (20) arranged along the tube (10) and arranged to focus reflected light onto the tube (10) so that the fluid inside the tube (10) is heated up. The arrangement (1) has a wall (30, 35) and a foot (40, 45) on its respective first and second end (1a, 1b) through which the tube (10) extends. The reflector (20) and the walls (30, 35) are rotatable in relation to the feet (40, 45). The walls (30, 35) and feet (40, 45) are so dimensioned that the reflector (20) can be rotated from its open position where it receives sunlight into a closed position where an inner side (22) of the reflector is enclosed by the walls (30, 35), and the rotated reflector. Hereby, the reflector can easily be protected when for example a sandstorm approaches.

Description

/ 22 Thermal solar collector arrangement for heating a fluid. Technical field

[001] The present invention relates generally to a solar thermal collector arrangement for heating a fluid. More specifically, the present invention relates to a solar collector arrangement comprising a solar energy absorber tube for a fluid and a reflector disposed along the solar energy absorber tube and configured to focus reflected light onto the solar energy absorber tube, so that the fluid inside the solar energy absorber tube is heated. Fundamentals of the technique

[002] Solar energy is a virtually inexhaustible energy resource received across the entire surface of the Earth during daylight hours. Furthermore, solar energy is a clean and renewable energy resource. Additionally, anyone can harness solar energy, since no one owns the energy of the sun's rays, unlike fossil fuels, hydroelectric power, etc. In short, this makes solar energy the most suitable energy resource for anyone, for example in poorer countries.

[003] One type of equipment for harnessing solar energy is a solar thermal collector. A solar thermal collector uses solar energy to heat a medium, especially a fluid, for example water. Typically, a solar thermal collector arrangement comprises a solar energy absorber tube for a fluid and a reflector arranged along the solar energy absorber tube and configured to focus reflected light onto the solar energy absorber tube, so that the fluid inside the solar energy absorber tube is heated.

[004] Examples of such arrangements of solar thermal collectors are described in the published international patent applications WO23187373A1 and Petition 870260043921, dated 09 / 05 / 2026, page 8 / 41 / 22 WO22245197A1. The solar thermal collectors described in these documents are rotatable to follow the sun's movement across the sky. Such solar thermal collectors are used in rural areas and will therefore be exposed to harsh weather conditions and other external impacts that can affect the solar thermal collector. For example, if the solar thermal collector arrangement in document WO22245197 is exposed to a sandstorm, the motors and transmissions that provide the rotational movement and tilting movement of the upper support structure may be destroyed. Furthermore, a sandstorm would impact the inner surface of the reflector. In short, a sandstorm would significantly reduce the lifespan of this solar thermal collector arrangement. Consequently, there is a need for a solar thermal collector arrangement that can withstand harsh weather conditions and other external impacts. Summary of the invention

[005] One objective of the embodiments of the present invention is to provide a solar thermal collector arrangement that can withstand severe weather conditions and other external impacts. Another objective of the embodiments is to provide a solar thermal collector arrangement that is economically efficient so that it is accessible to most people. Another objective is to provide a solar thermal collector arrangement that is easy to handle. It is possible to achieve at least one of these objectives through the use of a solar thermal collector arrangement as defined in any of the appended claims.

[006] According to one aspect, a solar thermal collector arrangement is provided that extends in an extension direction from its first end towards its second end. The solar collector arrangement comprises a solar energy absorber tube for receiving a fluid, the solar energy absorber tube having a central geometric axis that extends in the extension direction. The solar collector arrangement further comprises a reflector that extends along the absorber tube. Petition 870260043921, dated 09 / 05 / 2026, page 9 / 41 / 22 solar energy from its first end to its opposite second end. The reflector has an inner reflective surface facing the solar energy absorber tube. The reflector has a curved shape arranged so that the light incident on the inner surface of the reflector, after being reflected, falls on the solar energy absorber tube. The curved shape is a cross-sectional shape curved in a plane perpendicular to the direction of extension. The curved cross-sectional shape extends in the plane perpendicular to the direction of extension from a first cross-sectional end to a second cross-sectional end of the reflector. The solar collector arrangement further comprises a first wall fixed to the first end of the reflector, along the inner surface of the reflector.The first wall has a base that extends between the first cross-sectional end and the second cross-sectional end of the reflector, the base being spaced from the reflector between the first and second cross-sectional ends. The solar collector arrangement further comprises a second wall attached to the second end of the reflector, along the inner surface of the reflector. The second wall has a base that extends between the first cross-sectional end and the second cross-sectional end of the reflector, the base being spaced from the reflector between the first and second cross-sectional ends.The solar collector arrangement further comprises a first foot disposed at the first end of the solar collector arrangement, the first foot having a base for positioning on a ground surface or on a support, and a second foot disposed at the second end of the solar collector arrangement, the second foot having a base to be positioned on a ground surface or on a support. Additionally, the solar energy absorber tube extends through the first foot, the first wall, the second wall, and the second foot. The reflector, the first wall, and the second wall are rotatable relative to the first and second feet. Petition 870260043921, dated 09 / 05 / 2026, page 10 / 41 / 22 second feet and are rotatable around the central geometric axis of the solar energy absorber tube. Additionally, the first foot, the first wall, the second foot, and the second wall are dimensioned in such a way that the reflector, when rotated around the central geometric axis, can be rotated to a closed position in which the base of the first wall is level with the base of the first foot and the base of the second wall is level with the base of the second foot. Additionally, when the base of the first foot and the base of the second foot are positioned on a ground surface, the solar thermal collector is configured to be elevated when the reflector must be rotated around the central geometric axis to the closed position.

[007] In such a closed position, the base of the first wall is approximately at the same level as the base of the first foot. Furthermore, the base of the second wall is approximately at the same level as the base of the second foot. Additionally, when the bases of the first and second feet are positioned on the ground, this means that the bases of the first and second walls will also be on the ground.Additionally, since the first wall is fixed to the first end of the reflector, along the inner surface of the reflector, and the second wall is fixed to the second end of the reflector, along the inner surface of the reflector, when the reflector has been rotated to the closed position and the bases of the first and second feet are positioned on the ground, the first wall and the second wall form a more or less closed space together with the ground surface and the reflector, or, more specifically, the outer side of the reflector, at least as long as the ground surface is relatively uniform.Thus, by rotating the reflector to the closed position, along with the first and second walls that are fixed to the reflector, that is, so that the reflector is more or less inverted in relation to the open position, that is, when used as a reflector to reflect sunlight towards the solar energy absorber tube, the inner surface of the reflector is properly... Petition 870260043921, dated 09 / 05 / 2026, page 11 / 41 / 22 protected when, for example, sandstorms or other types of events occur that could damage the internal surface of the reflector. In the long term, by simply rotating the reflector when not in use and / or when adverse weather conditions approach, the lifespan of the solar collector array can be significantly extended. In the case where the bases of the first and second feet are positioned on the ground when the reflector needs to be rotated to the closed position, the solar thermal collector is configured to be elevated. This is done so as to allow the reflector to be rotated to the closed position without the reflector being impeded by the ground surface.In cases where the bases of the first and second feet are positioned on one or more supports, this rotation can be performed without any elevation, provided that the supports are high enough to allow free passage of the reflector relative to the ground on which the supports are arranged during the rotation. Protection against adverse weather conditions is not as effective in the closed position with this arrangement on supports compared to when placed directly on the ground. However, the protection is superior to that obtained when the arrangement is in the open position. Additionally, in order to obtain better protection against inclement weather when the arrangement is positioned on supports, the arrangement can be raised from the supports after the reflector has been rotated to the closed position and then placed in the closed position on the ground.

[008] According to one embodiment, a first wall position in which the solar energy absorber tube extends through the first wall, a second wall position in which the solar energy absorber tube extends through the second wall, a first foot position in which the solar energy absorber tube extends through the first foot, and a second foot position in which the solar energy absorber tube extends through the second foot are selected such that the reflector, when rotated around the central geometric axis, can be rotated to Petition 870260043921, dated 09 / 05 / 2026, page 12 / 41 / 22 a closed position in which the base of the first wall is level with the base of the first foot and the base of the second wall is level with the base of the second foot. Thus, it is defined that, through the appropriate selection of these positions, the reflector can be rotated to the closed position. According to one embodiment, the first wall has a hole in the first wall position through which the solar energy absorber tube extends, the first foot has a hole in the first foot position through which the solar energy absorber tube extends, the second wall has a hole in the second wall position through which the solar energy absorber tube extends, and the second foot has a hole in the second foot position through which the solar energy absorber tube extends.

[009] According to another embodiment, a first distance between a position of the first wall in which the solar energy absorber tube extends through the first wall and the base of the first wall, the first distance being perpendicular to the base of the first wall is approximately the same as a second distance between a position of the first foot in which the solar energy absorber tube extends through the first foot and the base of the first foot, the second distance being perpendicular to the base of the first foot.Furthermore, a third distance between a position on the second wall where the solar energy absorber tube extends through the second wall and the base of the second wall, the third distance being perpendicular to the base of the second wall, is approximately the same as a fourth distance between a position on the second foot where the solar energy absorber tube extends through the second foot and the base of the second foot, the fourth distance being perpendicular to the base of the second foot.

[0010] According to another embodiment, the first wall has a hole through which the solar energy absorber tube extends, and the first foot has a hole through which the solar energy absorber tube extends. Furthermore, a first distance between the hole of the first Petition 870260043921, dated 09 / 05 / 2026, page 13 / 41 / 22 wall and the base of the first wall, perpendicular to the base of the first wall, is approximately the same as a second distance between the hole of the first foot and the base of the first foot, perpendicular to the base of the first foot. Furthermore, the second wall has a hole through which the solar energy absorber tube extends, and the second foot has a hole through which the solar energy absorber tube extends. Furthermore, a third distance between the hole of the second wall and the base of the second wall, perpendicular to the base of the second wall, is approximately the same as a fourth distance between the hole of the second foot and the base of the second foot, perpendicular to the base of the second foot.

[0011] According to another embodiment, the first foot is positioned outside the first wall so that the first foot is facing a side of the first wall that is away from the second wall. Furthermore, the second foot is positioned outside the second wall so that the second foot is facing a side of the second wall that is away from the first wall.

[0012] According to yet another embodiment, the reflector has a circular shape in the plane of cross-section and an extension from its first cross-sectional extremity to its second cross-sectional extremity spanning approximately 180 degrees as seen from the center of a circle of the circular shape. Alternatively, the reflector has an elliptical shape in the plane of cross-section and an extension from its first cross-sectional extremity to its second cross-sectional extremity spanning approximately 180 degrees as seen from the center of an ellipse of the elliptical shape.

[0013] According to yet another embodiment, the base of the first wall provides a flat surface facing away from the inner surface of the reflector, and the base of the second wall provides a flat surface facing away from the inner surface of the reflector. In this way, a Petition 870260043921, dated 09 / 05 / 2026, page 14 / 41 / 22 good protection against surrounding sand etc., since the bases seal, to a greater or lesser degree, against the ground when the arrangement is positioned on the ground surface after being rotated to the closed position, provided that the ground is substantially flat.

[0014] According to another embodiment, the curved cross-sectional shape of the reflector in the Y-plane perpendicular to the extension direction is an arc of a circle, and the solar energy absorber tube is positioned offset from the center of the circle. Typically, such a reflector has an elliptical cross-sectional shape, and the solar energy absorber tube is positioned at one of the foci of the ellipse. By using an arc of a circle shape and positioning the solar energy absorber tube offset or decentralized from the center of the circle, the solar energy absorber tube can be positioned so that the sunlight reflected by the reflector falls more evenly over a larger portion of the tube's surface compared to the previous technique.

[0015] According to yet another embodiment, the first wall has the form of a substantially flat and solid half-cylinder, whose curved enveloping surface is fixed to the first end of the reflector. Furthermore, the second wall has the form of a substantially flat and solid half-cylinder, whose curved enveloping surface is fixed to the second end of the reflector.

[0016] According to yet another embodiment, the first foot has the form of a substantially flat and solid half-cylinder, whose straight surface opposite its curved enveloping surface constitutes the base of the first foot. Furthermore, the second foot has the form of a substantially flat and solid half-cylinder, whose straight surface opposite its curved enveloping surface constitutes the base of the second foot.

[0017] According to yet another embodiment, the first and second walls are made of a composite material comprising a Petition 870260043921, dated 09 / 05 / 2026, page 15 / 41 / 22 reinforced polymer with organic fiber material. This material is durable, that is, it withstands severe weather conditions, such as sandstorms. Furthermore, the material is easy to process, which facilitates the attachment of the respective first and second ends of the reflector to the respective first and second walls when these are manufactured with this material. Additionally, holes for the solar energy absorber tube can be easily and precisely produced in the walls by drilling.

[0018] According to yet another embodiment, the solar thermal collector arrangement further comprises one or more supports on which the first and second feet must be positioned, the one or more supports having a height that allows the reflector to be rotated to the closed position without needing to raise the solar thermal collector arrangement, when the solar thermal collector is positioned with its first and second feet on the one or more supports.

[0019] Other features and advantages of this solution will become apparent from the detailed description below. Brief description of the drawings

[0020] The solution will now be described in more detail by means of illustrative embodiments and with reference to the attached drawings, in which: Fig. 1 shows a perspective view of a solar thermal collector arrangement in an open position, according to embodiments of the invention.

[0021] Fig. 2 shows a cross-section in the YY plane of the reflector of the solar thermal collector array of Fig. 1.

[0022] Fig. 3 shows a perspective view of the solar thermal collector arrangement of Fig. 1 in a closed position.

[0023] Fig. 4 shows a perspective view of the solar thermal collector arrangement of Fig. 1 without the feet.

[0024] Fig. 5a shows a side view of the first wall of the arrangement. Petition 870260043921, dated 09 / 05 / 2026, page 16 / 41 / 22 of the solar thermal collector in Fig. 1.

[0025] Fig. 5b shows a side view of the first foot of the solar thermal collector arrangement of Fig. 1.

[0026] Fig. 6 shows a perspective view of a solar collector arrangement mounted vertically on a wall. Description of the modalities

[0027] A detailed description of one embodiment of a solar thermal collector arrangement 1 according to the invention is provided below, with reference to the accompanying figures.

[0028] Fig. 1 is a perspective view of an embodiment of the solar thermal collector arrangement 1. The solar thermal collector arrangement 1 has an elongated extension from its first end 1a to its second end 1b. The solar thermal collector arrangement 1 comprises a solar energy absorber tube 10 to receive a fluid to be heated, for example, water. The solar energy absorber tube 10 has a central geometric axis X. The elongated solar thermal collector arrangement 1, as well as its solar energy absorber tube 10, extends along the central geometric axis X. The solar energy absorber tube 10 may have a circular cross-section. The solar energy absorber tube 10 is made of a material that absorbs and conducts solar energy well, such as steel, copper, or any other heat-conducting material.The solar energy absorber tube 10 may have a dark color, preferably black, in order to absorb most of the solar energy directed at it. According to one embodiment, the solar thermal collector arrangement 1 also comprises a second tube 12 that surrounds the solar energy absorber tube 10. The second tube 12 is transparent to sunlight, so that the solar energy directed at the solar energy absorber tube 10 is transmitted through the second tube 12 and incident on the solar energy absorber tube 10. The second tube 12 may be made of a polymeric material. One purpose of such a second tube 12 is... Petition 870260043921, dated 09 / 05 / 2026, page 17 / 41 / 22 capture the air closest to the solar energy absorber tube 10, which can thus be heated by any residual heat from the solar energy absorber tube and thus secondarily contribute to heating the solar energy absorber tube and the fluid inside it. With such a second tube 12 made of transparent material, greater efficiency can be achieved for the solar thermal collector arrangement 1. The second tube 12 extends along the central geometric axis X coaxially with the solar energy absorber tube 10. The second tube 12 has a larger cross-section than the solar energy absorber tube 10, for example, a diameter that is twice the diameter of the solar energy absorber tube 10.

[0029] The solar thermal collector arrangement 1 further comprises a reflector 20 which is positioned at a distance from the solar energy absorber tube 10. The reflector 20 extends from its first end 20a to its second end 20b along the solar energy absorber tube 10, that is, parallel to the central geometric axis X of the solar energy absorber tube 10. The reflector 20 has a curved cross-sectional shape in a YY plane perpendicular to the central geometric axis X of the solar energy absorber tube 10. The cross-sectional shape of the reflector is shown in Fig. 2. The reflector 20 preferably has the same curved cross-sectional shape along its extension parallel to the central geometric axis X. The reflector 20 is preferably substantially thin, that is, it has a substantially reduced extension in a radial direction from the central geometric axis X of the solar energy absorber tube 10.The radial extent of reflector 20 is preferably approximately the same along the entire reflector, that is, reflector 20 has a uniform thickness. Reflector 20 has an outer surface 21 facing away from the solar energy absorber tube 10 and an inner surface 22 facing the solar energy absorber tube 10. Petition 870260043921, dated 09 / 05 / 2026, page 18 / 41 / 22 reflector 20 has such a curved shape and is positioned at such a distance from the solar energy absorber tube 10 that the light beams incident on the inner surface 22 of the reflector 20, after being reflected, fall on the solar energy absorber tube 10.

[0030] The reflector 20 extends, in cross-section, from a first cross-sectional end 23 to a second cross-sectional end 24 (Fig. 2). According to one embodiment, in cross-section in the YY plane, the reflector 20 has an extension around the solar energy absorber tube 10 from its first cross-sectional end 23 to its second cross-sectional end 24, so that it covers approximately 180 degrees around the solar energy absorber tube 10. In other words, and as illustrated in Fig. 2, perpendicular to the central geometric axis X, the reflector 20 covers an angle α of approximately 180 degrees taken from the center of the solar energy absorber tube 10. However, the angle covered may be slightly smaller or slightly larger, especially in the embodiment that will now be described.According to this embodiment, the solar energy absorber tube 10 is positioned slightly offset from a focal line of the reflector 20 parallel to the central geometric axis X, so that the light reflected by the reflector 20 falls in a distributed manner on the surrounding surface of the solar energy absorber tube 10, preferably on the entire part of the surrounding surface of the solar energy absorber tube 10 that can be illuminated by the reflected light. The larger the cross-section of the solar energy absorber tube 10 is perpendicular to its central geometric axis, the more the solar energy absorber tube 10 will be offset from the focal line.

[0031] According to a preferred embodiment, the reflector 20 has a cross-sectional shape that is a circular section, more preferably a semicircle. A cross-sectional shape Petition 870260043921, dated 09 / 05 / 2026, page 19 / 41 / 22 semicircular is particularly advantageous, since it fits well into a solid semicircular wall 30, 35, as will be explained later. According to another embodiment, the reflector 20 has an elliptical cross-sectional shape.

[0032] The inner surface 22 of the reflector 20 is made of a reflective material. The reflective material can be a metal, such as aluminum or steel, or any other type of reflective material. According to one embodiment, the reflector 20 has a base of an environmentally friendly and economically efficient material, such as cardboard or recycled plastic, coated with the reflective material, such as aluminum foil, on its inner surface 22. The base of a material such as cardboard can be coated on the outer surface 21 with a weather-resistant material, such as a polymer. Alternatively, the reflector 20 can be entirely made of a metal, such as stainless steel, which is very durable but more expensive.

[0033] As shown, for example, in Figs. In figures 1, 3, and 4, the solar thermal collector arrangement 1 further comprises a first wall 30 fixed to the first end 20a of the reflector 20. The first wall 30 is fixed to the first end 20a of the reflector 20 so that it rests against the inner surface 22 of the reflector at the first end 20a of the reflector 20. The first wall 30 has a first side, preferably in a shape complementary to the shape of the cross-section of the reflector 20, so that the first side follows the inner surface 2 of the reflector 20, i.e., the extension of the cross-section of the reflector 20 from its first cross-sectional end 23 to its second cross-sectional end 24, as shown in Fig. 2. The first wall 30 also has a base 32, see, for example, Fig. 1 and Fig. 4. The base 32 connects the opposite ends of the first side of the first wall 30.In other words, base 32 extends from the first cross-sectional end 23 to the second. Petition 870260043921, dated 09 / 05 / 2026, page. 20 / 41 / 22 cross-sectional end 24 of reflector 20 at the first end 20a of reflector 20. However, when the base 32 extends from the first cross-sectional end 23 to the second cross-sectional end 24 of reflector 20, it is spaced from reflector 20. Preferably, the base 32 of the first wall 30 provides a flat surface facing away from the inner surface 22 of reflector 20. The fact that the base 32 provides a flat surface facing away from the inner surface 22 of reflector 20 means that the surface of the base 32 extends as a straight plane between the first and second cross-sectional ends 23, 24 of reflector 20. According to one embodiment, the first wall 30 has a cross-section of a semicircle, wherein the diameter of the semicircle corresponds to the base 32 and the periphery of the semicircle corresponds to the first face.The first wall 30 has a thickness in the direction of extension of the solar thermal collector array 1, this thickness preferably being the same along the entire length of the first wall 30. According to one embodiment, the first wall 30 has the shape of a substantially flat and solid half-cylinder. The curved enveloping surface of the first wall 30 can be fixed to the first end 20a of the reflector 20. The first wall 30 can be fixed to the reflector 20 by means of a plurality of fastening means 51, 52, 53, such as screws or rivets, distributed along the periphery of the first end 20a of the reflector, as shown in Fig. 3.

[0034] The solar thermal collector arrangement 1 further comprises a second wall 35 fixed to the second end 20b of the reflector 20, that is, distal to the first wall 30. The second wall 35 is fixed to the second end 20b of the reflector 20 so that it rests against the inner surface 22 of the reflector at the second end 20b of the reflector 20. The second wall 35 has a base 37, see, for example, Fig. 1 and Fig. 4. The second wall 35 is arranged according to any of the Petition 870260043921, dated 09 / 05 / 2026, page 21 / 41 / 22 embodiments described above for the first wall 30. According to a preferred embodiment, the second wall 35 has the same size and shape as the first wall 30. The second wall 35 can be fixed to the reflector 20 by means of a plurality of fixing means 54, 55, 56, such as screws or rivets, distributed along the periphery of the second end 20b of the reflector 20, see Fig. 3.

[0035] In the embodiment in which there is a second tube 12 surrounding the solar energy absorber tube 10, the second tube 12 may extend between the first wall 30 and the second wall 35.

[0036] As shown in Figs. 1 and 3, the solar thermal collector arrangement 1 additionally features a first foot 40 disposed at the first end 1a of the solar collector arrangement. The first foot 40 has a base 42 for positioning on a ground surface or on a support (not shown in the figures). The base 42 is preferably substantially flat, or provides a flat surface, so as to remain stable when positioned on a ground surface or on a support. The base 42 preferably has a considerable surface area in order to ensure stability. The first foot 40 can be positioned externally to the first wall 30 so that the first foot 40 faces one side of the first wall 30 facing away from the second wall 35. According to one embodiment, the first foot 40 has the shape of a solid half-cylinder, wherein the rectangular side of the half-cylinder constitutes the base 42 of the first foot 40.The solid half-cylinder may be substantially flat. According to another embodiment, there is a recess 43 in the base 42 of the first foot 40. The recess 43 is positioned in the central part of the base 42, that is, in the center of a cylinder of which the half-cylinder is a part. The recess 43 may have the shape of a half-cylinder.

[0037] The solar thermal collector arrangement 1 additionally features a second foot 45 arranged at the second end 1b of the collector arrangement. Petition 870260043921, dated 09 / 05 / 2026, page 22 / 41 / 22 solar. The second foot 45 has a base 47 for positioning on a ground surface or on a support (not shown). The second foot 45 can be positioned externally to the second wall 35 so that the second foot 45 faces one side of the second wall 35 and is away from the first wall 30. The second foot 45 is arranged according to any of the embodiments described above for the first foot 40. According to a preferred embodiment, the second foot 45 has the same size and shape as the first foot 40. The first and second feet 40, 45 can be produced from a cylinder with a circular cross-section, wherein the first and second feet 40, 45 are produced by cutting the cylinder centrally along the central geometric axis of the cylinder.In the embodiment in which there is a recess 43 in the respective first and second feet 40, 45, the first and second feet may be produced by dividing into two equal parts a cylinder with a circular cross-section having a central hole with a circular cross-section that extends through the respective foot 40, 45.

[0038] The first and second walls 30, 35 may be manufactured from any material that is resistant to severe weather conditions. The material is preferably economically efficient. An example of a suitable material for walls 30, 35 is a composite material comprising a polymer reinforced with organic fiber material. Such a composite material is also suitable for the first and second feet 40.

[0039] Additionally, the solar energy absorber tube 10 extends through the first foot 40, the first wall 30, the second wall 35, and the second foot 45. The reflector 20, the first wall 30, and the second wall 35 are arranged in a rotatable manner relative to the first and second feet 40, 45 and are rotatable around the central geometric axis X of the solar energy absorber tube 10. In other words, once the first wall 30 and the second wall 35 are fixed to the reflector 20 and arranged in a rotatable manner relative to the first and second feet 40, 45, when the reflector Petition 870260043921, dated 09 / 05 / 2026, page 23 / 41 / 22 and walls 30, 35 are rotated, they rotate together around the central geometric axis X of the solar energy absorber tube 10, while the first and second feet 40, 45 do not rotate. The reflector 20 and walls 30, 35 are preferably rotated manually, i.e., no motor is provided for the rotation. However, in one embodiment, a motor may be provided for the rotation.

[0040] The first wall 30 and the second wall 35 may each have an opening 31, 36 through which the solar energy absorber tube 10 extends (see Fig. 4). The solar energy absorber tube 10 may not be fixed to the respective walls 30, 35, so that the reflector 20 and the first and second walls 30, 35 can be rotated without rotating the solar energy absorber tube 10. Alternatively, the respective wall 30, 35 may be provided with a bearing (not shown) fixed to the periphery of the respective hole 31, 36 on one side of the bearing and to the solar energy absorber tube 10 on the opposite side of the bearing, so that the reflector 20 and the first and second walls 30, 35 can be rotated without rotating the solar energy absorber tube 10, while still maintaining a fixed connection between the walls 30, 35 and the tube 10 by means of the bearings. Alternatively, the solar energy absorber tube 10 is fixed to the respective walls 30, 35 so that, when the reflector 20 and the first and second walls 30, 35 are rotated, the solar energy absorber tube 10 also rotates.

[0041] The first foot 40 and the second foot 45 may each have an orifice 41 through which the solar energy absorber tube 10 extends. (See Figs. 1 and 3; the hole in the second foot 45 is not shown in the figures). The solar energy absorber tube 10 may not be fixed to the respective feet 40, 45. Alternatively, the respective foot 40, 45 may be provided with a bearing (not shown) fixed to the periphery of the respective orifice 41 on one side of the bearing and to the solar energy absorber tube 10 on the opposite side of the bearing. In this way, the reflector 20 and the first and second walls 30, 35 may be Petition 870260043921, dated 09 / 05 / 2026, p. 24 / 41 / 22 rotated without rotating feet 40, 45, even in the alternative mode where the solar energy absorber tube 10 rotates together with the reflector 20. Alternatively, the solar energy absorber tube 10 is fixed to the respective feet 40, 45. In this alternative, the solar energy absorber tube 10 cannot be fixed to either of the walls 30, 35, since this would imply the rotation of feet 40, 45 when the reflector 20 is rotated.

[0042] Additionally, and according to the invention, the first foot 40, the first wall 30, the second foot 45 and the second wall 35 are dimensioned in such a way that the reflector 20, when rotated around the central geometric axis X, can be rotated from an open position, as shown, for example, in Fig. 1, in which it is facing the sky and away from the ground so as to receive sunlight, to a closed position in which the reflector points downwards towards the ground, and in which the base 32 of the first wall 30 is level with the base 42 of the first foot 40 and the base 37 of the second wall 35 is level with the base 47 of the second foot 45. This closed position is shown in Fig. 3.According to an embodiment that can be combined with those described above, the positions of the first wall 30, the second wall 35, the first foot 40 and the second foot 45 in which the solar energy absorber tube 10 extends through the first wall, the second wall, the first foot and the second foot, respectively, are selected in such a way that the reflector 20, when rotated around the central geometric axis X, can be rotated to a closed position in which the base 32 of the first wall 30 is level with the base 42 of the first foot 40 and the base 37 of the second wall 35 is level with the base 47 of the second foot 45.

[0043] Fig. 5a is a side view of the first wall 30. Fig. 5b is a side view of the first foot 40. According to one embodiment, a first distance d1 between hole 31 of the first wall 30 and base 32 of the first wall 30, perpendicular to base 32 of the first wall 30, is approximately the same as a second distance d2 between hole 41 Petition 870260043921, dated 09 / 05 / 2026, page. 25 / 41 / 22 of the first foot 40 and the base 42 of the first foot 40, perpendicular to the base 42 of the first foot 40. Thus, when the reflector 20 is rotated from an open position, as shown in Fig. 1, to a closed position, as shown in Fig. 3, the base 32 of the first wall 30 will be aligned with the base 42 of the first foot 40, and, as the base of the first foot rests on the ground, the reflector will be more or less closed when the arrangement is in the closed position of Fig. 3. The distance d1, as well as the distance d2, can be measured from the center of the respective hole 31, 41. Similarly, a third distance between the hole 36 of the second wall 35 and the base 37 of the second wall 35, perpendicular to the base 37 of the second wall 35, is approximately the same as a fourth distance between the hole of the second foot 45 and the base 47 of the second foot. 45, perpendicular to the base 47 of the second foot 45.

[0044] When the solar thermal collector arrangement 1 is not to be used for a certain period and / or when adverse weather conditions are approaching, the reflector 20 can be very easily rotated from its open position, as shown in Fig. 1, to its closed position, as shown in Fig. 3, simply by pushing the reflector so that it rotates around the central geometric axis X to its closed position. Depending on the implemented embodiment, it may be necessary to raise the arrangement during rotation in order to allow the reflector 20 to reach the closed position. In the embodiment where the first and second feet 40, 45 are positioned on the ground when the reflector 20 is to be rotated from the open position to the closed position, the solar thermal collector must be raised to allow the rotation of the reflector 20 to the closed position. After the reflector 20 has been rotated to the closed position, the solar thermal collector can be positioned on the ground again.The solar thermal collector may be provided with handles or grips to facilitate its lifting. Such handles or grips may be positioned, for example, on the parts of the solar energy absorber tube 10 that extend beyond the feet 40, 45, for example on the first ones. Petition 870260043921, dated 09 / 05 / 2026, page 26 / 41 / 22 and second connection portions 15, 16, defined further below. It may also be possible to simply raise the solar thermal collector without it having any handles or grips. For example, the solar thermal collector can be raised by its feet. In the embodiment where the first and second feet 40, 45 are positioned on one or more supports (not shown), the reflector 20 can be rotated from its open position to its closed position without the need for any raising, provided that one or more supports have a height that allows the reflector to be rotated to the closed position without being impeded by the underlying ground during rotation. In the case where the feet are positioned on supports, the solar thermal collector arrangement comprises one or more such supports. One or more supports are arranged or configured in such a way that they do not, by themselves, impede the rotation of the reflector.Depending on the model, one or more supports comprise a first support for the first foot and a second support for the second foot.

[0045] According to another embodiment, the solar energy absorber tube 10 is provided with a first connection portion 15 for connection to a hose or similar through which an inlet fluid can be supplied. The first connection portion 15 is located externally to the first foot 40, facing a surface of the first foot 40 that is facing away from the reflector 20. According to another embodiment, the solar energy absorber tube 10 is provided with a second connection portion 16 for connection to a hose or similar through which an outlet fluid can flow, such fluid being previously heated in the solar energy absorber tube 10. The second connection portion 16 is located externally to the second foot 45, facing a surface of the second foot 45 that is facing away from the reflector 20.

[0046] When using the solar thermal collector arrangement 1, an inlet fluid, here exemplified by water, can be supplied to the solar energy absorber tube 10 at the first end 1a of the solar collector arrangement. Petition 870260043921, dated 09 / 05 / 2026, page 27 / 41 / 22 thermal. During use, the solar collector arrangement 1 must be placed in its open position, as shown in Fig. 1, in a location such that sunlight can fall on the reflector and be reflected towards the solar energy absorber tube. When the water inside the solar energy absorber tube 10 has been heated for a certain period, the heated water can be withdrawn at the second end 1b of the solar collector arrangement 1. According to one embodiment, the thermal solar collector arrangement 1 may have a temperature gauge to measure the temperature of the fluid inside the solar energy absorber tube. According to another embodiment, the thermal solar collector arrangement 1 does not have such a temperature gauge. Instead, a temperature gauge may be located at a bypass position to which the arrangement 1 is connected by means of, for example, the second connection portion 16.

[0047] Fig. 6 describes another use case for the solar thermal collector arrangement 1. In this use case, the solar thermal collector arrangement 1 is arranged approximately vertically on a vertical external wall 5 of, for example, a building. The first and second feet 40, 45 are securely fixed to the wall 5, optionally by means of a respective support. As the reflector 20 is rotatable relative to the first and second feet 40, 45 and is rotatable around the central geometric axis X of the solar energy absorber tube 10, the reflector 20 can be rotated to follow the sun's movement across the sky from east to west. The rotation of the reflector 20 can be performed manually.Alternatively, and advantageously, the solar thermal collector arrangement 1 can be provided with a drive unit, i.e., a motor (not shown), connected to the reflector 20 in such a way that it can rotate the reflector 20 so that the reflector is positioned towards the sun during the day. The motor can be driven by a timer, so that the sun's movement can be easily tracked. This arrangement is particularly advantageous in countries. Petition 870260043921, dated 09 / 05 / 2026, page 28 / 41 / 22 relatively distant from the equator, where the sun is far from the zenith at noon, such as the Nordic countries, Canada and Russia. Additionally, and according to embodiments of the invention, the solar collector arrangement 1 is fixed, by means of its first foot 40, to a first support (not shown) which is fixed to the wall and, by means of its second foot 45, to a second support (not shown) which is fixed to the wall. By giving the first and second supports a height that allows the reflector 20 to be rotated to the closed position, in which the reflector 20 is directed with its inner reflective surface 22 facing the wall, the reflector 20 can be rotated to the closed position when not in use, for example, during the night, in order to protect the reflector 20.

[0048] Although the above description contains a plurality of specifics, these should not be interpreted as limiting the scope of the concept described herein, but only as illustrations of some exemplary embodiments of the concept described. It should be understood that the scope of the concept described herein fully encompasses other embodiments that may become apparent to those skilled in the art, and that, consequently, the scope of the concept described herein should not be limited. Reference to an element in the singular is not intended to mean “one and only one,” unless explicitly stated otherwise, but rather “one or more.” All structural and functional equivalents to the elements of the embodiments described above that are known to one skilled in the art are expressly incorporated by reference in this document and are intended to be covered by it.Furthermore, it is not necessary for a device or method to solve each and every problem that the concept described here seeks to address in order to be encompassed by it. In exemplary figures, a dashed line generally indicates that the feature contained within the dashed line is optional. Petition 870260043921, dated 09 / 05 / 2026, p. 29 / 41

Claims

1 / 6 CLAIMS 1. A solar thermal collector arrangement (1), characterized in that it extends in an extension direction from its first end (1a) towards its second end (1b), the solar collector arrangement (1) comprising: a solar energy absorber tube (10) for receiving a fluid, the solar energy absorber tube having a central geometric axis (X) extending in the extension direction, a reflector (20) extending along the solar energy absorber tube (10) from its first end (20a) to its opposite second end (20b), the reflector (20) having an inner reflective surface (22) facing the solar energy absorber tube (10), the reflector (20) having a curved shape arranged so that the light incident on the inner surface (22) of the reflector (20), after being reflected, falls on the solar energy absorber tube (10),the curved shape being a cross-sectional shape curved in a plane (Y) perpendicular to the direction of extension, from a first cross-sectional end (23) to a second cross-sectional end (24) of the reflector (20), a first wall (30) fixed to the first end (20a) of the reflector (20), along the inner surface (22) of the reflector (20), the first wall (30) having a base (32) extending between the first cross-sectional end (23) and the second cross-sectional end (24) of the reflector, the base (32) being spaced from the reflector (20) between the first and second cross-sectional ends (23, 24), a second wall (35) fixed to the second end (20b) of the reflector (20), along the inner surface (22) of the reflector (20), the second wall (35) having a base (37) extending between the first cross-sectional end (23) and the second cross-sectional end (24) of the reflector,the base (37) being spaced from the reflector (20) between Petition 870260043921, of 09 / 05 / 2026, page. 30 / 41 2 / 6 the first and second cross-sectional ends (23, 24), a first foot (40) disposed at the first end (1a) of the solar collector arrangement, the first foot (40) having a base (42) for positioning on a ground surface or on a support, and a second foot (45) disposed at the second end (1b) of the solar collector arrangement, the second foot (45) having a base (47) to be positioned on a ground surface or on a support, the solar energy absorber tube (10) extending through the first foot (40), the first wall (30), the second wall (35) and the second foot (45), wherein the reflector (20), the first wall (30) and the second wall (35) are arranged in a rotatable manner relative to the first and second feet (40, 45) and rotatable around the central geometric axis (X) of the solar energy absorber tube (10),and wherein the first foot (40), the first wall (30), the second foot (45) and the second wall (35) are dimensioned in such a way that the reflector (20), when rotated about the central geometric axis (X), can be rotated to a closed position in which the base (32) of the first wall (30) is level with the base (42) of the first foot (40) and the base (37) of the second wall (35) is level with the base (47) of the second foot (45), wherein, when the base (42) of the first foot (40) and the base (47) of the second foot (45) are positioned on a ground surface, the solar thermal collector (1) is configured to be raised when the reflector (20) is to be rotated about the central geometric axis (X) to the closed position.

2. Solar thermal collector arrangement (1) according to claim 1, characterized in that a position of the first wall (30) in which the solar energy absorber tube (10) extends through the first wall (30), a position of the second wall (35) in which the solar energy absorber tube (10) extends through the second wall (35), Petition 870260043921, dated 09 / 05 / 2026, page. 31 / 41 3 / 6 a position of the first foot (40) in which the solar energy absorber tube (10) extends through the first foot (40) and a position of the second foot (45) in which the solar energy absorber tube (10) extends through the second foot (45) are selected in such a way that the reflector (20), when rotated around the central geometric axis (X), can be rotated to a closed position in which the base (32) of the first wall (30) is level with the base (42) of the first foot (40) and the base (37) of the second wall (35) is level with the base (47) of the second foot (45).

3. Solar thermal collector arrangement (1) according to claim 1 or 2, characterized in that a first distance (d1) between a position of the first wall (30) in which the solar energy absorber tube (10) extends through the first wall (30) and the base (32) of the first wall (30), the first distance (d1) being perpendicular to the base (32) of the first wall (30) is approximately the same as a second distance (d2) between a position of the first foot (40) in which the solar energy absorber tube (10) extends through the first foot (40) and the base (42) of the first foot (40), the second distance (d2) being perpendicular to the base (42) of the first foot (40), and in that a third distance between a position of the second wall (35) in which the solar energy absorber tube (10) extends through the second wall (35) and the base (37) of the second wall (35),the third distance being perpendicular to the base (37) of the second wall (35) is approximately the same as a fourth distance between a position of the second foot (45) in which the solar energy absorber tube (10) extends through the second foot (45) and the base (47) of the second foot (45), the fourth distance being perpendicular to the base (47) of the second foot (45).

4. Solar thermal collector arrangement (1) according to claim 1, characterized in that the first wall (30) has an orifice (31) through which the solar energy absorber tube (10) extends, Petition 870260043921, dated 09 / 05 / 2026, p. 32 / 41 4 / 6 and the first foot (40) has a hole (41) through which the solar energy absorber tube (10) extends, and where a first distance (d1) between the hole (31) of the first wall (30) and the base (32) of the first wall (30), perpendicular to the base (32) of the first wall (30), is approximately the same as a second distance (d2) between the hole (41) of the first foot (40) and the base (42) of the first foot (40), perpendicular to the base (42) of the first foot (40), and wherein the second wall (35) has a hole (36) through which the solar energy absorber tube (10) extends, and the second foot (45) has a hole through which the solar energy absorber tube (10) extends,and wherein a third distance between the hole (36) of the second wall (35) and the base (37) of the second wall (35), perpendicular to the base (37) of the second wall (35), is approximately the same as a fourth distance between the hole of the second foot (45) and the base (47) of the second foot (45), perpendicular to the base (47) of the second foot (45).

5. Solar thermal collector arrangement (1) according to any of the preceding claims, characterized in that the first foot (40) is positioned externally to the first wall (30) such that the first foot (40) faces a side of the first wall (30) facing away from the second wall (35), and the second foot (45) is positioned externally to the second wall (35) such that the second foot (45) faces a side of the second wall (35) facing away from the first wall (30).

6. Thermal solar collector arrangement (1) according to any of the preceding claims, characterized in that the reflector (20) has a circular shape in the cross-sectional plane (Y) and an extension from its first cross-sectional end (23) to its second cross-sectional end (24) spanning approximately 180 degrees as seen from the center of a circle of the circular shape, or in that the reflector (20) has an elliptical shape in the cross-sectional plane (Y) and an extension from its first cross-sectional end (23) to its second cross-sectional end (24) spanning approximately 180 degrees as seen from the center of an ellipse of the elliptical shape.

7. Thermal solar collector arrangement (1) according to any one of claims 1 to 5, characterized in that the curved cross-sectional shape of the reflector (20) in the plane (Y) perpendicular to the extension direction is the shape of an arc of a circle, and in which the solar energy absorber tube (10) is positioned offset from a center of the circle.

8. Solar thermal collector arrangement (1) according to any of the preceding claims, characterized in that the base (32) of the first wall (30) provides a flat surface facing away from the inner surface (22) of the reflector (20), and in that the base (37) of the second wall (35) provides a flat surface facing away from the inner surface (22) of the reflector (20).

9. Solar thermal collector arrangement (1) according to any of the preceding claims, characterized in that the first wall (30) has the shape of a substantially flat and solid half-cylinder, whose curved enveloping surface is fixed to the first end (20a) of the reflector (20), and in that the second wall (35) has the shape of a substantially flat and solid half-cylinder, whose curved enveloping surface is fixed to the second end (20b) of the reflector (20).

10. Solar thermal collector arrangement (1) according to any of the preceding claims, characterized in that the first foot (40) has the shape of a substantially flat and solid half-cylinder, the straight surface opposite its curved enveloping surface of which constitutes the base (42) of the first foot (40), and in which the second foot (45) has a Petition 870260043921, dated 09 / 05 / 2026, page 34 / 41 6 / 6 shape of a substantially flat and solid half-cylinder, the straight surface opposite its curved enveloping surface of which constitutes the base (47) of the second foot (45).

11. Solar thermal collector arrangement (1) according to any of the preceding claims, characterized in that the first and second walls (30, 35) are made of a composite material comprising a polymer reinforced with organic fiber material.

12. Solar thermal collector arrangement (1) according to any of the preceding claims, characterized in that it further comprises a second tube (12) enclosing the solar energy absorber tube (10), the second tube (12) being made of a transparent material.

13. Thermal solar collector arrangement (1) according to any of the preceding claims, characterized in that it further comprises one or more supports on which the first foot (40) and the second foot (45) are to be positioned, the one or more supports having a height that allows the reflector (20) to be rotated to the closed position without needing to raise the thermal solar collector, when the thermal solar collector is positioned with its first and second feet (40, 45) on the one or more supports. Petition 870260043921, dated 09 / 05 / 2026, pp. 35 / 41

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