IMPROVED DESIGN REFLECTOR AND ITS MANUFACTURING PROCESS FOR THE SOLAR ENERGY SECTOR

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of manufacturing mirror reflectors shaped to reflect and direct light.

[0002] More specifically, it concerns the manufacture of reflectors whose mirror support structure is intended to be mobile in rotation along at least one pivot axis, in order to be able to orient the received light at different angles.

[0003] The invention applies in particular to the field of solar energy, with reflectors intended for the production of reflector fields for concentrated thermodynamic solar power plants, preferably of the type with cylindrical-parabolic mirrors, or with linear Fresnel mirrors. STATE OF THE PRIOR ART

[0004] For the manufacture of a reflector comprising a mirror supported by a support structure, a mold is usually provided on which the mirror is temporarily assembled, the mold giving the final shape to this mirror. Then, a step is carried out of positioning the mirror in relation to the support structure, by relative movement between the mold supporting the mirror and this same structure.

[0005] A known technique consists of ensuring that at the end of the aforementioned step, the mirror is at a distance from the support structure, these two elements adopting their final relative position. In this case, beads or blocks of glue previously installed on the support structure or on the mirror are deformed during this step of installing the mirror. After drying the deformed beads or blocks of glue, they ensure the mechanical connection between the mirror and its support structure.

[0006] This solution, described for example in document US 20090260753A1, however has drawbacks, the main ones of which are described below.

[0007] First, each reflector generally has several shaped mirror elements, which extend as a single piece over the entire surface of the reflector. During the mirror installation step, the relative movement between the set of very large mirror elements carried by the bulky mold on the one hand, and the support structure with similar dimensions on the other, makes handling and positioning difficult. These elements can each measure between 4 and 12 m in length.

[0008] Furthermore, bonding is achieved here by heating and softening the glue blocks. This heating is significant since the melting / softening point of the glue must be higher than the operating temperatures of the reflector. Therefore, during heating, there is a risk of deformation of the mold carrying the mirror, and / or a risk of deformation of the support structure. This can lead to poor control of the final surface of the mirror, and therefore to a loss of efficiency for the associated solar power plant.

[0009] In addition, for these bonding operations, the heating and cooling times are relatively long. Indeed, the elements to be bonded have high thermal inertia, and the heating and cooling powers must be correctly controlled in order to avoid any overheating of the structures, which is conducive to the appearance of the parasitic deformations mentioned above. As a result, the process requires significant thermal energy, it is slow, and the mold occupation times are significant. Given the number of reflectors to be manufactured to constitute a field of reflectors, this results in a need to increase the number of molds and tools for bonding, leading to significant impacts on the manufacturing costs of these reflectors.

[0010] Also, if a mirror breaks in situ on the solar power plant, replacing it is complex and costly. One solution is to replace the entire reflector, but this is extremely expensive. Another solution is to replace the broken part of the mirror, but this requires the use of the mold and the implementation of the glue heating process, which leads to preferring to carry out this repair in the factory after repatriating the damaged reflector. In all cases, this is a delicate operation because it is difficult to remove the glue residue and broken mirror.

[0011] Finally, the shape of the support structure must be adapted to the final shape of the mirror it supports, because the variation in glue thickness between these two elements is limited. In other words, the same support structure is often not able to adapt to all types of radii of curvature of the mirrors of a given solar field. Thus, when the radii of curvature of the mirrors are very different between two reflectors, it may be necessary to provide support structures of different shapes. This non-standardization of the support structure for the same reflector field can not only lead to an increase in manufacturing costs, but also to an increase in maintenance requirements.

[0012] To address this last drawback, a solution described in WO 2012 / 110438 has been proposed. This solution provides connecting elements between the mirror and the support structure, which in particular makes it possible to standardize the shape of this structure. However, the other drawbacks described above remain.

[0013] Another reflector is described in document DE 10 2008 051807 A1. STATEMENT OF THE INVENTION

[0014] The invention therefore aims to remedy at least partially the drawbacks mentioned above, relating to the achievements of the prior art.

[0015] To do this, the invention firstly relates to a reflector comprising the characteristics of claim 1.

[0016] The invention is firstly advantageous in that it provides for splitting the mirror into several separate mirror elements, which generally facilitates their handling as well as their installation on the support structure. This installation is also facilitated by associating with this mirror element a frame maintaining its shape and forming an interface between the support structure and the mirror element, and by reversibly mechanically assembling the frame on this structure. The mechanical and reversible / removable characteristics of the fixing means used not only facilitate assembly, but also simplify disassembly in the event of the need to replace one of the mirror elements, for example after damage to the latter.

[0017] The assembly of the reflector components is all the simpler since the module, formed by the mirror element and its frame, can be manufactured before being assembled on the support structure. It is then sufficient to place the module on the support structure comprising a reference surface, then to assemble the mechanical fixing means, without requiring precise adjustment. The simple positioning on this reference support surface is enough to ensure the correct relative positioning between the pivot axis of the reflector, and the optical axis of the mirror element. These positioning and fixing operations can also be carried out in situ on the solar power plant, whether during the manufacture of the reflector, or for a maintenance operation aimed at replacing one or more damaged / defective mirror elements.More generally, these operations of positioning and fixing the modules on the support structure can be carried out on a site other than that on which the assembly of the mirror element on its frame was carried out. Indeed, the fixing operations do not require any precision tools, unlike the operations of the prior art aimed at shaping the mirror or producing the reference support surface, which are operations generally unthinkable on site.

[0018] Furthermore, due to the simplicity of these operations which do not require any particular adjustment, it may be possible to automate the manufacture of such reflectors, to further reduce production costs.

[0019] In this regard, it is noted that thanks to the definition of the reference support surface by contact points on the support structure, in the event of extreme deformation of the latter, for example caused by wind and / or snow, the risk of transmission of these deformations to the frame and the mirror element remains reduced.

[0020] The invention also has other advantages. In particular, thanks to the particular design of the chassis with its side members and cross members, the mirror element can be fixed to the side members before being shaped on a mold. Only after this can the chassis side members be fixed to its cross members, and then the chassis fixed to the supporting structure. Consequently, the phase of fixing the mirror element, for example by gluing, becomes decorrelated from its shaping phase on the mold, which avoids the risks of deformation encountered in the prior art. In other words, in this scenario offered by the design according to the invention, there is no longer any risk of deformation of the mold during the heating step, and even less risk of deformation of the support structure. Similarly, if necessary, the removal of the glue during polymerization occurs before shaping on the mold.This improves the final surface quality of the mirror, and results in a beneficial gain in efficiency for the solar power plant.

[0021] Also, since the mirror fixing can be carried out outside the mold use phases, the time occupied by this mold is significantly reduced. This advantageously leads to a reduction in tooling costs.

[0022] Finally, the proposed solution allows the shape of the support structure to be standardized, while retaining the possibility of installing it in reflectors whose mirrors have different radii of curvature. It is in fact the frame that adapts to the non-planar shape of the mirror, this same frame being able to always cooperate in the same way with the support structure, whatever the shape of the mirror.

[0023] Preferably, said means for fixing the mirror element are glue, tape (i.e. adhesive tape), or mechanical means such as screws or rivets, or others. Each mirror element, particularly in the case of metal or polymer mirrors, may be fixed to the side members with mechanical means other than gluing, such as clipping, riveting, welding, bolting, etc. Preferably, these are non-reversible fixing means, i.e. requiring their at least partial destruction to allow separation between the mirror element and the side members of the chassis. These fixing means are then indifferently called non-reversible or non-removable.

[0024] The invention also provides the following optional features, taken individually or in combination.

[0025] Said mechanical fixing means are screw fixing means.

[0026] Said mechanical fixing means comprise: the positioning members provided on the support structure, these positioning members each taking the form of a stud comprising a shoulder forming one of said contact points, as well as a threaded portion projecting from the shoulder and passing through a complementary positioning member provided on the chassis; a nut gripping the complementary positioning member between the shoulder and this nut.

[0027] Alternatively, a reverse configuration could be made, in which the studs would be provided on the chassis.

[0028] The additional positioning devices are arranged on the cross members of the chassis, preferably at the ends of these cross members.

[0029] The studs are arranged orthogonally to said reference bearing surface, the latter being parallel to said at least one pivot axis of the reflector.

[0030] The cross members extend substantially orthogonally to said at least one pivot axis of the reflector, and said longitudinal members extend substantially orthogonally to the cross members and parallel to an axis of curvature of the mirror element.

[0031] Glue joints are interposed between the non-reflecting surface of the mirror element and the chassis side members, said glue joints all having substantially the same thickness.

[0032] The side members of each chassis are attached to the cross members using clinching attachment points. However, other conventional fastening techniques are also possible, such as riveting, welding, bolting, screwing, gluing, etc.

[0033] Each mirror element is made from glass, steel, aluminum, a polymer material or any other reflective surface material.

[0034] Each mirror element has a surface area of ​​between 0.4 and 4 m 2< , and preferably of the order of 1 m 2< .

[0035] Each mirror element preferably has a single-curved or double-curved shape. Mirror elements can indeed have a double-curved shape by using, for example, pre-curved side members and suitable side member fixing tools.

[0036] The invention also relates to a field of reflectors comprising a plurality of reflectors such as that described above.

[0037] Preferably, the field comprises at least two reflectors with mirrors of different shapes, these two reflectors comprising a support structure of identical shape. Preferably, all these support structures are identical within the same field, and can even be used to constitute several fields. For example, a single shape of support structure can be provided for eight different radii of curvature on the mirrors of the same field.

[0038] The invention also relates to a concentrated thermodynamic solar power plant comprising a field of reflectors as mentioned above, said plant preferably being of the type with cylindrical-parabolic mirrors, or with linear Fresnel mirrors.

[0039] The invention finally relates to a method of manufacturing such a reflector comprising, associated with each mirror element, the following steps: positioning the mirror element on a flat tool, so that the mirror element temporarily adopts a flat shape; fixing, preferably by gluing, the chassis side members to the non-reflecting surface of the mirror element held on the flat tool; placing the mirror element equipped with the side members on a mold, this placing causing the mirror element, when it has a non-planar shape, to deform elastically so as to adopt its final shape; fixing the chassis side members to the cross members, while the final shape of the mirror element is maintained by the mold, this step thus making it possible to precisely position the mirror element with respect to the support points of the cross members; after removal from the mold, placing the chassis equipped with the mirror element on the support structure; and fixing the chassis to the support structure.

[0040] It is noted that the steps of this method can be carried out at different sites. For example, the fixing of the chassis side members to the non-reflecting surface of the mirror element can be carried out at a particular site. Several such assemblies can be manufactured, before being stacked and shipped to another site for the implementation of the step of fixing the side members to the chassis cross members. Due to the substantially planar shape of the assemblies resulting from this fixing step, their stacking during transport has a reduced bulk, in comparison with that of a stack incorporating curved mirrors.

[0041] Other advantages and characteristics of the invention will appear in the detailed non-limiting description below. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] This description will be made with regard to the attached drawings, among which; THE Figures 1a to 1crepresent perspective views of a solar power plant according to a preferred embodiment of the invention, comprising a solar collector as well as a field of linear Fresnel-type reflectors; the figure 2 is a perspective view of a reflector of the field shown in the preceding figure; the figure 3 represents a side view of that of the previous figure; the figure 4 represents a side view of the reflector support structure shown in the figures 2 And 3 ; there Figure 5 is a schematic top view showing the cooperation between the positioning members provided on the support structure, and the complementary positioning members provided on a frame carrying a mirror element; and the Figures 6a to 6d schematize different stages of a manufacturing process of the reflector shown in the preceding figures, according to a preferred embodiment of the invention. DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0043] With reference first of all to the Figures 1a to 1c , a concentrated thermodynamic solar power plant is shown. This plant 1 comprises a solar collector 2 as well as a field of reflectors 4 concentrating the solar radiation on the collector 2. The plant is here of the Fresnel linear mirror type, but could alternatively be of the parabolic trough mirror type or, in the case of a double curvature shape, of the heliostat type mirrors of the "solar tower" type or of the parabolic dish type mirrors.

[0044] The field 4 comprises a row of reflectors 6 arranged side by side. As will be detailed below, each reflector 6 comprises a mirror split into several mirror elements each assembled on a support structure, via a frame specific to the invention. In addition, the support structures are rotatably mounted on a frame 8, along preferably parallel pivot axes 10. Their rotational control can be independent or dependent, and controlled so as to best concentrate the solar radiation on the sensor 2.

[0045] In this regard, the Figures 1a to 1c show three distinct configurations in which the incident light rays 12 have different orientations, each configuration being associated with a particular rotational setting of all the reflectors of the field 4, making it possible to best orient the reflected rays 14 onto the sensor 2, depending on the position of the sun.

[0046] It is preferably a so-called high flux sensor, for various applications, for example heating a heat transfer fluid such as water, oil or molten salt, or for the concentrated photovoltaic field. Its power is between several tens of kW / m 2< and a few MW / m 2< . Each reflector 6, of overall rectangular shape, has a surface area of ​​several square meters. The precision generally required on this type of system is of the order of 0.1° for the angular adjustment of the reflectors.

[0047] Referring now to the figures 2 And 3 , one of the reflectors 6 of the type used in the central unit 1 of the previous figures is shown.

[0048] The reflector 6 firstly comprises a mirror 16 of non-planar shape, made of glass with a thickness of the order of 4 mm, and typically between 0.1 and 7 mm. Its shape here is of simple curvature. However, other shapes can be envisaged, without departing from the scope of the invention.

[0049] The mirror 16 of the reflector 6 is split into several separate and independent mirror elements 16a, arranged adjacently and each also having a non-planar shape. On the figure 2 , only two mirror elements have been shown, but the latter can be provided in a much greater number. For example, each mirror element 16a can have a surface area of ​​the order of 1 m 2< , while the overall surface area of ​​the mirror 16 constituted by the elements 16a can for example be of the order of 5 to 50 m 2< .

[0050] The reflector 6 also comprises a support structure 18, for example of roughly parallelepipedal shape, solid or hollow. It can be made of steel, with large manufacturing tolerances which allow the use of economical processes. It has means allowing the rotation of the reflector 6 about the pivot axis 10, here two pivot members 19 arranged respectively at the two ends of the support structure 18. These pivot members 19, in the form of pins, are intended to cooperate with the frame of the solar power plant.

[0051] The mechanical connection between the support structure 18 and the mirror elements 16a is not made directly, but a frame 20 is interposed between each mirror element 16a and the structure 18. Each frame 20, which will be detailed below, comprises several parts assembled to each other and preferably metallic, but they could alternatively be made of ceramic or polymer material.

[0052] The frame 20 comprises crosspieces 22, preferably two crosspieces located at the ends of this frame in the direction of the pivot axis 10. These crosspieces 22 comprise a slightly curved upper surface so as to present a sort of parallelism with the associated mirror element 16a, as can be seen in the figure 3 Their lower surface is preferably flat.

[0053] The cross members 22 extend substantially orthogonally to the pivot axis 10, and fixedly carry side members 24, for example comprised in a number between 3 and 7. These side members 24 of the chassis project above the cross members 22, and are arranged substantially orthogonally to the cross members 22 as well as parallel to the axis 10 and to the axis of curvature of the mirror element 16a. The side members 24 of the chassis 20 are fixed at their ends to the two cross members 22 using mechanical fixing points produced by clinching.

[0054] The upper surface of the side members 24 carries glue joints 28, cooperating with a non-reflecting surface 30 of the mirror element 16a. This surface 30 corresponds to the surface opposite the functional surface of the mirror element, intended to reflect solar radiation.

[0055] In the invention, the shape of the frame 20 adapts to that of the mirror element 16a. Consequently, the glue joints 28 all have substantially the same thickness. They are also continuous along each spar 24, or else interrupted along the latter, for example by adopting a multi-point configuration.

[0056] The glue used may be of the single-component polyurethane paste type, for example glue sold by the company 3M ©< under the reference “Polyurethane Adhesive Sealant 560 ©<”. Another example is the glue sold by the company Hutchinson / ljf ©< under the reference “PR1440 ©<”«<<<. The viscosity of the glue chosen is preferably sufficient to remain localized at the level of the connection between the non-reflecting surface 30 and the side members 24.

[0057] The glue is chosen, more particularly, from among glues having, after drying, a Young's modulus of between 2 and 60 MPa, and a hardness of between 20 and 60 shore A.

[0058] Each frame 20 therefore has a shape adapted to the shape of its associated mirror element 16a, thanks to the freedom of positioning and fixing of the side members 24 on the cross members 22. This implies that the shape of these frames differs depending on the reflector on which they are arranged in the field of reflectors. On the other hand, for greater standardization, it is provided that the structure 18 of each reflector 6 of the reflector field is of identical shape, even for reflectors carrying mirrors of different shapes.

[0059] The reflector 6 is also equipped with removable mechanical fixing means 34, allowing the reversible mounting of the chassis 20 on the support structure 18. These means 34 are preferably screwed elements, such as nuts 36 cooperating with threaded rods 38.

[0060] Preferably, as is best seen on the figure 3 , the threaded rods 38 are integrated into the end of studs 40 forming positioning members of the chassis 20. These studs 40 are an integral part of the support structure 18, being fixed to the frames of this structure 18.

[0061] With joint reference to the figures 3 And 4, it is noted that each stud 40 has a wider base, defining a shoulder 42 at the junction with its threaded rod 38. This shoulder 42 forms a contact point for the chassis. The studs 40 are provided in number of three or four, distributed around the periphery of the associated chassis 20. They are arranged orthogonally to the pivot axis 10, the latter being parallel to a reference bearing surface 46 jointly defined by the four contact points 42.

[0062] Thus, the module formed by the frame 20 and its associated mirror element 16a can be positioned precisely on the support structure 18, without requiring any particular adjustment but only by placing the frame 20 on the contact points formed by the shoulders 42. To do this, the crosspieces 22 of the frame comprise at their ends complementary positioning members 50, preferably in the form of plates. These plates 50 are pierced with an orifice crossed by the threaded rod 38, and they come to bear on the shoulders 42. Once contact has been established between all the shoulders 42 and their associated plates 50, there is certainty as to the precise positioning of the frame 20 on the structure 18, and therefore certainty as to the position of the optical axis of the mirror element 16a relative to the pivot axis 10.

[0063] The nuts 36 are then used to clamp the plates 50 between the shoulders 42 forming contact points, and these same nuts 36.

[0064] There Figure 5 shows that the orifice 52 of each of the four plates 50 can cooperate in a different manner with its associated threaded rod 38. Indeed, a single precise adjustment can be applied between one of the rods 38 and its orifice 52, with substantially identical diameters. For two other assemblies, a significant radial clearance can be provided between the rod 38 and the orifice 52, allowing freedom of positioning in the plane of the reference surface 46. Finally, the fourth assembly can provide a rod 38 in an oblong orifice 52, allowing freedom of positioning in one direction of the plane of the reference surface 46.

[0065] However, it is noted that the positioning members 40 are not necessarily studs including a threaded rod 38 for fixing the chassis. The support / bearing function of the chassis can in fact be decorrelated from the chassis fixing function. Consequently, it is possible to provide simple positioning members 40 provided on the support structure 18 and comprising a simple bearing zone such as a shoulder or an end surface, intended to form one of the contact points 42 constituting the reference bearing surface, and cooperating with a complementary positioning member provided on the chassis 20. The means for fixing the chassis can then be distinct from these positioning members 40.

[0066] In operation, the structure 18, the frame 20 and the mirror formed by the mirror elements 16a are integral with each other, no relative movement being provided between them, and in particular no relative movement is provided between the support structure 18 on the one hand, and the assembly formed by the mirror 16 and the frame 20 on the other hand.

[0067] Referring now to the Figures 6a to 6d , a method of manufacturing the reflector 6 shown in the preceding figures will be described.

[0068] For each mirror element 16a of the reflector 6, the method comprises the following steps.

[0069] First of all, the mirror element 16a is positioned on a flat tool 60, for example a marble base. The purpose of this step is to press the mirror element 16a against this base 60 so that it temporarily adopts a flat shape, corresponding to that of the base, as shown diagrammatically in FIG. Figure 6a .

[0070] Next, the longitudinal members 24 are bonded to the non-reflecting surface 30 of the mirror element 16a, held on the base 60. The mirror element 16 equipped with the longitudinal members 24 is then placed on a mold 64 of appropriate shape. The purpose of this step is to see the mirror element 16a deform elastically and adopt its final shape. Advantageously, this operation is carried out outside the bonding time.

[0071] Then, the longitudinal members 24 are fixed to the crosspieces 22, while the final shape of the mirror element 16a is maintained by the mold 64, as shown in the Figure 6bTo do this, the crosspieces 22 are brought opposite the side members 24, the positioning of which is conditioned by the elastic deformation of the mirror element 16a applied by the mold 64. Once the positioning has been carried out, the mechanical fixing points 26 are made, preferably by clinching using appropriate tooling 70 shown on the Figure 6c. The preferred clinching technique has several advantages that are particularly useful in the case of a solar application, such as not requiring metal or a filler piece, unlike a bolt or a rivet, since the connection is ensured by deformation with a punch / die system. In addition, it allows a high production rate as well as a reduction in corrosion phenomena. Indeed, in the case of a connection on steel crosspieces and side members protected by a galvanized layer, the clinching connection makes it possible to avoid exposing the steel, so that a minimum thickness of galvanization is maintained at the connection point. In addition, the absence of a filler piece makes it possible to limit the galvanic couples that could appear between the different materials. This reduced sensitivity to corrosion ensures good performance of the power plant throughout its lifetime.

[0072] This clinching technique also allows a great capacity for adjusting the position of the fixing points. This remains interesting for producing mirror elements 16a having very different radii of curvature, and this with the same crosspieces 22.

[0073] After removal from the mold, the frame 20 equipped with the mirror element 16a is placed on the reference support surface 46 defined by the support structure 18. In this regard, it is noted that during the manufacture of the structure 18 shown in the figure 6d, the studs 40 and contact points 42 are attached to this structure in order to define the reference support surface 46 with suitable positioning precision, and this in a configuration where this structure 18 is maintained in the same support conditions as on the solar field. This makes it possible to define the reference surface 46 precisely and at lower cost, while taking into account any internal deformations of the structure 18 during operation.

[0074] Finally, the process is completed by fixing the crosspieces 22 to the support structure 18, via the nuts 36.

[0075] Of course, various modifications may be made by those skilled in the art to the invention which has just been described, solely by way of non-limiting examples.

Claims

1. Reflector (6) comprising a support structure (18) and a mirror (16) with a non-plane shape, fixed at its non-reflecting surface (30), said support structure (18) being provided with pivot elements (19) for rotating the reflector about at least one pivot axis (10), characterised in that the mirror (16) is composed of a plurality of adjacent mirror elements (16a) with a non-plane shape, in that the reflector also comprises a frame (20) associated with each mirror element (16a), inserted between the structure support (18) and said associated mirror element (16a), said frames (20) being independent of each other and each being associated with a unique mirror element (16a), each frame (20) comprising cross-members (22) on which stringers (24) are fixed, the non-reflecting surface (30) of the mirror element (16a) being fixed on the stringers (24) of the frame (20) by means of mirror element attachment means, and in that each frame (20) is mounted on the support structure (18) using removable mechanical attachment means (36, 38), said support structure (18) comprising positioning elements for each frame (20), the positioning elements forming contact points (42) that together define a reference bearing surface (46) for the frame (20) supporting the mirror element.

2. Reflector according to claim 1, characterised in that said attachment means of the mirror element are glue, scotch tape or mechanical means such as screws or rivets, and preferably non-reversible attachment means.

3. Reflector according to one of the preceding claims, characterised in that said mechanical attachment means (36, 38) are screwed attachment means.

4. Reflector according to any one of the preceding claims, characterised in that< / b> said mechanical attachment means comprise: - positioning elements (40) provided on the support structure, each of these positioning elements being in the form of a stud comprising a shoulder (42) forming one of said contact points, and a threaded portion (38) projecting from the shoulder and passing through a complementary positioning element (50) provided on the frame (20); - a nut (36) squeezing the complementary positioning element (50) between the shoulder (42) and this nut (36).

5. Reflector according to the preceding claim, characterised in that the complementary positioning elements (50) are arranged on the cross-members (22) of the frame (20), preferably at the ends of these cross-members.

6. Reflector according to any one of the preceding claims, characterised in that the cross-members (22) extend approximately orthogonal to said at least one reflector pivot axis (10), and in that said stringers (24) extend approximately orthogonal to the cross-members (22) and parallel to an axis of curvature of the mirror element (16a).

7. Reflector according to any one of the preceding claims, characterised in that glue joints (28) are inserted between the non-reflecting surface (30) of the mirror element(16a) and stringers (24) of the frame (20), said glue joints (28) all having approximately the same thickness.

8. Reflector according to any one of the preceding claims, characterised in that each mirror element (16a) is made based on glass, steel, aluminium, or a polymer material.

9. Reflector according to any one of the preceding claims, characterised in that each mirror element (16a) has a surface area of between 0.4 and 4 m2, and preferably of the order of 1 m2.

10. Reflector according to any one of the preceding claims, characterised in that each mirror element (16a) has a shape with single curvature or double curvature.

11. Reflector field (4) comprising a plurality of reflectors (6) according to any one of the preceding claims.

12. Reflector field according to the preceding claim, characterised in that it comprises at least two reflectors (6) with different shaped mirrors (16), and in that these two reflectors have an identically shaped support structure (18).

13. Concentrating thermodynamic solar power station (1) comprising a reflector field (4) according to the preceding claim, said power station preferably being of the type with cylindrical-parabolic mirrors, or linear Fresnel mirrors.

14. Method of manufacturing a reflector (6) according to any one of claims 1 to 10, characterised in that it comprises the following steps associated with each mirror element (16a): - positioning the mirror element (16a) on plane tooling (60) such that the mirror element (16a) provisionally adopts a plane shape; - attachment of stringers (24) of the frame (20) on the non-reflecting surface (30 ) of the mirror element (16a) held in place on the plane tooling (60), preferably by gluing; - placement of the mirror element (16a) fitted with stringers (24) on a mould (64), this placement being such that when put into its position, and if it is not flat, the mirror element will be deformed elastically so as to adopt its final shape; - attachment of stringers (24) of the frame (20) on the cross-members (22), while the final non-plane shape of the mirror element (16a) is maintained by the mould (64); - after the mould (64) has been removed, placement of the frame (20) equipped with the mirror element (16a) on the support structure (18); and - attachment of the frame (20) on the support structure (18).