The present invention relates to a solar collector tracker support system. It more particularly relates to a tracker support system that can be oriented along two axes of rotation, a horizontal axis of rotation for a rotation making it possible to track the sun as it rises and lowers, and a vertical axis of rotation for a rotation making it possible to track the sun from East to West, respectively.
The subject-matter of the invention falls within the field of tracker support systems, also called solar trackers, with two axes, in other words which can be oriented in terms of azimuth and elevation.
The invention is applicable in solar trackers with two axes supporting solar collectors, in particular of the following types:
In the field of solar trackers with two axes, it is known, in particular from document WO 2009/147454, to provide a tracker support system comprising a stationary single pillar anchored in the ground and a moving structure including two arms rotated along the vertical axis of rotation using a first motorized gear motor unit positioned at the end of the single pillar. The tracker support system also integrates a second structure that is rotatable in terms of elevation and bearing the solar collectors.
These single pillar tracker support systems thus have a relatively small ground print dimension, in this case equivalent to the diameter of the single pillar, which therefore limits the surface area of the solar collectors that can be supported. In fact, as the surface area of the solar panels increases, the influence of the wind increases as well. Under the action of the wind, the solar panels exert a torque effect often exceeding 170,000 Nm (newton meter) at the anchoring point of the single pillar in the ground.
To resolve this issue when the solar collector surface area reaches values greater than or equal to approximately 50 m2, traditionally, a concrete boot is used in which the single pillar is anchored, with the drawbacks of making the assembly and disassembly operations more complex and expensive.
The present invention aims to resolve this drawback by proposing a tracker support system for a solar tracker that makes it possible to provide anchoring in the ground without a concrete boot, while making it possible to achieve solar collector surface areas greater than or equal to approximately 50 m2.
Another aim of the invention is to propose a tracker support system for a solar tracker that is quick and easy to assemble, while favoring the use of standard parts.
Another aim of the invention is to propose a tracker support system for a solar tracker that offers a ratio between the steel mass used and the surface area of the solar collectors that is less than 25 kg of steel per square meter of solar collector, thereby facilitating the handling and placement operations.
Another aim of the invention is to propose a tracker support system for a solar tracker that makes it possible to achieve a safety threshold of approximately 70 km/h, that safety threshold corresponding to the wind speed beyond which an automatic securing system is activated to flatten the solar collectors, i.e., to make them horizontal.
To that end, the invention proposes a tracker support system for a solar collector, of the type that can be oriented along two axes of rotation, i.e., a vertical axis of rotation and a horizontal axis of rotation, respectively, and comprising:
From a mechanical perspective, the solution proposed by this tracker support system is particularly advantageous, as it proposes to monitor the ratio between the largest ground print distance and the zenith height to guarantee a robust architecture, suitable for ground anchoring of the support meeting the constraints due to wind and gravity with solar collector surface areas greater than or equal to approximately 50 m2, this ratio of approximately from 0.5 to 1.5 in particular making it possible to reach acceptable traction and compression strains for the ground anchoring means.
In a first advantageous embodiment of the invention, the fixed structure is made up of a pylon having feet on which the anchoring points are provided and extending over a predetermined height from the ground anchoring plane, the ratio of said height of the pylon to the zenith height being comprised in a span ranging from 0.5 to 0.9, and preferably in a span ranging from 0.7 to 0.8.
Such a ratio between the height of the pylon and the zenith height guarantees sufficient stiffness for the expected results, i.e., the ability to bear solar collectors with large surface areas with high-performance ground anchoring.
Preferably, the pylon has:
Such a configuration has the advantages of considerable ground stability, which guarantees mechanical strength of the fixed structure, allowing an increased surface area of the solar collectors.
According to one possibility of the invention, the pylon is made up of an assembly of metal profiles, typically of the angle iron type, having a length smaller than approximately 3 m, a transverse section whereof the dimensions are smaller than approximately 150 mm by 150 mm, preferably smaller than approximately 100 mm by 100 mm.
These metal profiles have the advantage of reducing manufacturing costs, in particular by selecting profiles that are commercially available, for example such as the angle irons used for transmission towers.
It is of course advantageous for the moving structure and/or the first framework and/or the second framework also to be made up of an assembly of such metal profiles.
Advantageously, the metal profiles are assembled by screwing, bolting or riveting, thereby ensuring quick and easy assembly.
In the second embodiment, the fixed structure includes a ring gear on which the first framework is rotatably mounted along the vertical axis of rotation, and several feet distributed on the periphery of the ring, in particular regularly, defining ground anchoring points and provided to fix anchoring members.
According to one feature, the second framework includes a platform defining the support plane for the solar collectors and at least two guy ropes positioned on either side of the vertical axis of rotation, each guy rope extending substantially orthogonally to said support plane and having a part fixed on the platform and at least one free end connected to the platform using connections, in particular of the tension rope, rigid rod or metal profile type.
Using such guy ropes has the advantage of limiting the deformations of the platform, considerable rigidity of the platform being particularly advantageous for the large surface areas of solar collectors, and in particular for concentration photovoltaic solar panels.
The presence of such guy ropes thereby makes it possible to have a platform with a width two times larger than the depth, which makes it possible to limit the torque effect due to the effect of the wind on the platform at the ground anchoring.
According to another feature, each guy rope extends on either side of the platform and has two opposite free ends connected to the platform using connections, each guy rope having a central part fixed on the platform.
In this way, the rigidifying effect of the guy ropes on the platform is increased.
In one particular embodiment, the at least two guy ropes comprise two pairs of guy ropes positioned on either side of the vertical axis of rotation.
Thus, two guy ropes are provided on both sides of the platform, i.e., a total of at least four guy ropes that contribute to increasing the stiffness of the platform.
Advantageously, the second framework includes a platform defining the support plane of the solar collectors and which comprises:
Using these sidepieces and beams guarantees the production of a platform that is quick and easy to manufacture. Furthermore, the guy ropes can be fixed on said sidepieces.
In one particular embodiment, the tracker support system further comprises anchoring members, preferably at least three anchoring members, configured to cooperate with the ground anchoring points to anchor the fixed structure in the ground, said ground anchoring members, in particular of the screw, pile, rod or peg type, being designed to penetrate the ground and anchor the tracker support system.
The architecture of the tracker support system is particularly well suited to these anchoring members, since it makes it possible to have traction/compression strains below 40,000 N on the anchoring members, thereby ensuring effective anchoring for large solar collector surface areas.
The present invention relates to the feature by which the first framework includes at least two arms secured to each other and rotatably mounted on the fixed structure, the use of these two arms making it possible to limit the deformation of the support plane of the solar collectors, under the effect of the wind and the weight of the solar collectors.
Preferably, the two arms form a V-shaped structure.
This V-shaped structure makes it possible to separate the ring gear sectors and thereby optimize the deflected curves on the second framework. In other words, with such a V-shaped structure, it is advantageously possible to decrease the bending on the second framework and thereby lighten the weight of the tracker system.
According to one feature, the first framework includes two supports fixed on the upper ends of the two arms, respectively, and each having a first bearing and a second bearing in which the transmission shaft and the corresponding ring gear sector are respectively rotatably mounted.
Thus, the transmission shaft is rotatably mounted in the first bearings of the supports and the ring gear sectors are rotatably mounted in the second bearings of the corresponding supports, these supports guaranteeing the structural cohesion and mechanical strength of the assembly to limit the risks of torsion of the second framework.
In one particular embodiment, the tracker support system comprises a motorized system for rotating the first framework along the vertical axis of rotation, including:
Such a motorized system thereby makes it possible to perform the vertical rotation function with a reduced bulk.
According to one particular embodiment, the tracker support system comprises a motorized system for rotating the second framework along the horizontal axis of rotation, including:
This motorized system for driving horizontal rotation is particularly advantageous to stabilize the rotation of the second framework with its central transmission shaft, and thereby guarantee high-precision tracking of the sun, which is particularly essential for concentration photovoltaic solar panels. Furthermore, the coupling of the pinions by the transmission shaft makes it possible to rigidify the second framework and avoid torsion thereof under the effect of non-uniform pressure from the wind.
Advantageously, the horizontal axis of rotation is separated from the vertical axis of rotation by a predetermined distance such that the second framework can be moved into a position in which the support plane is vertical.
Such a possibility is particularly suitable, or even essential, for concentration photovoltaic solar panels.
The invention also relates to a solar assembly including a tracker support system according to the invention, and solar collectors supported by the second framework of the tracker support system.
Other features and advantages of the present invention will appear upon reading the detailed description below, of two non-limiting example embodiments, done in reference to the appended figures, in which:
The following detailed description is done in reference to
The rest of this description therefore pertains to embodiments of a tracker support system 1 according to the invention, in which the elements or members that are structurally or functionally identical or similar are designated using identical numerical references.
Each tracker support system 1 comprises a fixed ground anchoring structure 2.
In reference to
The pylon 2 is made up of an assembly of metal profiles having a length smaller than approximately 3 m, and a transverse section whereof the dimensions are smaller than approximately 100 mm by 100 mm, said metal profiles being assembled by screwing, bolting or riveting. Preferably, these metal profiles are made up of angle irons, with an L-shaped transverse section, widely marketed and commercially available.
The lower ends 21 of the feet 20 constitute ground anchoring points, said anchoring points 21 defining a ground anchoring plane orthogonal to the vertical axis of rotation AV; said pylon 2 extends over a predetermined height HP from the ground anchoring plane.
In reference to
In reference to
The ring 23 is thus secured to several identical fastening tabs 27, which protrude outside the ring 23 and are angularly separated from each other, thereby making it possible to fix the ring 23 on the ground using a number of fixing members suitable for the nature of the ground.
In both embodiments, the anchoring points 21, 24 are thus separated from each other in the anchoring plane by predetermined distances, called ground print distances, including a largest ground print distance DE established between the two anchoring points that are furthest apart. In the first embodiment, this largest ground print distance DE is established between two lower ends 21 situated at two opposite corners of the rectangle or square, along a rectangle or square diagonal. In the second embodiment, this largest ground print distance DE is established between two feet 24 positioned diametrically opposite on the ring 23.
Each tracker support system 1 also comprises anchoring members 9 that cooperate with the anchoring points 21, 24 to anchor the fixed structure 2 in the ground. These anchoring members 9 are of the screw, pile, rod or peg type, and are thus designed to penetrate the ground and anchor the tracker support system 1. To that end, the anchoring members 9 are securely fixed on the lower ends 21 of the feet 20, or on the tabs 27 described above.
As an example, each anchoring member 9 is of the screw type and includes an upper cylindrical portion, for example tubular, that extends in the extension of a slender inner portion provided with a helical projection (not shown) forming the screw pitch. As an example, the anchoring members 9 may have a length HE close to 1.5 m or 2 m, or even greater than those values.
Each tracker support system 1 further comprises a moving structure 3 rotatably mounted on the fixed structure 2 along the vertical axis of rotation AV. In the first embodiment, the moving structure 3 is rotatably mounted on the upper end of the pylon 2, and more specifically on the upper end of the mast 22, while in the second embodiment, the moving structure 3 is rotatably mounted on the ring 23.
Each moving structure 3 comprises a first framework 4 rotatably mounted on the fixed structure 2, whether on the upper end of the mast 22 of the pylon 2 or on the ring 23, along the vertical axis of rotation AV.
In both embodiments, the first framework 4 includes two arms 40 that are symmetrical relative to the vertical axis of rotation AV, where:
In each embodiment, the two arms 40 are secured to each other moving away from the vertical axis of rotation AV to form a V-shaped structure. In other words, the arms 40 are inclined relative to said vertical axis of rotation AV, such that their respective projections in the horizontal anchoring plane extend partially outside the projection, in that same plane, of the ground print of the anchoring members 9.
In the first embodiment, to ensure the rotation of the first framework 4 around the vertical axis of rotation AV, the tracker support system 1 comprises a motorized system 41, illustrated in detail in
In the second embodiment, to ensure the rotation of the first framework 4 around the vertical axis of rotation AV, the tracker support system 1 comprises a motorized system 91, illustrated in detail in
In both embodiments, the moving structure 3 also comprises a second framework 5 designed to bear the solar collectors (not shown) and rotatably mounted on the two arms 40 of the first framework 4 along the horizontal axis of rotation AH; said horizontal axis of rotation AH extending at a predetermined distance, called zenith height HZ, from the anchoring plane, in other words from the anchoring points 21, 24.
Each second framework 5 includes a platform 6 defining a support plane of the solar collectors, said platform 6 comprising:
The sidepieces 60 and the beams 61 are for example made up of metal profiles of the same type as those forming the pylon 2. It is also possible to provide a platform without beams 61, but rather with several sidepieces 60 placed side by side.
In the first embodiment, the second framework 5 also includes two pairs of guy ropes 71a, 71b and 72a, 72b positioned on either side of the vertical axis of rotation AV symmetrically, each pair of guy ropes comprising an upper guy rope 71a , 72a fixed on a sidepiece 60, in this case the upper sidepiece, and a lower guy rope 7 fixed on the other sidepiece 60, in this case the lower sidepiece, said guy ropes 7 extending orthogonally to the support plane and each having:
The first pair of guy ropes 71a , 71b is positioned on one side of the vertical axis of rotation AV (on the left in
To ensure the rotation of the second framework 5 on the horizontal axis of rotation AH, each tracker support system 1 comprises a motorized drive system 8 (shown in detail in
Thus, the rotational driving of the transmission shaft 82 leads to a synchronous rotation of the two drive pinions 81, which rotate, still synchronously, the ring gear sectors 80 and the associated crosspieces 83, to ultimately pivot the platform 6 around the horizontal axis of rotation AH.
In both embodiments, the first framework 4 includes two supports 46 fixed on the respective free ends of the two arms 40 and each having two bearings, i.e.:
In the first embodiment, the support 46 is made in the form of a platen extending substantially parallel to the ring gear sectors 80 and in which the two bearings 47, 48 are mounted.
In the second embodiment, each support 46 includes:
In the case of the second embodiment, the first framework 4 also includes a reinforcing beam 51 connecting the upper ends of the arms 40, and more particularly connecting the yokes 50, extending substantially parallel to the horizontal axis of rotation AH.
In the first embodiment, the guy ropes 71a , 71b of the first pair are positioned substantially at the intersection of the first crosspiece 83 with the respective sidepieces 60, while the guy ropes 72a , 72b of the second pair are positioned substantially at the intersection of a second crosspiece 83 with the respective sidepieces 60.
In both embodiments, from the geometric perspective, the ratio of the largest ground print distance DE to the zenith height HZ is comprised in a span ranging from 0.5 to 1.5, and preferably in a span ranging from 0.8 to 1.2, which means that:
0.5 HZ≦DE≦1.5 HZ;
or 0.8 HZ≦DE≦1.2 HZ;
or further DE=HZ.
In the particular case of the first embodiment, the ratio of the height HP of the pylon 2 to the zenith height HZ is comprised in a span ranging from 0.5 to 0.9, and preferably in a span ranging from 0.7 to 0.8, which means that:
0.5 HZ HP 0.9 HZ;
or 0.7 HZ HP 0.8 HZ.
Furthermore, the platform 6 defines a support surface area of the solar collectors comprised between approximately 40 and 100 m2, preferably between approximately 50 and 75 m2. The zenith height HZ may be comprised between 2 and 5 m.
Furthermore, as shown in
Of course, the example embodiment described above is in no way limiting, and other improvements and details may be added to the tracker support system according the invention, without going beyond the scope of the invention, where other assembly forms of the frameworks may for example be used.
Number | Date | Country | Kind |
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11/01659 | May 2011 | FR | national |
11/62002 | Dec 2011 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FR2012/051199 | 5/29/2012 | WO | 00 | 3/21/2014 |