This application claims the benefit of the filing date of the German Patent Application No. 10 2012 211 073.9, filed 27 Jul. 2013, the disclosure of which is hereby incorporated herein by reference.
Embodiments of the present invention relate to a solar collector system and in particular a solar collector system with an opening and closing mechanism for solar collectors arranged in pairs, which solar collectors can close together with respect to one another.
A collector system with mirror-concentrating collectors which are tracked bi-axially is presented in WO 2005 003644. In addition to the bi-axial tracking, the possibility is shown to close the collectors in pairs at the mirror ends. As a result, on the one hand, an effective protection against damaging environmental influences can be achieved, on the other hand, the wind attack area is halved in the protected state. The protective position is particularly important in order to prevent damage in the event of extreme environmental influences (sandstorm, hail, . . . ) and in order to reduce the rate of soiling.
A considerable technical outlay is necessary in order to allow the opening and closing of the collectors in pairs, which should be minimized.
There may be a need to provide a solar collector system, in which drive and joint forces for the opening and closing procedure are kept as low as possible and thus the constructional outlay for hydraulic and/or spindle drives as well as for the support apparatus may be kept low.
The object may be solved by means of the solar collector system according to the independent claim. Preferred exemplary embodiments will be described in the dependent claims.
According to an exemplary aspect, a solar collector system with an opening and closing mechanism is provided, the solar collector system comprising solar collectors and an opening and closing mechanism with movement axes, an actuator, and two holding apparatuses arranged mirror-symmetrically with respect to one another in pairs. The holding apparatuses are configured to accommodate one or a plurality of solar collectors in such a manner that two fixed movement units are formed, which are movable in a mirror-symmetric manner at two movement axes in each case within a movement plane, such that it is possible to move between a closed state, in which the solar collectors touch in pairs in each case, and an open state, in which the pairs of solar collectors are arranged mirror-symmetrically with respect to one another in an essentially parallel alignment. Further, the movement axes are arranged normal to the movement plane and the actuator is configured to move the two movement units between the closed state and the open state mirror in a symmetric manner along predetermined paths.
In particular, a movement unit may be formed from a holding device and from solar collectors, e.g. one, two, three or four, which connect in pairs to the collectors of the second movement unit in the closed state. In particular, the opening and closing mechanism may be formed from two holding devices, the actuator, and the movement axes. For example, it may be that the movement axes are also part of the holding apparatuses. In particular, the movement axes may therefore be representational axes or guides.
For example, the solar collectors may be coupled to accommodation elements of the holding device or be accommodated by the same.
For example, the solar collectors may be constructed in a key-like manner or in the shape of a truncated pyramid, wherein edges of the solar collectors touch each other in the closed state in such a manner that a closed space can be formed.
Preferably, edges of the solar collectors comprise seals. It may be possible by means of such seals at the edge of the solar collectors that in the closed state, a sealed space can be provided by means of the pair of solar collectors.
In particular, the actuator may be configured to carry out a lifting movement which is carried out along a movement axis for example.
In particular, it may thus be possible to keep the center of gravity of the solar collectors predominantly in the horizontal during the movement for opening and closing (slight change in potential energy). According to the principle of virtual displacement, it can be deduced that the adjustment forces via the drives and furthermore the forces on rotary joints and support apparatuses may be kept low.
Further embodiments of the solar collector system will be described in the following.
According to an exemplary embodiment of the solar collector system, the opening and closing mechanism comprises at least one joint, which is attached in a movable manner at at least one of the movement axes such that the solar collectors carry out a rotation during the movement from the open state to the closed state. In particular, the rotation may be a 90° rotation.
According to an exemplary embodiment of the solar collector system, the opening and closing mechanism comprises two guides, by means of which the movement paths are defined.
In particular, the guides can be formed by means of pendulum supports and/or linear guides. For example, one guide may be a linear guide, whereas the second guide is formed by means of a pendulum support. Alternatively, both guides may be formed by means of linear guides. The linear guide may be formed by means of an axis, which can optionally comprise stops. In the case that linear guides are provided, one or a plurality of the linear guides may be formed by means of a double guide. The provision of a double guide, for example two axes located next to one another, may lead to a better guiding, for example by preventing tipping or twisting along the linear guides.
According to an exemplary embodiment of the solar collector system, the linear guide of the joints for the movement along one of the movement paths is realized by means of double guides. In particular, a movement path can be realized by means of double guides, which in the exemplary design experiences a pure back and forth movement, so that the initial position and the end position coincide.
According to an exemplary embodiment of the solar collector system, the guide of the joints for the movement along one of the movement paths is realized by means of pendulum supports. In particular, a movement path can be realized by means of double guides, which in the exemplary design experiences a pure back and forth movement, so that the initial position and the end position coincide.
According to an exemplary embodiment of the solar collector system, the actuator is a spindle drive. In particular, a movement axis may be a part of the axis drive. For example, the one movement axis may be the spindle of the spindle drive. Alternatively or additionally, a hydraulic drive may be provided.
According to an exemplary embodiment of the solar collector system, the solar collector system comprises four solar collectors, which can be moved between the open state and closed state by means of an individual actuator. Therefore, in particular, only one individual or a single actuator may be provided for the four solar collectors.
In particular, the solar collector system may comprise a multiple of four solar collectors, for example eight or sixteen solar collectors. Preferably, four solar collectors are combined in each case to form a group or a module on an opening and closing mechanism, which solar collectors can be moved by means of one individual common actuator.
According to an exemplary embodiment of the solar collector system, the solar collector system further comprises at least one tracking unit and is configured in such a manner that the solar collectors can be tracked to a position of the sun.
In particular, a tracking unit with two tracking axes may be provided, which enable tracking along directions that are perpendicular to one another. For example, one of the tracking axes can be suitable for taking a horizontal movement of the sun into account, whilst the other tracking axis enables a tracking with respect to the height of the sum's orbit path. In other words, one tracking axis may allow for an azimuth movement and the other allows for a zenith movement. It should be noted that the tracking unit is to be differentiated from the closing mechanism. Whilst the closing mechanism is used in particular to move two solar collectors against one another in such a manner that they can be transitioned from the open state to the closed state and vice versa, whereas a potential tracking unit is configured to align the solar collectors to a position of the sun that has changed in the course of the day respectively of the year. Such a potential tracking unit therefore does not form a necessary part of a closing mechanism.
According to an exemplary embodiment of the solar collector system, at least one tracking axis comprises an elastic element, which is configured to compensate forces, which arise during the tracking, at least to some extent. In particular, the forces may arise due to a change in center of gravity during the tracking. For example, the elastic element may be a spring or a pneumatic or hydraulic system.
According to an exemplary embodiment of the solar collector system, the solar collector system furthermore comprises a cleaning system, which is attached in the solar collector system in such a manner that in the closed state, the cleaning system is located between the solar collectors of a pair of solar collectors.
For example, the cleaning system may comprise a cleaning unit for each pair of solar collectors, which cleaning unit may for example be formed by an individual nozzle or a ring of nozzles and which cleaning unit is located next to the solar collectors of a pair of solar collectors in the open state, whilst in the closed state, the same is located within a space, which is enclosed by the solar collectors of one pair.
According to an exemplary embodiment of the solar collector system, the cleaning system is rigidly fastened at the solar collector system.
In this connection, the term “rigidly” may in particular mean that the cleaning system does not move or rotate during the movement between the open state and the closed state.
According to an exemplary aspect, a solar collector system with an opening and closing mechanism may be provided, which is characterized in that solar collectors and holding apparatuses form fixed movement units, which are arranged mirror-symmetrically in pairs and in each case can be rotated by ±90° via two axes arranged fixedly at the movement units, which are aligned normal to the movement plane, in predetermined paths of a support apparatus or of the holding apparatuses via the lifting movement of an actuator.
In other words, it may thereby be achieved that solar collectors and holding apparatuses form fixed movement units, which may be arranged mirror-symmetrically in pairs and may be attached via displaceable joints to a support apparatus, which is in turn fixedly or movably attached to a supporting frame. Each movement unit is mounted in a displaceable manner via in each case two spatially parallel axes at right angles to the movement plane in guide paths predetermined by the support apparatus. The individual rotary joints at the movement units may be positively guided in different paths via linear guides or pendulum supports, which are anchored at the support apparatus, so that a 90° rotation can be realized by means of a lifting movement of a hydraulic apparatus or a spindle drive.
A rotation of ±90° for each movement unit results during the movement from the open to the closed state and vice versa, with a small change of the vertical position of the center of gravity. Due to the mirror-symmetrical arrangement of the two movement units, collector pairs closed at the mirror ends can be brought to the open state with the same alignment by means of the equal and opposite rotation by ±90° into the open state, without the center of gravity of the movement units being significantly displaced.
Specifically, according to exemplary embodiments, a mechanism may be provided, which provides a linear guide (first guide) for the axes of the individual movement units in each case and a further guide (second guide) arranged mirror-symmetrically to the first guide, which second guide specifies a path which runs approximately normal (±30° deviation) to the direction of the first guide. Ideally, the connecting line of the two rotary joints of each movement unit in the end positions (open or closed, or open state and closed state) has an angle of ±45° to the direction of the first guide. In this manner, the collectors realize the desired angle of ±90° when opening and closing. Joints in the second guide experience a pure back and forth movement in this configuration, so that the initial position and the end position coincide. This may provide the option to delimit the desired ±90° rotation of the two movement units between open and closed collector position via stops in the second guide. A further option for delimiting the movements to the ±90° rotation results in that stops are provided in the first guide. For realizing the movements, the joints can for example be driven in the first guide. This can take place by means of a spindle drive or a hydraulic sliding system, at which the joints are mounted. Spindle drives or hydraulic sliding systems form a part of the support apparatus and predetermine the direction of the first guide. The two paths of the first guide can be provided at a certain spacing from the center line of the hydraulic or the spindle unit or else coincide on the center line. The joints of the first guide therefore move along two parallel guide lines or along a common guide line. The axes can in this case be formed by means of actual units in particular.
According to a further additional or alternative exemplary aspect, solar collector systems or collector installations can be provided, which are equipped with opening and closing modules, which in each case consist of four collectors, two holding apparatuses and a support apparatus with drive and connecting devices. Depending on the design of the collector installations, one or a plurality of support apparatuses are either mounted fixedly at supporting frames or are attached to the same via rotary joints. The supporting frames are tracked to the sun mono- or bi-axially.
According to a further exemplary aspect, a fixedly fastened cleaning device is attached at the supporting apparatus. This for example positions two rings equipped with cleaning nozzles (cleaning rings) in the mirror plane of the movement units which are arranged in pairs. Ideally, the centers of the cleaning rings are positioned on the axes of the rotationally symmetrical mirror collectors, which encompass the same in the closed state. This position of the cleaning rings makes it possible that in the open state, no shading onto the capture surfaces of the mirrors takes place and that no collisions take place during the opening and closing of the collectors. The cleaning rings can also be mounted in a rotatable manner or in a pivotable manner. The rotation takes place in the closed state of the collectors during the cleaning procedure. It is conceivable, instead of the cleaning rings, to provide other nozzle carriers also, such as for example a linkage system or a spherical nozzle arrangement (nozzle head). In order to prevent collisions at the supporting rods of the nozzle carriers, the mirrors are designed recessed at retraction points for the supporting rods of the nozzle carriers. The retraction points at the collectors are preferably at the deepest position of the mirrors in the closed state. Thus, the cleaning water can flow away to the outside via openings towards the supporting rods respectively can be captured for re-use. The sealing rubbers at the mirror ends can preferably also constitute a sealed encompassing at the retraction points for the supporting rods. Thus, it may be better possible to preheat the mirrors using water vapor and to leave the vapor to dissolve dirt for a certain time, before the rinsing procedure starts. With this method, the water consumption may be minimized, a gentle cleaning may be ensured, and the dirty water can be captured optimally.
The hydraulic pressure in the cleaning system (5-10 bar) is sufficient to operate a hydraulic drive or the hydraulic cylinder thereof for the opening and closing of the collectors. As the thrust may be kept to a minimum on the basis of the present kinematics, a small cross section of the pressure cylinder is to be preferred, which may minimize the discharge loss during the sliding movements. This water also can of course be captured.
Thus, a solar collector system may be provided, which comprises an opening and closing mechanism for solar collectors arranged in pairs, wherein the paired solar collectors are able to close together with respect to one another. In particular, different designs of modularly constructed collector systems with bi-axial tracking and optionally built-in cleaning mechanism can be developed. In this specific case, rotationally symmetrical solar collectors, for example mirror collectors, are considered here, which may form a delimited space by means of the closing together in pairs. With the closing together of the collectors at the outer mirror ends it is achieved that sensitive components such as mirrors, absorbers or solar cell modules are protected from damaging environmental influences and from soiling. In addition, the option may be given to install cleaning systems, so as to be able to advantageously use the closed state with the delimited and ideally also sealed interior space for an optimum cleaning with a low water consumption, if required also with the capture of the dirty water. Furthermore, a design is also be shown, which makes it possible to modularly configure bi-axially tracked collector units of different sizes equipped with four to sixteen collectors and to provide the option for the installation of a cleaning mechanism, even on the basis of retrofitting.
Further advantages and features of embodiments of the present invention result from the following exemplary description of currently preferred embodiments. The individual Figures in the drawing of this application are merely to be seen as schematic.
Further features and details of embodiments of the present invention result from the following description of the Figures. In the Figures:
Exemplary embodiments of the invention are described in the following with reference to the Figures, wherein mirror-symmetrical, identical or similar elements or parts with identical function being designated with identical or similar reference numbers in the various Figures.
In summary, according to an exemplary embodiment, an opening and closing module for solar collector installations may be provided, in which solar collectors and holding apparatuses form fixed movement units, which are arranged in a mirror-symmetric manner in pairs and are attached via displaceable joints to a support apparatus, which is fixedly or movably attached to a supporting frame. The individual rotary joints at the movement units are positively guided via linear guides or pendulum supports, which are anchored at the support apparatus.
Embodiments of the invention are not only limited to the variants presented here, but rather also to obvious combinations that can be derived therefrom. In the case of the features according to embodiments of the invention that are schematically illustrated in all Figures, it should be pointed out that the individual components can be manufactured in all diverse design variants and materials. In addition, it is to be pointed out that “comprising” does not exclude any different elements or steps and “a” or “an” does not exclude a multiplicity. Furthermore, it may be pointed out that features or steps, which have been described with reference to one of the above exemplary embodiments, can also be used in combination with other features or steps of other above described exemplary embodiments. Reference numbers in the claims are not to be seen as limiting.
Number | Date | Country | Kind |
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10 2012 211 073.9 | Jun 2012 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2013/063296 | 6/27/2013 | WO | 00 |