WO2008003431A1 - Tracking system for solar collectors - Google Patents

Abstract

Tracking system for solar collectors (P) consisting of a static frame on which a pivotable main frame with an axis (D) arranged parallel to the axis of the earth for the time-of-day tracking motion (Rd) is mounted, and on which the collector (P) or its frame is mounted with the axis (A) of the seasonal tracking motion (Ra) at an angle of 90° to the axis (D) of the time-of-day tracking motion (Rd), the seasonal tracking motion (Ra) being derived from the time-of-day tracking motion (Rd), wherein the transmission and conversion of the seasonal tracking motion (Rd), in relation to the static anchored structure (2, 2a, 2b, 2c / 12, 12a, 12b, 12c, 12d) of the system, take place via a threaded spindle mechanism (6) with screw-nuts (7a) which acts between the main frame (3a, 3b, 3c / 20, 20b, 20c), with mounting (2d, 2e / 15b), for the purpose of performing the time-of-day tracking motion (Rd), and the collector (P) or the collectors, the frame (Ra) of which is mounted in a pivotable manner on said main frame, wherein the threaded spindle (6) is mounted on the main frame and the drive of the threaded spindle / screw-nut mechanism (6, 7a) takes place via a tappet lever (10) which is mounted in a pivotable manner directly or indirectly on the static anchored structure (2, 2a, 2b, 2c / 12, 12a, 12b, 12c, 12d) and which, during the progress of the threaded spindle / screw-nut mechanism (6, 7a), acts in one direction, with the possibility of reversing the direction of action.

Description

 REFUND FOR SUN COLLECTORS

DESCRIPTION

There are so-called tracking or tracking systems known to the tracking of solar panels the course of the sun during the daytime, for the purpose of vertical irradiation of the collectors, regardless of the time of day and the season and thus independent of the rotation of the earth about its own axis and circulation (Revolution) of the earth to reach the sun.

The vertical irradiation causes the maximum yield of the efficiency of the collector, generally these systems are used for the tracking of photovoltaic panels.

For the tracking by means of sensors and electronic computer, which control electromechanical or hydraulic tracking units, complicated and expensive systems are known.

Furthermore, as far as daytime tracking is concerned, WO 2005/028969 discloses automated systems, which are equipped with a device which enables the periodic manual correction of the seasonal tracking. These systems are all based on the rotatable mounting of the collector around a vertical axis for daytime tracking and a horizontal axis for the seasonal tracking which can be performed continuously automatically or periodically, possibly manually.

From DE 20317666 the storage of the collector with the axis of rotation parallel to the axis, known which is achieved that at the installation points the angle of the collector surface to the bottom surface (line tangent to the globe) equals 0 ° in the equatorial region and equals 90 ° at the two poles; in contrast, in the intervening areas, said angle is exactly equal to the latitude of the particular point of deployment. The rotatable part of this bearing has a plate which is itself rotatable about the same axis, which due to the inclined axis of rotation, performs a wobbling movement and occupies the outermost positions on the days of the solstice. The support frame of the solar collector is hinged to the rotatable member with the axis of rotation parallel to the earth axis so as to follow the orientation of the wobbling plate, provided that at each daily rotation the plate is rotated by 1/365 of complete rotation. This rotation is derived by using a driver mechanism of the daytime rotation. In this case, a driving mechanism acts on the toothed ring, the circumference of the wobbling disc in that a weight which is attached to the end of a pivot arm and pivots in one or the other direction by the movement of the swash plate.

This tracking mechanism allows the precise alignment of the collector, but has the disadvantage that the driving mechanism works with the pivoting weight is not very reliable and, in relation to external loads, such. caused by gusts of wind is prone.

Furthermore, the seasonally pivoting construction which occurs through the progressive rotation of the swashplate has static problems which are not easily solved.

The invention has the object to provide a tracking device for solar panels of the type described above which is suitable to carry out the Nachführbewegungen after two axes, has a simple structure, is reliable in the operation, is low-cost manufacturable, requires little maintenance and is suitable, together with a noteworthy Series of identical devices, via a single drive unit to be operated.

To solve this problem, the invention proposes the use of a stable on the ground, on buildings or the like, anchored structure which is suitable a main frame, which is mounted parallel to the earth's axis, to carry on which, according to a horizontal axis pivotable and at least in the right Angle to the axis of rotation arranged parallel to the axis, the solar collector, or its support frame, or the frame of various grouped collectors, is pivotally mounted.

The rotation of the main support frame, together with the solar collector, about the axis parallel to the earth axis, takes place by means of a known drive group consisting of motor and reduction gear, which is e.g. from a timing relay at intervals, e.g. of about 1 ° each 4 minutes or continuously, synchronously with the earth's rotation, is controlled. This rotation starts from the extreme east-facing position, which may be determined by the presence of mountains or buildings that limit direct sunlight, and goes to the extreme west-facing position, which may also be determined by the presence of mountains or buildings. at noon, the orientation is exactly south. Advantageously, the return to the "morning" - start position, in the evening with different, possibly relatively fast, rotational speed to hit a limit switch or even in the evening, without precluding that the return movement takes place continuously or at intervals by simply reversing the rotation and without exclusion that the morning starting position is reached by completing the rotation in the same direction.

The movement of the "seasonal" tracking according to the pivot axis which forms an angle of 90 ° with the axis of the daily time tracking, according to the invention by means of a threaded spindle / nut Mechanism, wherein on the nut a Mitnehmerklinke acts which is pivotally mounted on the fixed structure of the device. This threaded spindle is displaceable in the longitudinal direction and not rotatable on the main frame of the device, substantially perpendicular to the axis of the daytime tracking this frame, however, shifted to the axis of the seasonal tracking of the solar collector, or its support frame stored. The back of the collector facing the end of the threaded spindle is hinged to the support frame, while a certain freedom from sliding in the direction substantially parallel to the axis of daytime tracking movement, within own guides, given while provided at the opposite end with a substantially radially projecting drive wings or drive projections provided nut is at which a driving pawl acts which is provided on a projecting from the fixed anchored structure or fixed bracket. The provided on the threaded spindle nut is mounted so that it rests in the longitudinal direction front and back of a stop so that, by the rotation of the nut, the axial displacement of the threaded spindle, with respect to the fixedly connected to the main frame of the device holder of the nut , he follows. This causes the end of the threaded spindle which is at the rear of the solar collector, or on its support frame, with limited Gieitfreiheit, offset from the axis of the seasonal tracking articulated, the pivoting of the collector, in dependence on the pitch of the thread of the threaded spindle, the angle of rotation which is effected by the action of the driving pawl on the threaded spindle in the passage under the fixed position of the driving pawl and the distance between the axis of the seasonal pivoting and the articulation of the end of the threaded spindle, causes. The said driving pawl is mounted so pivotally that they, as a result of a stop, during the tracking from east to west (daytime) or from west to east (nocturnal feedback) causes the rotation of the nut while pivoting in the corresponding rotation in the opposite direction, the same driving pawl free can and is moved across the nut without them to drive because no stop is provided for this direction of movement. This seasonal pivotal movement of the solar collector according to an axis which is perpendicular to the axis which is parallel to the earth axis, arranged must be carried out so that the collector progressively from a more inclined position on December 21 (winter solstice) in a less inclined position on 21. June (summer solstice) is brought; the angular width of this pivoting movement is the same for all geographical latitudes. After the latter date, a return from the less inclined to the more inclined position occurs again, so the nut must be rotated in the opposite direction; This can be done by reversing the whole

Mechanism of the driving pawl happen so that the stop acts in the opposite direction or by changing the position of the sole stop so that the action of the driving pawl takes place in the opposite direction; it is not excluded the attachment of two pawls which work alternately for the two pivoting directions. According to the invention, the nut is provided with at least three radially projecting drive vanes or drive projections, in this way takes place during each pass under the Mitnehmerklinke a rotation of about 120 ° and an axial displacement of the threaded spindle by about 1/3 of the thread pitch. However, it is not excluded to provide that the nut is moved under two or more, in the direction of movement successively arranged, pawls therethrough so as to achieve a further rotation of the nut.

The invention does not exclude that the nut is provided with an outer sprocket which meshes over a certain distance with a rack which is connected to the fixed anchored structure and that between the sprocket and the nut a known freewheel mechanism is provided with switching the freewheeling direction.

According to a further development of the inventive concept, the threaded spindle can rotate on the main frame of the device, in essential parallel position to the axis of daytime tracking, be stored and at the end which is moved closer to the fixed anchored structure of the device, be provided with operating wing or operating projections on soft, already described manner, attached to the fixed structure driving pawl acts. By rotation of said threaded spindle, a nut which is provided on the threaded spindle and according to the longitudinal axis of this, for example, on the main frame, slidably mounted, along the threaded spindle in response to the rotation and the pitch of the thread moves. This displacement of the nut can be transmitted to the collector or on its frame by means of cables and corresponding pulleys or by means of another mechanical system which consists for example of simple or combined levers. In particular, when using a cable pull, it may be advantageous to have one of the directions of the pivoting movement of the solar collector performed by a spring. Furthermore, it does not preclude hydraulic transmission from the nut to the collector by providing the necessary hydraulic cylinders and hydraulic lines.

The invention will be explained in more detail with reference to two inventive preferred embodiments of a tracking device for solar panels, the drawings meet purely explanatory, non-limiting purpose.

Fig. 1 shows schematically in perspective view, seen substantially from behind, a tracking device according to the invention for solar panels while the collector is aligned on one of the days of the equinox to the south; in order to derive the seasonal tracking movement of the daily time tracking movement, a threaded spindle is axially displaceable, not rotatable, mounted and a driving pawl acts on a rotatable nut on the threaded spindle. Fig. 2 shows the schematic plan view of the same in Fig. 1 illustrated tracking device with the identical orientation (south, winter solstice).

Fig. 2a shows the schematic plan view of the same in Figs. 1 and 2 shown tracking device with the collector oriented to the east on the day of the winter solstice.

Fig. 2b shows the schematic plan view of the same in Figs. 1, 2 and 2a shown tracking device with the collector aligned west on the day of the winter solstice.

Fig. 3 shows the side view of the tracking device shown in Fig. 1 with an indication of the seasonal pivoting movement of the solar collector.

Fig. 4 shows in perspective, on an enlarged scale, the detail of the drive mechanism for the seasonal tracking movement.

Fig. 5 shows a perspective view, substantially from behind, another embodiment of a tracking device according to the invention, wherein for the daily time tracking a spoked wheel-shaped frame is rotatably mounted on a substantially T-förmigeπ anchored to the ground frame, the storage for seasonal tracking in the area the lower edge of the collector or its frame is provided and wherein a threaded spindle is rotated by the daytime tracking movement via a driving pawl whereby a slidably but not rotatably supported, penetrated by the threaded spindle, nut causes the seasonal inclination of the collector.

FIG. 6 shows the side view of the tracking device shown in FIG. 6

At the bottom 1 or on the fixed structure of a building or the like, the fixed support structure 2, 2a, 2b, 2c anchored which consists of a front vertical support 2 and two spread rear supports 2a, 2b, from the upper end of which a cantilevered arm 2c projects. Between the upper end of the support 2 with support 2d and the upper end of the cantilevered arm 2c with support 2e, a main support frame for the solar collector P or for several rotatable collectors Rd, according to a parallel to the axis of rotation of the rotation axis D, stored. This main frame consists essentially of the parallel arms 3a, 3c which are provided with the corresponding bearing journals 5a and 5b and are connected by a tubular profile 3b. The bearing pin 5a is provided with a gear 5 or other known element for the direct or indirect transmission of movement from a drive group, not shown, consisting of motor and reduction gear. At the tube profile 3b a bow-shaped structure is fixed which consists of a tube profile 3e and two parallel arms 3f, provided at the free ends of the storage 3g for the laterally from the collector P, or from the support frame of this collector or a group of collectors, projecting pins is; this support frame is pivotable about an axis A which is perpendicular to the axis D and through the bearing journals of the collector or the support frame of the collector P and through the corresponding bearings 3g on the two arms 3f. The daily-time tracking movement Rd of the main frame 3a, 3b, 3c, 3e, 3f and the collector P about the axis D is used according to the invention for maintaining the seasonal tracking movement Ra of the collector P; To achieve this, behind the collector, in a vertically offset position relative to the position of the axis A of the seasonal tracking movement Ra, an axially displaceable 6s mounted 6a, 6c threaded spindle 6 is provided. The bearings 6a, 6c are

Plain bearings of which the bearing 6c on the profile 3b of the main frame 3a, 3b, 3c, 3e, 3f and the bearing 6a on an L-shaped arm 8 which is fixedly connected to said profile 3b, are provided. Of course, the two sliding bearings 6a, 6c are arranged coaxially with one another in order to be able to receive the threaded spindle 6 axially slidably 6s. On said threaded spindle 6, in a position on the one hand adjacent to the bearing 6a and on the other hand fitting to a pipe section 6d which is inserted over the threaded spindle 6, one with radial protruding actuating wings 7 provided nut provided 7a. The pipe section 6d lies with that end which is opposite to the end resting against the nut 7a on the bearing 6c or on the profile pipe 3b. The end of the threaded spindle 6 which faces the back of the collector P or the frame is held in a provided with slots or grooves connecting element 6b so that a rotation of the threaded spindle 6 prevents, but a limited shift substantially in the direction of the axis D, is possible ,

According to the area which is traversed daily by the nut 7a with wings 7 by means of a fixed, by the arm 2c of the fixed structure of the device, projecting arm 9, a driving pawl 10 is provided which is pivotable in a direction about the axis X 10a and with a Stop is provided to prevent the pivoting movement in the opposite direction. During the movement of the radial vanes 7 of the screw nut 7a under the position of the driving pawl 10, this impinges on at least one of said vanes 7 and causes the rotation 6r of the screw nut 7a and thus the axial displacement 6s of the threaded spindle 6 by the daily-time tracking movement Rd which causes the pivoting Ra of the collector P and thus the daily correction of the seasonal tracking.

The only manual intervention which is to be carried out twice a year, in each case for the respective winter and summer solstice, consists in reversing the entrainment action of the entrainment pawl 10 either by rotating the entrainment mechanism or by switching the stop for the entrainment pawl 10 thereby reversing the direction of the seasonal tracking movement Reach Ra.

The invention does not preclude a different mounting of the threaded spindle 6, eg parallel to the axis D of the daytime tracking Rd (FIG. 6. 7); In this case, there is the possibility of the threaded spindle 6 itself, above radial protruding wings 7 or via a toothing and by means of one or more driving pawls 10, to set in rotation 6m whereby a displacement 7b of the nut 7 is achieved which can be transmitted mechanically or hydraulically to the collector P or on its frame. Furthermore, according to the invention, the driving pawl 10 can be replaced by a fixed driver which acts on a ring gear or a wing ring, or a ring with radial projections, wherein between the said rim and the threaded spindle a freewheel mechanism is provided with switching the freewheeling direction.

The above-mentioned embodiment is exemplified in FIGS. 6 and 7. By means of legs 12, 12a, 12b anchored to the base 1, a support structure 12d, 12c with bearing journals 15a is fastened. The axis D of the bearing pin 15a is aligned parallel to the earth axis, at this pin 15a is a spoked wheel-shaped frame consisting of an outer ring profile 20 with circumferential groove 20a and spokes 20b rotatably mounted Rd. The ring profile 20 runs on, or between, on the T-shaped frame 12c, 12d provided rollers 15. For driving the spoke wheel-shaped frame 20, 20b, the rollers 15 can be used or it can be driven by a cross in the groove 20a chain (Straps, cables). The rotation Rd is the daily time tracking for the collector P softer on two mutually parallel from the Spoke wheel frame 20, 20b parallel to the axis D protruding arms 20c in bearing 13g about the axis A pivotally mounted Ra is mounted. The pivotal movement Ra is the seasonal tracking movement for the collector P; this movement takes place in the derivation of the daily time tracking Rd via a threaded spindle / screw nut mechanism 6, 7a. On one of the spokes 20b of the spoke wheel-shaped frame 20, 20b, the threaded spindle 6 is mounted rotatably 6m by means of the angle arm 21, 22 substantially parallel to the axis of rotation D. The bottom 1 facing the end of the threaded spindle 6 is provided with an impeller 7 on which a driving claw 10 acts which is built on the fixed frame 12d so that at each daily time tracking Rd the impeller 7 is guided past the pawl to a twist 6m of the impeller 7 and thus to reach the threaded spindle 6. The nut 7a is limited, but not rotatably mounted on the arm 19 projecting from the collector frame in longitudinal slots. Upon rotation of 6m of the threaded spindle 6 is thus a longitudinal adjustment 7b of the nut 7a and thus a pivoting Rb of the arm 19 about the axis A, which causes a rotation Ra of the collector P and thus the seasonal tracking day after day. Of course, the direction of action of the pawl 10 must be reversed in this embodiment on the day of the winter and summer solstice.

The tracking device according to the invention enables the simple mechanical connection, by means of mechanical transmission elements such as cables, chains, belts, the bearing pin 5a, or the spoke wheel-shaped frame 20, 20b, a plurality provided with collectors P or groups of collectors main frame to easily connected to all

Tracking devices, by means of a single motor to achieve the synchronized tracking according to both axes D and A of Nachführbewegungen.

Claims

1. tracking device for solar panels (P) consisting of a fixed frame on which a pivoting main frame with parallel to the axis of the earth axis (D) for the daytime Tracking movement (Rd) is mounted and on which the collector (P) or its frame with the axis (A) of the seasonal tracking movement (Ra) is mounted at an angle of 90 ° to the axis (D) of the daytime tracking movement (Rd), wherein the seasonal tracking movement (Ra) in derivation of the daytime Tracking movement (Rd), characterized in that the transmission and conversion of the daytime tracking motion (Rd) with respect to the fixed anchored structure (2, 2a, 2b, 2c / 12, 12a, 12b, 12c, 12d) of the device, via a threaded spindle mechanism (6) with a screw nut (7a) which takes place between the main frame (3a, 3b, 3c / 20, 20b, 20c) with bearing (2d, 2e / 15b) for carrying out the daytime tracking movement (Rd) and the collector (FIG. P) or the collectors whose frame is pivotally mounted (Ra) on said main frame, acts that the threaded spindle (6) is mounted on the main frame and that the drive of the Threaded spindle / nut mechanism (6, 7a) via a driving pawl (10) which is directly or indirectly pivotally mounted on the fixed anchored structure (2, 2a, 2b, 2c / 12, 12a, 12b, 12c, 12d) and during the passage of the threaded spindle / nut mechanism (6, 7a) in one direction, with the possibility of reversing the direction of action acts. 2. tracking device according to claim 1, characterized in that the threaded spindle (6) axially displaceable (6s) on the main frame in a substantially orthogonal to the axis (A) of the seasonal Tracking movement (Ra) of the collector (P) or the relevant frame for collectors stored (6a, 6c), wherein the end of the spindle which is directed against the back of said collector (P) or its frame, on the collector (P) or on its frame by means of an element (6b) with slots or longitudinal grooves, hinged so that these non-rotatable but limited, substantially in the direction parallel to the rotation axis (D) of the daytime tracking movement (Rd), displaceable (6s) and that provided with radial wings (7) or projections nut (7a) is held on the threaded spindle (6) between two fixed stops in position with, through the rotation (6r) of the nut (7a) with the radial vanes (7) or protrusions by means provided on the fixed frame Mitnehmerklinke (10), the axial displacement (6s) of the spindle (6) which causes the seasonal tracking movement (Ra) of the collector (P), takes place. 3. tracking device according to claim 1, characterized in that the threaded spindle (6) substantially parallel to the axis (D) of the daily time tracking movement (Rd) is rotatably mounted (6m) on the main frame (20, 20a, 2Ob ₁ 20c) that this is provided with a crown radial wing (7) or projections on which a anchored to the fixed structure (12, 12a, 12b, 12c, 12d) Mitnehmerklinke (10) acts that the nut (7a) which is provided on the threaded spindle (6) on the main frame of the collector (P) axially displaceable (7b) but is not rotatably guided by the rotation of the spindle (6), the axial displacement ( 7b) of the nut (7a) which is mechanically connected to the collector (P) or its frame to effect the seasonal tracking movement (Ra). 4. tracking device according to claim 1 and one of claims 2 or 3, characterized in that the driving pawl (10) has the shape of a Tooth or a fixed stop has or is replaced by a rack and that the nut (7a), or, the Threaded spindle (6) is equipped with a crown radial wing (7), projections or teeth which is equipped with a freewheel mechanism with the possibility of switching the freewheeling direction. 5. tracking device according to claim 1, characterized in that the Drive group of the tracking device is a single for both Nachführbewegungen (Rd, Ra) and directly on the spoke wheel-shaped main frame (20, 20b), or on one of the bearing journals (5a, 5b) of the main frame (3a, 3b, 3c, 3e, 3f) with a rotation axis (D) parallel to the earth's axis and that several tracking devices operate via known motion Transmission elements are connected whereby the synchronous tracking of the collectors (P) via a single drive group takes place. 6. tracking device according to claims 1, 2 and 5, characterized in that the axial displacement (6s) of the threaded spindle (6), or the axial displacement (7b) of the nut (7a), acts on a hydraulic cylinder which hydraulically with a connected to the second cylinder which acts on the collector (P) or on the frame so that this performs the seasonal tracking movement (Ra).