DE102013108119B4 - Substructure element and photovoltaic system for use on a loose, especially sandy substrate - Google Patents

Abstract

The invention relates to a substructure element for use on a loose, in particular sandy, ground, for example, in desert regions with moving sand dunes. The substructure element has a base element (2) on which at least one floating body (3) is arranged, and a vibration generator (4) in order to vibrate the at least one floating body (2). The invention further relates to a solar system, in particular for use in desert regions.

Description

The invention relates to a substructure element and a photovoltaic system for use on a loose, in particular sandy, substrate, for example in desert regions with moving sand dunes.

In sandy desert regions, structural constructions with a firmly anchored foundation threaten to be buried partially or completely under sand due to the constant drifting of the desert sand. In desert landscapes, sand dunes can also form due to the wind movements, which can migrate and change their shape, so that solid building foundations can disappear therein.

This problem also arises, for example, in the installation of solar thermal systems or photovoltaic (PV) systems in (sand) desert regions. Usual mounting frames are spilled by the sand or it is not at all possible to anchor them in the sand so that they stand upright. The use of very massive foundations, which are still sufficiently high to not be buried under the sand, however, is hardly feasible due to the high material requirements for transport and cost reasons.

Similar problems also occur in small buildings such as warehouses or treasure huts o. Ä. On.

From the pamphlets DE 103 02 746 A1 and DE 10 2006 019 753 A1 are floating on solar water systems known in which a float carries solar cells. However, floats can not prevent spillage, as floating bodies in the sand will not float by themselves when spilled or spilled.

The object of the invention is therefore to provide a sub-element of the type mentioned, which can be placed, for example, in sandy desert regions without sinking there in the sand, and also cost-effective, material-saving and structurally simple. It is another object to provide a PV system for use in such sandy desert regions.

The object is achieved by a substructure element or a photovoltaic system with the respective features of the independent claims.

An inventive sub-element of the type mentioned has a base member on which at least one float is arranged, and a vibration generator to enable the at least one float to vibrate.

According to the invention, the substructure is equipped with floats with which the substructure on the loose ground, z. B. the sand rests. By the vibration generator, such as an unbalance motor, the vibrating body can be set in vibration. The vertical portions of the floats lead to a periodic alternating unloading and loading condition of the floats. It creates such short-term relief phases that u. U. can lead to a short lifting the float. Since sand is cohesive in the dry state and can flow almost freely, the surrounding sand then flows under the float, causing it to float in the surrounding sand and thus be protected from being spilled by sand. Instead of a massive foundation, the base frame can be produced with low material costs. In addition, transport costs are significantly lower compared to a massive foundation.

The flow of sand is supported by the vibrations also transmitted to the sand, since the vibrations in the sand there also leads to relief conditions, whereby the caused by gravity friction of the sand grains is reduced or eliminated, which leads to an even better flow behavior. Another advantage of the vibrations is that sand deposited on the substructure is shaken down.

In an advantageous embodiment of the substructure, the at least one floating body is designed as a hollow body, preferably cylindrical. The base element may for example have a tubular frame or be formed by a tubular frame. More preferably, a mounting frame is mounted on the base member. Particularly preferred is this mounting frame for receiving a photovoltaic generator, in particular a photovoltaic module is formed. In this embodiment, the sub-element can serve as a support for PV modules. Compared to known massive mounting bases, the substructure is characterized by a low material usage. The inherent protection against silting makes it possible to build PV systems with low maintenance even on sandy ground.

In a further advantageous embodiment, the base element has a ground anchor. This is preferably attached via a chain or a rope, in particular a steel cable, to the base element. By connecting with the ground anchor is limited the lateral movement of the sub-element, without taking the vertical freedom of movement completely. It prevents a sub-assembly or composite from moving too far away from its actual location. In addition, connecting lines may preferably be routed along the steel cable or the chain along the base element to the ground anchor. The steel cable or the chain then protects against a demolition of the connecting cables.

In a further advantageous embodiment, the substructure element is designed such that a plurality of such substructure elements can be connected to one another to form a composite. In the composite, the distance between adjacent substructure elements is fixed to each other, to complicate lateral migration of the substructure elements. For this purpose, spacer bars may be provided between adjacent substructure elements, such that a certain tilting and vertical displacement of adjacent substructure elements relative to each other is possible. The sub-elements may then be slid in their vertical orientation, but are more defined in their horizontal location by the composite than is a single sub-element. Also, the composite reduces the risk of tilting on steep slopes, which can occur on sand dunes, because the substructure elements mutually support one another.

A photovoltaic system according to the invention with one or more photovoltaic modules is characterized in that at least one of the abovementioned substructure elements is used to hold the photovoltaic module (s). This results in the advantages mentioned in connection with the substructure element.

Further advantageous embodiments of the invention are specified in the respective subclaims.

An embodiment of the invention will be described below with reference to the accompanying drawings. Show it:

1 a schematic representation of a sub-element used in a PV system, in a first side view and

2 the substructure of the 1 in a second side view.

In the 1 and 2 is a substructure element 1 for use on a loose surface 10 represented, for example, in a sand desert landscape. The figures show the substructure element 1 in side views of two different directions.

The substructure element 1 has a ground-based base element 2 on, for example, as shown here may be a tubular frame. In alternative embodiments, a base plate as a base element 2 be used. The basic element 2 is preferably rectangular. However, other shapes are conceivable within the scope of the invention.

To a list of the substructure element 1 in a desert landscape with shifting sands or moving sand dunes are possible on the base element 2 at its edge areas and / or its bottom float 3 arranged. These floats 3 are preferably made of a plastic material and are formed as a hollow body, so that they are correspondingly light. It is also conceivable to manufacture the floats from a metal such as aluminum or steel. In particular, it is provided the floats 3 form cylindrical and two floats 3 at the two side edges of the base element 2 to arrange in longitudinal extension.

To a sinking of the sub-element 1 in the sand z. B. in a moving dune, is beyond a vibration generator 4 on the base element 2 attached to the base element 2 offset in a vertical and / or horizontal vibration. The vibrations are transmitted to those on the base member 2 mounted vibrating body. It is such a single vibration generator on the base member 2 attached, for example, in the center of the base member 2 , sufficient to all oscillating bodies 3 to vibrate. As a vibration generator 4 For example, an unbalance motor, so a motor, on the rotary shaft, a mass is mounted uncentered, are used.

Sand is cohesive when dry and can flow almost freely. The vertical parts of the floats 3 lead to a periodic alternating unloading and loading condition of the floats 3 , In the short-term relief phases, the u. U. up to a short lift off the float 3 The surrounding sand then flows under the float 3 , causing it to float in the surrounding sand. The underlying phenomenon is also called perdotation. In this case, a compression of the underlying sand continues to take place, while causing oscillations upwards loosening of the sand, which is the floating of the floating body 3 additionally supported. This mechanism is all the more effective, the lower the cohesion of the substrate material. The method of floating is therefore particularly effective for sand as a substrate, but the application is not limited to sand; an insert can also occur with other loose substrate materials. Another advantage of the vibrations is that on the substructure element 1 Shaken off sand that has been deposited.

The choice of the frequency and the amplitude of the vibration depends, inter alia, on the chosen shape and size of the float 3 and the base element 2 from. It can be provided, the frequency and the amplitude of the vibration generator 4 adjustable to make it possible for the floats to float as effectively as possible 3 to achieve by well adapted vibration parameters. Suitable frequencies are for example in the range of a few tens to a few hundred hertz (Hz), preferably between 90 and 180 Hz.

In the illustrated 1 and 2 becomes the substructure element 1 used in a PV system to PV modules 7 to carry a PV generator. This is present on the base element 2 a pyramid-shaped mounting frame 5 mounted, at the top of the PV modules 7 are arranged. In this case, a tracking device is preferred 6 between the mounting frame 5 and the PV modules 7 provided the PV modules 7 can rotate and / or tilt in the direction of optimum sunshine. In the pyramid-shaped mounting frame 5 can additional devices such. As inverters of the PV system or junction boxes o. Ä. Be arranged.

Especially when using the substructure element 1 for mounting PV modules 7 a PV plant, it makes sense from the PV modules 7 generated electrical energy to drive the motor for the vibration generator 4 to use. In this case, a rechargeable battery for temporarily storing the energy may be present around the vibration generator 4 if necessary, to be able to use, if there is no sunshine.

For large PV systems, a plurality of the sub-elements shown in the figures 1 with PV modules 7 be provided. It may then be useful, the distance between adjacent substructure elements 1 fix each other to a lateral hiking of the substructure elements 1 to complicate. For this purpose, on the sub-element 1 Fastening means for connecting elements, for example, for spacer bars, be formed. The fastening means and / or the connecting elements are preferably designed so that a certain tilting and vertical displacement of adjacent substructure elements 1 against each other is possible. The substructure elements 1 can then be shifted in their vertical orientation, but are more defined in terms of their horizontal location by the composite than a single sub-element 1 is. Also, the compound reduces the risk of tipping on steep slopes that may arise on sand dunes, as the substructure elements 1 in mutual support.

In addition, in the composite as well as a single sub-element 1 be provided, a sub-element 1 To connect with a ground anchor, for example by a steel cable or a chain. As a ground anchor z. B. serve a solid concrete block. The connection with the ground anchor causes the lateral movement of the substructure element 1 restricted, without taking the vertical freedom of movement completely. It prevents a substructure element 1 or a composite moves too far away from its actual location. It can also be provided that connection lines to said steel cable or the chain along the base element 1 be led to the ground anchor. The steel cable or the chain then protects against a demolition of the connecting cables.

There's sand on the PV modules 7 If the yield of the PV generator is reduced, the generated current can, under known irradiation conditions, be used as a measure of the amount of deposited sand. The irradiation conditions can be z. B. be determined by a protected from sand deposits insolation sensor. It may be provided, after detecting sand deposits, the vibration generator 4 turn. The generated vibrations lead to a shaking off of the deposited sand and to the previously described floating of the substructure element 1 ,

Overall, a structurally simple, but very effective substructure element for use in sandy desert areas is created by the invention, which is well suited not only for the recording of PV modules shown in the embodiment.

In a comparable manner, for example, a thermal solar system can be mounted on one or more such substructure elements. A thermal solar system may comprise a mirror arrangement, a so-called concentrator, through which the sunlight is focused on a liquid-conducting element of a medium cycle. As concentrators, for example, parabolic mirrors are used which direct the sunlight onto a liquid-carrying tube serving as a heat exchanger. Such parabolic mirrors may have a parabolic shape in one or two spatial directions. Usually they are used together with a tracking device.

It can be provided that the liquid is vaporized by the absorbed heat and supplied in gaseous form via the medium circuit of a turbine, which drives a generator for generating electricity. In such a system, other components may be provided, for example, one or more pumps for circulating the medium circuit, storage and pressure equalization tank, capacitors to convert the medium from a gaseous back to the liquid state and systems for controlling such a system. The said components of such a solar system can be mounted on one or even a composite of several according to the application substructure elements to install them on a loose or sandy ground, without any risk of spillage exists. If a plurality of sub-elements are used, they can be held in position relative to each other by rods or similar spacers with respect to their horizontal distances.

Of course, thermal solar systems that do not work on the concentrator principle, but directly exposed to sunlight collectors, z. B. flat or tubular collectors are mounted on the according to the application substructure elements.

There are a variety of other uses conceivable, for example as a substructure for smaller buildings such as storage rooms or treasure huts. A use as a substructure for a so-called fog trap for drinking water supply or irrigation purposes is possible. This is a z. B. V-shaped frame, which spans a network of fine mesh plastic, mounted on the base element. The net absorbs the finest drops of water from the air (fog, general humidity) and passes them on to a tank. Advantageously, the tank may be integrated into the float or formed by the float. Such a fogger works easily and reliably and is inexpensive to implement.

Another application is the recovery of spilled, massive objects z. B. vehicles or containers. With a temporarily mounted vibration generator or only in the environment, the surrounding sand can be made to flow, which makes it easy to lift the spilled object out of the sand. Cavities in the object itself can act as floats, if necessary, additional floats can be attached to the object.

If the substructure element is covered by a building or housing construction, then wall constructions are useful, which are characterized by inclined planes from which the sand can fall off. It can also be provided that the individual walls of the building or housing construction are likewise set in vibration by the vibration generator in order to allow the sand to fall off the side and / or roof surfaces of the housing.

Also in primary other use can be provided to provide the sub-element with a PV module and a battery charged by this to supply the vibration generator.

LIST OF REFERENCE NUMBERS

1

Substrate element

2

base element

3

float

4

vibration generator

5

mounting frame

6

tracking device

7

PV module

10

underground

Claims (17)

Substructure element for use on a loose, especially sandy subsoil, for example in desert regions with moving sand dunes, with a base element ( 2 ), on which at least one floating body ( 3 ), and a vibration generator ( 4 ) to the at least one float ( 2 ) to vibrate. Substructure element according to Claim 1, in which the at least one floating body ( 3 ) is designed as a hollow body. Substructure element according to Claim 2, in which the at least one floating body ( 3 ) is cylindrical. Substructure element according to one of Claims 1 to 3, in which the base element ( 2 ) has a tubular frame. Substructure element according to one of claims 1 to 4, in which on the base element ( 2 ) a mounting frame ( 5 ) is mounted. Substructure element according to Claim 5, in which the mounting frame ( 5 ) for receiving a photovoltaic generator, in particular comprising one or more photovoltaic modules ( 7 ), is trained. Substructure element according to claim 6, wherein between the mounting frame ( 5 ) and / or the photovoltaic generator, a tracking device ( 6 ) is provided. Substructure element according to one of Claims 1 to 7, in which on the base element ( 2 ) a housing or a cabin is mounted. Substructure element according to one of Claims 1 to 8, in which the vibration generator ( 4 ) is an unbalance motor. Substructure element according to one of Claims 1 to 9, in which the vibration generator ( 4 ) on the base element ( 2 ) is arranged to the base element ( 2 ) and indirectly to the at least one floating body ( 3 ) to vibrate. Substructure element according to one of Claims 1 to 9, in which the vibration generator ( 4 ) is arranged so that the at least one floating body ( 3 ) is immediately vibrated. Substructure element according to one of claims 1 to 11, comprising a ground anchor. Substructure element according to Claim 12, in which the ground anchor is attached to the base element by means of a chain or a cable, in particular a steel cable ( 2 ) is attached. Substructure element according to one of claims 1 to 13, which is designed such that a plurality of such substructure elements can be connected to one another to form a composite. Solar system, in particular for use in desert regions, with at least one solar collector, characterized in that for holding the at least one solar collector at least one sub-element according to one of claims 1 to 14 is provided. Solar system according to claim 15, designed as a photovoltaic system, wherein the at least one solar collector comprises one or more photovoltaic modules. Solar system according to claim 15, designed as a solar thermal system, wherein the at least one solar collector is a thermal solar collector, in particular with a concentrating mirror arrangement.

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