DE4210975A1 - Highly efficient sun collector - comprises photovoltaic collectors and thermal collectors stacked together with thermal black body irradiator on inside of sun collector - Google Patents

Abstract

Highly efficient sun collector using a combination of photovoltaic collectors and thermal collectors comprises photovoltaic collectors (3) stacked with thermal collectors (2, 5) in such a way that they lie over one another. A black body (4), arranged in the inside of the sun collectors, is a thermal irradiator on the reverse side of the photovoltaic collector (3) such that the irradiator and photovoltaic collector (3) are enclosed by a heat transfer medium (6). The outer form of the sun collectors is arranged such that the sun collectors are arranged over each other or next to each other. USE - To convert the sun's energy into usuable energy.

Description

The invention relates to a highly efficient Solar panel with to achieve a high overall efficiency optimal arrangement of the components used according to the preamble of claim 1.

The field of application of the invention lies in the utilization the solar energy striking the earth through their conversion into energy for use.

The usage energy provided in this way is subject to naturally fluctuations in season and time of day. By the special design of the highly efficient Solar panel, which allows selective acting combined thermal and photovoltaic energy receivers and taking advantage of physical laws Apply, the overall efficiency of the highly effective Solar panel increased. This is an application of the highly efficient solar collector even under less favorable Irradiation conditions where a purely photovoltaic Collector fails and / or a thermal collector conventional design is no longer usable, enables.

Known and already used to a significant extent are photovoltaic collectors. They are used for conversion the solar energy striking the surface of the earth in electrical energy. You benefit from the entire spectrum the area of the visible solar energy  Light between about 300. . . 700 nm, the exact Spectral range depends on the transducer base material used. Their efficiency is currently 10. . . 12%, 20% seem to be achievable in perspective. Your construction is very easy. Under a translucent The protective layer is on a flat support assembled and suitably connected solar cells. This flat collector will be more suitable Way so attached that on its photosensitive Sunlight incident on the top side is as perpendicular as possible.

Thermal collectors are also known and used various construction principles, simple black-painted, containers filled with water or complicated collectors with one from a heat transfer medium flowed through pipe system. This thermal Collectors can reduce the principle Radiation losses through an evacuated vessel (e.g. in DE 40 07 839) or by a thermal back Shielding must be protected. Thermal collectors can due to a suitable construction also for sub-roof installation be applicable or they can be in conventional roof tiles be integrated (as shown in DE 40 11 289). The use is common to all thermal collectors the long-wave portion of the infrared range (<< 1000 nm).

Also the combination of both types of collectors in one Housing is already known (see DE 39 23 821). Here the arrangement is chosen so that from the direction of incidence the solar radiation, the photovoltaic Collector arranged behind the thermal collector is.  

It is also known from the limited Passband of the frequently used flat glass Greenhouse effect where visible light and a Part of the adjoining spectral ranges almost can be passed unhindered (passband of the Flat glass about 250. . . 2500 nm), while the long-wave Infrared range is retained. This too With a suitable collector structure, the effect is already effective for thermal collectors used.

To improve efficiency, thermal Collectors are used as heat transfer media Dissociation processes (DE 37 29 758) or quantum processes (DE 40 01 891) use. The use of these processes necessary heat transfer media or additives to these condition u. U. a coloring of the heat transfer medium and thus the absorption of certain spectral ranges.

All solutions have in common that they either only individual spectral ranges of the incident solar energy exploit, or are only suitable for certain designs, or also emit energy again, resulting in a Reduction in efficiency leads.

Based on this state of the art, it is the task of Invention, through a new arrangement of thermal-photovoltaic Collectors and the targeted exploitation of the Combination effect of both collectors the overall efficiency to increase the plant so that its use too economically sensible under unfavorable radiation conditions becomes.

For this, on the one hand, the known technical solutions  be combined in a suitable manner. On the other hand takes advantage of the fact that one with a Part of the body exposed to (light) radiation absorbed energy again as long-wave infrared radiation delivers. This process is used in a targeted manner.

An inventive solution to this problem is in claim 1 specified. Developments of the invention are characterized in the subclaims.

The highly efficient solar collector uses the natural radiation of a body stimulated by radiation (Stefan- Boltzmann's law). From the radiation law of Planck follows that the radiant power of a black one Body always a function of wavelength and temperature is. In the working temperature range in question for a solar collector between about <0 ° C. . . 100 ° C it is always long-wave infrared radiation (<2500 nm), for which normal flat glass is impermeable. The use of standard flat glass simplifies the construction a thermal trap.

To use the natural radiation, an inside of the Solar panel black body, preferably the photovoltaic collector with blackened back, Targeted flow around on all sides by the heat transfer medium. That requires a special, sandwich-like Structure of the thermal collector if specified optical pass and blocking areas for its construction parts.

This sandwich-like structure is characterized by the following features featured. In the radiation direction from outside to inside  the sunlight hits first as a flat collector consisting of several, spaced layers Flat glass, built-in thermal trap. The cavities or Chambers between the flat glass layers can be evacuated or be thermally insulated in another suitable manner.

A first thermal trap follows this thermal trap Collector, each made of two disc-like elements made of flat glass or other suitable materials is formed, the flow chambers for the passage of the Include heat transfer medium. These flow chambers, the formed by means of conventional gas-tight spacers are or monolithic the spacers or subdivisions can include to achieve the desired Circulation of the heat transfer medium divided accordingly be. Furthermore there are assembly and connection points for the heat transfer medium is available.

The materials for this first thermal collector are to be selected so that the required passage and blocking ratios for the corresponding spectral ranges surrender.

It can be made of flat glass instead of disc-like elements in connection with spacer and sealing elements too in two parts, for example by injection molding processed plastic materials exist, the the spacers or subdivisions on both halves include integratively.

The is on the first thermal collector photovoltaic collector on; or at his There is a thermal dark radiator on the back. Preferably, the back of the photovoltaic Collector or the subsequent second thermal  Collector designed as a thermal dark heater.

A second is connected to the photovoltaic collector thermal collector, which is analogous to the first thermal Collector is built. It follows that the photovoltaic collector of two thermal collectors is included, d. H. it is from the heat transfer medium flows around.

The two chambers carrying the heat transfer medium can operated in parallel or in series, they but can also be used independently.

This construction of a solar collector is completed internally from a thermal design carried out in a known manner Insulation.

Of course, can be built in the above way Solar collector can be operated directly or indirectly.

When using self-convection, i.e. H. the ascending Own movement of a heat transfer medium when heated, the strength of this convection movement depends on the temperature difference between inlet and outlet temperature of the heat transfer medium in the solar collector and thus from its own temperature. The self convection will both from the incident solar radiation resulting external warming, as well as from the outside stimulated natural radiation from inside the solar collector located black body promoted.

The use of self-convection is further supported, provided that the one connected to the solar collector Circulation of the heat transfer medium allows this through  a corresponding circulation-appropriate structure of Chambers for the heat transfer medium and a sensible location the connection points for the entry and exit of the same.

A high selectivity of the heat transfer medium with regard to high light transmission (300 ... 700 nm) at the same time good absorption capacity of infrared radiation (< 1000 nm) is achieved by using silicone oil as Heat transfer medium and by adding a small addition of suitable substances (e.g. graphite particles) in the colorless basic medium silicone oil. Silicone oil combines good stability in a wide temperature range with good thermal properties.

The outer shape of the solar panels is in the way trained that they like roof tiles on top of each other and / or are arranged side by side.

The design is designed so that on the one hand the individual solar panels slightly mutually overlap, with the front active areas connect to each other, and then the back of the Solar panels are such that one of them usual roof tiles analog installation is possible. The Inlet and outlet for the heat transfer medium of the thermal Collectors and the connections of the photovoltaic Collectors lie in a fixed grid, for example in two rows per solar panel, so that it is made possible with the help of the prefabricated grid following Connectors and connectors a quick and assembly adapted to the respective circumstances to reach several solar panels.

Native, specially shaped transition and auxiliary elements, which can also include active areas  the integration of the highly effective solar collectors in existing roof chairs or in the usual roof coverings.

The modular system thus available secures when inserting into an existing roof skin with existing roof structure on the one hand the functional transition or the functional one Montage, on the other hand, it ensures a Continuation of the order, even if it is behind the Roof trusses on certain solar panels Make no use of solar panels with rear Trim permitted. With a separate structure of highly effective Solar panels (not as a component an existing roof skin) ensure the transition and Auxiliary elements in connection with a grid mounting frame for a defined closure of the overlap zones. This is an extremely versatile use of the Solar panels with good manufacturing properties guaranteed. (Series production of less standardized elements with individual use at the same time.)

To ensure the rainproofness of the roof covering used modular system of solar panels the overlap zone is designed accordingly. Guts or notches using snap-in technology, sealing elements and drip edges secure the without further aids Tightness of the solar panels used as roof skin against penetrating moisture.

The further embodiment of the invention can be removed.

The following are associated with the application of the invention essential advantages.  

The incident solar energy can be compared to known Applications even under less favorable radiation conditions be used economically.

The circulation of the heat transfer medium can be natural Paths by taking advantage of the diminishing in warming density of the heat transfer medium going on. It forms in the proposed design of the collector and its insertion into a suitable circuit a gravity cycle out of the heat transfer medium, at which the resulting flow velocity in direct connection with the energy input in the highly effective solar collector.

The solar collector can be constructed using a sandwich construction and use of ordinary flat glass easily and inexpensively getting produced.

By manufacturing in a modular system is an adjustment of the entire energy collection system to many different ones Conditions without recourse to special constructions possible.

There is also the possible functional connection of the highly effective Solar collector as an energy collector with the roof skin function.

The invention is intended below without limitation of general inventive idea of exemplary embodiments to be discribed.

Show in the accompanying drawings

Fig. 1 is a schematic sectional view of the highly efficient solar collector,

Fig. 2, the modular-design of a solar collector module,

Fig. 3 shows the design of the overlap zone of a solar collector assembly according to the invention in the installed state.

Fig. 1 shows a single, with all the functional features of a highly effective solar collector featured element of the modular system.

The structure is subsequently from the outside in, so to speak the light rays incident in the solar collector described below.

The solar collector is closed to the outside by a thermal trap 1 designed as a flat collector. This thermal trap consists of two chambers 10 , which are enclosed by three layers of flat glass 1.1 , 1.2 , 2.1 , for example simple window glass. In the exemplary embodiment, the two chambers 10 are evacuated and the inside of the flat glass elements 1.1 and 1.2 have an internal mirroring as the reflection layer 12 .

The actual first thermal flat plate collector 2 is connected to this thermal trap. In the same way, it consists of two flat glass elements 2.1 and 2.2 , which delimit the flow chambers 11 in the direction of incidence, and spacers 7 , which at the same time assume the function of sealing elements in the edge section, ensure the desired circulation of the heat carrier 6 .

The photovoltaic collector 3 , for example in the form of a polycrystalline silicon solar cell, directly adjoins the limiting disk 2.2 of the first thermal collector 2 . The back of the photovoltaic collector 3 facing a second thermal collector 5 is designed as a thermal dark radiator 4 .

Analogous to the first thermal collector, the second thermal collector 5 consists of two flat glass elements 5.1 , 5.2 , which form the second flow chamber 11 with the distance specified by the spacers 7 .

The entire sandwich arrangement of the solar collector is held by a frame and is joined by means of mechanical locks and adhesive connections. The frame is covered with an external thermal insulation 9 . The heat transfer medium 6 is fed into and out of the flow chambers of the thermal collectors 2 and 5 by means of connecting pieces 8 .

This results in a solar collector constructed in this way following functional sequence.

A solar collector according to Fig. 1 is so exposed to the atmosphere penetrating solar radiation that it as vertically as possible to the solar collector. The visible part of sunlight penetrates almost unhindered from the multiple layers 1.1 , 1.2 ; 2.1 and 2.2 existing outer part of the solar collector and strikes the photovoltaic collector 3 . In this, about 10% of the sunlight striking it is converted into electrical energy in a known manner and can be removed.

In all elements that the light beam has passed through before it hits the photovoltaic collector, the absorbed energy is emitted again in the form of long-wave infrared radiation in accordance with Stefan-Boltzmann's law and Planck's law on radiation. This also applies to the photovoltaic collector 3 , in which a high proportion of the solar radiation striking it is absorbed (approx. 90%). For this reason, its rear side 4 is blackened.

The transmission properties of flat glass prevent the long-wave infrared radiation generated inside from being emitted to the outside. This possibility only exists for the outermost glass pane 1.1 . This heats up the inner parts of the solar collector. This "trapped" energy in the solar collector can be extracted in a known manner in the form of thermal energy through the heat transfer medium, which is particularly suitable for receiving the long-wave infrared radiation.

To reduce heat conduction losses, the solar collector is at the rear and partially thermally insulated on the side 9 . For the same reason, the cavities 10 between the outer flat glass arrangement (thermal trap) can be evacuated or otherwise equipped with poor heat conduction properties and sealed in a known manner.

If a gravity cycle of the heat transfer medium is sought, so are the individual solar panels too "interconnect" that an unimpeded rise of the heat transfer medium is achieved. The gravity cycle sets one analog to known gravity heaters Building the cycle ahead. He has the advantage of Saving the usually to maintain the Circulation of the heat transfer medium necessary additional energy.

Both electrical and thermal energy can be used in the usual way.

In FIG. 2, the modular design of the compliant outer solar collector is illustrated. The representation 2.1 shows the outside of the roof-top solar panels placed one above the other and / or next to each other and the representation 2.2 shows the rear.

When installed, see also FIG. 3, the active solar collector 20 close to each other and lie on the supernatants of 21 of the or the respective neighboring elements.

The two sectional representations 2.3 and 2.4 once again clearly show the actual active part of the solar collector component with light entry surface 20 and the mounting part 22 of the solar collector with roof support surface 23 .

The mounting part 22 takes on the function of thermal insulation and protection of the solar panel in addition to its determination as a mounting element.

The connection points 24 for the photovoltaic collector 3 and 25 for the heat transfer medium 6 of the thermal collectors 3 and 5 can also be seen .

In addition to FIG. 2, FIG. 3 shows a section of a roof skin consisting of highly efficient solar collectors as a top view and as a sectional illustration.

The detail y illustrates the formation of an overlap zone. The mounting parts 22 of two collector modules snap into one another by means of a stabilizing bead 27 and a guide lug 28 using a snap-in technique. The connection is supplemented by sealing elements 29 and drip edge 30 .

Claims (14)

1. Highly efficient solar collector using a combination of photovoltaic collectors and thermal collectors, the thermal collectors being designed as flat collectors with internal mirroring of the glass panes, characterized in that the photovoltaic collectors ( 3 ) in the manner with the thermal collectors ( 2 , 5 ) stacked and thus arranged in series, so to speak, that a black body ( 4 ) located inside the solar collector is arranged as a thermal dark radiator on the back of a photovoltaic collector ( 3 ) so that the dark radiator ( 4 ) and photovoltaic collector ( 3 ) on all sides are surrounded by the purposefully moved heat transfer medium ( 6 ) and the outer shape of the solar collectors is such that they can be arranged one above the other and / or flat next to one another in the manner of roof tiles. 2. Highly efficient solar collector according to claim 1, characterized in that it has the following circuit and thus the following chamber systems in the direction of sun entry from the outside in:

• a) thermal trap ( 1 ) consisting of several layers of flat glass ( 1.1 , 1.2 , 2.1 ) or other suitable material with cavities or chambers ( 10 ) in between,
• b) a first thermal collector ( 2 ), each consisting of two disc-like elements ( 2.1 , 2.2 ) made of flat glass or other suitable materials, gas-tight spacers ( 7 ) or subdivisions, which in the flow chamber ( 11 ) the desired flow direction for the circulating Cause heat transfer medium ( 6 ) and assembly and connection points for the heat transfer medium,
• c) photovoltaic collector ( 3 ) with a thermal dark radiator ( 4 ) located on its rear,
• d) a second thermal collector ( 5 ), which is constructed analogously to b),
• e) frame and thermal insulation ( 9 ).

3. Highly efficient solar collector according to claim 1 or 2, characterized in that the thermal trap ( 1 ) by means of the flat glass elements ( 1.1 , 1.2 , 2.1 ) preferably forms two chambers ( 10 ). 4. Highly efficient solar collector according to one of claims 1 to 3, characterized in that the chambers ( 10 ) are evacuated or filled with a thermally insulating gas. 5. Highly efficient solar collector according to one of claims 1 to 4, characterized in that the flat glass elements ( 1.1 , 1.2 ) each have a metallic reflection layer ( 12 ) on their inside facing the chamber ( 10 ). 6. Highly efficient solar collector according to one of claims 1 to 5, characterized in that the subdivisions in the flow chambers ( 11 ) and the related structural parts are arranged geometrically so that they ensure self-convection of the heat transfer medium ( 6 ). 7. Highly efficient solar collector according to one of claims 1 to 6, characterized in that the flow chambers ( 11 ) are made in two parts from, for example, injection molded plastic materials, the chamber halves containing the spacer elements ( 7 ) or subdivisions monolithically. 8. Highly efficient solar collector according to one of claims 1 to 7, characterized in that the rear of the photovoltaic collector ( 3 ) and / or the thermal collector ( 5 ) arranged behind the photovoltaic collector is designed as a thermal dark radiator ( 4 ). 9. Highly efficient solar collector according to one of claims 1 to 8, characterized in that the two before and behind the photovoltaic collector ( 3 ) arranged chambers ( 11 ) for the heat transfer medium ( 6 ) can be used separately. 10. Highly efficient solar collector according to one of claims 1 to 9, characterized in that the inlet and outlet ports ( 8 ) for the heat transfer medium ( 6 ) and the connections of the photovoltaic collectors are easy to assemble in a fixed grid, for example two rows per solar collector, are arranged , and that their connection is made with prefabricated connectors and connectors. 11. Highly efficient solar collector according to one of the claims 1 to 10, characterized in that silicone oil as the heat transfer medium with the addition of a small addition more suitable Substances, for example graphite particles, can be used is. 12. Highly efficient solar collector according to one of claims 1 to 11, characterized in that the actual active solar collector surfaces ( 20 ) connect to each other for roof tile-like installation of the solar collectors on the front, but their rear sides have protrusions ( 21 ) on which the collector elements to be connected or At the end of the collector surface, the roof tiles lie in an overlap zone ( 26 ). 13. Highly efficient solar collector according to claim 12, characterized in that transition and auxiliary elements with or without active solar collector surfaces ( 20 ) for integrating the highly effective solar collectors into the existing roof structure or roof covering are available. 14. Highly efficient solar collector according to claim 12 and 13, characterized in that the solar collectors or transition and auxiliary elements in the overlap zone ( 26 ) fillets, notches ( 27 , 28 ) to support the locking effect or the snap-in technology and sealing elements ( 29 ) and drip edges ( 30 ).