DE4307705A1 - Solar cell arrangement - Google Patents

Description

The invention relates to a solar cell arrangement, wherein the solar cells with a fluid to dissipate heat are interconnected.

Such solar cell arrangements are known per se. For example, reference is made to the unpublished patent application message P 42 40 616.1.

The background of such a technique is one if possible effective use of both electrical energy, wel the solar cells, as well as the thermal ones Energy used in converting solar radiation is released in electricity from the solar cells, and this is the case up to 90 ° of the radiated energy. The thermi released during the conversion of electrical energy energy on the surfaces of the solar cells reduced in favor of the electrical energy yield or used more effectively. Such solar cell arrangements can are used in single and multi-family houses, mobile Objects such as boats and trains, at municipal, farmer economic and industrial objects and the like. Anywhere where both electrical energy as well as heat, e.g. B. needed for water heating is or can be used.

It is known, not least from the above Patent application, solar cells on a liquid or gas flowing through a heat exchanger-like element apply and over the wall of this element the released during the generation of electrical energy Dissipate heat and use it. Through the Heat dissipation increases the conversion efficiency from solar energy to electrical energy and thus when used of the heated heat transfer medium the total efficiency  of solar energy conversion. The previously proposed Compound solutions are admittedly with regard to certain applications cases very advantageous, but it should be noted that the production of such a network technologically is also economically complex, and a variety of Individual problems, especially with regard to different expansion quotients, different short and Long-term load capacities of the solar cells or the Be layering materials and element materials too is. In addition, there are complex encapsulations of the solar cell len required to provide reliable protection of the sensitive solar cells from external influences such as Allow corrosion, dust, hail, etc.

Based on the state of the art described above an object of the present invention is seen in specify a solar cell arrangement with which possible most beneficial both thermal and electrical energy from solar radiation can be harnessed can.

This task is first and foremost Subject of claim 1 solved, being abge is that the solar cells immediately in front and the fluid can flow around the back. Invention Ge It has been recognized that a radiation-transparent Fluid, this can be a gas, but also, as below detailed, preferably a liquid be due to the much better heat transfer conditions, also passing in front of solar cells can be carried out with the advantages achieved Dissipation of the radiation heat generated by the solar cells that are somewhat, but not significantly impaired te, on the front of the solar cells after passage radiation still incident on the fluid more than  compensates. With this arrangement, the solar cells can however, since they are not immediately external influences are significantly "emaciated", d. H. For their mechanical protection, not much effort is required float. In an embodiment it is provided that the solar cells themselves are not encapsulated. According to the invention thus provided the complete, contacted solar cell len directly in the form in which they are made will be used. It is also provided that the Solar cells due to natural convection from that Fluid flows around. The flow paths in front and behind the solar cells are designed accordingly, that there is a clear natural convection and is maintained. This is preferred, for example achieved by that the depth of the flow paths, d. H. a thickness of a fluid layer on the front or the Back of a solar cell is different. It emp if the fluid thickness on the front of the To provide solar cell relatively small, on the back the solar cell, on the other hand, is relatively large. E.g. can a Depth of the flow path on the front 2 to 5 mm amount, on the other hand a multiple, for example, two to four times. It is also preferred provided that the fluid is electrically non-conductive. This also makes it possible with regard to the electrical Connect the solar cells as it were in the raw state leave. A complex insulation of the connections or other parts of the solar cells are not required. It is further preferred that the fluid is transparent Is liquid, which is in this context Oil, for example a silicone oil, is recommended. Silicone oil is toxic logically harmless, chemically inactive with regard to Solar cells and also recyclable. Furthermore however, a fluid is also particularly preferred Paraffin base, just like it is for latent heat storage  is known (see below). In line with the to be exercised by the fluid in the present context Function is desired that the fluid has a wide range Temperature spectrum is liquid, which is preferably a C14 paraffin is used. In another form device is provided that the fluid which the solar cell len flows directly in a closed system flows. Preferably the system essentially exists only one flow path on the front and one Flow path on the back of the solar cells. About that In addition, short-circuit-like flow can also occur paths, distributed over the height, between the solar cells be provided. This makes sense, for example, if the Solar cell arrangement is partially shaded. It can then there is a certain circulation flow in only one Form (lower) part of the solar cell arrangement. The The fluid is heated on the front, weh rend the back flow path of the fluid in turn Heat exchange is performed to a second fluid. A Flow path for the second fluid is accordingly in Form another layer below or level adjacent to the back of the solar cells Flow path of the fluid formed. The is preferred Flow path for the second fluid over the entire length (and accordingly also width) of the flow path of the first fluids on the back of the solar cells. In In this context, it is particularly preferred if the second fluid is a latent storage medium of a Is latent heat storage or with such a latentw heat storage is in heat exchange. Regarding the Latentw heat storage is at an extensive level of tech nik to refer, why here for the sake of simplicity patent application 42 43.202.2 and the one cited there further literature is referenced. The mentioned patent is hereby reported with regard to its disclosure  full content in the present application locked in. Affect other advantageous measures the mounting of the solar cells with respect to the front and back flow paths of the first fluid. In this Connection, it is preferred that the solar cells with supported on the front and rear spacer knobs are. E.g. the structure can be designed in detail be that on a housing wall (transparent front wall) are arranged in a grid pattern on which the Solar cells can be placed. On another Housing wall (rear wall) are knobs in the same way arranged. By folding the knob sides of this Both housing walls result in an overall housing that from a first housing wall, knobs, the hissing ten solar cells, further knobs of the second housing wall and the second housing wall. This corresponds to accordingly the first housing wall made transparent to radiation forms the solar radiation through to the solar cells to let kick. The nub lengths are according to the Different versions above see that on the front of the solar cells, which faces the solar radiation, one in its Depth (thickness) smaller flow path than on the back side te of the solar cells. In this regard, it is also recommended to use one wall, e.g. the front one Wall, flexible design. In particular, this can then be of importance if it is desired that Distribution of exploitation between electrical and to change thermal energy. Through a change the depth of the flow path on the front of the Solar cells also change the relative yield electrical energy. An increase in the thickness of this Flow path leads to a reduction in yield of electrical energy, conversely a reduction the thickness to increase the yield of electrical  Energy. As far as one or both housing walls are flexible are formed by means of a pump or the like System pressure of the fluid can be increased or decreased. If so, as described in detail above ben, a natural circulation of the first fluid is preferred, can also be a forced circulation by means of a Pump or the like are recommended, not least in the rear look at the last mentioned control of the Auftei energy efficiency.

The invention also relates to an arrangement for Thermal insulation, with a front and a rear Housing wall, the housing walls being transparent and a distance perpendicular to a plane of the housing walls between the housing walls is small, for example 5 to 10 mm is. For such an arrangement, the principle corresponds to an ordinary double-pane window, be there is a need for effective thermal insulation to reach. For this purpose it is provided that the space with a latent heat storage material, in particular Base paraffin, is filled. You will find the above Complete explanations of the paraffin material here too application. It is preferably further provided that in this arrangement between the housing washers as a quasi-static latent heat storage is trained. This term is first based on the DE-A1 27 41 829 to refer. From this it is, for example knows, paraffin enclosed in a plastic cover quantities as a heat storage medium in a latent heat storage to use. The plastic sleeves are located again in a storage vessel filled with water. With such latent heat storage, the heat takes place transport only through heat conduction through art fabric wrapping to the paraffin. One calls such Storage as static storage. Furthermore, so-called  te dynamic latent heat storage known, for example. reference is made to DD 2 36 862 and DD 2 80 113. The state of the art is further in this context to refer to DE-A1 41 22 859. Same thing the unpublished German patent application 42 43 202 and also the unpublished German Patent application P 43 07 217.8. The revelation content the aforementioned unpublished patent applications is hereby fully contained in the disclosure content This application included. Is preferred with this arrangement the space becomes a very large part, for example 95% or more, with latent heat Chemical material, preferably paraffin-based, filled. The remaining volume can be, for example, water, if appropriate also be filled with oil, the latter as heat transfer germ medium works. The heat transfer medium provides - in very small extent - a certain dynamic behavior ten, which is why above of a quasi-static Latent heat storage is spoken by the Arrangement described here is formed. The - if also slight - dynamic character of the latent heat mespeichers is particularly important in that that a desired foam formation is essential is promoted. Foamed paraffin (in the freeze state) or paraffinic hydrocarbon regarding the achievable thermal insulation values more particulate than homogeneously solidified paraffinic coals hydrogen. The ratio of heat transport medium, for example, oil, to paraffinic hydrocarbon move, for example, in the order of 1: 100. A Residual volume in the space remains free. Furthermore there may be overpressure or underpressure in this space to rule. The overpressure will realistically change in the Move the area to about 1 atm, the negative pressure in the loading ranging from 0.1 to 0.5 atm to almost complete  Vacuum. The latent heat storage material can accordingly erial a foaming additive, for example in the form of a known th surface relaxing agent. The The foaming tendency of the latent heat storage is, as already mentioned, consciously supported. Overall, the arrangement is preferably designed like a window, or should be a window be used. Practically you can a conventional insulating glass window in accordance with the above concept ken further train according to the invention that the evacu ized space in the manner described Latent heat storage material, preferably on paraffin base that is filled. In a further embodiment is also provided that the arrangement on three housing walls points, each with a small vertical distance to each other the, and that both spaces with latent heat material are filled. In this context emp it is still particularly true in the two so born interspaces between latent heat storage material fill different melting point. While that in a gap between the latent heat spit for example, has a melting point of 5 ° C. can the latentw in the other space heat storage material have a temperature of 10 ° C.

When used as an ordinary window, for example in industry built, there is the effect that the filling Temperatures that are above the melting point, so especially in summer, is completely transparent. In this case, heat is only stored via sensi keep warm. Nevertheless, there is a comparative poor heat transfer, d. H. is the coefficient of thermal conductivity (in the desired way) very small. As an effect a buffering of solar radiation in summer (Ver mitigation of overheating of the rooms without expensive Ventilation systems; delivery delayed at night  the rooms or the environment). The heat transfer coefficient (reduced) improves to at least half Values of known constructions (thermo glass has approximately a value of 2.4 W / qm / grad, while one described here This arrangement has such a value of 0.8 W / qm / grad e.g. can reach). And this even at low sinks right spacing of the housing walls, i.e. those between 5 and 10 mm. If the temperature falls below a certain level tures arises due to the nature of the latent heat chermaterials a phase change, the low-melting Material solidifies at a constant temperature inside a certain time. With the solidification changes but also the heat transfer value and it turns out constant small heat losses. Especially then if, as preferred, the latent heat storage material in kind of foams up. In this time and after foaming results in an increased Insulation effect. On sunny winter days it can even to melt and thus also to this Way to use solar energy (passive), which then - delayed - on one side of the Windows located rooms is passed on. It leaves some control can even be achieved. The heating the requirement is reduced. When falling below the solar border radiation will solidify again len what a sudden cold snap in the rooms prevented through the windows. The regulatory effort of Heating system is reduced. The inventive idea ke is not otherwise on a space limits, but can also be on two twos rooms, continuing the system described, extend. It can also be advantageous here the individual gaps latent heat storage material to be provided with different melting points.  

The invention is further based on the following attached drawing, which however is only an embodiment represents example, explained. Here shows:

Figure 1 is a plan view of a rear housing wall with a dimpled grid, partially covered with solar cells.

Fig. 2 is a sectional view of a solar cell arrangement;

FIG. 3 shows an enlarged sectional illustration of a detail from the illustration according to FIG. 2; FIG.

4 shows a cross section through an arrangement for heat insulation with two housing walls.

FIG. 5 shows a perspective, partially sectioned illustration of the object according to FIG. 4;

Fig. 6 is a cross section through an arrangement according to Figure 4, with three housing walls.

Fig. 7 is a perspective view, partly in section, of the article of FIG. 6.

With reference first to Fig. 2, a solar cell arrangement is shown, which consists of solar cells 1 , which are arranged between a front, transparent housing wall 2 and a rear housing wall 3 . On the upper and lower side with respect to the arrangement shown, flow connections 4 and 5 are created, which enables a flow around the solar cells 1 by the paraffin-based fluid in the housing from a front-side flow path 6 to a back-side flow path 7 . Overall, the system of flow paths 6 , 7 including diversions 4 , 5 is a closed flow system.

The solar cells 1 are unclad solar cells directly in the configuration customary for manufactured solar cells. Since the fluid is also electrically insulating, no further insulation measures are required on the electrical connections of the solar cells. The use of a paraffin-based fluid also has a significant further advantage. If the temperature of the system drops so far that the fluid solidifies, the circulation is interrupted. Here, the fluid also has a cold-insulating effect, so that a discharge of the thermally downstream storage is hindered or greatly delayed.

In the exemplary embodiment shown, a heat exchanger housing 8 is also provided on the rear or underside of the rear flow path 7 , in which a second fluid flows as a heat transfer medium, preferably in countercurrent to the first fluid. The fluid flowing in the second housing is conducted via a line 9 , for example to a consumer or a heat store, in particular a latent heat store. The return run is provided via the lower line 10 . The heat transfer medium in the housing 8 can be ordinary water, for example. Further below the housing 8 or, as shown in Fig. 2, in a further layer, thermal insulation 13 'is provided.

The front housing wall is transparent, so it exists for example made of glass or transparent plastic.  

A depth (thickness) t1 of the front flow path 6 is significantly smaller than a depth (thickness) t2 of the rear flow path 7 . In this way, an effective natural circulation of the first fluid can be achieved. When flowing through the first flow path 6 , the fluid is exposed to the sun's radiation and, moreover, takes up heat in the heat exchange from the solar cells 1 , so that overall there is considerable heating of the fluid flowing in the flow path 6 . This is connected to an expansion, whereas on the back, in the flow path 7 , heat is dissipated and the fluid contracts accordingly. As a result, an effective natural circulation is achieved overall.

It can also be seen that the solar cells 1 are held by knobs 11 , 12 , which start from the rear housing wall 3 or the front housing wall 1 . In addition, the knobs can still be connected to each other by locking means.

This is explained in more detail in relation to FIG. 1. Here, the rear housing wall 3 can be seen, on which knobs 12 are arranged in a grid-like manner. In the illustration according to FIG. 1, a row of solar cells 1 is already placed on the knobs 12 in the upper region of the housing wall 3 .

It is also preferably provided that a mask-like plastic part 13 is placed on the Nop pen 12 , which has a plurality of generally square openings 14 .

As appears particularly from the cross sectional view according to Fig. 3, is described in detail in the plastic part 13 is formed beyond a stage 15, in which the solar cells 1 can be inserted. You can also be arrested there. On the other hand it is also possible to mount the solar cells 1 in the installed state, the foot of a tern upper dimples 11 to spread a.

In Fig. 1 is also indicated that in a, preferably lower, region of the solar cell arrangement in the plastic part 13 through openings 16 are formed between two inserted solar cells 1st This makes it possible that, as it were, in the short circuit or bypass, as indicated by the arrows in Fig. 2, only a limited section over a certain section Umlaufström can form or additionally trained.

The plastic part 13 can also - which is not shown in detail - at the crossing points of the openings 14 forming the webs, that is to say in the assembled state in the region of the knobs 11 or 12 , have openings through which a connecting rod between individual knobs 11 and 12 is inserted can be, for example. Can be firmly connected to one of the knobs 11 or 12 and for which a receiving bore can also be formed in the other knobs. On the other hand, the plastic part 13 can have such extensions, which are received in corresponding receiving bores in the knobs 11 and 12 after assembly.

In Fig. 4 shows an arrangement for thermal insulation with a front housing wall 2 and a further housing wall 3, the vertical distance t2 is comparatively low, moves mm in the range of about 5 to 10. The housing walls 2, 3 can consist of window glass, for example. The space between the two housing walls 2 , 3 is filled with a heat storage material based on paraffin. There is also a certain overpressure or underpressure in the intermediate space 17 , as is also explained in detail above.

In Fig. 5, the object of Fig. 4 is shown in perspective shear, partially sectioned form. It can be seen that, with the exception of the filling of the intermediate space 17 , this can be a conventional window construction.

In Fig. 6, a comparable Anord voltage is shown with three housing walls 2 , 3 , 18 in cross section. Correspondingly, there are spaces 19 and 20 which are filled with a latent heat storage material in the same manner as described above. Here, the latent heat storage material in the intermediate space 20 has a different melting point than the latent heat storage material in the intermediate space 19 . E.g. the melting point in the space 20 can be 10 ° C and in the space 19 it can be 5 ° C. It may also be advisable to form the interspaces with different vertical distances from the housing walls. For example, the interior space facing the interior of the room with a larger vertical distance. Accordingly, the amount of latent heat storage material therein is then larger. If at the same time the lower melting point is set, the outer space will first reach the melting temperature (solidification temperature) if the temperature drops on the outside. Then, when the larger intermediate space facing the interior reaches the melting temperature (solidification temperature), the relatively large amount of heat released in this way will benefit the space to a very large extent, since the outer intermediate layer with the already solidified latent heat storage material now has a significant insulation effect.

In Fig. 7 the object of FIG. 6 is shown in perspectively sheared, partially sectioned form.

The in the above description, the drawing and Features of the invention disclosed in the claims can both individually and in any combination for the realization of the invention may be of importance. All the features disclosed are essential to the invention. In the disclosure of the application is hereby also the Disclosure content of the associated / attached priori full documents (copy of the pre-registration) included.

Claims (24)

1. Solar cell arrangement, the solar cells ( 1 ) being interconnected with a fluid for dissipating heat, characterized in that the solar cells ( 1 ) can be flowed around directly in front and on the rear side by the fluid that is trans parent. 2. Solar cell arrangement according to claim 1 or insbesonde re thereafter, characterized in that the solar cells ( 1 ) are not encapsulated. 3. Solar cell arrangement according to one or more of the preceding claims or in particular according thereto, characterized in that the fluid flows around the solar cells ( 1 ) due to natural convection. 4. Solar cell arrangement according to one or more of the previous claims or in particular according there characterized in that the fluid is not electrically is leading. 5. Solar cell arrangement according to one or more of the previous claims or in particular according there characterized in that the fluid is a liquid. 6. Solar cell arrangement according to one or more of the previous claims or in particular according there characterized in that the fluid consists of paraffin. 7. Solar cell arrangement according to one or more of the previous claims or in particular according there characterized in that the fluid is an oil, for example. Sili is Konöl.   8. Solar cell arrangement according to one or more of the previous claims or in particular according there characterized in that a layer thickness of the fluid on a front exposed to solar radiation the solar cells are thin, for example 2 to 5 mm. 9. Solar cell arrangement according to one or more of the preceding claims or in particular according thereto, characterized in that the fluid circulates in a closed system, which essentially only consists of the flow paths in front of and behind the solar cells ( 1 ). 10. Solar cell arrangement according to one or more of the preceding claims or in particular according thereto, characterized in that the fluid flowing around the solar cells ( 1 ) leads in heat exchange to a second fluid. 11. Solar cell arrangement according to one or more of the preceding claims or in particular according thereto, characterized in that a flow path of the second fluid corresponding to a further layer below a flow path ( 7 ) of the first fluid with respect to the solar cells ( 1 ) is formed. 12. Solar cell arrangement according to one or more of the previous claims or in total thereafter, thereby characterized in that the second fluid is a latent fluid medium of a latent heat storage or with a such is in heat exchange. 13. Solar cell arrangement according to one or more of the preceding claims or in particular according thereto, characterized in that the solar cells ( 1 ) by means of front and rear spacing knobs ( 11 , 12 ) are tert. 14. Solar cell arrangement according to one or more of the preceding claims or in particular according thereto, characterized in that the spacer knobs ( 11 , 12 ), the solar cells ( 1 ) between a front, transparen th wall ( 2 ) and a rear wall ( 3 ), which Hold walls ( 2 , 3 ) at the same time, limit the front and rear flow paths ( 6 , 7 ) of the fluid. 15. Solar cell arrangement according to one or more of the preceding claims or in particular according thereto, characterized in that a wall ( 2 , 3 ), for example the front wall, is flexible. 16. Solar cell arrangement according to one or more of the previous claims or in particular according there characterized in that the flow of the first flu ids, for example by an intermediate pump is enough, there is a forced flow. 17. Solar cell arrangement according to one or more of the previous claims or in particular according there characterized in that a fluid pressure of the first Fluid is adjustable. 18. Solar cell arrangement according to one or more of the preceding claims or in particular according thereto, characterized in that the solar cells ( 1 ) in an opening ( 14 ) having a plastic part ( 13 ) are men. 19. Solar cell arrangement according to one or more of the preceding claims or in particular according thereto, characterized in that the plastic part ( 13 ) with the inserted solar cells ( 1 ) is held between the knobs ( 11 , 12 ). 20. The arrangement for heat insulation with a front and rear housing wall (2, 3), wherein the housing walls (2, 3) are transparent and a to a plane of the housing walls (2, 3) vertical distance (t2) between the housing walls (2, 3 ) is small, for example 5 to 10 mm, characterized in that the intermediate space ( 17 ) is filled with a latent heat storage material, in particular based on paraffin. 21. Arrangement according to claim 20 or in particular according thereto characterized by a window-like formation. 22. Arrangement according to one of claims 20 or 21 or in particular according thereto, characterized in that three housing walls ( 2 , 3 , 18 ) are provided, each with a small vertical distance from each other, and that both spaces ( 19 , 20 ) with latent heat storage material are filled with erial. 23. Arrangement according to one of claims 20 to 22 or in particular according thereto, characterized in that the spaces ( 19 , 20 ) are filled with latent heat storage material of different melting points. 24. Arrangement according to one or more of the preceding the claims or in particular according thereto, thereby records that a melting point of the latent heat chermaterials is comparatively low, for example 10 ° C.