Patent Publication Number: US-2013247901-A1

Title: Solar collector

Description:
The invention relates to a solar collector with the features of the introductory part of claim  1 . 
     Conventional solar collectors (also solar panels) are used to convert light energy from the sun into heat and to release the latter to a coolant that flows through the solar collector. Using the coolant, the heat usually is drawn off from the solar collector and then is either used directly or stored. 
     Solar collectors can be present in various embodiments: for example, as flat plate collectors with a conventional insulation material, or else as vacuum-flat plate collectors, which are distinguished by a flat design and a good gross/net surface ratio and a vacuum insulation. 
     A solar collector of the above-mentioned type is known from DE 195 28 361 C1. This known solar collector is intended to generate heated air or heated water, whereby in particular plastics and films are to be used. FIG. 2 of DE 195 28 361 C1 shows that air guides made of polystyrene that produce a meandering flow of the medium to be heated through the solar collector can be provided inside the collector. 
     It is the object of the invention to further develop solar collectors of the above-mentioned type in such a way that they have better efficiency than conventional solar collectors. 
     An additional object of the invention is to further develop solar collectors of the above-mentioned type in such a way that their guides are of a simple design and can be matched to the respective requirements better than in the case of conventional solar collectors. 
     This object is achieved according to the invention with a solar collector, which has the features of claim  1 . 
     Preferred and advantageous configurations of the invention are subjects of the subclaims. 
     Since, in the solar collector according to the invention, which preferably is designed as a (vacuum)-flat plate collector, the interior space is divided by these dividing guides, so that the coolant flows in a meandering manner (like a wavy line) through the solar collector, not only is better efficiency produced, but also a greater stability of the solar collector according to the invention. This is the case in particular when the solar collector is designed as a (vacuum)-flat plate collector, since the latter are supported and are held spaced apart from one another by the guides between the upper and lower boundary walls that are divided over the surface of the solar collector. 
     The guides between the upper and lower boundary walls of the solar collector according to the invention can be plastic guides or guides made of plastic with strips, for example strips made of glass, metal or plastic. In this embodiment of the solar collector according to the invention with two panels that bound its interior space and guides that hold the panels spaced apart from each other, whereby the interior space of the solar collector is divided by the guides with the formation of a flow path, for example a wavy or meandering chamber for the flow of the coolant that flows through the solar collector, it is preferred if the guides have strips, in particular made of metal, that are connected via plastic strands to the inner sides of the panels of the solar collector. 
     Thus, an embodiment is preferred in which the guides in the solar collector according to the invention are formed by strips that are connected via strands made of plastic to the inner sides of the two boundary walls. 
     If the guides are plastic guides, they can be made of one piece or two; in each case, strands exist that hit approximately in the center between the panels of the collectors and that are connected to one another by pressing. 
     By the division of the interior space into a, for example, meandering or wavy chamber between the boundary walls (in particular glass panels), which are formed by the guides, not only is an advantageous division of the chamber produced, but also a static support of the two boundary walls, which is especially important if these boundary walls are panels, in particular glass panels, or photovoltaic modules. 
     Because of the high stability of the solar collector according to the invention, there is also the possibility of designing one of the two boundary walls as a solar module for obtaining electrical current from sunlight in photovoltaic units. 
     The configuration of the solar collector according to the invention also allows the advantage that inflow to the collector and return from the collector, for example to a reservoir or to a consumer point, can be arranged on the same edge of the solar collector according to the invention. This produces advantages in the incorporation of the collector and the closing thereof at the inflow and return lines. 
     In an embodiment of the invention, it can be provided that the guides bounding the interior space of the solar collector toward the outside have strips, for example metal strips, which are connected via plastic strands to the inner side of the panels of the solar collector. 
    
    
     
       Other details and features of the invention follow from the description below of preferred embodiments based on the drawings. Here: 
         FIG. 1 , in top view and in schematic form, shows a solar collector according to the invention, 
         FIG. 2 , in a partial section, shows a first embodiment, 
         FIG. 3  shows a second embodiment, and 
         FIG. 4 , in section, shows a third embodiment for the guides that bound/divide the chamber provided in the collector. 
     
    
    
     In the preferred embodiment depicted in the drawing, a solar collector according to the invention, designed in the example as a flat plate collector, consists of two boundary walls, parallel to one another and connected spaced apart from each other, in the form of panels  2 ,  3  that are, for example, both glass panels. The upper panel  2  that in the position of use faces the solar radiation is made transparent at least for the infrared portion of sunlight; conversely, the lower panel  3  that in the position of use faces away from sunlight can be made dark, in particular blackened. 
     The interior space  4  of the solar collector  1  according to the invention is divided by guides  5  in such a way that coolant fed via an inflow  6  to the interior space  4  of the solar collector  1 , for example, flows through like a wavy line or in a meandering manner (cf. the arrows in  FIG. 1 ) in order to get to the return  7 . 
     The guides  8  that bound the interior space  4  of the solar collector  1  toward the outside can be designed as further described below for the guides  5  ( FIG. 2 ) and comprise, for example, strips that are connected via plastic strands  12  to the panels  2  and  3 , or these are guides that are designed as shown in  FIG. 3  or in  FIG. 4 . 
     In the embodiment, the guides divide the interior space  4  of the solar collector  1  according to the invention in such a way that the coolant flows through the interior space  4  like a wavy line or in a meandering manner. In this embodiment, the guides  5  are designed starting alternately from (lengthwise) edges  9 ,  10  opposite from one another and connected to the latter, and they end spaced apart from the opposite edge  9 ,  10 , as is shown in  FIG. 1 . Thus, good efficiency of the solar collector  1  according to the invention is produced. 
     The guides  5  that divide the chamber  4  can, as shown in  FIG. 2 , be strips  11  made of metal, glass or plastic, which are connected via plastic strands  12 , in particular strands made of silicone plastic, to the panels  2 ,  3  of the solar collector  1 . 
     In another embodiment, the guides  5  are formed exclusively from plastic strands, whereby in the embodiment shown in  FIG. 2 , two plastic strands  13  are provided, from which each is attached to the inner side of one of the two panels  2 ,  3  of the solar collector  1  according to the invention, and the strands  13  are then connected to one another by bringing the panels  2 ,  3  of the solar collector close together. 
     In the embodiment shown in  FIG. 4 , the guides  5  are formed by an integral strand that consists of plastic, in particular silicone, and that extends over the entire height of the inner space  4  between the panels  2 ,  3 . 
     The embodiment according to the invention allows the panel  2  that faces toward the sunlight and optionally also the panel  3  that faces away from the sunlight to be designed as a solar module (“photovoltaic module”) for the recovery of electrical current from sunlight. It is advantageous in this embodiment that the temperature of the solar module can be kept in the temperature range that is suitable for its optimal efficiency, since the solar module can be cooled by the coolant flowing through the solar collector  1 , whereby the extent of the cooling can be set to the respectively desired (advantageous) value by regulating the amount of flow depending on the unit of time. 
     In summary, an embodiment of the invention can be described as follows: 
     A solar collector  1  consists of two panels  2 ,  3 , of which at least one panel  2  can be designed as a solar module, whereby the panels  2 ,  3 , are connected to one another by guides  5 , which are divided over the surface of the solar collector  1  and are held spaced apart from each other. The guides  5  between the panels  2 ,  3  of the solar collector  1  are arranged in such a way that the interior space  4  is divided by forming a flow path, which can be achieved in that the guides  5  start alternately from an edge  9 ,  10  of the solar collector  1  and are spaced from the opposite edge  10 ,  9 . The guides  5  are strips that are connected via plastic strands  12  to the inside surfaces of the panels  2  and  3 .