Abstract:
An integrated solar concentrator assembly ( 10 ) which is built to allow an opposing criss-cross optics pattern, creating a more compact, structurally sound unit having a nearly perpendicular light path into a mixing optic ( 32 ). This improves optical efficiency and allows for the mixing optic ( 32 ) to have a flat outer surface, thereby improving manufacturability. This criss-cross optical pattern also allows the opposite mirror structure to be used to support the solar receiver components, eliminating additional brackets. The configuration of the integrated solar concentrator assembly ( 10 ) allows frame mounts to be placed on the outboard corners of the assembly, improving the inherent aim accuracy, as well as simplifying installation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/401,613 filed on Aug. 16, 2010. The disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a solar concentrator system which has several integrated components. 
       BACKGROUND OF THE INVENTION 
       [0003]    Current concentrating solar power optics systems are complex and costly to manufacture, and are typically composed of many molded reflector elements and solar cell receivers assembled on a frame. This poses many problems with cost and accuracy during assembly. Furthermore, the mixing optic in the receiver is expensive and difficult to manufacture. 
         [0004]    Accordingly, there exists a need to develop a lower cost, simpler solar concentrator system which can be assembled quickly and accurately using fewer, easier to manufacture parts on a simple frame. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is an integrated solar concentrator assembly which is built to allow an opposing criss-cross optics pattern, creating a more compact, structurally sound unit having a nearly perpendicular light path into a mixing optic. This improves optical efficiency and allows for the mixing optic to have a flat outer surface, thereby improving manufacturability. This criss-cross optical pattern also allows the opposite mirror structure to be used to support the solar receiver components, eliminating additional brackets. The configuration of the integrated solar concentrator assembly allows frame mounts to be placed on the outboard corners of the assembly, improving the inherent aim accuracy, as well as simplifying installation. 
         [0006]    The cost of manufacture is reduced by simplifying the mixing optic and combining many reflector brackets and cell receiver brackets into one molded piece containing the mirrors, mixing optic, and cell-heatsink assembly. 
         [0007]    The system also provides for lower part count, lower overall system cost, improved aim accuracy, lower sensitivity to assembly variation, and ease of assembly in the field. 
         [0008]    In one embodiment, the integrated solar concentrator system includes a reflector body molding, a frame rail integrally formed with the reflector body molding, and a mirror mount surface having at least one concave mirror surface mounted to the reflector body molding. A receiver housing is molded as part of the reflector body molding and mounted to the frame rail. 
         [0009]    A mixing lens is disposed within the receiver housing, and operable for receiving light from the concave mirror surface. The system also includes a heatsink solar cell assembly connected to the receiver housing operable for receiving light from the mixing lens. 
         [0010]    A heatshield/mixing lens retainer is mounted to the receiver housing, the heatshield/mixing lens retainer maintains the position of the mixing lens in the receiver housing. Light is reflected off of the concave mirror surface and directed toward the mixing lens, where the light passes through the mixing lens such that the mixing lens focuses and directs the light to the heatsink solar cell assembly. 
         [0011]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0013]      FIG. 1  is a perspective view of a solar concentrator system, according to the present invention; 
           [0014]      FIG. 2  is a perspective view of two mixing lenses used in a solar concentrator system, according to the present invention; 
           [0015]      FIG. 3  is a first perspective view of a receiver housing used in a solar concentrator system, according to the present invention; 
           [0016]      FIG. 4  is a second perspective view of a receiver housing used in a solar concentrator system, according to the present invention; 
           [0017]      FIG. 5  is an exploded view of a receiver housing, a mixing lens, and a heatshield/mixing lens, used in a solar concentrator system, according to the present invention; 
           [0018]      FIG. 6  is a perspective view of the corner of a reflector body molding having an incorporated mounting tab, used in a solar concentrator system, according to the present invention; 
           [0019]      FIG. 7  is a cross-sectional view of a solar concentrator system taken along lines  7 - 7  of  FIG. 1 , according to the present invention; and 
           [0020]      FIG. 8  is a cross-sectional view of the circled portion shown in  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
         [0022]    Referring to the Figures generally, an overall view of a solar concentrator assembly according to the present invention is shown generally at  10 . The solar concentrator assembly  10  is made up of the reflector body molding  12  with incorporated features, such as a plurality of mounting tabs, shown generally at  14 , a frame rail  16 , a mirror mount surface, shown generally at  18 , and a plurality of receiver housings  20 . In this embodiment, the mirror mount surface  18  is made several smaller concave mirror surfaces in the form of a first concave mirror surface  18 A, a second concave mirror surface  18 B, a third concave mirror surface  18 C, a fourth concave mirror surface  18 D, a fifth concave mirror surface  18 E, and a sixth concave mirror surface  18 F. There are also several attached components, which in this embodiment are heatsink solar cell assemblies, shown generally at  22 , each of which includes a heatshield/mixing lens retainer  24 . 
         [0023]    Each mounting tab  14  includes two side flanges  26 , and a middle flange  28  having an aperture  30 . A fastener (not shown) is inserted through the aperture  30  to mount the assembly  10  as desired. 
         [0024]    Each receiver housing  20  is connected to a heatshield/mixing lens retainer  24 . At least partially disposed within each housing  20  is a mixing lens, shown generally at  32 . The receiver housing  20 , heatsink solar cell assembly  22 , heatshield/mixing lens retainer  24 , and mixing lens  32  form a concentration assembly. In this embodiment, there are six concentration assemblies mounted on each side of the mirror mount surface  18  as shown in  FIG. 1 . However, for demonstrative purposes, only two complete concentration assemblies are shown. Only the receiver housings  20  for the remaining concentration assemblies are shown. 
         [0025]    The mixing lens  32  includes a substantially flat output port  34  connected to a first optical section, shown generally at  36 . The mixing lens  32  couples light through an index matching jell (not shown) to a solar cell (not shown). The first optical section  36  is connected to a second optical section, shown generally at  38 , and the second optical section  38  is connected to a step portion  40 . The step portion  40  is connected to a mounting flange  42 , which has a substantially flat input port  44 . 
         [0026]    The mounting flange  42  is substantially square-shaped, which provides for proper alignment of the orientation of the mixing lens  32  with a square-shaped solar cell. The step portion  40  also functions to provide a sealing surface for an O-ring  100 . The first optical section  36  is has a plurality of flat tapered walls  46 , each of which is connected to the flat output port  34 . The flat tapered walls  46  are also connected to the second optical section  38 . In this embodiment, the first optical section  36  is a blending optical section  36 . The second optical section  38  in this embodiment is a parabolic optical section  38 , having flat surfaces  48 A and parabolic surfaces  48 B. The light enters through the flat input port  44 , and the optical sections  36 , 38  use total internal reflection (TIR) to provide for the focusing of off-axis rays using the parabolic section  38  and blending from the flat tapered walls  46 . 
         [0027]    Referring now to  FIGS. 3 and 4 , the receiver housing  20  is molded as an integral part of reflector body molding  12 . The receiver housing  20  has attachment features  50 , which are integrally molded as part of the housing  20 , and each attachment feature  50  has an aperture  52 . Each aperture  52  is in alignment with a corresponding aperture  54  formed as part of the heatshield/mixing lens retainer  24 . A fastener (not shown) such as a bolt is operable for extending through the aperture  54  and into the aperture  52  to secure the retainer  24  to the housing  20 . 
         [0028]    The housing  20  is substantially box-shaped, and has two outer walls  56 , upon which the attachment features  50  are mounted. There is also an upper wall  58  and a lower wall  60 . The housing  20  also has a rear wall portion  62 , and the rear wall portion  62  has an aperture  64 . The rear wall portion  62  includes a stepped feature, shown generally at  66 , which has a sealing surface  68 , which functions as O-ring sealing surface. The O-ring  100  is disposed between the O-ring sealing surface  68  and the mounting flange  42 , and circumscribes the step portion  40  when the mixing lens  32 , the housing  20 , and the retainer  24  are assembled together. Once the retainer  24  is secured to the housing  20 , the mounting flange  42  is disposed between the retainer  24  and the rear wall portion  62  of the housing  20 , and the flange  42  is also surrounded by the inner surface  72 . 
         [0029]    There is also a lip portion  70  formed as part of the housing  20 , and the lip portion  70  surrounds the rear wall portion  62 , best seen in  FIG. 3 . The lip portion  70  has an inner surface  72 , which functions an an alignment feature. More specifically, the inner surface  72  surrounds the mounting flange  42  when the mixing lens  32  is assembled to the housing  20 . Referring now to  FIG. 4 , the receiver housing  20  has a cavity, shown generally at  74 , formed by the walls  56 , 58 , 60 . Also shown in  FIG. 4  are attachment features  76  formed as part of the housing  20 ; the attachment features  76  are arranged in a square pattern at the corners of where the walls  56 , 58 , 60  connect, which facilitates mounting in any of four orientations. Each attachment feature  76  includes an aperture  78  used for receiving a fastener (not shown) such as a bolt. The heat sink solar cell assembly  22  is connected to the housing  20  through the use of the attachment features  76 . 
         [0030]    Formed as part of each of the walls  56 , 58 , 60  the housing  20  is a groove  80 , which at least partially surrounds the cavity  74 . The groove  80  is used to retain an elastomeric seal (not shown) to provide weather tightness between the housing  20  and the heat sink solar cell assembly  22  when the assembly  22  is attached to the housing  20 . The reflector body molding  12  is formed with at least one molded in stiffness flange  82 , which provides support for attachment ribs  84 . The attachment ribs  84  are connected to the frame rail  16  by molding the housing  20 , the stiffness flange  82 , and ribs  84  as a single unit. In an alternate embodiment, the ribs  84  and housing  20  are molded separately from the frame rail  16 , and attached to the stiffness flange  82  and frame rail  16  through an adhesive, fasteners, or the like. 
         [0031]      FIG. 5  is an exploded view of the receiver housing  20 , the mixing lens  32 , and the heatshield/mixing lens retainer  24 . The heatshield/mixing lens retainer  24  includes a central aperture  86  which is substantially the same shape and circumference as the portion of the second optical section  38  connected to the step portion  40  (i.e., the area of the second optical section  38  with the largest cross-section). 
         [0032]    Referring now to  FIG. 6 , a close up view of the corner of the reflector body molding  12  and incorporated mounting tab  14 . The aperture  30  is accessible from the front and lies outside the boundaries of the reflector body molding  12 , providing accurate alignment due to the maximized mounting baseline and direct placement on frame rails  16  that could be parallel to either the short edge  88  or the long edge  90  of the reflector body molding  12 . 
         [0033]      FIG. 7  shows a cross-sectional view through the assembly  10 . Sunlight enters the solar concentrator assembly  10  along ray lines  92 , and moves as indicated by the arrows. Light bounces off each side and is focused back across the opposite mirror to the corresponding mixing lens  32 . This criss-cross light pattern allows each concave mirror surface  18 A, 18 B, 18 C, 18 D, 18 E, 18 F to function as the support for each corresponding receiver housing  20 . 
         [0034]    As mentioned above, when assembled, the heat sink solar cell assembly  22 , the heatshield/mixing lens retainer  24 , the mixing lens  32 , and the receiver housing  20  form a light a concentration assembly. In this embodiment, there are several concentration assemblies mounted to the frame rail  16 . There is a first concentration assembly  94 A, a second concentration assembly  94 B, a third concentration assembly  94 C, a fourth concentration assembly  94 D, a fifth concentration assembly  94 E, and a sixth concentration assembly  94 F. Each concave mirror surface  18 A, 18 B, 18 C, 18 D, 18 E, 18 F directs light to a respective concentration assembly. 
         [0035]    More specifically, the first concave mirror surface  18 A directs light towards the first concentration assembly  94 A. The second concave mirror surface  18 B directs light towards the second concentration assembly  94 B. Furthermore, the third concave mirror surface  18 C directs light towards the third concentration assembly  94 C, the fourth concave mirror surface  18 D directs light towards the fourth concentration assembly  94 D, the fifth concave mirror surface  18 E directs light towards the fifth concentration assembly  94 E, and the sixth concave mirror surface  18 F directs light towards the sixth concentration assembly  94 F. 
         [0036]    Since each concave mirror surface  18 A, 18 B, 18 C, 18 D, 18 E, 18 F and concentration assembly  94 A, 94 B, 94 C, 94 D, 94 E, 94 F operates in substantially the same manner, the operation of only one concave mirror surface  18  and concentration assembly  94  will be described. In operation, light received by the concave mirror surface  18 A is reflected in the direction indicated by the ray lines  92  such that the light from the concave mirror surface  18 A then passes through the central aperture  86  of the heatshield/mixing lens retainer  24 , and into the input port  44 , where the light then passes through the parabolic optical section  38 , and then through the blending optical section  36  and passes out of the output port  34 . The light passing out of the output port  34  enters into a solar concentrator  96 . Connected to each solar concentrator is a pair of heat sinks  98 ; however, it is within the scope of the invention that more or less heat sinks  98  may be used. 
         [0037]    As can be seen in  FIG. 1 , there are a total of six concentration assemblies, three of which are mounted on each side of the reflector body molding  12 . Each concave mirror surface  18 A, 18 B, 18 C, 18 D, 18 E, 18 F directs light toward a corresponding concentration assembly  94  on the opposite side of the reflector body molding  12 , best indicated by the ray lines  92  shown in  FIG. 7 . This produces a “criss-cross” pattern of light distribution, allowing the system  10  to be efficient and reduced in size. 
         [0038]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the essence of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.