Linear solar energy collection system with secondary and tertiary reflectors

Abstract

A modular linear solar energy collection system comprises one or more reflector units each having a light-weight generally planar aluminum frame that mounts a number of solar panels in a fixed position at angles which progressively increase from the frame centerline outwardly to its perimeter so as to collectively form a surface having a shape approximating that of a parabola. Sunlight incident on the solar panels is reflected by a combination of secondary and tertiary reflectors onto a receiver tube mounted in a fixed position concentric to the centerline of the frame. The frame is connected to a drive mechanism operative to pivot the frame and solar panels in order to track the position of the sun during the course of a day.

1 . A solar energy collection system, comprising:
 at least one frame;   a number of solar panels each having a reflective surface, said solar panels being mounted to said at least one frame in position to reflect sunlight incident on said reflective surface thereof;   a receiver tube within which a heat transfer fluid is circulated;   a first secondary reflector having a reflective surface;   a tertiary reflector having a reflective surface;   a second secondary reflector having a first reflective surface, a second reflective surface and an opening, said second secondary reflector being positioned with respect to said solar panels such that sunlight reflected from said reflective surface of at least some of said solar panels is incident on said first reflective surface of said second secondary reflector, reflected from said first reflective surface thereof onto said tertiary reflector and then reflected from said tertiary reflector onto said receiver tube, said second secondary reflector being positioned with respect to said first secondary reflector such that sunlight incident on said second reflective surface of said second secondary reflector is reflected onto said reflective surface of said first secondary reflector, from said reflective surface of said first secondary reflector through said opening in said second secondary reflector and onto at least one of said receiver tube and said tertiary reflector.   
   
   
       2 . The system of  claim 1  in which said reflective surface of said first secondary reflector is formed in the shape approximating that of a parabola with a focal line substantially coincident with said receiver tube. 
   
   
       3 . The system of  claim 1  in which said tertiary reflector comprises a first tertiary reflector and a second tertiary reflector spaced from one another. 
   
   
       4 . The system of  claim 3  in which each of said first and second tertiary reflectors has a reflective surface formed in the shape approximating that of a parabola. 
   
   
       5 . The system of  claim 3  in which said receiver tube is positioned in substantial alignment with said space between said first and second tertiary reflectors. 
   
   
       6 . The system of  claim 3  in which said second secondary reflector comprises a pair of second secondary reflectors spaced from one another, each one of said pair of second secondary reflectors having a convex reflective surface that collectively form said first reflective surface and a concave reflective surface that collectively form said second reflective surface. 
   
   
       7 . The system of  claim 6  in which said convex reflective surface of one of said pair of second secondary reflectors reflects light from at least some of said solar panels onto said first tertiary reflector, and said convex reflective surface of the other of said pair of second secondary reflectors reflects light from at least some of said solar panels onto said second tertiary reflector, said sunlight incident on said first and second tertiary reflectors being reflected onto said receiver tube. 
   
   
       8 . The system of  claim 6  in which said concave reflective surface of each of said pair of second secondary reflectors reflects incident sunlight onto said reflective surface of said first secondary reflector, said reflective surface of said first secondary reflector being effective to reflect said sunlight from said second secondary reflectors through said space between them and onto said receiver tube. 
   
   
       9 . The system of  claim 1  in which said reflective surface of said first secondary reflector is effective to reflect said sunlight from at least some of said solar panels through said opening in said second secondary reflector and onto said receiver tube. 
   
   
       10 . The system of  claim 1  in which said at least one frame comprises opposed end walls and opposed side walls interconnected to form a substantially planar structure having a centerline, said receiver tube being concentrically disposed about said centerline. 
   
   
       11 . The system of  claim 10  in which said solar panels are arranged in a first array extending from said receiver tube to one of said side walls, and a second array extending from said receiver tube to the other of said side walls, each of said solar panels in both said first and second arrays having a first end fixed to one of said end walls and a second end fixed to the other of said end walls. 
   
   
       12 . The system of  claim 11  in which said solar panels in said first array and said second array each have opposed side edges extending between said first and second ends thereof, said solar panels in each of said first array and said second array being oriented side-by-side with a space between the side edge of adjacent solar panels. 
   
   
       13 . The system of  claim 11  in which said solar panels in each of said first array and said second array are oriented at an angle with respect to said secondary reflector, the angle of each solar panel within said first and second arrays progressively increasing from said centerline of said frame to said opposed side walls thereof. 
   
   
       14 . The system of  claim 13  in which said second secondary reflector comprises a pair of second secondary reflectors, said angulation of said solar panels in said first array and in said second array collectively forming a surface having a shape approximating that of a parabola with a focal line substantially coincident with the focal point of said first secondary reflector, each one of said pair of second secondary reflectors being positioned between one of said first and second array of solar panels and said focal point of first secondary reflector. 
   
   
       15 . The system of  claim 1  in which each of said at least one frame comprises a number of frames located side-by-side, each of said frames mounting a number of said solar panels. 
   
   
       16 . The system of  claim 1  in which each of said solar panels comprises a first section formed of honeycomb aluminum, a second section having said reflective surface and a third section connecting said first section to said second section. 
   
   
       17 . The system of  claim 16  in which said first section of honeycomb aluminum has opposed ends and opposed sides, said first section being formed in a concave shape between said opposed sides. 
   
   
       18 . The system of  claim 1  in which said at least one frame is pivoted to track the movement of the sun during the course of a day, said frame being pivoted relative to said receiver tube which is mounted in a fixed position. 
   
   
       19 . The system of  claim 18  further including a conduit connected to said receiver tube, said conduit being mounted in a fixed position relative to said frame. 
   
   
       20 . The system of  claim 1  in which said frame has opposed end walls and opposed side walls interconnected to one another, said receiver tube and said secondary reflector extending between said opposed end walls of said frame. 
   
   
       21 . The system of  claim 20  in which said secondary reflector directs reflected sunlight along substantially the entire extent of said receiver tube. 
   
   
       22 . A solar energy collection system, comprising:
 a number of reflector units oriented side-by-side, each of said reflector units comprising:
 (i) a frame; 
 (ii) a number of solar panels each having a reflective surface, said solar panels being mounted to said at least one frame in position to reflect sunlight incident on said reflective surface thereof; 
 (iii) a receiver tube within which a heat transfer fluid is circulated; 
 (iv) a first secondary reflector having a reflective surface; 
 (v) a tertiary reflector having a reflective surface; 
 (vi) a second secondary reflector having a first reflective surface, a second reflective surface and an opening, said second secondary reflector being positioned with respect to said solar panels such that sunlight reflected from said reflective surface of at least some of said solar panels is incident on said first reflective surface of said second secondary reflector, reflected from said first reflective surface thereof onto said tertiary reflector and then reflected from said tertiary reflector onto said receiver tube, said second secondary reflector being positioned with respect to said first secondary reflector such that sunlight incident on said second reflective surface of said second secondary reflector is reflected onto said reflective surface of said first secondary reflector, from said reflective surface of said first secondary reflector through said opening in said second secondary reflector and onto at least one of said receiver tube and said tertiary reflector. 
   
   
   
       23 . The system of  claim 22  in which said reflective surface of said first secondary reflector of each of said reflector units is formed in the shape approximating that of a parabola with a focal line substantially coincident with said receiver tube. 
   
   
       24 . The system of  claim 22  in which said tertiary reflector of each of said reflector units comprises a first tertiary reflector and a second tertiary reflector spaced from one another. 
   
   
       25 . The system of  claim 24  in which each of said first and second tertiary reflectors has a reflective surface formed in the shape approximating that of a parabola. 
   
   
       26 . The system of  claim 24  in which said receiver tube is positioned in substantial alignment with said space between said first and second tertiary reflectors. 
   
   
       27 . The system of  claim 24  in which said second secondary reflector of each of said reflector units comprises a pair of second secondary reflectors spaced from one another, each one of said pair of second secondary reflectors having a convex reflective surface that collectively form said first reflective surface and a concave reflective surface that collectively form said second reflective surface. 
   
   
       28 . The system of  claim 27  in which said convex reflective surface of one of said pair of second secondary reflectors reflects light from at least some of said solar panels onto said first tertiary reflector, and said convex reflective surface of the other of said pair of second secondary reflectors reflects light from at least some of said solar panels onto said second tertiary reflector, said sunlight incident on said first and second tertiary reflectors being reflected onto said receiver tube. 
   
   
       29 . The system of  claim 27  in which said concave reflective surface of each of said pair of second secondary reflectors reflects incident sunlight onto said reflective surface of said first secondary reflector, said reflective surface of said first secondary reflector being effective to reflect said sunlight from said second secondary reflectors through said space between them and onto said receiver tube. 
   
   
       30 . The system of  claim 22  in which said reflective surface of said first secondary reflector of each of said reflector units is effective to reflect said sunlight from at least some of said solar panels through said opening in said second secondary reflector and onto said receiver tube.