Inverted channel focusing solar collector

• US 4,370,974 A
• Filed: 03/12/1980
• Issued: 02/01/1983
• Est. Priority Date: 03/12/1980
• Status: Expired due to Term

• Current Assignee: Donald R. Maxey
• Original Assignee: Donald R. Maxey
• Inventors: Maxey, Donald R.
• Primary Examiner(s): Yeung, James C.
• Assistant Examiner(s): Barrett, Lee E.
• Application Number:
  US06/129,649
• Time in Patent Office: 1,056 Days
• Field of Search: 126/438, 126/439, 126/441, 126/429, 350/293, 136/259
• US Class Current: 126/621
• CPC Class Codes: F24S 20/67 in the form of roof constructions in the form of shingles or tiles F24S20/69
• CPC Class Codes: F24S 23/70 with reflectors
• CPC Class Codes: F24S 23/79 with spaced and opposed interacting reflective surfaces
• CPC Class Codes: F24S 23/80 having discontinuous faces
• CPC Class Codes: F24S 50/80 for controlling collection or absorption of solar radiation
• CPC Class Codes: F24S 80/56 characterised by means for preventing heat loss
• CPC Class Codes: Y02B 10/20 Solar thermal
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02E 10/44 Heat exchange systems

Abstract

A solar energy collector in the shape of an inverted geometric cusp of the second kind which permits the collection of direct and diffuse solar radiation, and which attenuates losses by thermal convection, conduction, and reverse radiation or re-radiation of energy to the cold or night sky. The solar collector when utilized in a composite unit is compact, has an aesthetically pleasing low profile, and alleviates the need for elaborate sensing and tracking mechanisms.

Claims

1. A solar device comprising a horizontally oriented radiant and thermal energy absorber and a collector having two reflective curved planar surfaces curving downward from said absorber from a common side of a vertical plane drawn tangent to said absorber, one of said planar surfaces curving downward from one side of said absorber, and the other of said planar surfaces curving downward from the opposite of said one side of said absorber and each being in direct thermal conductive contact with said absorber, said curved planar surfaces supported by said horizontally oriented absorber, wherein the lowermost of said curved reflective surfaces approaches a plane of horizontal tangency sufficiently forward of the horizontal tangency of the uppermost reflective surface to delineate an aperture plane for the entrance of solar radiation which has an optimum angular inclination for the latitude;

said reflective surfaces conforming essentially with the geometry of a cusp of the second kind in that they would intercept along a line of double tangency to a common reference plane if extended above said horizontally mounted radiant and thermal energy absorber.

2. The solar collector of claim 1 wherein said absorber is a fluid-containing conduit.

3. The solar collector of claim 1 wherein said absorber is a photovoltaic cell array.

4. The solar collector of claim 1 wherein the lowermost of said two curved planar surfaces is formed as a part of the natural terrain.

5. The solar collector of claim 1 wherein the internal surface of the lowermost of said two curved planar surfaces includes radiation entrapment facets.

6. The solar collector of claim 1 wherein the lowermost of the internal surfaces of said two curved planar surfaces comprise a thermal conductive layer on a relatively non-thermal conductive surface and said layer contains a linear parting in the said conductive surface to thereby reduce conductive loss.

7. A solar unit comprising a plurality of solar devices each including a horizontally oriented radiant and and thermal energy absorber and a collector having two reflective curved planar surfaces curving downward from said absorber from a common side of a vertical plane drawn tangent to said absorber, one of said planar surfaces curving downward from one side of said absorber, and the other of said planar surfaces curving downward from the opposite of said one side of said absorber and each being in direct thermal conductive contact with said absorber, said curved planar surfaces supported by said horizontally oriented absorber, wherein the lowermost of said curved reflective surfaces approaches a plane of horizontal tangency sufficiently forward of the horizontal tangency of the uppermost reflective surface to delineate an aperture plane for the entrance of solar radiation which has an optimum angular inclination for the latitude;

said reflective surfaces conforming essentially with the geometry of a cusp of the second kind in that they would intercept along a line of double tangency to a common reference plane if extended above said horizontally mounted radiant and thermal energy absorber.

8. The unit of claim 7 wherein said solar devices comprise a plurality of individually formed curved elements of insulating material provided with a reflective surface and said individual elements mated to provide a dual function as the top surface of one collector cusp and the lower surface of the adjoining cusp.

9. The unit of claim 8 wherein said insulating material is a polymeric foam and said reflective surface is made by wrapping said foam with aluminized Mylar.

10. The unit of claim 8 wherein said insulating material is a polymeric foam and said reflective surface is made by wrapping said foam with aluminum foil.

11. The unit of claim 7 wherein said unit includes convection grooves at the front surface of said unit and at the back surface of said unit to provide thermal circulation.

12. The unit of claim 11 wherein said unit includes opening and closing means on said convection grooves.

13. The unit of claim 7 wherein said unit forms an integral part of a roof structure with said reflective curved planar surfaces being comprised of a flexible fabric suspended from said absorber.

14. The unit of claim 13 wherein said reflective flexible fabrics are comprised of aluminized Mylar.

15. The unit of claim 13 wherein said reflective flexible fabrics comprise aluminum foil laminates in caternary suspension.