Solar energy concentrator

• US 4,318,394 A
• Filed: 01/11/1980
• Issued: 03/09/1982
• Est. Priority Date: 01/11/1980
• Status: Expired due to Term

• Current Assignee: William C. Alexander
• Original Assignee: William C. Alexander
• Inventors: Alexander, William C.
• Primary Examiner(s): Jones, Larry
• Application Number:
  US06/111,202
• Time in Patent Office: 788 Days
• Field of Search: 126/438, 126/425, 126/451, 126/439, 126/424, 250/203 R, 353/3, 350/288, 350/289, 350/292, 350/295, 350/320
• US Class Current: 126/575
• CPC Class Codes: F24S 23/81 flexible F24S23/715, F24S23/745 take precedence
• CPC Class Codes: F24S 25/70 with means for adjusting the final position or orientation of supporting elements in relation to each other or to a mounting surface; with means for compensating mounting tolerances
• CPC Class Codes: F24S 30/425 Horizontal axis
• CPC Class Codes: Y02E 10/47 Mountings or tracking
• CPC Class Codes: Y10S 359/90 Methods

Abstract

A solar energy concentrator is provided which includes a flexible reflective surface to focus solar flux on absorber tubes. The surface is mounted above a plurality of partially evacuated chambers. As the relative position between the sun and the concentrator change, the position of the absorber tubes and curvature of the reflective surface are changed to maintain an optimum reflective surface curvature for solar energy concentration.

Claims

1. A solar energy apparatus, comprising:

(a) absorber means for absorbing solar flux;

(b) flexible reflective means for receiving incident solar flux and concentrating same on said absorber means;

(c) means for mounting said sheet of reflective material on a surface to receive solar flux;

(d) means for moving the position of said absorber means with respect to said flexible reflective means according to the flux distribution of the solar flux received by said absorber means; and

(e) means for adjusting the shape of said flexible reflective means according to the position of said absorber means, said means for adjusting comprising;

(1) a plurality of adjacent compartments formed beneath a plurality of adjacent sections of said flexible reflective means;

(2) means for controlling the pressure in said compartments to control the curvature of said sections of said flexible reflective means;

(3) means for adjusting the cross length of said flexible reflective means relative to the width between said mounting means; and

(4) computer means for coordinating said means for adjusting the cross length and said means for controlling the pressure to control the shape of said flexible reflective means, and

(f) means for pressure isolation between said compartments.

2. The apparatus of claim 1, further including:

initial locator means for forming an initial indication of the approximate angle of the sun with respect to said flexible reflective means.

3. The apparatus of claim 2, wherein said initial locator means comprises:

plural solar cells each mounted at right angles with respect to the others and forming an output signal proportional to the amount of solar flux received.

4. The apparatus of claim 1, wherein said flexible reflective means comprises:

an elongate quadrilateral sheet having a specularly reflective surface;

means for mounting said sheet of reflective material on a stationary surface to receive solar flux.

5. The apparatus of claim 1, wherein said means for adjusting includes:

7. The apparatus of claim 5, further including:

means for sensing the pressure differential between ambient air pressure and each of said plurality of compartments.

8. The apparatus of claim 1, wherein said absorber means comprises:

means for converting the concentrated solar flux into another form of energy.

9. The apparatus of claim 1, wherein said means for moving comprises:

(a) motor means for adjusting the position of said absorber means with respect to said flexible reflective means; and

(b) control means for controlling the operation of said motor means.

10. The apparatus of claim 8, wherein said control means includes:

means for sensing the flux distribution on said absorber means.

11. The apparatus of claim 1, wherein said means for adjusting comprises:

means for detecting the position of said absorber means with respect to said flexible reflective means.

13. The method of claim 11, further including the step of:

forming an initial lindication of the approximate angle of the sun with respect to the flexible reflective surface.

14. The method of claim 11, wherein the flexible reflective surface has plural compartments therebeneath and wherein said step of adjusting comprises:

controlling the pressure within the compartments to control the shape of the flexible reflective surface.

15. The method of claim 13, further including the step of:

sensing the pressure differential between ambient air pressure and the compartments.

16. The method of claim 11, wherein said step of moving includes the steps of:

(a) sensing the incident heat flux on the absorber; and

(b) moving the absorber in a direction to maximize the incident heat flux on the absorber.

17. The method of claim 11, wherein said step of adjusting includes the step of:

detecting the position of the absorber with respect to the flexible reflective surface.

6. means for pressure isolation between said compartments.

12. A method of concentrating solar energy on a solar flux absorber with a flexible reflective surface, comprising the steps of:

(a) moving the position of the absorber with respect to the flexible reflective surface according to the flux distribution on the absorber; and

(b) adjusting the shape of the flexible reflective surface according to the position of the absorber by performing the steps of;

(1) controlling the pressure in adjacent compartments formed beneath the flexible reflective surface to control the curvature of the surface;

(2) adjusting the cross length of the flexible reflective surface relative to the width of structure between which the reflective surface is mounted; and

(3) coordinating said steps of adjusting of the cross length and controlling the pressure to control the shape of the flexible reflective surface.

18. The method of concentrating solar energy on a solar flux absorber with a flexible reflective surface, comprising the steps of:

(a) adjusting the flexible reflective surface to approximate a parabolic section which corresponds to the incident solar flux angle and which further has a focal point which conincides with the locus of possible solar flux absorber positions said adjusting comprising the steps of;

(1) controlling the pressure in adjacent compartments formed beneath the flexible reflective surface to control the curvature of the surface;

(2) adjusting the cross length of the flexible reflective surface relative to the width of structure between which the reflective surface is mounted;

(3) coordinating said steps of adjusting of the cross length and controlling the pressure to control the shape of the flexible reflective surface; and

(b) moving the position of the absorber with respect to the flexible reflective surface in order to position the absorber at the focal point of the parabolic section.

19. An apparatus for concentrating solar energy on a solar flux absorber with a flexible reflective surface, comprising:

(a) means for adjusting the flexible reflective surface to approximate a parabolic section which corresponds to the incident solar flux angle and which further has a focal point which coincides with the locus of possible solar flux absorber positions said means for adjusting comprising;

(1) a plurality of adjacent compartments formed beneath a plurality of adjacent sections of the flexible reflective surface;

(2) means for controlling the pressure in said compartments to control the curvature of said sections of the flexible reflective surface;

(3) means for adjusting the cross length of the flexible reflective surface relative to the width between said mounting means; and

(4) computer means for coordinating said means for adjusting the cross length and said means for controlling the pressure to control the shape of the flexible reflective surface; and

(b) means for moving the position of the absorber with respect to the flexible reflective surface in order to position the absorber at the focal point of the parabolic section.