In-ground solar trough

• US 8,490,620 B1
• Filed: 10/23/2008
• Issued: 07/23/2013
• Est. Priority Date: 10/23/2008
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Bae, Koeunyi, Monforto, Stephen A., Taber, Alan E., Munsky, David S.
• Primary Examiner(s): McAllister, Steven B
• Assistant Examiner(s): MASHRUWALA, NIKHIL P
• Application Number:
  US12/256,749
• Time in Patent Office: 1,734 Days
• Field of Search: 126/600, 126/605, 126/696, 126/415, 126/634, 136/4, 353/3
• US Class Current: 126/605
• CPC Class Codes: F24S 2023/87 Reflectors layout
• CPC Class Codes: F24S 2030/133 in the form of flexible elements, e.g. belts, chains, ropes
• CPC Class Codes: F24S 2030/145 Tracks
• CPC Class Codes: F24S 23/74 with trough-shaped or cylindro-parabolic reflective surfaces
• CPC Class Codes: F24S 23/82 characterised by the material or the construction of the reflector
• CPC Class Codes: F24S 30/425 Horizontal axis
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02E 10/47 Mountings or tracking

Abstract

A solar trough includes a light receiver for transporting a fluid to be heated by the solar trough, at least one rail partially or fully disposed in a trench, a parabolic light collector slidably mounted on the at least one rail, and a drive unit for rotating the parabolic light collector within the trench. Further, a solar trough system made up of a plurality of the solar troughs.

Claims

1. A system for collecting solar energy comprising:

a light receiver;

a rail comprising a curved bearing surface on a to surface of the rail;

a reflector configured to redirect light toward the light receiver;

at least one riser coupled to the reflector on a first side of the riser, the at least one riser comprising a first end and a second end, and a curved bearing surface having a length extending from the first end to the second end of the riser on a second side thereof for coupling with the curved bearing surface of the rail,

wherein sliding the bearing surface of the at least one riser along the curved bearing surface alters the angular orientation of the reflector,

wherein each riser is slidably coupled to the curved bearing surface via a clip, the clip attached to the second side of each riser and slidably coupled with a downward facing portion of the rail, and

wherein the curved bearing surface of the riser and the curved bearing surface of the rail comprise an equal radius of curvature such that the curved bearing surface of the riser is in contact with the curved bearing surface of the rail over the entire length of the curved bearing surface of the riser.

2. The solar trough system of claim 1, wherein the bearing surface of the rail extends from a point proximate a first end of the rail to a point proximate a second end of the rail.

3. The solar trough system of claim 1, wherein the rail has an I-shape cross section including a first flange comprising the bearing surface, and a second flange configured for securing the rail within a trench.

4. The system of claim 3, wherein the trench is elongated and the rail is disposed transverse to a longitudinal axis of the trench.

5. The system of claim 1, wherein the reflector is formed by an array of light concentrators.

6. The system of claim 1, further comprising a drive unit, wherein the drive unit includes a motor and a cable arrangement coupled to the reflector, the motor for winding and unwinding the cable arrangement to slide the reflector along a length of the bearing surface of the rail.

7. A solar trough comprising:

a light receiver for transporting a fluid to be heated by the solar trough;

at least one rail partially or fully disposed in a trench having a curved bearing surface along a length thereof; and

a parabolic light collector slidably mounted on the bearing surface of the at least one rail, the parabolic light collector for focusing sun-light on the light receiver;

wherein the parabolic light collector includes a plurality of risers and a plurality of mirror segments, each of the risers including at least one of said plurality of mirror segments on a first side thereof and each of the risers having a bottom curved bearing surface for slidably coupling with the curved bearing surface on a second side thereof of the at least one rail,

wherein each riser of the plurality of risers is connected in series so as to form a curved shape about the light receiver,

wherein each riser is slidably coupled to the curved bearing surface via a clip, the clip attached to the second side of each riser and slidably coupled with a downward facing portion of the rail, and

wherein the curved bearing surface of the riser and the curved bearing surface of the rail comprise an equal radius of curvature such that the curved bearing surface of the riser is in contact with the curved bearing surface of the rail over the entire length of the curved bearing surface of the riser.

8. A method for making a solar trough, the method comprising:

forming a trench in a ground area;

laying at least one rail in the trench;

mounting a parabolic light collector on a first side of a riser, wherein the parabolic light collector includes a plurality of risers and a plurality of mirror segments, each of the risers including at least one of said plurality of mirror segments and having a bottom curved bearing surface on a second side thereof;

slidably mounting the bottom curved bearing surface of each of the risers on a curved bearing surface formed on a length of the at least one rail;

coupling a drive unit to the parabolic light collector, the drive unit for sliding the curved bearing surface of the riser along the curved bearing surface of the at least one rail within the trench; and

locating a light receiver at a focal point of the parabolic light collector, the light receiver for transporting a fluid to be heated by the solar trough,

wherein each riser of the plurality of risers is connected in series so as to form a curved shape about the light receiver,

wherein each riser is slidably coupled to the curved bearing surface via a clip, the clip attached to the second side of each riser and slidably coupled with a downward facing portion of the rail, and

wherein the curved bearing surface of the riser and the curved bearing surface of the rail comprise an equal radius of curvature such that the curved bearing surface of the riser is in contact with the curved bearing surface of the rail over the entire length of the curved bearing surface of the riser.

9. A system for collecting solar energy comprising:

a light receiver;

a rail comprising a curved bearing surface on an upper surface of the rail;

a reflector configured to redirect light toward the light receiver;

at least one riser coupled to the reflector on a first side thereof, and having a curved bearing surface on a second side thereof, the at least one riser slidably coupled to the curved bearing surface of the rail,

wherein sliding the at least one riser along the curved bearing surface alters the angular orientation of the reflector,

wherein the at least one riser is slidably coupled to the curved bearing surface, of the rail via a clip, the clip attached to the second side of the at least one riser and slidably coupled with a downward facing portion of the rail, and

wherein the curved bearing surface of the riser and the curved bearing surface of the rail comprise an equal radius of curvature such that the curved bearing surface of the riser is in contact with the curved bearing surface of the rail over the entire length of the curved bearing surface of the riser.

10. The system of claim 9, wherein the rail comprises a flange, and the clip is slidably attached to the flange.

11. The system of claim 10, wherein a top surface of the flange comprises the curved bearing surface, and the clip is configured to engage a bottom surface of the flange, opposite the top surface.

12. The system of claim 11, where in clip is configured to slidably capture the flange between itself and the second side of the at least one riser.

13. The system of claim 9, further comprising:

wherein the drive system comprises;

a first tensioning member connected on a first end thereof to a first end of at least one of the at least one riser and the reflector, and connected on a second end thereof to a rotatable drive unit;

a second tensioning member connected on a first end thereof to a second end opposite the first end of the at least one of the at least one riser and the reflector, and connected on a second end therefore to the rotatable drive unit,

wherein rotation of the drive unit in a first direction tensions one of the first and second tensioning members, sliding the at least one riser along the curved bearing surface for altering the angular orientation of the reflector, and rotation of the drive unit in the second direction tensions the other of the first and second tensioning members.

14. The system of claim 13, wherein the drive system further comprises:

a first pulley arranged proximate a first end of the rail for guiding the first tensioning member, and

a second pulley arranged proximate a second end of the rail for guiding the second tensioning member.

15. The system of claim 13, wherein the drive unit comprises at least one drive shaft, wherein the rotation of the drive shaft is configured to wind a length of one of the first or second tensioning members around the at least one drive shaft, while unwinding a length of the remaining one of the first or second tensioning members.