Radiation collector

• US 8,469,023 B2
• Filed: 09/28/2007
• Issued: 06/25/2013
• Est. Priority Date: 09/27/2006
• Status: Expired due to Fees

• Current Assignee: Airlight Energy IP SA
• Original Assignee: Airlight Energy IP SA
• Inventors: Pedretti, Andrea
• Primary Examiner(s): Basichas, Alfred
• Application Number:
  US12/311,306
• Publication Number:
  US 20090272375A1
• Time in Patent Office: 2,097 Days
• Field of Search: 126/696, 126/697, 126/710, 126/711, 126/624, 126/625, 126/684
• US Class Current: 126/696
• CPC Class Codes: F24S 20/20 Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants
• CPC Class Codes: F24S 23/715 flexible
• CPC Class Codes: F24S 23/745 flexible
• CPC Class Codes: F24S 23/81 flexible F24S23/715, F24S23/745 take precedence
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02E 10/46 Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines

Abstract

Disclosed is a radiation collector comprising a pressure cell which is subdivided into a first pressure chamber and a second pressure chamber by means of the concentrator. The small pressure difference between the pressure chambers keeps the concentrator operational in a beam-concentrating form and reduces the wear on the reflective layer of the concentrator. The radiation collector further comprises adequately designed means for establishing the desired pressure in the respective pressure chamber, said means making it possible to compensate changes of the pressure chamber volume resulting from wind load, for example.

Claims

1. A radiation collector comprising:

a pressure cell at least partially formed from a first flexible membrane and comprising a transparent region;

a concentrator fixed within the pressure cell, the concentrator comprising a second flexible membrane comprising a first side facing the transparent region and a second side facing away from the transparent region;

wherein the concentrator is disposed between a first pressure chamber and a second pressure chamber formed within the pressure cell;

wherein the first pressure chamber and the second pressure chamber are fluidly coupled to an exterior environment; and

wherein, responsive to deformations caused by external influences of at least one of the first pressure chamber and the second pressure chamber, a predefined pressure range within the first pressure chamber and the second pressure chamber is maintained.

2. The radiation collector according to claim 1, comprising an overflow region fluidly connecting the first pressure chamber and the second pressure chamber.

3. The radiation collector according to claim 1, wherein:

the concentrator is held pneumatically in an operating position via pressure prevailing on the first side;

the first pressure chamber comprises a higher operating pressure than the second pressure chamber; and

the first pressure chamber and the second pressure chamber are maintained at a predefined pressure difference when a volume of at least one of the first pressure chamber and the second pressure chamber is altered by external influences during operation.

4. The radiation collector according to claim 3, wherein the predefined pressure difference is in a range from approximately 0.05 mbar to approximately 0.2 mbar.

5. The radiation collector according to claim 3, wherein the operating pressure in the first pressure chamber is in a range from approximately 1 mbar to approximately 5 mbar.

6. The radiation collector according to claim 3, wherein:

the pressure cell comprises an upper flexible membrane face and a lower flexible membrane face, the upper flexible membrane face and the lower flexible membrane face together define a lens-shaped contour with a round outline;

the upper flexible membrane face is transparent;

the concentrator is arranged between the upper flexible membrane face and the lower flexible membrane face in such a manner that, during operation, the first pressure chamber is convex and the second pressure chamber is concave shape; and

the pressure cell is suspended along an edge region on a frame.

7. The radiation collector according to claim 6, wherein the frame comprises at least one of concrete and prefabricated concrete elements.

8. The radiation collector according to claim 3, wherein:

the pressure cell has a contour which is cushion-shaped with a rectangular outline and comprises an upper membrane face and a lower membrane face, the upper membrane face being configured to be transparent for radiation to be concentrated;

the concentrator is arranged between the upper membrane face and the lower membrane face such that it runs as far as an edge zone such that the first pressure chamber has a convex shape and the second pressure chamber has a concave shape; and

the pressure cell is suspended along an edge region on a frame.

9. The radiation collector according to claim 3, wherein:

the first pressure chamber and the second pressure chamber are filled with a fluid;

a first fluid duct opens into the first pressure chamber and a second fluid duct opens into the second pressure chamber;

fluid can flow through the first fluid duct and the second fluid duct in both directions in order to maintain a setpoint operating pressure;

a fluid pump operated such that the respective setpoint operating pressure prevails in the associated pressure chamber.

10. Radiation collector according to claim 9, wherein the first pressure chamber and the second pressure chamber are connected to each other by means of the second fluid duct.

11. The radiation collector according to one of claim 3, wherein;

the second pressure chamber comprises;

a centrally placed core zone;

means for operationally maintaining a core pneumatic pressure in the centrally placed core zone, and

the core pneumatic pressure is smaller than a pressure of an area within the second pressure chamber but not within the centrally placed core zone.

12. The radiation collector according to claim 11, wherein:

the means comprise;

a sealing arrangement which operationally separates the centrally placed core zone from other regions of the second pressure chamber; and

a fluid duct for allowing fluid flow out of the centrally placed core zone.

13. The radiation collector according to claim 12, wherein:

the core zone and the other regions of the second pressure chamber are connected to each other by at least one fluid duct;

wherein the at least one fluid duct is adapted to allow fluid to flow in both directions therethrough to maintain a setpoint pressure difference;

a fluid pump is disposed in the at least one fluid duct such that the setpoint operating pressure prevails in an associated pressure chamber.

14. The radiation collector according to claim 12, wherein a sealing arrangement comprises a sealing lip which interacts operationally with the membrane of the concentrator.

15. The radiation collector according to claim 14, wherein:

the sealing lip comprises a distance from the concentrator and a semi-permeable foam strip such that a quantity of fluid that flows out of surrounding regions into the core zone is smaller than a quantity of fluid that is conveyed by the fluid pump.

16. The radiation collector according to claim 12, wherein the sealing arrangement is part of a support structure of the pressure cell and comprises concrete.

17. The radiation collector according to claim 1, wherein an overpressure zone is divided into a plurality of segments.

18. The radiation collector according to claim 17, wherein two adjacent segments bear against a fluid duct which is connected to an opening and are operationally connected to the fluid duct.

19. The radiation collector according to claim 1, wherein;

the concentrator comprises a membrane

the membrane comprising at least one of PVC, PU, silicone-coated polyester fabric, a polyester foil, and fibreglass fabric; and

the reflective layer comprises vapour-deposited aluminium.

20. The radiation collector according to claim 1, wherein:

the first pressure chamber and the second pressure chamber comprise ethylene tetrafluoroethylene (ETFE); and

the first pressure chamber and the second pressure chamber are reinforced with at least one of high-strength PET and a steel or plastic web.

21. The radiation collector according to claim 1, wherein the collector has a rotationally symmetrical shape in an operating position and is configured as at least one of a parabolic mirror and a reflective spherical calotte.

22. The radiation collector according to claim 21, wherein a pressure chamber wall is drawn in towards the concentrator at an axis of symmetry such that the pressure chamber has approximately a configuration of an annular chamber in the operating position.

23. The radiation collector according to claim 21, wherein the collector has a shape of at least one of a well and a trough in the operating position.

24. The radiation collector according to claim 21, wherein the collector has a shape of a well with a parabolic cross section in the operating position.

25. The radiation collector according to claim 1, wherein a pressure chamber wall is drawn in towards the concentrator along a surface line of the concentrator such that the chamber has at least two segments that run parallel with respect to each other.

26. The radiation collector according to claim 1, wherein a peripheral support ring mechanically stabilizes the pressure cell and is connected in one piece to the pressure cell.

27. The radiation collector according to claim 26, wherein the peripheral support ring is an inflatable structure.

28. The radiation collector according to claim 1, wherein the first flexible membrane is pneumatically held in a first-membrane operating position solely via pressure within the first pressure chamber and the second flexible membrane, at least partially forming the second pressure chamber is pneumatically held in a second-membrane operating position via pressure within the second pressure chamber.

29. A radiation collector comprising:

a pressure cell at least partially formed from a first flexible membrane and comprising a transparent region;

a concentrator fixed within the pressure cell, the concentrator comprising a second flexible membrane comprising a first side facing the transparent region and a second side facing away from the transparent region;

wherein the concentrator is disposed between a first pressure chamber and a second pressure chamber formed within the pressure cell;

wherein the first pressure chamber and the second pressure chamber are fluidly coupled to an exterior environment; and

wherein, responsive to changes caused by external influences of a volume of at least one of the first pressure chamber and the second pressure chamber, a predefined pressure range within the first pressure chamber and the second pressure chamber is maintained.