BROADBAND REFLECTORS, CONCENTRATED SOLAR POWER SYSTEMS, AND METHODS OF USING THE SAME

• US 20120011850A1
• Filed: 12/21/2009
• Published: 01/19/2012
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Hebrink, Timothy J., Clear, Susannah C., Weber, Michael F., Yu, Ta-Hua, Sherman, Audrey A., Gilbert, Laurence R.
• Granted Patent: US 9,523,516 B2
• Time in Patent Office: Days
• US Class Current: 60/641.15
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 15/082 comprising vinyl resins; comprising acrylic resins
• CPC Class Codes: B32B 15/085 comprising polyolefins
• CPC Class Codes: B32B 15/088 comprising polyamides
• CPC Class Codes: B32B 15/09 comprising polyesters
• CPC Class Codes: B32B 15/18 comprising iron or steel B32B15/011, B32B15/012 and B32B15/013 take precedence
• CPC Class Codes: B32B 15/20 comprising aluminium or copper B32B15/016 and B32B15/017 take precedence
• CPC Class Codes: B32B 2250/42 Alternating layers, e.g. ABAB(C), AABBAABB(C)
• CPC Class Codes: B32B 2255/10 on synthetic resin layer or on natural or synthetic rubber layer
• CPC Class Codes: B32B 2255/205 Metallic coating
• CPC Class Codes: B32B 2307/416 Reflective
• CPC Class Codes: B32B 2311/08 Silver
• CPC Class Codes: B32B 2311/12 Copper
• CPC Class Codes: B32B 2311/24 Aluminium
• CPC Class Codes: B32B 2311/30 Iron, e.g. steel
• CPC Class Codes: B32B 2323/00 Polyalkenes
• CPC Class Codes: B32B 2325/00 Polymers of vinyl-aromatic compounds, e.g. polystyrene
• CPC Class Codes: B32B 2327/00 Polyvinylhalogenides
• CPC Class Codes: B32B 2331/00 Polyvinylesters
• CPC Class Codes: B32B 2333/12 Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B32B 2367/00 : Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2377/00 : Polyamides
• CPC Class Codes: B32B 2383/00 : Polysiloxanes
• CPC Class Codes: B32B 2551/00 : Optical elements
• CPC Class Codes: B32B 2551/08 : Mirrors
• CPC Class Codes: B32B 27/283 : comprising polysiloxanes
• CPC Class Codes: B32B 27/302 : comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 27/304 : comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• CPC Class Codes: B32B 27/306 : comprising vinyl acetate or vinyl alcohol (co)polymers
• CPC Class Codes: B32B 27/308 : comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/325 : comprising polycycloolefins
• CPC Class Codes: B32B 27/34 : comprising polyamides
• CPC Class Codes: B32B 27/36 : comprising polyesters
• CPC Class Codes: B32B 7/023 : Optical properties
• CPC Class Codes: B32B 7/12 : using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: F03G 6/06 : with solar energy concentrating means
• CPC Class Codes: F03G 6/061 : Parabolic linear or trough concentrators
• CPC Class Codes: F03G 6/063 : Tower concentrators
• CPC Class Codes: F24S 10/00 : Solar heat collectors using working fluids
• CPC Class Codes: F24S 10/70 : the working fluids being conveyed through tubular absorbing conduits
• CPC Class Codes: F24S 20/00 : Solar heat collectors specially adapted for particular uses or environments
• 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 2023/87 : Reflectors layout
• CPC Class Codes: F24S 2025/601 : by bonding, e.g. by using adhesives
• CPC Class Codes: F24S 2030/136 : for moving several solar collectors by common transmission elements
• CPC Class Codes: F24S 2030/16 : Hinged elements; Pin connections
• CPC Class Codes: F24S 23/00 : Arrangements for concentrating solar-rays for solar heat collectors
• CPC Class Codes: F24S 23/70 : with reflectors
• CPC Class Codes: F24S 23/74 : with trough-shaped or cylindro-parabolic reflective surfaces
• CPC Class Codes: F24S 23/77 : with flat reflective plates
• 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: F24S 50/20 : for tracking
• CPC Class Codes: G02B 17/006 : Systems in which light light is reflected on a plurality of parallel surfaces, e.g. louvre mirrors, total internal reflection [TIR] lenses Fresnel mirrors G02B5/09, Fresnel lenses G02B3/08
• CPC Class Codes: G02B 19/0019 : having reflective surfaces only (e.g. louvre systems, systems with multiple planar reflectors)
• CPC Class Codes: G02B 19/0042 : for use with direct solar radiation
• CPC Class Codes: G02B 5/0841 : comprising organic materials, e.g. polymers
• CPC Class Codes: G02B 6/0011 : the light guides being planar or of plate-like form
• CPC Class Codes: H01L 31/0547 : comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
• CPC Class Codes: H02S 20/00 : Supporting structures for PV modules
• CPC Class Codes: Y02E 10/40 : Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02E 10/44 : Heat exchange systems
• CPC Class Codes: Y02E 10/46 : Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines
• CPC Class Codes: Y02E 10/47 : Mountings or tracking
• CPC Class Codes: Y02E 10/52 : PV systems with concentrators
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/3154 : Of fluorinated addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31681 : Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31692 : Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/3175 : Next to addition polymer from unsaturated monomer[s]
• CPC Class Codes: Y10T 428/31757 : Polymer of monoethylenically unsaturated hydrocarbon
• CPC Class Codes: Y10T 428/31786 : Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31909 : Next to second addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31913 : Monoolefin polymer
• CPC Class Codes: Y10T 428/31928 : Ester, halide or nitrile of addition polymer

Abstract

Broadband reflectors include a UV-reflective multilayer optical film and a VIS/IR-reflective layer. In various embodiments, the VIS/IR reflective layer may be a reflective metal layer or a multilayer optical film. Concentrated solar power systems and methods of harnessing solar energy using the broadband reflectors and optionally comprising a celestial tracking mechanism are also disclosed

Claims

1. A broadband reflector comprising:

a UV-reflective multilayer optical film having a first major surface and comprising a UV-reflective optical layer stack, wherein the UV-reflective optical layer stack comprises first optical layers and second optical layers, wherein at least a portion of the first optical layers and at least a portion of the second optical layers are in intimate contact and have different refractive indexes; and

a VIS/IR-reflective metal layer disposed on at least a portion of the first major surface.

2. The broadband reflector of claim 1, further comprising an adhesive layer disposed on the metal layer opposite the UV-reflective multilayer optical film.

3. The broadband reflector of claim 1, wherein the VIS/IR-reflective metal layer comprises at least one of silver, copper, stainless steel, or aluminum.

16. A concentrated solar power system comprising:

at least one broadband reflector according to claim 1 capable of being aligned to direct solar radiation onto a hollow receiver; and

a heat transfer fluid partially disposed within the hollow receiver.

17. The concentrated solar power system of claim 16, further comprising an electrical generator in fluid communication with the hollow receiver.

18. The concentrated solar power system of claim 16, further comprising a celestial tracking mechanism for the at least one broadband reflector.

19. The concentrated solar power system of claim 18, wherein the celestial tracking mechanism comprises a louver pivotally mounted adjacent the hollow receiver, wherein the louver comprises the at least one broadband reflector.

24. A method of harnessing solar energy, the method comprising reflecting solar radiation using at least one broadband reflector according to claim 1 onto a hollow receiver containing a heat transfer fluid to provide a heated heat transfer fluid.

28. A method of using the broadband reflector of claim 1, the method comprising:

adhering the broadband reflector to an existing solar reflector adapted for use in a concentrated solar power system.

31. The broadband reflector of claim 1, wherein at least one of the following conditions is met:

the broadband reflector has an average light reflectivity of 90 percent over a wavelength range of 300 to 400 nanometers;

or

the broadband reflector has an average light reflectivity of at least 95 percent over a wavelength range of 350 to 2494 nanometers.

32. The broadband reflector of claim 1, wherein the first optical layers and second optical layers respectively comprise a polyethylene terephthalate and a coPMMA, a sPS and an OTP, a sPS and a THV, a PMMA and a THV, a COC and a THV, or an EVA and a THV.

33. The broadband reflector of claim 1, wherein the UV-reflective multilayer optical film further comprises a tie layer that comprises the first major surface of the UV-reflective multilayer optical film.

34. The broadband reflector of claim 1, wherein the UV-reflective multilayer optical film further comprises a second major surface opposite the first major surface, and wherein the UV-reflective multilayer optical film further comprises an abrasion resistant layer that forms the second major surface of the UV-reflective multilayer optical film.

4. A broadband reflector comprising:

a UV-reflective multilayer optical film having a first major surface and comprising a UV-reflective optical layer stack, wherein the UV-reflective optical layer stack comprises first optical layers and second optical layers, wherein at least a portion of the first optical layers and at least a portion of the second optical layers are in intimate contact and have different refractive indexes, and wherein the UV-reflective optical layer stack is reflective to UV-light;

a VIS/IR-reflective multilayer optical film comprising a VIS/IR-reflective optical layer stack, wherein the VIS/IR-reflective optical layer stack comprises third optical layers and fourth optical layers, wherein at least a portion of the third optical layers and at least a portion of the fourth optical layers are in intimate contact and have different refractive indexes, and wherein the VIS/IR-reflective multilayer optical film is reflective to VIS/IR-light; and

a UV-absorbing layer disposed between the first major surface of the UV-reflective multilayer optical film and the VIS/IR-reflective multilayer optical film, wherein the UV-absorbing layer comprises a polymer and a UV-absorber.

5. The broadband reflector of claim 4, wherein the third optical layers and fourth optical layers respectively comprise a polyethylene terephthalate and a THV, a polyethylene terephthalate and an OTP, a PEN and a THV, a PEN and an OTP, a PEN and a PMMA, a polyethylene terephthalate and a coPMMA, a PEN and a coPMMA layer pairs, a coPEN and a PMMA layer pairs, a coPEN and an OTP, a coPEN and a THV, a sPS and an OTP, a sPS and a THV, a PMMA and a THV, a COC and a THV, or an EVA and a THV.

6. The broadband reflector of claim 4, further comprising an adhesive layer disposed on the VIS/IR-reflective multilayer optical film opposite the UV-absorbing layer.

7. The broadband reflector of claim 4, wherein at least one of the following conditions is met:

the broadband reflector has an average light reflectivity of 90 percent over a wavelength range of 300 to 400 nanometers;

or

the broadband reflector has an average light reflectivity of at least 95 percent over a wavelength range of 350 to 2494 nanometers.

9. The broadband reflector of claim 4, wherein the first optical layers and second optical layers respectively comprise a polyethylene terephthalate and a coPMMA, a sPS and an OTP, a sPS and a THV, a PMMA and a THV, a COC and a THV, or an EVA and a THV.

10. The broadband reflector of claim 4, wherein the UV-reflective multilayer optical film further comprises a tie layer that comprises the first major surface of the UV-reflective multilayer optical film.

13. The broadband reflector of claim 4, wherein the UV-reflective multilayer optical film further comprises a second major surface opposite the first major surface, and wherein the UV-reflective multilayer optical film further comprises an abrasion resistant layer that forms the second major surface of the UV-reflective multilayer optical film.

8. (canceled)

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29-30. -30. (canceled)