Solar reflector in composite material based on resin reinforced with cut fibres, and uses in solar plants
The invention relates to a solar reflector for concentrated solar power plants, comprising a substrate a) in composite material based on resin reinforced with cut fibers, said substrate having means b) for attachment without either perforation or gluing, and a metallic reflective coating layer c). The reflector of the invention is used in solar collectors and in solar plants operating on concentrated solar power, more particularly for producing electricity, steam and/or heat.
1. A solar reflector comprising:
a curved or planar moulded substrate comprising composite resin material reinforced with cut fibres, wherein the moulded substrate with the cut fibres has a mean roughness of less than 30 nm and is made by a moulding process selected from the group consisting of Sheet Moulding Compound, Bulk Moulding Compound and vacuum infusion, and
a reflective layer of silver-based metallic coating with a thickness of from 60 to 200 nm and a reflectance of more than 94% in accordance with standard ISO 9050,
wherein the solar reflector is without a glass layer.
2. The solar reflector of claim 1 , wherein said metallic coating is applied directly to said moulded substrate.
3. The solar reflector of claim 1 , wherein said metallic coating is applied to a first organic, adhesion-promoting coating, wherein the adhesion-promoting coating is disposed between said moulded substrate and said metallic coating.
4. The solar reflector of claim 3 , wherein said adhesion-promoting coating reduces the roughness of said moulded substrate.
5. The solar reflector of claim 3 , wherein the thickness of said adhesion-promoting coating is from 0.1 to 20 μm.
6. The solar reflector of claim 1 , wherein said moulded substrate comprises interlocking edges.
7. The solar reflector of claim 1 , wherein said moulded substrate comprises at least one thermosetting or thermoplastic resin, and optionally further comprising moulding additives.
8. The solar reflector of claim 7 , wherein said at least one thermosetting or thermoplastic resin is a thermosetting resin selected from the group consisting of an unsaturated polyester resin, epoxy resin, vinyl ester resin, phenolic resin, and polyurethane resin; or derivatives or mixtures thereof.
9. The solar reflector of claim 7 , wherein said at least one thermosetting or thermoplastic resin is a thermoplastic resin selected from the group consisting of a polypropylene, polyamide, polybutylene terephthalate, polyethylene terephthalate, polyphenyl sulfone, polycarbonate, and polyphenylene oxide (PPO); or mixtures or alloys thereof.
10. The solar reflector of claim 1 , wherein said reinforcing cut fibres are selected from the group consisting of glass fibres, aramid fibres, basalt fibres, flax fibres, hemp fibres, and bamboo fibres.
11. The solar reflector of claim 3 , further comprising a second organic adhesion-promoting coating with a thickness of from 0.1 to 20 μm, wherein said second organic adhesion-promoting coating is applied to said metallic coating on the opposite side of said first organic adhesion-promoting coating.
12. The solar reflector of claim 3 , further comprising an organic corrosion-protecting coating with a thickness of 10 to 150 μm, wherein said organic corrosion-protecting coating is applied directly to said metallic coating.
13. The solar reflector of claim 12 , wherein said organic corrosion-protecting coating promotes adhesion and protects against corrosion.
14. The solar reflector of claim 12 , further comprising an organic anti-UV coating with a thickness of 10 to 150 μm, wherein said organic anti-UV coating is applied directly to said corrosion-protecting organic coating.
15. The solar reflector of claim 1 , further comprising an organic abrasion-protecting coating with a thickness of from 1 to 20 μm, wherein said organic abrasion-protecting coating is applied in a last layer as a superficial external layer.
16. The solar reflector of claim 15 , wherein said organic abrasion-protecting coating comprises anti-fouling additives of nanometric titanium dioxide, wherein the particle size of the titanium dioxide is less than 200 nanometers; silver nanoparticles; or nanotubes.
17. The solar reflector of claim 11 , wherein said first organic adhesion-promoting coating or said second organic adhesion-promoting coating comprises at least one acrylic resin and at least one thermally crosslinkable or radiation-crosslinkable acrylic monomer.
18. The solar reflector of claim 12 , wherein said organic corrosion-protecting coating comprises a crosslinkable organic binder and at least one antioxidant additive selected from the group consisting of sterically hindered phenols and phosphites; or a combination thereof.
19. The solar reflector of claim 14 , wherein said organic anti-UV coating comprises at least one aliphatic crosslinkable organic binder and at least one anti-UV additive.
20. The solar reflector of claim 15 , wherein said organic abrasion-protecting coating comprises at least one crosslinkable organic binder selected from the group consisting of siloxane resins, urethane resins, and acrylic resins.
21. A solar collector comprising at least one solar reflector of claim 1 .
22. The solar collector of claim 21 , further comprising at least one receiver of solar radiation reflected by said solar reflector or assembly of solar reflectors.
23. The solar reflector of claim 11 , further comprising an organic corrosion-protecting coating with a thickness of 10 to 150 μm, wherein said corrosion-protecting organic coating is applied to said second organic adhesion-promoting coating.
24. The solar reflector of claim 1 , further comprising an organic anti-UV coating with a thickness of 10 to 150 μm, wherein said anti-UV organic coating is applied directly to said metallic coating.