Title: High temperature solar selective coatings

Abstract

Improved solar collectors (40) comprising glass tubing (42) attached to bellows (44) by airtight seals (56) enclose solar absorber tubes (50) inside an annular evacuated space (54. The exterior surfaces of the solar absorber tubes (50) are coated with improved solar selective coatings {48} which provide higher absorbance, lower emittance and resistance to atmospheric oxidation at elevated temperatures. The coatings are multilayered structures comprising solar absorbent layers (26) applied to the meta surface of the absorber tubes (50), typically stainless steel, topped with antireflective Savers (28) comprising at least two layers 30, 32) of refractory metal or metalloid oxides (such as titania and silica) with substantially differing indices of refraction in adjacent layers. Optionally, at least one layer of a noble metal such as platinum can be included between some of the layers. The absorbent layers cars include cermet materials comprising particles of metal compounds is a matrix, which can contain oxides of refractory metals or metalloids such as silicon. Reflective layers within the coating layers can comprise refractory metal silicides and related compounds characterized by the formulas TiSi. Ti.sub.3SiC.sub.2, TiAlSi, TiAN and similar compounds for Zr and Hf. The titania can be characterized by the formulas TiO.sub.2, Ti.sub.3O.sub.5. TiOxmore » or TiO.sub.xN.sub.1-x with x 0 to 1. The silica can be at least one of SiO.sub.2, SiO.sub.2x or SiO.sub.2xN.sub.1-x with x=0 to 1. « less

Inventors:

Kennedy, Cheryl E

Issue Date:

2014-11-25

Research Org.:

National Renewable Energy Laboratory (NREL), Golden, CO (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1164359

Patent Number(s):

8893711

Application Number:

12/745,319

Assignee:

Alliance for Sustainable Energy, LLC (Golden, CO)

Patent Classifications (CPCs):

F - MECHANICAL ENGINEERING F24 - HEATING F24S - SOLAR HEAT COLLECTORS

G - PHYSICS G02 - OPTICS G02B - OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS

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F - MECHANICAL ENGINEERING F24 - HEATING F24S - SOLAR HEAT COLLECTORS

F24S10/45 - {the enclosure being cylindrical}
F24S70/225 - for spectrally selective absorption
F24S70/30 - Auxiliary coatings, e.g. anti-reflective coatings

G - PHYSICS G02 - OPTICS G02B - OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS

G02B5/281 - {designed for the infra-red light}

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02E - REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

Y02E10/44 - Heat exchange systems

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DOE Contract Number:  

AC36-99GO10337

Resource Type:

Patent

Resource Relation:

Patent File Date: 2007 Oct 18

Country of Publication:

United States

Language:

English

Subject:

14 SOLAR ENERGY; 36 MATERIALS SCIENCE