SOLAR COLLECTOR COMPRISING AN OPAQUE COVER

摘要

A solar collector has an opaque cover heated by solar energy. Heat flows from the opaque cover by conduction, convection, and infrared emittance across a gap within an at least substantially airtight enclosure to an absorber containing a working fluid. The exterior surface of the opaque cover has high solar energy absorptance and the interior surface has high infrared emittance. The exterior surface preferably has low infrared emittance. In one embodiment, fully wetted surface geometry permits direct and reflected infrared absorption by the absorber. The opaque cover eliminates the weight, cost and other shortcomings of glass. A hollow continuous side wall with rounded corners provides an embodiment that is robust yet economical, that is easy to manufacture and seal, that permits a reduced thickness of the opaque cover and mitigates the destructive potential of severe winds, and that can withstand the compressive forces experienced by an evacuated solar collector.

主权项

1. A solar collector for heating a working fluid, comprising:
an opaque cover disposed to receive incident solar energy and coupled to an upper portion of a housing, said opaque cover and said housing together defining an at least substantially airtight enclosure; an exterior surface of said opaque cover having solar energy absorptance greater than about 0.80; an interior surface of said opaque cover having infrared emittance greater than about 0.80; an absorber disposed within the at least substantially airtight enclosure in an opposing spaced apart relationship with said opaque cover, said absorber comprising a vessel for the working fluid; a first conduit disposed to supply the working fluid to the solar collector, projected through said housing and coupled to said absorber; and a second conduit disposed to extract the working fluid from the solar collector, projected through said housing and coupled to said absorber.