Semi-concentrating solar energy collector

DETAILED DESCRIPTION This invention relates to a solar collector comprising an insulative frame member enclosing a plurality of transparent tubes for circulating the heat transfer fluid, an efficient solar energy absorber disposed in the tubes, a long reflector of generally semi-circular cross section surrounding each of the tubes, a light transmissive covering over the reflectors to maintain the heat energy adjacent the tubes and free from loss due to ambient convective currents, and an outer protective skin of transparent material.
The transparent tubes have an internal covering containing cube corner prisms affording total internal reflection in the areas of each of the cube corner prisms to block light passing through the tubes from reaching the absorber disposed centrally with respect to the tubes when the heat transmitting fluid is drained from the tubes.
The frame of the solar energy collector of the present invention is a large trough formed of insulative styrene or similar light-weight material within which is a plurality of parallel extending reflectors and clear transparent fluid circulating tubes preferably of plastic.
It is recognized that the frame may be made of a variety of other insulative materials, e.
g.
, wood.
The barrier over the reflectors is preferably a sheet of material having anti-reflective surfaces permitting the solar energy to readily pass through the sheet.
The outer protective layer is formed preferably of a light-transmissive polymeric material which has sufficient strength to protect the solar collectors and not become readily damaged or scratched by the normal environmental elements, preferrably having antireflecting surfaces.