improvement in systems concentrators of radiant energy, especially in solar energy collectors

摘要

A curved prismatic, Fresnel-type lens primarily used for concentrating sunlight in a solar energy collector. The lens comprises a substantially smooth, convex outer surface and a plurality of prisms arranged side-by-side along a curve on the inner surface to direct incoming light to a common area. Each of the individual prisms has a front and back face joined by a bottom face. The front and back faces of the prisms are oriented such that the angle of incidence of the incoming light with the front face is equal to the angle of incidence of the outgoing light with the back face. Further, each of the prisms is arranged along the curve such that they do not obstruct light passing through any adjacent prism. The bottom face of each prism is over-extended beyond the path of the light passing through the prism to prevent loss of light due to blockage by the bottom face or the rounded point between the back face and bottom face. The improved lens is used in combination with a solar energy collector comprising the improved concentrator and a suitable energy receiver for converting incident sunlight into a useful energy output.