US 4,546,757 A · Fixed position concentrating solar collector

Abstract

A fixed position concentrating solar collector in the form of a trough having an inner surface reflective to solar radiation and formed to direct the sun's rays entering the trough onto a radiation absorber element, the trough having end structures capable of selectively reflecting solar radiation into the trough or of being made transparent for passing solar radiation into the trough which would otherwise be blocked off by the trough end. Devices responsive to the position of the sun relative to the trough automatically control clearness-reflectiveness of the trough ends. End structures include flexible sheets on a roller, movable ends, jointly movable slats, leaves which may be aligned or fanned out, inflatable bags and flexible sheets controlled by bourdon tubes. A highly efficient configuration of the trough reflecting surface has a transverse plane profile defined by a compound parabolic curve comprising a half parabola joined to the other half of the parabola by a quarter circle shifted 90.degree. with respect to the first half, the distance between the focus of the parabola being equal to the radius of the quarter circle and the focus of both of the half parabolas and the circle being in the same position.

Claims25

Dependent claims

In a solar collector having a reflective trough directing entering rays of the sun onto a heat absorbing element, convertable end structures formed for rendering the trough ends selectively penetrable to the rays of the sun and internally reflective to solar radiation, and control means for said convertable end structures automatically operating said convertable end structures to make the sunward end of said trough penetrable to the rays of the sun and the opposite end of said trough reflect the sun's rays encountering same into said trough.

A fixed position concentrating solar collector, comprising

a structure providing an elongated open trough mountable in position to admit the sun's rays to the interior thereof,
reflective surfaces on the interior of said trough formed for directing the sun's rays entering said trough onto a focal area,
a radiation absorber element positioned in said focal area,
and adjustable means at the opposite ends of said trough formed for rendering such ends selectively reflective of and penetrable to the rays of the sun at different times of the day,
the end of said trough farthest from the sun being formed to reflect the sun's rays into said trough and the end of said trough nearest the sun being formed to allow the sun's rays to enter said trough substantially unimpeded.

2 more elements

Dependencies are inferred from the claim text.

Fixed position concentrating solar collector

Life of this patent

Fixed position concentrating solar collector

Life of this patent

Abstract

Claims25