Radiant energy collection

Claim 2

A non-imaging radiant energy concentrator, said concentrator comprising: a trough-shaped body having, a longitudinally extending radiant energy entrance aperture with first and second opposing edges separated by a transverse distance d1, a longitudinally extending radiant energy exit aperture, disposed opposite said entrance aperture, with first and second opposing edges separted by a transverse distance d2, a pair of symmetrical substantially concave radiant energy reflecting and guiding side wall means interconnecting laterally corresponding edges of said apertures, a field of acceptance for radiant energy, an angular acceptance for radiant energy within said field of acceptance and determinable at said entrance aperture, and, an optical axis determinable by reference to distances separating entrance and exit aperture opposing edges, wherein the ratio of the distances d2 to d1 is no less than the sine of said angular acceptance, the profile curve of each of said wall means is a parabola having as its parabolic focus the opposing edge of said exit aperture and as its parabolic axis a line forming an angle with said optical axis of said body numerically equal to said angular acceptance, and the field of acceptance of the body, when represented in terms of optical direction cosines, is an ellipse of semi-minor axis equal to the sine of said angular acceptance and semi-major axis substantially equal to one.

Claim 3

A concentrator according to claim 1 wherein the distance separating said apertures is no more than one half the sum of d1 and d2 multiplied by the cotangent of said angular acceptance.

Claim 4

A concentrator according to claim 1 further including trough end wall means enclosing the space between by said energy reflecting and guiding side wall means.

Claim 5

A concentrator according to claim 3 wherein said end wall means are radiant energy reflective.

Claim 6

A concentrator according to claim 1 wherein said trough is filled with a medium having an index of refraction greater than 1 and said entrance aperture is in optical contact with a medium having an index of refraction lesser than that of the medium filling said trough.

Claim 7

A concentrator according to claim 1 further including a second such trough-shaped body disposed contiguous to said exit aperture, the transverse distance separating first and second edges of the entrance aperture of said second trough body being identical to the transverse distance separating first and second edges of said exit aperture.

Claim 8

A concentrator according to claim 6 wherein said trough is filled with a medium having a given index of refrection, said second trough is filled with a medium having an index of refraction greater than that of the medium filling said trough, and the angular acceptance for energy rays entering the second trough is the inverse sine of the ratio of the index of refraction of the medium filling the first trough to the index of refraction of the medium filling the second trough.

Claim 9

A non-imaging radiant energy concentrator, said concentrator comprising: a trough-shaped Body having, a longitudinally extending radiant energy entrance aperture with first and second opposing edges separated by a transverse distance d1, a longitudinally extending radiant energy exit aperture disposed opposite said entrance aperture with first and second opposing edges separated by a transverse distance d2, a linear radiant energy reflecting and guiding side wall means interconnecting laterally corresponding first edges of said apertures, a substantially concave, curving radiant energy reflecting and guiding side wall interconnecting laterally corresponding second edges of said apertures, a field of acceptance for radiant energy, an angular acceptance for radiant energy within said field of acceptance and dterminable at said entrance aperture, and, an optical axis determinable by reference to distances separating entrance and exit aperture opposing edges, wherein the ratio of the distances d2 to d1 is no less than the sine of said angular acceptance, the profile curve of said curving wall means is a parabola having as it parabolic focus a point, in the plane of said exit aperture, spaced away from said first edge of said exit aperture a distance equal to d2 and as its parabolic axis a line forming an angle with said optical axis of said body numerically equal to said angular acceptance, and the field of acceptance of the body, when represented in terms of optical direction cosines, is an ellipse of semiminor axis equal to the sine of said angular acceptance and semi-major axis substantially equal to one.

Claim 10

A non-imaging radiant energy concentrator, said concentrator comprising: a trough-shaped Body having, a longitudinally extending radiant energy entrance aperture with first and second opposing edges separated by a transverse distance d1, a longitudinally extending radiant energy exit aperture disposed opposite said entrance aperture with first and second opposing edges separated by a transverse distance d2, a linear radiant energy reflecting and guiding side wall means interconnecting laterally corresponding first edges of said apertures, a substantially concave, curving radiant energy reflecting and guiding side wall interconnecting laterally corresponding second edges of said apertures, a field of acceptance for radiant energy, an angular acceptance for radiant energy within said field of acceptance and dterminable at said entrance aperture, and, an optical axis determinable by reference to distances separating entrance and exit aperture opposing edges, wherein the ratio of the distances d2 to d1 is no less than the sine of said angular acceptance, the profile curve of said curving wall means is a parabola having as it parabolic focus a point, in the plane of said exit aperture, spaced away from said first edge of said exit aperture a distance equal to d2 and as its parabolic axis a line forming an angle with said optical axis of said body numerically equal to said angular acceptance, and the field of acceptance of the body, when represented in terms of optical direction cosines, is an ellipse of semiminor axis equal to the sine of said angular acceptance and semi-major axis substantially equal to one.

Claim 11

A concentrator according to claim 8 wherein the distance separating said apertures is no more than one half the sum of d1 and d2 multiplied by the cotangent of said angular acceptance.

Claim 12

A concentrator according to claim 8 further including trough end wall means enclosing the space between said wall means.

Claim 13

A concentrator according to claim 10 wherein said end wall means are radiant energy reflective.

Claim 14

Solar energy concentration apparatus, said apparatus comprising: a concentrator element including, a pair of longitudinally extending substantially parallel walls having substantially concave opposing inner solar energy reflecting surfaces, each of said reflecting surfaces being sloped inwardly from an upper edge at an energy entrance aperture to a lower edge at an energy exit aperture, said exit aperture being of lesser transverse cross-sectional dimension than said entrance aperture, a field of acceptance for solar energy and an angular acceptance within said field, determinable at said entrance aperture, an optical axis determinable by reference to distances separating respective opposing upper and lower reflecting surface edges, the profile curve of each of said reflecting surfaces being a parabola having as its parabolic focus the lower edge of the opposing reflecting surface and as its parabolic axis a line forming an angle with said optical axis numerically equal to the angular acceptance of the concentrator, the dimensions of said apertures and the slope of said reflecting surfaces being such that said field of acceptance is capable of including an arc segment of coordinates equal to those described by the apparent motion of the sun within at least one hour before and after reaching zenith point at solstice; and, a solar energy trap at said energy exit aperture.

Claim 15

Solar energy concentration apparatus, said apparatus comprising: a concentrator element including, a pair of longitudinally extending substantially parallel walls having substantially concave opposing inner solar energy reflecting surfaces, each of said reflecting surfaces being sloped inwardly from an upper edge at an energy entrance aperture to a lower edge at an energy exit aperture, said exit aperture being of lesser transverse cross-sectional dimension than said entrance aperture, a field of acceptance for solar energy and an angular acceptance within said field, determinable at said entrance aperture, an optical axis determinable by reference to distances separating respective opposing upper and lower reflecting surface edges, the profile curve of each of said reflecting surfaces being a parabola having as its parabolic focus the lower edge of the opposing reflecting surface and as its parabolic axis a line forming an angle with said optical axis numerically equal to the angular acceptance of the concentrator, the dimensions of said apertures and the slope of said reflecting surfaces being such that said field of acceptance is capable of including an arc segment of coordinates equal to those described by the apparent motion of the sun within at least one hour before and after reaching zenith point at solstice; and, a solar energy trap at said energy exit aperture.

Claim 16

Apparatus according to claim 12, wherein the height of said concentrator element is no more than one-half the sum of the transverse cross-sectional dimensions of said entrance and exit apertures multiplied by the cotangent of said concentrator angular acceptance.

Claim 17

Apparatus according to claim 12 wherein the ratio of the transverse cross-sectional dimensions of said concentrator element exit aperture to said entrance aperture is no less than the sine of said angular acceptance.

Claim 18

Apparatus according to claim 12 furtheR including solar energy reflecting end wall means at the ends of said parallel walls of said concentrator element.

Claim 19

Apparatus according to claim 12 wherein said concentrator angular acceptance is 6*.

Claim 20

Apparatus according to claim 12 wherein said concentrator element is filled with a medium having an index of refraction greater than 1 and said entrance aperture is in optical contact with a medium having an index of refraction less than that of the medium filling said concentrator.

Claim 21

Apparatus according to claim 12 further including a second concentrator element geometrically similar to said concentrator element and disposesd between said concentrator element and said solar energy trap contiguous to said concentrator element exit aperture, the transverse cross-sectional distance separating opposing upper edges of said second concentrator element reflecting surfaces being identical to the transverse cross-sectional distance separating opposing lower edges of said concentrator element reflecting surfaces.

Claim 22

Apparatus according to claim 18 wherein said concentrator element is filled with a medium having a given index of refraction, said second concentrator element is filled with a medium having an index of refraction greater than that of the medium filling said concentrator element, and the angular acceptance for energy rays entering said second concentrator element is the inverse sine of the ratio of the index of refraction of the medium filling said concentrator element to the index of refraction of the medium filling said second concentrator element.

Claim 23

Solar energy concentration apparatus, said apparatus comprising: a concentrator element including, a pair of longitudinally extending substantially parallel walls having opposing inner solar energy reflecting surfaces, one of said reflecting surfaces being substsantially concave and sloped inwardly from an upper edge at an energy entrance aperture to a lower edge at an energy exit aperture and the other of said reflecting surfaces extending linearly from an upper edge at said energy entrance aperture to a lower edge at said energy exit aperture, said exit aperture being of lesser transverse cross-sectional dimension than said entrance aperture, a field of acceptance for solar energy and an angular acceptance within said field, determinable at said entrance aperture, an optical axis determinable by reference to distances separating respective opposing upper and lower reflecting surface edges, the profile curve of said sloping reflective surface being a parabola having as its parabolic focus a point, in the plane of said exit aperture, spaced away from said linearly extending reflective surface lower edge a distance equal to said exit aperture transverse cross-sectional dimension and as its parabolic axis a line forming an angle with said optical axis of said concentrator numerically equal to said angular acceptance, the dimensions of said apertures and the slope of said sloping reflecting surface being such that the field of acceptance of said concentrator is capable of including an arc segment of coordinates equal to those described by the apparent motion of the sun within at least one hour before and after reaching zenith point at solstice; and, a solar energy trap at said exit aperture.

Claim 24

Solar energy concentration apparatus, said apparatus comprising: a concentrator element including, a pair of longitudinally extending substantially parallel walls having opposing inner solar energy reflecting surfaces, one of said reflecting surfaces being substsantially concave and sloped inwardly from an upper edge at an energy entrance aperture to a lower edge at an energy exit aperture and the other of said reflecting surfaces extending linearly from an upper edge at said energy entrance aperture to a lower edge at said energy exit aperture, said exit aperture being of lesser transverse cross-sectional dimension than said entrance aperture, a field of acceptance for solar energy and an angular acceptance within said field, determinable at said entrance aperture, an optical axis determinable by reference to distances separating respective opposing upper and lower reflecting surface edges, the profile curve of said sloping reflective surface being a parabola having as its parabolic focus a point, in the plane of said exit aperture, spaced away from said linearly extending reflective surface lower edge a distance equal to said exit aperture transverse cross-sectional dimension and as its parabolic axis a line forming an angle with said optical axis of said concentrator numerically equal to said angular acceptance, the dimensions of said apertures and the slope of said sloping reflecting surface being such that the field of acceptance of said concentrator is capable of including an arc segment of coordinates equal to those described by the apparent motion of the sun within at least one hour before and after reaching zenith point at solstice; and, a solar energy trap at said exit aperture.

Claim 25

Apparatus according to claim 20 wherein the height of said concentrator elemenet is no more than the sum of the transverse cross-sectional dimensions of said entrance and exit apertures multiplied by the cotangent of said concentrator angular acceptance.

Claim 26

Apparatus according to claim 20 wherein the ratio of the transverse cross-sectional dimensions of said concentrator element exit aperture to said entrance aperture is no less than the sine of said angular acceptance.

Claim 27

Apparatus according to claim 20 further including solar energy reflective end wall means at the ends of said parallel walls of said concentrator element.

Claim 28

Apparatus according to claIm 20 wherein said concentrator angular acceptance is 6*.