Fractal Light Concentrator

Abstract

A device for concentrating parallel light into parallel light of smaller cross-section and higher fluence, characterized in that it comprises a combination of at least two reflective surfaces having at least one parabolic profile in the same direction (11). Figure for the abstract: Figure 1

Description

Title of the invention: FRACTAL LIGHT CONCENTRATOR Technical field of the invention

[0001] Parallel light is of major importance in many fields, including energy, science, and industry.

[0002] Through this invention, we propose a new light concentration system using a three-dimensional repetition (Fractal) Fig-1 of a parabolic element 1, 2, 3, 4 allowing the light captured over a large surface to be concentrated into a parallel light beam of small cross-section on the order of m2 to cm2. Technical background

[0003] There are many light concentration devices using either transmission devices such as optical lenses, which can reach sizes on the order of m2 such as Fresnel lenses, or reflection devices such as concave spherical, parabolic mirrors, which can reach sizes greater than m2.

[0004] However, these devices produce a convergent beam at a given point or in a restricted useful area, prohibiting concentrated transport of light over a random distance while allowing concentrated deposition at a point of variable distance chosen.

[0005] It is always possible to produce a more or less parallel beam of light using combinations of converging and diverging lenses from a light source. However, the problem arises of capturing and producing light to obtain significant fluences exceeding one kW, the problem becoming extremely complex or even insoluble for fluences on the order of 10 kW or MW.

[0006] In addition to these problems of capture and production, there is the problem of degradation of materials traversed or reflecting significant fluences.

[0007] Alternatives are increasingly used by injecting light into optical fibers to concentrate and transmit it over a distance, and then deliver it to a point at a chosen distance by adding a convergence system at the fiber's output. However, the problem arises of the fluence that the optical fiber material can withstand; the energy deposition site depends on the fiber's flexibility and length. Meanwhile, fluence attenuation increases significantly with fiber length. Summary of the invention

[0008] Through a reflection device using a parabolic element in a three-dimensional, fractal, repeating model, in which the parabolic element undergoes scaling homotheties and rotations, we propose a device for concentrating parallel light captured on a surface I between a few square centimeters and one km2, preferably between 1 m2 square and 100 square meters, into a parallel light ray with a cross-section smaller than the capture surface, said cross-section preferably being between 1 m2 and 1 cm2.

[0009] The invention relates to a device for concentrating parallel light into parallel light of smaller cross-section and higher fluence, characterized in that it comprises a combination of at least two reflective surfaces having at least one parabolic profile in the same direction, the combination comprising at least: • a first parabolic surface I carried by a parabola such that said parabolic surface is concave reflective. • a second convex reflective parabolic surface K, obtained by a homothety of factor k between -1 and -0.000000001 and of center FI corresponding to the focal length FI of the parabolic surface I, said surface K being obtained, by said homothety of factor k applying to an opposite section J of the surface I on the parabola such that J corresponds to the section captured by a solid angle formed by a beam f, of parallel light projected onto I perpendicular to the base B of the parabola supporting I, after reflection on I.

[0010] The device according to the invention may comprise one or more of the following features:

[0011] - the device comprises a combination of at least two reflective surfaces additional such as • a third surface L, with a concave reflective face such that the surface includes at least one parabolic profile, the surface includes at least one spherical profile, positioned above the second surface K, such that the direction DL of the concave section such as parabolic, spherical supporting L is perpendicular to the directions DI and DK of the parabolic section supporting the surfaces I and K. • a fourth surface M, with a reflective concave face, homothetic to L with a factor m between -1 and -0.000000001 and with center FL corresponding to the focal length of the concave section supporting L such that it is parabolic, spherical;

[0012] - the device comprises at least one flat reflective surface, possibly mobile, allowing the parallel light of smaller cross-section and higher fluence, exiting the device, to be redirected by reflection;

[0013] - the device includes at least one focusing device possibly adaptive allowing modification such as reorientation, focusing, parallel light of smaller cross-section and higher fluence, exiting the device by any combination of adaptive mirrors, non-adaptive mirrors, optical lenses;

[0014] - the parallel light projected onto the first parabolic surface I, perpendicular to the base B of the parabola, either obtained by means such as, natural light by orienting the parabola I towards the sun, exposure to artificial light, or by any combination of these means;

[0015] - a parallel light is projected onto the third surface L, perpendicular to the base of the parabola supporting L;

[0016] - the walls of reflective or mirror surfaces include channels of circulation of fluid intended to cool or thermostat reflective surfaces. Brief description of the figures

[0017] The invention will be better understood and other details, features and advantages of the invention will become apparent upon reading the following description, given by way of non-limiting example with reference to the accompanying drawings, in which:

[0018] [Fig.1]

[0019] [Fig.2]

[0020] [Fig.3]

[0021] [Fig.4]

[0022] [Fig.5]

[0023] [Fig.6] Detailed description of the invention

[0024] 1) The process consists of using a first concave surface with a parabolic profile in at least one direction I [Fig. 1 ]-1, [Fig.2]-1 which may have a large capture area size, said size being preferably between 1m2 and 100 m2, but which may be reduced to less than 1 m2 or extended to more than 1 km2.

[0025] The parabola I can be of surface whose projection is circular [Fig.2]-1 with the parabolic profile present in the directions of the circular revolution of the parabola, but preferably of surface whose projection is rectangular so as to form a cylindroparabolic surface [Fig. 1]-1 with the parabolic profile inscribed in a single direction.

[0026] The advantage of structures I having a parabolic profile inscribed in a single direction 11, such as cylindrical parabolic structures [Fig. 1]-1, lies in the fact to be able to more easily produce large structures compared to structures whose parabolic profile is inscribed in several directions such as circular projection parabolas [Fig. 1]-2, cylindrical parabolic structures offer better optimization of the useful surface both spatially and energetically.

[0027] The concave surface I [Fig. 1]-1 of the parabola [Fig.3]-5 supporting I, carrying out the reflection, is coated with a reflective material so as to form a concave mirror with a parabolic profile with a focal point defined at FI, [Fig.3]-6, such that a beam f [Fig.3]-7 of parallel light directed perpendicularly to the base B [Fig.3]-8 of the parabola supporting I converges at FI, which can be either a point in the case of a parabola with a circular projected surface [Fig.2], or a line for a cylindroparabolic parabola [Fig. 1].

[0028] 2) A parabolic element K, [Fig.1]-2, [Fig.2]-2, [Fig.3]-2, convex with profile parabolic in the at least the same direction of the parabolic profile of I, defined and arranged by a homothety, of center FI [Fig.3]-6 and of factor k between (-1 and 0), of the section J [Fig.3]-9 opposite I for the at least one parabolic direction of I and opposite to I, such that J corresponds to the section of capture of the solid angle, after the focal FI, defined by the reflection of the beam f [Fig.3]-7 of parallel light directed perpendicular to the base B of the parabola on I and reflected by the surface I.

[0029] Thus, for systems with a single parabolic direction, K will be a convex parabolic surface of the cylindroparabolic type. [Fig.1]-2, whereas for parabolic systems with circular revolution, K will have an annular shape with a parabolic cross-section [Fig.2]-2.

[0030] The convex face of element K [Fig.4]-2,[Fig.2]-2 being coated with a reflective material, such that the reflection on K of beam f [Fig.4]-7-[Fig.2]-7 after reflection on I, leads to a beam of light f [Fig.4]-10, [Fig.2]-10 parallel to f [Fig.4]-7 (same direction) but in the opposite direction, such that the fluence f is equal to:

[0031] Fluence of f. (SI / SK). r

[0032] where SI and SK are the respective surfaces of I and K and r the reflection yield defined by the reflecting material.

[0033] 3) Above element K [Fig.1]-2, [Fig.2]-2 is arranged an element L [Fig.1]-3, [Fig.2]-3 concave such as parabolic concave, spherical concave, covering the entire element K [Fig.1]-2 , [Fig.2]-2 such that the direction DL [Fig.1]-12 of the section of the concavity 12, parabolic or spherical of L is perpendicular to the directions DI and DK [Fig. 1]-11 of the parabolic sections I and K. The beam f after reflection on L, converges into a converging beam f', into a focal FL [Fig.4]-13, [Fig.2]-13.

[0034] such that the fluence f' = Fluence of f . (SK / SL). r

[0035] where SK and SL are the respective surfaces of K and L and r is the reflection efficiency defined by the reflective material.

[0036] In the case of a circular geometry for the parabola I [Fig.2]-1, the elements K and L can adopt an annular geometry, having a hole in the center [Fig.2]-2,3. In this particular case the geometry of the element L [Fig.2]-3 can be spherical instead of parabolic.

[0037] 4) An element M [Fig.1]-4, [Fig.2]-4, [Fig.5]-2, defined by a homothety with center FL and with a factor l between (-1 and 0), is placed such that M is a concave parabolic or spherical element defined by L and having a reflective material on the concave face so that the beam f' after the focal point FL is reflected by M as a beam f" [Fig.2]-14, [Fig.5]-14 of parallel light such that:

[0038] the fluence f" = Fluence of f'. (SL / SM). r

[0039] where SL and SM are the respective surfaces of L and M and r the yield of the reflection defined by the material.

[0040] 5) In a preferred embodiment, a plane mirror [Fig.2]-15, [Fig.5]-15, A mirror with a chosen angle is placed in the path of the parallel beam f" to deflect its trajectory by plane reflection towards a chosen point. In some embodiments, the plane mirror can be movable so as to control the direction of reflection by changing the position of the reflecting plane mirror.

[0041] 7) In certain embodiments the plane mirror [Fig.2]-15, [Fig.5]-15 can be replaced by a concave mirror to focus the reflection at a given point

[0042] 8) In certain embodiments the concave mirror may have variable focal length by modification of the radius of curvature of said mirror, in order to define the focal point.

[0043] 9) In certain particular embodiments of transmission devices Optical devices such as transparent optical lenses, magnetic optical lenses formed by a magnetic or electric field, and thermal optical lenses formed by the optical distortion of a gas under the effect of heat, can be placed on the optical paths of f', f', f', f' in order to modify the paths of the optical beams.

[0044] 10) In a particular embodiment, the walls of the mirrors and elements reflective [Fig.5]-16 will include cooling fluid circulation channels [Fig.5]-17 in order to dissipate energy not reflected by the mirrors or to thermostat the reflective surfaces.

[0045] In a particular embodiment, the wall of the mirrors and reflective elements may be made of polycarbonate, polyamide, Teflon, alumina, aluminum, steel or carbon fiber, fiberglass, etc.

[0046] 11) In a particular embodiment, the light source illuminating the parabola I will come from solar radiation [Fig.6]-18, a device orienting the parabola towards the sun allowing to follow the course of the sun can be used.

[0047] In other embodiments the light source will be artificial [Fig.6]-19 such as a light projector, laser light, LED, diode, or any artificial light source or combination of natural and artificial light source.

[0048] 12) In certain embodiments the light source or combinations of light sources will be supplemented or substituted by a light source projected onto the concave face of element L by passing between elements K or through a hollow element K.

[0049] Legends for all figures

[0050] 1)1 first concave parabolic surface

[0051] 2) K second convex parabolic surface defined by the homothety with factor k with k between (-1 and 0) and center FI, of the section J of the face of the parabola opposite to I.

[0052] 3) The concave parabolic element, covering the entire element K such that the direction of the section of the parabola L is perpendicular to the section of the parabolas I and K.

[0053] 4) M homothety with center FL and factor l between (-1 and 0) of the ement L.

[0054] 5) Parabola supporting the concave reflective surface I and corresponding surface J to the capture of solid angle J after reflection on I.

[0055] 6) FI Focal length of element I

[0056] 7) f parallel beam of light directed perpendicularly to the base B of the parabola supporting I and J

[0057] 8) B base of the parabola supporting I and J

[0058] 9) J solid angle capture section of a parallel beam of light directed perpendicular to the base B of the parabola supporting I and J, reflected by the surface I.

[0059] 10) f concentrated beam of light parallel to f (same direction) but in the direction reverse

[0060] 11) DK,DI: direction of the section of the parabola K and I

[0061] 12) DL: direction of the section of the parabola L

[0062] 13) FL, focal point of the parabola M

[0063] 14) f' beam after the focal point FL reflected by M

[0064] 15) reflective elements or plane mirror

[0065] 16) mirror or reflective elements

[0066] 17) cooling or thermostatic fluid circulation channels

[0067] 18) solar light source

[0068] 19) artificial light source

Claims

Demands

1. A device for concentrating a parallel light into a parallel light of smaller cross-section and higher fluence, characterized in that it comprises a combination of at least two reflective surfaces having at least one parabolic profile in the same direction (11), the combination comprising at least: - a first parabolic surface 1(1) carried by a parabola (5) such that said parabolic surface is concave and reflective, - a second convex reflective parabolic surface K (2), obtained by a homothety with factor k between -1 and -0.000000001 and center FI (6) corresponding to the focal length FI of the parabolic surface I, said surface K being obtained, by said homothety with factor k applied to an opposite cross-section J (9) of the surface I on the parabola (5) such that J corresponds to the cross-section captured by a solid angle formed by a beam f (7),of parallel light projected onto I perpendicularly to the base B (8) of the parabola (5) supporting I, after reflection on I.,

2. Device according to claim 1, characterized in that it comprises a combination of at least two additional reflective surfaces such that: - a third surface L (3), of concave reflective face such as surface comprising at least one parabolic profile, surface comprising at least one spherical profile, positioned above the second surface K (2), such that a direction DL of the concave section such as parabolic, spherical supporting L is perpendicular to directions DI and DK of the parabolic section supporting surfaces I and K, - a fourth surface M (4), of concave reflective face, homothetic to L with factor m between -1 and -0.000000001 and center FL corresponding to the focal length of the concave section supporting L such as parabolic, spherical.

3. Device according to claim 1 and 2, characterized in that it comprises at least one flat reflective surface (15), optionally movable, allowing the parallel light of smallest cross-section and highest fluence, exiting the device, to be reoriented by reflection.

4. Device according to any one of claims 1 to 3, characterized in that it comprises at least one focusing device possibly adaptive for modifying such as reorienting, focusing, the parallel light of smallest cross-section and highest fluence, exiting the device by any combination of adaptive mirrors, non-adaptive, optical lenses.

5. Device according to any one of claims 1 to 4, characterized in that the parallel light projected onto the first parabolic surface I, perpendicular to the base B of the parabola (5), is obtained by means such as natural light by orientation of the parabola I towards the sun (Fig6-a), exposure to artificial light (Fig6-b), or by any combination of these means (Fig6).

6. Device according to any one of claims 1 to 5, characterized in that a parallel light is projected onto the third surface L (Fig6-d), perpendicular to the base of the parabola supporting L.

7. Device according to claim 2, characterized in that the walls of the reflective or mirror surfaces comprise fluid circulation channels for cooling or thermostating the reflective surfaces.

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