KR20010094713A - Reflector structure design of radiant energy collector - Google Patents

Abstract

PURPOSE: A structure of reflector of an optical concentrator is provided to focus efficiently light energy by improving a structure of a reflective mirror. CONSTITUTION: A main reflective mirror(1,1') has a reflective face of a parabolic shape. The second reflective mirror(2,2') has the reflective face of the parabolic shape or an elliptical shape. The main reflective mirror(1,1') is formed with two reflective mirrors(1,1') which are symmetrical to each other. The second reflective mirror(2,2') is located between the reflective mirrors(1,1') of the main reflective mirror(1,1') in order to connect the reflective mirrors(1,1') with each other. An endothermic face(3) or an endothermic tube is formed in the second reflective mirror(2,2'). The second reflective mirror(2,2') is formed with two reflective mirrors(2,2'). The main reflective mirror(1,1') and the second reflective mirror(2,2') have a common focus.

Description

Reflector structure design of radiant energy collector

The present invention relates to a structure for forming a reflector in a solar energy utilizing light focusing apparatus.

In general, optical energy concentrators are applied by the merger of optical devices and energy converters, which virtually apply to all applications that convert light energy such as solar energy into thermal energy or electrical energy. Optical devices are applied to a number of devices that focus light energy, but are particularly applied to solar cell arrays such as heat collectors requiring high temperatures and power panels of satellites requiring high efficiency.

Solar energy utilization technology is well known and has been developing devices for decades, especially those that generate high temperatures and use them as power sources. The high temperature concentrators are classified into various types according to the purpose and shape to be used. The representative ones are parabolic concentrators, and two-dimensional concentrators of parabolic troughs composed of two-dimensional parabolas as shown in FIG. There is a three-dimensional concentrator that is a compound parabolic concentrator (CPC) of a dish type (Parabolic Dish) consisting of a three-dimensional parabolic as shown in FIG.

A two-dimensional focuser is generally used when the focusing ratio is less than 10, and a three-dimensional focuser is used when a higher focusing ratio is required.

Here, the light focusing ratio is defined as the ratio of the area of the opening surface (incident surface) where light enters to the area of the exit surface (heat absorbing surface) of the light of the collector.

Parabolic focusers are sensitive to errors in both two and three dimensions and require accurate sun tracking. For example, if the focusing ratio is 100, the optical efficiency of 70% or more can be obtained if the error limit of the entire parabolic focuser is within ± 1.5 °. The smaller the margin of error, the higher the accuracy of the device and the more expensive the equipment.

As described above, in general, the high temperature optical concentrator has an inherent problem such as the weight, volume, accuracy of solar tracking, and limited error limits of the optical component .

In particular, satellites have been applied as a power source, and future satellite missions require solar cell arrays that can cover 100 to 600 kW in order to meet more requirements. Power is practically impossible with flat panel devices, and therefore, the use of a light concentrator, which is a three-dimensional device, is required.

The relatively high power of such large satellites and the high currents or high voltages that occur incidentally raises the issue of the creation of more new devices than the solar cell power source devices used in existing small satellites.

That is, it is necessary to overcome various problems such as weight and volume, safe dissipation of thermal energy, and price of solar cells, which are inherent limitations in the application of the optical focusing apparatus to satellites. The device could not solve the technical problem of these satellites.

In order to solve such problems, many inventions have been invented in the related art. US Patent No. 4,003,638 (name; Radiant Energy Concentration) and US Patent No. 4,002,499 (name; Cylindrical Concentrators for Solar Energy) It is a kind.

These efforts do not basically overcome the reflecting surface structure of the conventional parabolic light concentrator shown in FIGS. 1 and 2, and do not clearly solve the above-mentioned problems of the light concentrator.

In order to solve the problems of the conventional optical focusing apparatus as described above, the present invention has been made, the technical problem to be solved by using the special optical properties of the aspherical optical curved surface of two or more different parabolic reflectors By specially combining to widen the range of error of solar tracking, it is applied to the basic device for focusing the light energy to focus solar heat on the heat absorbing surface and to generate higher temperature. By concentrating high light energy to achieve a higher practical electrical energy conversion efficiency.

That is, the optical concentrator which achieves the object of the present invention has a high focusing ratio for a given limit incident angle by arranging specially combining two sets of reflectors of parabolic surfaces, that is, one pair of main reflectors and one set of second reflectors, In order to be less sensitive to the accuracy of and to make the energy density at the endothermic or light-receiving surface substantially uniform, the reflector is a parabolic surface and tilted by the limiting incident angle to symmetrically on a certain axis. The present invention provides an optical focusing apparatus having a concentrator structure by inverting and symmetrically installing the second reflector.

Focusing machine according to the object of the present invention by changing the basic structure of the simple combination of the optical reflector and tilting the main reflector and the second reflector at a specific angle to minimize the light loss after the incident light is reflected within a given limit incident angle We want to increase the energy density and increase the energy density for a given marginal incident angle.

1 is a schematic configuration diagram of a conventional two-dimensional parabolic light concentrator

2 is a schematic configuration diagram of a conventional three-dimensional parabolic light concentrator

Figure 3 is a half cross section of the basic structure in the reflector forming structure of the optical concentrator according to the present invention

Figure 4 is a shear plane of the basic structure in the reflector forming structure of the optical concentrator according to the present invention

5 is a schematic configuration diagram of a three-dimensional focusing machine of the first embodiment according to the reflector forming structure of the present invention;

6 is a schematic configuration diagram of a two-dimensional focuser of a first embodiment according to the present invention;

7 is a half cross section of the basic structure when the second reflector according to the present invention is an ellipsoid;

8 is a shear plane of the basic structure when the second reflector according to the present invention is an ellipsoid

9 is a basic configuration when the second reflector is a parabolic plane when the reflector is tilted by a limiting incident angle in the present invention

10 is a basic configuration when the second reflector is inclined by the limit incident angle when the second reflector is an ellipsoid in the present invention

11 is a cross-sectional basic configuration of the parabolic second reflecting mirror cut parallel to the Y axis in the present invention;

12 is a comparative explanatory view of the basic principle of the conventional optical focusing machine and the basic principle of the present invention

13 is a basic model of the auxiliary reflector formed as another embodiment of the present invention

14 is a basic model view in which a glass tube accommodates a second reflector and an endothermic tube of a focuser as another embodiment of the present invention;

15 is a model view in which the glass tube accommodates the entire concentrator as another embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

1, 1 ': main reflector 2, 2': second reflector 3: endothermic surface

5: endothermic tube 6: auxiliary reflector 8: support

31, 32: glass tube 41: incident light 42: reflected light

F, F ': shared focus Φ: annular focus φ: linear focus

The reflector forming structure of the optical concentrator according to the present invention will be described in detail below with reference to the accompanying drawings.

3 and 4 are cross-sectional views showing the basic structure of the reflector according to the first embodiment in the reflector forming structure of the optical concentrator according to the present invention, and FIG. Fig. 4 shows a half cross section of Fig. 4 is an entire cross section.

In the present invention, the basic structure of the reflector according to the first embodiment is a second reflector parabolic surface and a second inverted reflection parabolic surface, as shown in FIGS. 3 and 4. Is composed of a reflecting mirror (2, 2 ') and a light receiving surface (3). The light receiving surface 3 may be replaced by a plane, a sphere, a cylinder or another form.

As shown in FIGS. 3 and 4, the reflector according to the first embodiment of the optical concentrator according to the present invention, when viewed in cross section, has two main mirrors that are symmetrical with each other in a parabolic plane that forms the outermost part. A heat absorbing surface 3 formed of two reflecting mirrors 1, 1 ', and connecting the two reflecting mirrors at the bottom side between a pair of main reflecting mirrors 1, 1' consisting of two reflecting mirrors, and a heat absorbing surface 3 The second reflector (2,2 ') consisting of two reflectors is formed in an inverted shape in the center of the upper surface of the lens. The two reflectors of the second reflector (2,2') face each other. It is formed so as to face the two main reflectors (1, 1 ') and the reflecting surface facing each other.

In the basic structure according to the first embodiment of the present invention, the focal points of the main reflector 1 and the second reflector 2 are shared at the focus F, and the axis SS 'parallel to the x axis of the spatial coordinate system and passing through the focal F is defined. Form to share. The lower end point of the inverted parabolic surface of the second reflecting mirror 2 coincides with the geometric midpoint G of the heat absorbing surface 3, and the geometric upper point E of the second reflecting mirror 2 is the heat absorbing surface ( It coincides with the geometric one-sided end point H of 3). The point E of the second reflecting mirrors 2, 2 '(2) is the ray 42 in which the incident light beam 41 coming in parallel to the x-axis of the spatial coordinates is reflected at the upper point N of the main reflecting mirror 1; And the rays 43 coming in toward one end H of the heat absorbing surface 3 meet each other.

It is formed as shown in FIG. 4 when rotated 180 degrees about LL 'which is the axis of symmetry of the reflector of the optical concentrator according to the first embodiment of the present invention, which coincides with the x-axis of the spatial coordinate system. Therefore, the optical concentrator according to the first embodiment of the present invention constitutes a reflector by two main reflectors 1 and 1 'and two second reflectors 2 and 2' which are formed symmetrically, and thus, two focal points F , F ') is formed. The lower ends of the two second reflectors 2, 2 ′ are joined together and the joined ends lie at the geometric center G of the heat absorbing surface 3, and the lower points of the two main reflectors 1, 1 ′. The lower part has a structure erected coincident with both end points H and H ' of the endothermic surface 3, respectively. Full rotation ( 180 ° rotation ) about the reflector central axis LL 'of the optical concentrator becomes a three-dimensional concentrator according to the first embodiment having a reflector structure according to the present invention as shown in FIG. Extending the cross section in the longitudinal (y-axis) direction results in a two-dimensional concentrator according to the first embodiment of the trough shape having the reflector structure of the present invention as shown in FIG.

(Axis LL 'is parallel to the x-axis of the spatial coordinate system, i.e. a vertical line through a point on line HGH' can be chosen). The lower end points of the two second reflecting mirrors 2, 2 'may overlap each other on the heat absorbing surface 3 or may be spaced apart from the heat absorbing surface 3. In this case, in the case of overlapping, the vertex G where the two second reflecting mirrors meet is spaced above the lower end of the main reflecting mirrors 1, 1 '.

The latter (when the second reflecting mirror overlaps each other) is useful when a cylindrical heat absorber is used as the heat absorbing surface 3. In the case of a two-dimensional focuser (FIG. 6), the focal points F and F 'have a linear focus φ and this region becomes hot, and in the case of a three-dimensional focuser (FIG. 5), the focus F is an annular focus Φ and this linear or The light beam is focused at the annular focal point φ, Φ and becomes high temperature. In the optical concentrator having the reflector structure of the first embodiment according to the present invention, the incident light propagates to the main reflector 1,1 'and the heat absorbing surface 3 by the width EE' by the second reflector 2,2 '. Since the light is blocked (see Figs. 5 and 6), the loss of light energy by the area is caused. This light blocking area is referred to as a disturbing area.

All light rays that enter the incident surface (opening surface) of the light collimator in parallel with the axis LL 'are once reflected by the main reflectors 1, 1' and then converge at the focal points F and F ', and once again the second reflector 2, 2 ') and then proceeds in the incident direction parallel to the axis to reach the heat absorbing surface 3. At this time, the energy reaching the endothermic surface 3 becomes an energy of high density in proportion to the focusing ratio of the focusing machine and is evenly distributed.

FIG. 7 shows a half cross section according to the second embodiment as another embodiment of the reflector structure of the optical concentrator according to the present invention, and FIG. 8 shows the entire cross section.

The basic structure of the second embodiment according to the present invention is the main reflecting surfaces 1, 1, which are parabolic surfaces sharing the axis SS ', and the second reflecting surface 4, which is an elliptical surface, and the heat absorbing surface 3, as shown in FIG. It consists of. The heat absorbing surface (or light receiving surface) 3 may be replaced by a flat, spherical, cylindrical or other shape.

The focal point of the paraboloidal main reflecting surface 1 and the first focal point of the ellipsoid in this structure share one another in F and also share the axis SS 'parallel to the x coordinate axis of the spatial coordinate system and passing through the shared focal point F. The second focal point F ′ of the ellipsoidal surface 4 is on the axis SS ′ of the ellipsoidal surface 4 and lies substantially below the bottom surface of the heat absorbing surface 3.

The second focal point F ″ is a focal point formed by an optical characteristic by an ellipsoidal geometry.

In this regard, the second embodiment is different from the first embodiment, but the second embodiment has two focal points formed unlike the first embodiment.

The lower point of the second reflecting surface 4 coincides with the geometric midpoint G of the heat absorbing surface 3, and the upper point coincides with the point E. Point E is the point where the incident light beam 41 coming in parallel to the axis meets the light beam 42 reflected at the disadvantage N of the main reflector 1 and the light beam coming toward the disadvantage H of the heat absorbing surface 3. to be.

The complete cross-sectional view of the optical concentrator according to the second embodiment of the present invention is the half-section of [FIG. 7] of FIG. 7 when it is rotated 180 degrees about the symmetry axis LL 'parallel to the x-axis of the spatial coordinate system. Is formed in the shape of [Fig. 8]. Therefore, the light concentrator according to the second embodiment is composed of two main reflectors 1 and 1 'and two second reflectors 4 and 4' which are symmetrically formed and the reflecting surface and four focal points F , F ', F', F '). The two second focal points lie outside the collector, i.e., below the bottom of the heat absorbing surface 3. The lower points of the two second reflectors are combined and at the same time lie at the geometric center G of the heat absorbing surface 3, and the lower points of the two main reflectors 1, 1 ′ are at the edges of the heat absorbing surface 3. It is touching. Full rotation around the axis LL 'of the bone reflector parallel to the x-axis of the spatial coordinate system forms a three-dimensional focuser similar to [Fig. 5], and when the main section is extended in the length (y-axis) direction, [Fig. It is formed by a similar trough two-dimensional integrator. (The perspective view of the three-dimensional integrator and the two-dimensional integrator according to the second embodiment of the present invention is omitted.)

In the present embodiment, in the case of the second reflecting mirror having the reflecting surface of the ellipsoidal surface, all the light rays that enter the incident surface (opening surface) of the light concentrator in parallel with the central axis LL 'of the concentrator are the main reflecting surfaces (1, 1'). Is reflected once at the focal points F and F ', and once again reflected at the second reflectors 2, 2' and then proceeds to the second focal points F ″ and F ″ of the second reflecting surface, 2 ') or light receiving surface. At this time, the energy reaching the heat absorbing surface 3 or the light receiving surface can obtain energy of high density in proportion to the focusing ratio of the focusing machine compared to the second reflecting mirror of the parabolic surface.

In particular, the present embodiment is useful when a hole is formed in the center of the light receiving surface, such as the case where the heat absorbing surface 3, which is the light receiving surface, has a donor shape.

As another embodiment of the present invention, in Fig. 3, the main reflective surface 1, 1 'is rotated in the counterclockwise direction by the limit incident angle θc around the shared focal point F of the axis SS' of the main reflective surface 1, 1 '. Rotate with (See [Figure 9]). In this case, it becomes a composite paraboloid, and the characteristics of the parabolic surface are based on the light tracking results, and the light coming from the angle within the limit incident angle θc is reflected by the main reflectors 1, 1 'and then the second reflectors 2, 2' All or some reach the endothermic surface directly.

The light rays reaching the second reflectors 2 and 2 'both reach the heat absorbing surface 3 or partially return out after reflection depending on the structure and characteristics of the second reflectors 2 and 2'. In the latter case, the second reflecting mirror 2 can be prevented or minimized by reclining clockwise by an angle θe. If the size of the heat absorbing surface is fixed, the focal point or eccentricity (in the case of an ellipsoid) of the second reflecting mirrors 2 and 2 'is adjusted through tracking analysis of the optical path to adjust the lower points of the second reflecting mirrors 2 and 2'. It should be located at the geometric center of the heat absorbing surface (3). In addition, the energy distribution on the heat absorbing surface 3 should be as uniform as possible (see FIG. 9 and FIG. 10).

Rotation of the main reflectors 1, 1 'reduces the width or straightness of the incidence plane, reducing the focusing ratio of the focuser, which extends the end points N, M of the main reflector 1 until the same focusing ratio. You can adjust the rain by raising it.

Hereinafter, the optical characteristics of the reflector in the reflector structure of the optical concentrator according to the present invention will be described in more detail.

In the integrator according to the present invention, the basic structure of the first reflecting mirrors 1 and 1 'has a parabolic surface MGN as a reflecting surface as shown in FIG. Focus F lies on axis VF. Light rays coming parallel to this axis are reflected once and then converge at focal point F. In contrast, the light emitted from the focal point reflects off the parabola and then travels parallel to the axis. This reflection curved surface is expressed by the following equation with respect to the coordinate system origin O shown in FIG.

z ² = 4f _p (x + f _p ) (1)

Where f _p is the focal length and is determined by the following relationship by the focal ratio of the device and the area of the endothermic or light-receiving surface.

f _p = (R / 2) C (two-dimensional) (2)

f _p = (R / 2) √C (three-dimensional) (3)

C is the focal ratio of the integrator, and R is the radius or half width of the heat absorbing surface 3.

The basic structure of the second reflectors 2, 2 'of the present integrator has the same parabolic surface as the main reflectors 1, 1' or the focal length is different and the reflecting surfaces are located upside down. The parabola seen from the coordinate system of FIG. 11 is represented by the following formula.

z ² = 4f _ps (x + f _ps ) (4)

Where f _ps is the focal length of the second reflector and is determined according to the size of the main reflector and the heat absorbing surface 3.

In the case of using an ellipse for the second reflecting mirrors 2, 2 'of the collector, the coordinate system shown in FIG. 12 is expressed by the following equation.

b ² (x + f _h ) ² -a ² z ² = a ² b ² (5)

Where f _h is the focal length, a (= f _h / e) is the major axis, b (= a√ (1-e ² )) is the short axis, and e (= √ (1-b ² / a ² )) is Eccentricity. The eccentricity determines the distance between the focal points and at the same time determines the blockage area of the focuser.

When the second reflectors 2 and 2 'use a curved surface represented by a general polynomial, the curved surface is generally expressed by the following expression.

x = ∑a _n z ⁿ

= a ₀ + a ₁ z + a ₂ z ² + .... + a _n z ⁿ (6)

Where a _n is a coefficient to be determined according to the characteristics of the surface, and n is 0 or a non-zero general power.

For example, if n = 1, then the surface is expressed as x = a ₀ + a ₁ z, which is a straight line passing through the point whose slope is a ₁ and is a ₀ away from the origin on the x axis. In this case, it becomes a V-shaped or hat-shaped curved surface according to the sign of a ₁ .

Hereinafter, a mathematical expression of the focusing device having the reflector structure of the light focusing device according to the present invention will be described.

(a) the second reflecting surfaces 2, 2 'are parabolic

If the radius or half-width (R) of the focusing ratio (C) and the heat absorbing side 3 of the house shorthand given, the main reflecting mirror (1, 1 ') in the coordinate system shown in FIG. 3 by angle (-θ _c) When tilting in the counterclockwise direction and tilting the second reflectors 2, 2 'clockwise by (+ θ _e ), the mathematical expression of each variable of the focusing machine is as follows (see [FIGS. 9, 10]).

Geometric focusing ratio (C):

C = (x _N -x _E ) / R (for two-dimensional focuser) (7)

C = (x _N ² -x _E ² ) / R ² (for 3-D Integrator) (8)

Relation of main reflector (1, 1 '):

sin ² θ _c z ² -2cosθ _c (2f _p + xsinθ _c ) z + x ² cos ² θ _c -4f _p (f _p + xsinθ _c ) = 0

z = cosθ _c (2f _p + xsinθ _c ) / sin ² θ _c * { 1- [ 1-tanθ _c [x ² cos ² θ _c -4f _p (f _p + xsinθ _c )] / (2f _p + xsinθ _c ) ² ] ^1/2 } (9)

Focal length of the main reflector:

f _p = (-(x _N + 2R) / (2sinθ _c ) / 2-A _o + B _o ) / 2 (10)

B _o = { 3 [(x _N + 2R) / (2sinθ _c )] ² / 4-R _o ² -2 {(1 + sin ² θ _c ) x _N + R} R / sin ² θ _c )

-(4 (x _N + 2R) / (2sinθ _c ) * {(1 + sin ² θ _c ) x _N + R} R / sin ² θ _c -8 (x _N + 2R) / (2sinθ _c )

-[(x _N + 2R) / (2sinθ _c )] ³ ) / (4A _o ) } ^1/2

A _o = { (a / 2) ² -{(1 + sin ² θ _c ) x _N + R} R / sinθ _c

-2 {√ (-α / 3)} * cos (φ / 3) + [(1 + sin ² θ _c ) x _N + R] R / sin ² θ _c / 3 } ^1/2

φ = cos ^-1 [{(β / 2) ² / (α / 3) ³ }] ^1/2

α = { 3 [(x _N + 2R) / (2sinθ _c ) * R ² x _N / sinθ _c +4 (Rx _N / (2tanθ _c ) ² ]

-[{(1 + sin ² θ _c ) x _N + R} R / sin ² θ _c ] ² } / 3

β = { 2 [-{(1 + sin ² θ _c ) x _N + R} R / sin ² θ _c ] ³ } +9 [{(1 + sin ² θ _c ) x _N + R} R / sinθ _c ] *

[(x _N + 2R) / (2sinθ _c ) * R ² x _N / sinθ _c +4 (Rx _N / (2tanθ _c ) ² ] + 27λ } / 27

λ =-(x _N + 2R) / (2sinθ _c ) ² * {-(Rx _N / (2tanθ _c ) ² }

+4 [{(1 + sin ² θ _c ) x _N + R} R / sin ² θ _c ] * [-(Rx _N / (2tanθ _c ) ² ]-{R ² x _N / sinθ _c } ²

x _N = (√C-1) R (for three dimensions) (11)

x _N = (C-1) R (for two dimensions) (12)

Relation of the second reflecting mirror:

z = { -{(cosθ _e -xcosθ _e sinθ _e / 2f _e ) / 2} + [ {(cosθ _e -xcosθ _e sinθ _e / 2f _e ) / 2} ²

-(sin ² θ _e / 4f _e ) * (xsinθ _e -f _e + x ² cos ² θ _e / 4f _e ) ] ^1/2 } / (sin ² θ _e / 4f _e ) (13)

Focal length of the second reflector:

f _e = {-(R + fpsinθc) sinθe-fpcosθccosθe + {[-(R + f _p sinθ _c ) cosθ _e-

f _p cosθ _c sinθ _e ] ² + [-(R + f _p sinθ _c ) sinθ _e -f _p cosθ _c cosθ _e ] ² } ^1/2 } / 2 (14)

Aperture width (D):

D = 2 {x _N + (Rx _Q )} (15)

x _Q = f _p sinθ _c

Injector Depth (H):

H = z _N + f _p cosθ _c (16)

Width of breaking area (D _B ):

D _B = 2 {x _E + (Rf _e sinθ _c )} (17)

x _E = { -(sinθ _e + m * cosθ _e ) + { [(sinθ _e + m * cosθ _e )] ²

_{+ [{cosθ e -m * sinθ} e) 2/4]} 1/2} / [{cosθ e -m * sinθ e) 2 / (4f e)] (18)

m = [(-R + f _e cosθ _e ) sinθ _e -f _e cosθ _e cosθ _e ] / [(-R + f _e sinθ _e ) cosθ _e -f _e cosθ _e sinθ _e ] (19)

Height (h) of the secondary reflecting surface:

h = f _p + 2f _e (1-cosθ _e ) / sin ² θ _e (20)

When the main reflector and the second reflecting surface are not inclined, that is, when θ _c = 0 and θ _e = 0, the relation of the integrator is as follows.

D = 2 (R + x _N ) (21)

f _p = x _N / [2 (1 + x _N / R) ^1/2 ] (22)

H = x _N ² / (4f _p ) (23)

f _e = -f _p {1- [1+ (R / f _p ) ² ] ^1/2 } (24)

D _B = 2 (R + 4f _e ² / R) (25)

h = f _p + f _e (26)

(b) the second reflecting surface (2, 2 ') is an ellipsoid

The process of finding a relation for a variable is similar to that of (a). The main reflecting surface is the same as the relational expression (1-14). The basic relation for the second elliptic reflecting surface is as follows.

Relation of ellipse tilted clockwise at angle θ _e :

b ² (xcosθ _e -zsinθ _e ) ² -a ² (xsinθ _e + zcosθ _e ) ² = a ² b ² (27)

Focal length: f _e = (-a / 2-R _o + E _o ) / 2 (28)

E _o = (3a ² / 4-R _o ² -2b)-[4ab-8c-a ³ ] / (4R _o )} ^1/2

R _o = {(a / 2) ² -b + y _o } ^1/2

y _o = 2 (-α '/ 3) ^1/2 cos (φ / 3)-p / 3

φ = cos ^-1 [(β '/ 2) ² / (-α' / 3) ³ ]

α '= (3q-p ² ) / 3

β '= (2p ³ -9pq + 27r)

p = -b

q = ac-4d

r = -a ² d + 4bd-c ²

a = 2γ / δ

b = (k ² δ ² -Cδ ² + 2Bβδ-Aβ ² ) / k ² δ ²

c = (-2 γδ C + 2B (αδ + βγ) -2Aαβ) / k ² δ ²

d = (-Cγ ² + 2Bαγ-Aα ² ) / k ² δ ²

α = -Rsinθ _e

β = [(1-e) cosθ _e sinθ _e- (1-e) cos ² θ _e ] / e

γ = -Rcosθ _e

δ = [(1-e) cosθ _e sinθ _e + (1-e) cosθ _e sinθ _e ] / e

A = [(1-e ² ) sin ² θ _e -cos ² θ _e ]

B = -e ² cosθ _e sinθ _e

C = [(1-e ² ) cos ² θ _e -sin ² θ _e ]

k = [(1-e ² ) / {e ² * (Rf _p cosθ _c )}]

Eccentricity: e = [1+ (b / a) ² ] ^1/2 (29)

Relation of line GN: z = mx 30

m = [{-R + (af _e ) cosθ _e } sinθ _e- (af _e ) cosθ _e cosθ _e ]

/ [(-R + (af _e ) sinθ _e ) cosθ _e + (af _e ) cosθ _e sinθ _e ] (31)

Given the value of the variable eccentricity in relations (27) to (31), the relation for each variable of the collector as in the case of (a) is a function of the focusing ratio (C) and the half-width (R) of the endothermic surface (3). Is obtained.

The basic principle of the light focusing according to the present invention by the structure of the reflector as described above is superior in comparison with the light focusing principle of the conventional composite parabolic light collector. Existing The basic principle of the light focus of the compound parabolic collector is the angle?_cAs long as the focus F_pTilt counterclockwise around. The focal point of the opposite symmetrical reflecting surface is F_p'Located on the endothermic surface diameter or width F_pF_pIs configured to match ' The characteristic of the composite paraboloid is that the focusing ratio (C) is C = 1 / sinθ_c(If two-dimensional), or C = 1 / sin²θ_c(In three dimensions), ± θ_cAll light rays incident at an angle within the heat absorbing surface F_pF_p'Reach.

In the present invention, the incident surface BA is wider than the incident surface BC of the basic CPC with respect to the size of the same endothermic surface 3 when the main reflective surfaces 1, 1 'are inclined at the same angle θ _c . In the concentrator of the present invention, there is a loss of energy as much as the blocking area, but since the total incident surface area is larger than the blocking area, more energy reaches the endothermic surface than in the conventional case.

13, 14 and 15 are still other embodiments of a two-dimensional focusing apparatus having a reflector structure of an optical focusing apparatus according to the present invention. It is an application embodiment applicable to the embodiment.

The first application embodiment shown in FIG. 13 is composed of a main reflector 1, a second reflector 2, a cylindrical heat absorbing tube 3, and an auxiliary reflector 6, which is different from the above-described embodiment. It has a point where the surface 3 is made into the cylindrical heat absorbing tube 5, and the auxiliary reflector 6 which sawtooth-connected to connect the lower end of the main reflectors 1 and 1, and was bent in a semi-spherical shape is provided. .

In this application embodiment the main reflectors 1, 1 focal point F (F ') share the focus of the second reflectors 2, 2, and the main reflectors 1, 1 are counterclockwise by an angle θ _c . The second reflecting mirrors 2 and 2 are inclined clockwise by θ _e . At this time, θ _c becomes the marginal incident angle and θ _e is determined according to the ray tracing result. Since the auxiliary reflector 6 is spaced apart when the reflector device of the collector and the heat absorber should be separated from each other in structure, the light does not enter parallel to the axis of the main reflector 1, 1 'such as the light beam JP. If it does not reach 5) it is a device that is reflected by the secondary reflector 6 to reach the heat absorbing tube (5). In the structure of the auxiliary reflector 6, a plurality of teeth are arranged in a circle, and one tooth may be used. The number of teeth may be formed differently according to the distance between the heat absorbing tube 5 and the auxiliary reflecting mirror 6. The tooth spacing may fall by the radius of the maximum heat absorbing tube (5). A support 8 for supporting the auxiliary reflector 6 is connected to the lower part of the main reflectors 1, 1 '.

14 shows a heat absorbing tube 5 by inserting the heat absorbing tube 5 and the second reflecting mirrors 2 and 2 'into the cylindrical glass tube 31 of the apparatus of the first application embodiment. It is a device not only to reduce the loss of radiant heat generated from the surroundings, but also to minimize the pollution caused by the external environment and the invasion caused by the wind.

In the third application embodiment shown in FIG. 15, the entire concentrator is inserted into the glass tube 32 for the same purpose as the second application embodiment shown in FIG. FIG. 15 is more efficient and expensive than this FIG. 14 for this purpose.

Since the area of the entire incident surface is larger than the blocking area, a greater amount of energy reaches the endothermic surface 3.

The present invention can adjust the incidence limit angle according to the inclination angle of the main reflector for a given focusing ratio and at the same time adjust the inclination angle of the second reflector to minimize the outgoing light after reflection to improve the efficiency of the integrator much Can also reduce the weight and size. For the same limit incident angle, the focal ratio increases with the increase of the opening surface than the conventional compound parabolic concentrator (CPC), so that the energy density can be further increased for the given limit incident angle.

The present invention is capable of generating the required medium and high temperatures, and unlike a dish-shaped (three-dimensional) or trough-shaped (two-dimensional) integrator, which uses only a pair of reflectors as a conduit with a special combination of aspherical optical reflectors, 2 by reflector Since the light path can be collected in the lower part of the collector, the endothermic device can be located in the lower part of the collector, which alleviates the limitations of problems such as weight, volume, and work space of the heat absorber, and uses only a pair of reflectors. Unlike the (three-dimensional) or trough-shaped (two-dimensional) focuser, the energy density focused on the heat absorbing tube or the light receiving surface can be increased for the same limit incident angle.

The tolerance of the angle of incidence is much higher than that of a similar device consisting of a general spherical surface or a dish or trough shaped concentrator consisting of only a parabolic surface, and thus the optical performance of the device is much improved, and at the same time, more uniform energy is distributed on the heat absorbing surface or the light receiving surface. As a result, the efficiency of the device can be increased, and the margin of error in manufacturing and solar tracking can be widened.

The path of focused light energy travels in the same direction as the path of incident light energy, so that the position of the heat absorber or light receiver is located under the optical concentrator, minimizing the blocking of the incident light energy, and also The center of gravity is located below the center of the whole device to reduce the errors of mechanical movement, facilitate the installation of endothermic or light-receiving devices, facilitate the manufacture of solar tracking and optical components, and reduce the size and weight of the device. To achieve and simplify the optical concentrator device and the whole device.

Claims (11)

It is composed of a main reflector (1, 1 ') whose reflecting surface is a parabolic surface, a second reflecting mirror (2, 2') which is an inverted parabolic surface or an ellipsoidal surface and an endothermic surface (3) or a heat absorbing tube (5). The main reflectors 1,1 'are formed of two reflectors 1,1' which are symmetrical with each other in the outermost parabolic plane, and are arranged at the bottom between the main reflectors 1,1 'consisting of two reflectors. A heat absorbing surface 3 or a heat absorbing tube 5 is formed to connect the reflecting mirrors 1 and 1 ', and is smaller in the shape of inverted in the center of the upper surface of the heat absorbing surface 3 or the heat absorbing tube 5. A second reflector (2, 2 ') consisting of two reflectors of parabolic or ellipsoidal surfaces is formed. The two reflectors of the second reflector (2, 2') are formed with their backs against each other to form two main reflectors (1,1 '). Reflector formation structure of the optical concentrator formed to face each other and the reflecting surfaces face each other 2. The main reflectors 1, 1 according to claim 1, wherein the main reflectors 1, 1 having the inner surface of the parabolic surface as the reflecting surface and the second reflecting mirrors 2, 2 'having the reflecting surface of the parabolic surface or the elliptical surface share the focal point F. Reflector forming structure of the optical focuser, characterized in that The reflector forming structure of an optical concentrator according to claim 1, wherein the reflecting curved surfaces of the second reflecting mirrors (2, 2 ') have a structure represented by a general polynomial in cross section. The device according to claim 1 or 2, wherein the main reflectors (1, 1) are inclined counterclockwise by the angle of incidence with respect to the shared focal point (F) so that the device does not need to track the sun and at the same time the error limit of the device is reduced. Reflector forming structure of the optical concentrator, characterized in that for widening The method according to claim 1 or 2, wherein the second reflectors (2, 2 ') are centered on the shared focal point (F). Clockwise θ_eReflector forming structure of the light concentrator which inclines as much as possible to control the light path and minimize the loss of light 3. The method according to claim 1 or 2, wherein when the reflecting surfaces of the second reflecting mirrors 2, 2 'are parabolic, the focal length of the shared focal point F, which the second reflecting mirror and the main reflecting mirror cooperate with each other, is represented by the relation f _e = { -(R + f _p sinθ _c ) sinθ _e -fpcosθccosθ _e + {[-(R + f _p sinθ _c ) cosθ _e -f _p cosθ _c sinθ _e ] ² + [-(R + f _p sinθ _c ) sinθ _e -f _p cosθ _c cosθ _e ] ² } ^1/2 } / 2 Reflector Formation Structure of Optical Integrator 3. The focal length of the shared focal point F according to claim 1, wherein when the reflecting surface of the second reflecting mirror is an ellipse, the second reflecting mirrors 2, 2 ′ are linked to the main reflecting mirrors 1, 1 ′. Reflector forming structure of optical concentrator satisfying relation f _e = (-a / 2-R _o + E _o ) / 2 The heat absorbing surface 3 or the heat absorbing tube 5 may be replaced by a plane, a spherical shape, a cylindrical shape, or another shape, and the reflecting mirror 3 may be replaced with the reflecting glass 3 regardless of the shape of the heat absorbing surface 3 or the heat absorbing tube 5. Reflector forming structure of the optical concentrator, which can move the symmetry axis LL 'of the reflecting mirrors 1, 1', 2, 2 'while maintaining the forming structures of 1, 1', 2, 2 '. Reflector forming structure of the light concentrator for accommodating the heat absorbing surface 3 or the heat absorbing tube 5 and the second reflecting surfaces 2, 2 'of the light concentrator together in the glass tube 31 The reflector formation structure of the optical concentrator of Claim 1 which accommodates the whole optical concentrator in the sealed normal glass tube 32. 11. The reflector forming structure of the optical concentrator according to claim 10, wherein the inside of the glass tube (32) is vacuumed when the entire optical concentrator is accommodated in a sealed ordinary glass tube (32).