JP5013684B2 - Condensing lens, condensing lens structure, concentrating solar power generation device, and manufacturing method of condensing lens structure - Google Patents

Description

  The present invention relates to a condensing lens, a condensing lens structure, a concentrating solar power generation apparatus using the condensing lens, and a method of manufacturing the condensing lens structure.

  Photovoltaic power generation devices that convert solar energy into electric power have been put into practical use. However, in order to achieve low costs and further improve photoelectric conversion efficiency (power generation efficiency) to obtain high power, it is collected by a condensing lens. A concentrating solar power generation apparatus of a type that takes out electric power by irradiating solar light that is smaller than the light receiving area of a condensing lens with sunlight is put into practical use.

  Since the concentrating solar power generation device condenses sunlight with a condensing lens, the solar cell element only needs to have a small light receiving area capable of receiving sunlight condensed by the optical system. That is, since the solar cell element having a size smaller than the light receiving area of the condensing lens may be used, the size of the solar cell element can be reduced, and the amount of the solar cell element that is the most expensive component in the solar power generation device It is possible to reduce the cost by reducing (amount of use). Due to such advantages, the concentrating solar power generation apparatus is being used for power supply in an area where power can be generated using a large area.

  FIG. 13 is an explanatory view for explaining a concentrating solar power generation device as a conventional example, in which (A) is a plan view showing an overview viewed from an incident surface of sunlight, and (B) is (A). It is sectional drawing which shows the cross section in the arrow BB of.

  A concentrating solar power generation device 100 as a conventional example (see, for example, Patent Document 1) includes a case 101 whose one end surface is open, and a non-imaging system fitted in the opening of the case 101 so as to function as a primary optical system. Fresnel lens 102, seat plate 103 provided at the bottom of case 101, solar cell element 104 installed on the bottom surface of case 101, which is a condensing position of non-imaging Fresnel lens 102, that is, on seat plate 103, secondary A cylindrical reflecting mirror 105 that functions as an optical system is provided.

  The concentrating solar power generation apparatus 100 needs a cylindrical reflector 105 corresponding to the solar cell element 104 to condense sunlight Ls, and to hold the non-imaging system Fresnel lens 102. There is a problem that the optical system becomes complicated and the manufacturing process becomes complicated. For example, it is necessary to form a frame portion corresponding to each of the non-imaging Fresnel lens 102 in the case 101.

  In addition, since the non-imaging Fresnel lens 102 is held by the frame portion of the case 101, there is a limit to the size of the case, and the concentrating solar power generation device 100 capable of condensing a large area can be obtained. There is a problem that it is difficult.

  In addition, since the non-imaging Fresnel lens 102 is held by the frame portion of the case 101, it is necessary to increase the accuracy of the frame portion shape, and the position where each frame portion needs to be aligned with the condensing position. There are problems that alignment is difficult, the manufacturing process becomes complicated, and high-precision alignment is difficult.

In addition, when a secondary optical system such as a reflecting cylinder is used, sunlight reaching the solar cell element 104 always passes through the reflecting cylinder or the like, and thus there is a problem of causing light loss due to the transmittance of the reflecting cylinder itself or reflection. .
JP 2003-174183 A

  The present invention has been made in view of such circumstances, and the second surface includes a protruding region having an inclined surface inclined with respect to the planar first surface and a planar region parallel to the first surface. By using a condensing lens or a condensing lens structure that holds such a condensing lens with a translucent substrate, there is no bias in the entire condensing region (light-receiving region of the solar cell element) and reliable concentrating. An object of the present invention is to provide a condenser lens, a condenser lens structure, and a method for manufacturing the condenser lens that can emit light and can improve the light collection efficiency.

  In addition, the present invention makes it possible to easily perform high-precision alignment with a simple optical system by aligning the condensing lens and the condensing region by using the planar region of the condensing lens. It is another object of the present invention to provide a condensing lens structure that can be simplified and improve condensing efficiency, and a method for manufacturing the same.

  In addition, the present invention is a concentrating solar power generation apparatus using the above-described condensing lens structure, so that high accuracy can be achieved between the condensing lens and the light receiving region (condensing region) of the solar cell element. Another object is to provide a concentrating solar power generation apparatus capable of simplifying the manufacturing process, improving the light collection efficiency, and realizing high power generation efficiency because the alignment can be easily performed.

A condensing lens according to the present invention includes a flat first surface and a second surface that is formed with a protrusion having an inclined surface that is inclined with respect to the first surface and faces the first surface. The second surface includes a planar region having a plane parallel to the first surface, and a projection region having the projections concentrically around the planar region, the pitch of the projections The protrusion has an inclination change pitch which is a pitch for changing the inclination angle of each of the plurality of continuous protrusions, and the protrusion height of the protrusion is decreased from the end toward the center for each inclination change pitch. It is characterized by being.

The condensing lens structure according to the present invention includes a condensing lens having a planar first surface and a second surface opposed to the first surface, the protrusion having an inclined surface inclined with respect to the first surface. And a translucent substrate for fixing and holding a plurality of the condensing lenses, wherein the second surface has a plane region having a plane parallel to the first surface, and A projection region having the projections concentrically around a planar region, and having an inclination change pitch that is a pitch for changing the inclination angle of the projection for each of a plurality of continuous projections with respect to the pitch of the projection. The protrusion height of the protrusion is reduced from the end toward the center for each inclination change pitch, and between the translucent substrate and the first surface, corresponding to the planar area, A planar area fixing part for fixing the translucent substrate and the condenser lens; Characterized in that the peripheral fixing portion corresponding to the peripheral portion of the projection area to fix the said condensing lens and said light-transmissive substrate is formed.

  Preferably, the planar area fixing part and the peripheral edge fixing part are formed of a double-sided adhesive tape.

  Preferably, a filling portion filled with an adhesive is formed between the translucent substrate and the first surface.

A concentrating solar power generation device according to the present invention includes a condensing lens structure including a condensing lens and a translucent substrate that holds and fixes a plurality of the condensing lenses, and is disposed corresponding to the condensing lens. a concentrating solar power generation apparatus and a solar cell element which is, the condenser lens structure, Ri condenser lens structure der according to the present invention, the planar region directly facing the solar cell element characterized tare Rukoto defining a circle of diameter that surrounds the light receiving area of. In addition, the inclination angle of the inclined surface with respect to the first surface and the inclination change pitch as a pitch for changing the inclination angle concentrate light in a wavelength region that determines a short-circuit current of the solar cell element in the light receiving region. It is set as follows.

The method for manufacturing a condensing lens structure according to the present invention includes a planar first surface and a second surface that is formed with a protrusion having an inclined surface that is inclined with respect to the first surface and faces the first surface. A condensing lens and a translucent substrate that holds the condensing lens in a fixed manner, and the second surface includes a planar region having a plane parallel to the first surface, and a periphery of the planar region. A projection region having the projections concentrically, and having an inclination change pitch that is a pitch for changing the inclination angle of the projection for each of a plurality of continuous projections with respect to the pitch of the projection, and the projection has The height of the protrusion is reduced from the end toward the center for each inclination change pitch, and between the translucent substrate and the first surface, the translucent substrate corresponds to the planar area. A flat area fixing portion for fixing the condenser lens, and a peripheral edge of the protruding area Corresponding to the light-transmitting substrate and a peripheral edge fixing part for fixing the condenser lens, and a planar positioning tool for determining the position of the planar region, Fitting and aligning the planar region with the planar positioning tool of a positioning jig base provided with a substrate edge positioning tool that determines the position of the end of the translucent substrate; and the plane on the first surface Forming the planar area fixing portion for fixing the translucent substrate and the condensing lens at a position corresponding to the area, and the transparent area at a position corresponding to a peripheral edge of the protruding area on the first surface. A step of forming the peripheral edge fixing portion for fixing the optical substrate and the condensing lens; and an end portion of the translucent substrate in contact with the substrate end positioning tool to fix the translucent substrate to the planar region Joining the portion and the peripheral edge fixing portion; Characterized in that it comprises a step of filling an adhesive between the KiToruhikari substrate and the condensing lens. Further, the step of filling the adhesive between the translucent substrate and the condensing lens is performed after exhausting air between the translucent substrate and the condensing lens. Features.

  According to the condensing lens according to the present invention, since the planar region is arranged directly opposite the light receiving region, sunlight incident perpendicularly to the planar region is incident directly on the light receiving region and sunlight incident on the projection region. Is refracted by the inclined surface and condensed on the light receiving region. Therefore, the light incident on the planar region is free from chromatic aberration due to the condensing lens, and variation in the light intensity distribution on the light receiving surface of the solar cell element can be reduced, and the power generation efficiency can be improved.

  According to the condensing lens structure and the manufacturing method thereof according to the present invention, the alignment between the condensing lens and the translucent substrate (condensing region) is performed using the boundary between the planar region and the protruding region. High-precision alignment can be easily performed, and the manufacturing process can be simplified. Moreover, since the mechanical strength of the condensing lens can be reinforced by the translucent substrate, the condensing lens having a predetermined shape necessary for condensing can be obtained, and it has a desired condensing characteristic and has a large area. There is an effect that it is possible to provide a condensing lens structure capable of condensing light.

  According to the concentrating solar power generation apparatus according to the present invention, since the condensing lens structure according to the present invention is used, the manufacturing process is simple, the condensing characteristics are good, and the power generation efficiency and the reliability are high. There exists an effect that a concentrating solar power generation device can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view partially showing an arrangement relationship of main parts of a concentrating solar power generation device according to an embodiment of the present invention.

  The concentrating solar power generation device 10 of the present embodiment covers the mounting plate 3 on which the solar cell element 1 and the solar cell element 1 bonded to the receiver 2 are mounted, and the mounting plate 3 is mounted from sunlight Ls. A frame bottom portion 4 that shields the plate 3, a frame side portion 5 that extends vertically from two opposite end portions of the frame bottom portion 4, and is opposed to each other, and a frame side portion that faces the frame bottom portion 4. 5 is arranged corresponding to the upper end of the solar cell element 1 and collects the sunlight Ls in the light receiving area (condensing area) of the solar cell element 1. 5 is provided with a translucent substrate 6 attached to the upper end of 5. The translucent substrate 6 and the condensing lens 7 constitute a condensing lens structure 8.

  Since the number of parts is reduced by configuring the structural members corresponding to the functions, the assembly is easy, the size and weight can be reduced, and the concentrating solar power generation device 10 having high mechanical strength is obtained. Can do.

  For example, a total of ten solar cell elements 1 mounted on the receiver 2 are arranged on the mounting board 3 in two rows of five. The solar cell element 1 (light receiving region) is arranged corresponding to the light collecting position (light collecting region) of the condenser lens 7. The mounting plate 3 is formed in a dish shape having a recess that secures a space for storing the solar cell element 1 and the receiver 2 in units of ten, and a flange 3a for attachment to the frame bottom 4 is formed on the periphery. The mounting board 3 is made of, for example, aluminum in consideration of heat dissipation and weight reduction.

  A total of 10 condenser lenses 7 are arranged and fixed on the translucent substrate 6 in two rows of 5 so as to correspond to each of the 10 solar cell elements 1 to constitute a lens array. The condensing lens 7 is made of, for example, PMMA (acrylic resin) in consideration of processability and translucency, and is a Fresnel lens in consideration of moldability and cost.

  The condensing lens 7 is disposed such that the planar first surface 7f is fixed to the translucent substrate 6 and the second surface 7s faces the frame bottom 4 (see FIG. 7). The second surface 7s includes a planar region 7sf having a plane parallel to the first surface 7f and a projection region 7sp in which a projection 7p having an inclined surface inclined with respect to the first surface 7f is formed (FIG. 7).

  The translucent substrate 6 is made of, for example, glass in consideration of translucency, strength, environmental resistance, and the like, and prevents the influence of wind and rain from the surrounding environment where the concentrating solar power generation device 10 is installed. can do. The condensing lens 7 is bonded and fixed (held) to the translucent substrate 6 with an appropriate translucent adhesive or the like, and constitutes a condensing lens structure 8 (see FIG. 10).

  Since the condensing lens 7 is adjusted in optical distance (defined based on the focal length) so as to condense in the light receiving region of the solar cell element 1, the sun condensed by the condensing lens 7. The light Ls becomes extremely large energy around the solar cell element 1. Moreover, when it is set as the structure which tracks sunlight Ls, the solar cell element 1 may not always be able to maintain the relationship where it always opposes the condensed sunlight Ls, and also a tracking apparatus stops by generation | occurrence | production of an abnormal condition. It is also assumed that That is, the condensed sunlight Ls may be irradiated not on the light receiving region of the solar cell element 1 but on the peripheral members of the mounting board 3, and in such a case, the irradiated portion may be damaged by burning or the like. .

  Therefore, the frame bottom 4 has a structure that blocks the sunlight Ls so as to prevent the occurrence of damage due to the concentrated sunlight Ls, so that the sunlight Ls does not affect other than the light receiving region of the solar cell element 1. It is configured. In addition, in order to enable the solar cell element 1 to receive light in conjunction with the light shielding function, the solar cell element 1 receives the transmission hole 4a that transmits the concentrated sunlight Ls and irradiates the light receiving region of the solar cell element 1. Positioning is provided so as to face the region.

  That is, the transmission hole 4a is formed corresponding to each of the ten solar cell elements 1 mounted on the mounting plate 3, and the position of the transmission hole 4a is set to the position of the solar cell element 1 and the condenser lens. It is extremely important to align with the light collecting position of 7 in order to ensure power generation efficiency. In addition, the frame bottom portion 4 is disposed adjacent to the bottom portion of the frame side portion 5 in the vicinity of the mounting plate 3 in order to reliably realize the function of the transmission hole 4a.

  In order to ensure and improve the mechanical strength of the concentrating solar power generation device 10 and to improve productivity, it is preferable that the frame bottom portion 4 and the frame side portion 5 are integrally formed by continuous molding. Therefore, the frame bottom portion 4 and the frame side portion 5 are integrally formed by, for example, roll forming a metal plate such as an iron plate or a steel plate to constitute the frame 11.

  By forming the frame bottom part 4 integrally with the frame side part 5, it is not necessary to use another member as the frame bottom part 4, and productivity can be improved. Further, since the position of the frame bottom portion 4 (transmission hole 4a) can be defined integrally with the frame side portion 5, the mounting plate 3 (solar cell element 1) and the condensing lens structure 8 (condensing lens 7) are aligned. Can be performed with high accuracy.

  A flange 5a for supporting the condensing lens structure 8 (translucent substrate 6) is integrally formed at the upper end of the frame side portion 5 at the time of roll forming, so that the condensing lens 7 is positioned reliably. Can be done. That is, the mounting plate 3 and the translucent substrate 6 (the condensing lens 7) can be accurately aligned with the frame 11 constituted by the frame side portion 5 and the frame bottom portion 4 as a reference position (basic shape). And accurate light collection can be made possible.

  The mounting board 3 is attached to the frame bottom part 4 and houses the ten solar cell elements 1 together with the frame bottom part 4 to form a protective space for protection from the external environment. A trapezoidal portion 4b that is convex on the upper end side of the frame side portion 5 for mounting the mounting plate 3 is integrally formed on the frame bottom portion 4 during roll forming.

  The translucent substrate 6 for fixing the condenser lens 7 is attached to the upper end (the ridge 5a) of the frame side portion 5. Further, since the condensing lens 7 needs to be arranged so that the sunlight Ls that has passed through the condensing lens 7 is condensed on the light receiving region of the solar cell element 1, the height of the frame side portion 5 is condensing. In consideration of the focal length of the lens 7, the optical distance (the distance necessary for generating the maximum power) is defined between the solar cell element 1 and the condenser lens 7. .

  In other words, the height of the frame side portion 5 is such that the sunlight Ls incident on the condenser lens 7 passes through the transmission hole 4a in the frame bottom portion 4 when the solar cell element 1 and the sunlight Ls are in a directly-facing state. Thus, the entire light receiving area of the solar cell element 1 mounted on the receiver 2 is set so as to be reliably condensed and irradiated. Note that the direct facing refers to a relationship in which the optical axis directions are aligned.

  In the longitudinal direction of the frame side portion 5, a fitting groove 5b capable of fitting the frame side portion 5 (of an adjacent concentrating solar power generation device (not shown)) to each other is integrally formed at the time of roll forming. A concentrating solar power generation apparatus having a larger power generation capacity can be configured by fitting the fitting grooves 5b and connecting a plurality of frame side portions 5 in the short direction intersecting the longitudinal direction. Since the fitting groove 5b fits the frame side portions 5 to each other, the frame 11 having high mechanical strength can be maintained even when a plurality of the fitting grooves 5b are connected.

  The mounting board 3 and the translucent substrate 6 are mounted by being divided into a plurality of parts in the longitudinal direction of the frame side part 5 (frame 11). With this configuration, even if the length of the frame 11 in the longitudinal direction is increased in order to increase the size of the concentrating solar power generation device 10, the ease of assembly can be ensured, so that productivity can be improved and maintenance inspection can be performed. This makes it possible to easily perform repairs.

  Further, by shortening the mounting plate 3 and the translucent substrate 6 with respect to the length of the frame 11 in the longitudinal direction, the alignment of the solar cell element 1 and the condensing lens 7 with respect to the frame 11 is adjusted to the frame bottom 4 (transmission). Since it suffices to perform within a narrow range (divided range) with respect to the hole 4a) and the frame side portion 5, accurate alignment can be performed.

  When the mounting board 3, the frame 11, and the translucent substrate 6 are made of different materials, the coefficients of thermal expansion are different. Therefore, the longer the length, the greater the influence of thermal expansion, and the position shift due to temperature changes. There is a risk that the solar cell element 1 will not be irradiated with the sunlight Ls collected by. However, by dividing and shortening the mounting board 3 and the translucent substrate 6, it is only necessary to consider thermal expansion in a short length (narrow range), so that the influence of thermal expansion can be reduced. It becomes possible.

  The side wall in the short direction of the frame side part 5 is covered with a plate material that passes between the opposing frame side parts 5, but is covered in a breathable state to prevent a temperature rise in the frame 11. That is, the side wall in the short direction of the frame side portion 5 is covered with a plate material in which a ventilation hole or a net material that can ensure ventilation while preventing dust from entering.

  FIG. 2 is a schematic side view transparently showing an arrangement relationship of main parts viewed from the side surface in the longitudinal direction of the concentrating solar power generation device according to the embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view showing a cross-sectional outline at the arrow AA in FIG. 2.

  The frame 11 (the frame bottom part 4 and the frame side part 5) has a length suitable for the concentrating solar power generation device 10 formed by continuously bending a roll forming process, for example, approximately in the longitudinal direction. It is formed by cutting to about 3 m.

  A mounting plate 3 and a translucent substrate 6 each having a length of about 1 m divided into a plurality of pieces (for example, three pieces) in the longitudinal direction are arranged and fixed on the rear surface of the frame bottom portion 4 and the upper end of the frame side portion 5, respectively. (Installed). For example, since the length of the translucent substrate 6 is about 1 m, the condensing lenses 7 arranged in the longitudinal direction are about 200 mm square. Therefore, the width of the frame bottom 4 and the translucent substrate 6 is about 400 mm in the short direction. The width of the mounting board 3 is about 300 mm. Since the mounting board 3 and the translucent substrate 6 are divided into a plurality of parts, the influence of thermal expansion can be reduced according to the number of divisions.

  The sunlight Ls incident from the surface of the translucent substrate 6 and transmitted through the condenser lens 7 is collected, passes through the transmission hole 4a of the frame bottom 4 and is mounted on the mounting plate 3 on the solar cell element 1. Irradiated.

  The mounting plate 3 is mounted with a flange 3a in contact with the back surface of the frame bottom portion 4 (trapezoidal portion 4b) connected to the lower end of the frame side portion 5. The mounting board 3 is positioned at the center of the flange 3a corresponding to one long side of the mounting board 3, and is firmly fixed by an appropriate fixing member (not shown), and the flange 3a at other positions is appropriately locked by the fixing member. (Loosely fixed). By positioning and fixing at the center portion, it is possible to halve the position shift due to thermal expansion compared to, for example, positioning at the end portion. In addition, when the four sides of the mounting board 3 are fixed with the same strength, the influence of warpage due to thermal expansion is increased, but only the central part is fixed firmly, and the other positions are fixed loosely. Therefore, the occurrence of warping (bending) can be prevented, and the influence of thermal expansion can be reduced.

  That is, by positioning and fixing at the center of the flange 3a (mounting board 3) having a length of about 1 m, it is possible to suppress the range in which the influence of the positional deviation due to thermal expansion occurs to about 0.5 m, which is half. In addition, when fixing, two separate fixing points are provided at the center so that the positional deviation due to the rotation of the mounting board 3 does not occur. Although the two fixing points are not shown in the drawing, the same effect can be obtained by arranging the two fixing points in the same manner as two substrate frame alignment portions 6b for positioning a light-transmitting substrate 6 described later (see FIGS. 11 and 12).

  The translucent substrate 6 has a surface on which the condensing lens 7 is attached facing the frame bottom 4, and a substrate frame portion between the end of the attached condensing lens 7 and the end of the translucent substrate 6. 6a is constituted. Similar to the mounting board 3, it is positioned and fixed with respect to the flange protrusion 5c formed in the flange 5a by a through hole formed as a substrate frame alignment portion 6b at the center corresponding to one long side of the substrate frame 6a. (See FIGS. 11 and 12). Also in the case of the translucent substrate 6, since the same effect as the mounting board 3 is produced with respect to the thermal expansion, the displacement can be suppressed.

  The translucent substrate 6 is attached to and fixed to the flange 5a by pressing the substrate frame 6a to the flange 5a by using an appropriate fixing member (not shown) shaped around the translucent substrate 6. Can be performed. Moreover, what is necessary is just to fix between the adjacent translucent board | substrates 6 with the fixing member (not shown) of the shape which passes between each other.

  The mounting plate 3 and the translucent substrate 6 are positioned and fixed with the same accuracy with respect to the common (same) frame 11 (the transmission hole 4a of the frame bottom 4 and the flange 5a at the upper end of the frame side 5). Therefore, the positioning accuracy of the concentrating solar power generation device 10 as a whole can be improved, and the utilization efficiency of sunlight can be reliably improved.

  The condensing lens 7 is formed with a size of about 200 mm square corresponding to each solar cell element 1 in consideration of processability at the time of molding, and for example, an acrylic resin is injected and injected into a Fresnel lens-shaped mold. It is molded as a flat Fresnel lens. By using a Fresnel lens, the condensing lens 7 can be thinned even when the condensing lens 7 having a large area condenses on the solar cell element 1 having a small area. Thinning makes it possible to make it lightweight, inexpensive and easy to hold.

  The condensing lens 7 may be formed by integrally molding a plurality of Fresnel lenses so as to correspond to the plurality of solar cell elements 1 instead of individually molding each of the solar cell elements 1. In addition, since the thinned condenser lens 7 can be bonded to the translucent substrate 6 to ensure strength and flatness, it is possible to obtain a lens shape with good condensing characteristics.

  FIG. 4 is a plan view showing an arrangement state of the solar cell elements mounted on the concentrating solar power generation device according to the embodiment of the present invention at the receiver.

  In the present embodiment, the solar cell element 1 is processed from a wafer into a 7 mm square chip by forming a PN junction, an electrode, and the like by a known semiconductor manufacturing process using a GaAs compound semiconductor. The solar cell element 1 is electrically and mechanically connected and bonded (mounted) to a copper receiver 2 of about 60 mm square by a back electrode. A reference hole 2p is drilled with high accuracy in a corner portion of the diagonal position of the receiver 2, and the solar cell element 1 is positioned and bonded with reference to the reference hole 2p.

  When a bypass diode Di is connected in parallel with the solar cell element 1 and the solar cell element 1 operates as a resistor by shielding light of sunlight Ls, a current path to the adjacent solar cell element 1 is configured and specified. Even when the solar cell element 1 does not perform the power generation function, the power generation function can be maintained as the entire concentrating solar power generation device 10.

  The surface of the receiver 2 is exposed in the region where the substrate electrode of the solar cell element 1 and the substrate electrode of the bypass diode Di that require electrical connection are connected, and the region of the substrate electrode connection portion 2b. Is covered with an insulating resist 2i. A surface electrode connection portion 2t serving as an electrode for extracting output is formed on a part of the surface of the insulating resist 2i with an appropriate thin plate-like conductor.

  The surface electrodes formed on the opposite ends of the chip of the solar cell element 1 are wire-bonded to the surface electrode connection portion 2t via the wire Ws, and the output can be taken out with the substrate electrode connection portion 2b. . Further, the surface electrode of the bypass diode Di is wire-bonded to the surface electrode connecting portion 2t via the wire Wd, and a bypass operation can be performed.

  Conductive leads 2c for connecting the adjacent solar cell element 1 to the surface electrode connecting portion 2t and the substrate electrode connecting portion 2b are connected to each other, and the solar cell elements 1 are connected in series using the conductive leads 2c. Large capacity power generation is possible by connecting them in parallel.

  FIG. 5 is an explanatory view showing a mounting state of solar cell elements and an arrangement state of transmission holes mounted on the concentrating solar power generation device according to the embodiment of the present invention, and (A) is viewed from the side. It is a side perspective view which shows a state transparently, (B) is the top view which looked at the light-shielding plate (transmission hole) from the condensing lens side.

  Solar cell element 1 and bypass diode Di solder-bonded to the exposed surface of receiver 2 are surrounded by a sealing dam 2sd (planar periphery) and are resin-sealed with sealing resin 2sr. By disposing the sealing glass 2sg on the surface of the sealing resin 2sr, the moisture resistance of the resin sealing 2sr (on the surface on the frame bottom 4 side) can be improved. The sealing dam 2sd is formed of, for example, a white silicone resin, and the sealing resin 2sr is formed of, for example, a highly transparent silicone resin.

  Since the receiver 2 is made of copper, it functions as a heat dissipating means for the solar cell element 1 that becomes extremely hot when irradiated with the concentrated sunlight Ls. The receiver 2 on which the solar cell element 1 is mounted is bonded to an aluminum mounting plate 3 via an insulating heat conductive sheet 3i, and dissipates heat of the solar cell element 1 from the mounting plate 3 to the atmosphere while maintaining an insulating state. .

  Positioning and fixing between the receiver 2 and the mounting board 3 are performed by forming a receiving hole 3p accurately aligned with the mounting board 3 with respect to the reference hole 2p provided in the receiver 2, and the reference hole 2p and the receiving hole. By inserting and fixing the rivet 2r that is covered with insulation 3p, it can be performed with high accuracy.

  The shape and size of the transmission hole 4a is such that the sunlight Lsa in the short wavelength region in the sensitivity wavelength light of the solar cell element 1 that is refracted by the condenser lens 7 with respect to the sunlight Ls incident on the condenser lens 7 with parallel rays. The solar cell element 1 may be opened so as to irradiate a range where sunlight Lsb in the long wavelength region of the sensitivity wavelength light of the solar cell element 1 reaches the edge on the near side of the solar cell element 1 on the edge side away from the solar cell element 1. preferable. With respect to a solar cell element 1 having a light receiving area of 7 mm square and a condensing lens 7 having a focal length (distance condensing in a planar shape on the light receiving area of the solar cell element 1: an optical distance) of 300 mm, the length b is 13 mm square. An opening is provided. Needless to say, the distance between the frame bottom portion 4 and the mounting board 3 is appropriately adjusted.

  Although the shape of the transmission hole 4a can be punched to a size of b = 13 mm square, the peripheral edge of the transmission hole 4a is drawn to form a bent portion 4c bent on the mounting board 3 side, and transmitted obliquely. Then, it is preferable to form it with a function (angle) for blocking sunlight (Lsd) that may irradiate portions other than the solar cell element 1.

  Further, the surface (incident side surface) 4s on the condenser lens 7 side of the bent portion 4c is mirror-finished, so that the sunlight Ls irradiated to the bent portion 4c is reflected to the solar cell element 1 side to increase the incident efficiency. be able to.

  FIG. 6 is a plan view of the condensing lens structure according to the embodiment of the present invention. FIG. 7 is an enlarged schematic cross-sectional view of the condensing lens structure of FIG. 6 and shows a partial schematic cross-section from the center of the condensing lens structure to the arrow A. It is noted that only one condenser lens 7 (hatching is omitted in consideration of the visibility of the drawing) is fixed to the translucent substrate 6 in consideration of the visibility of the drawing. In addition, FIG. 7 is an enlarged view of the vertical direction in the drawing.

  The translucent substrate 6 constitutes a condensing lens structure 8 by fixing the planar first surface 7 f of the condensing lens 7. The condenser lens 7 has a first surface 7f and a second surface 7s opposite to the first surface. On the second surface 7s, a plurality of projections 7p having an inclined surface inclined with respect to the first surface 7f are formed concentrically with a pitch pp, and light can be condensed on a light condensing region (light receiving region) (not shown). As a Fresnel lens.

  The protrusion 7p has a pitch pp of 0.5 mm in consideration of processability at the time of molding, and has an inclination angle with respect to a triangular wave shape (projection height h, first plane 7f (plane area 7sf)) formed by an inclined plane and a vertical plane. θ). Since the projection 7p composed of an inclined surface and a vertical surface is formed concentrically, when molding a Fresnel lens by injecting and curing resin into the mold, the molded product can be removed from the mold without stress. Is easy, and a highly accurate Fresnel lens can be obtained.

  The second surface 7s includes a planar region 7sf having a plane parallel to the first surface 7f and a projection region 7sp having a projection 7p. A boundary 7b between the plane region 7sf and the projection region 7sp is defined by a step between the plane region 7sf and the projection 7p, and the step is defined by a plane of the plane region 7sf and a vertical plane of the projection 7p. By using the boundary 7b (the step), the planar region 7sf can be accurately aligned with the condensing region (see FIGS. 8 to 10).

  Between the translucent substrate 6 and the condensing lens 7 (first surface 7f), a flat area fixing portion 8a for fixing the translucent substrate 6 and the condensing lens 7 is formed corresponding to the flat area 7sf. Thus, the position of the planar region 7sf can be reliably fixed. Similarly, a peripheral edge fixing portion 8b for fixing the translucent substrate 6 and the condenser lens 7 is formed corresponding to the peripheral edge portion of the projection region 7sp, so that the large-area condenser lens 7 is securely translucent. It can be fixed to the substrate 6. Further, a filling portion 8c is formed to remove and fill the air layer between the translucent substrate 6 and the condenser lens 7.

  In the projection region 7sp, four continuous projections 7p are formed with the same inclination angle θ. The four continuous projections 7p are configured with the same inclination angle θ, and the inclination change pitch ph as the pitch for changing the inclination angle θ is 2 mm. That is, each wavelength light in the sunlight Ls is similarly refracted with a width of 2 mm corresponding to the inclination change pitch ph.

  For example, in the case of the 200 mm square condenser lens 7, the projection 7p at the end of the corner section has an inclination angle θc of 36 degrees with respect to the first plane 7f and a projection height hc of about 0.4 mm (note that the projection height) Since hc is located on the outermost periphery of the concentric circle, it becomes the highest protrusion 7p). Further, in the direction passing through the center of the concentric circle and perpendicular to the side, the inclination angle θ of the four outermost protrusions 7p is 29.73 degrees, and the inclination angle θ of the four inner protrusions 7p is 29 degrees ( Not shown). Further, the inclination angle θa of the four protrusions 7p adjacent to the planar area 7sf is 4.71 degrees, and the protrusion height ha is about 0.1 mm.

  Thus, the thickness of the projection 7p (projection height h) decreases from the lens end toward the lens center. Further, the plane area 7sf at the center of the lens is defined as a circle having a diameter that surrounds the 7 mm square of the light receiving area of the solar cell element 1 and thus has a diameter of 10 mm. When the condensing lens structure 8 is directly opposed to the sunlight Ls, the sunlight Ls incident perpendicularly to the plane region 7sf has no chromatic aberration due to the condensing lens and enters the light receiving region of the solar cell element 1 as it is. Since the variation in the light intensity distribution can be reduced, the power generation efficiency can be improved.

  In the present embodiment, since solar cell element 1 is a three-junction type, light in a wide wavelength band (ultraviolet to blue to green to red to infrared) corresponding to each junction in the depth direction of the chip. On the other hand, a photovoltaic power is generated. The short-circuit current of the solar cell element 1 according to the present embodiment is such that when standard solar radiation (AM1.5) is received, a cell (solar cell element 1 having a light receiving sensitivity in a short wavelength region in the sensitivity wavelength light). It is limited by the short-circuit current of one of the elements stacked in three layers. Therefore, the output of the solar cell element 1 is improved by condensing the light in the short wavelength region more appropriately than the light in other wavelength regions. Since the direction of refraction by the condenser lens 7 varies depending on the wavelength of light, ultraviolet light having a wavelength of 400 nm is used so that the solar cell element 1 can efficiently receive light in the short wavelength region (ultraviolet to red) of the sensitivity wavelength light of the solar cell element 1. Of the projection 7p so that it is condensed (refracted) to the edge side of the photovoltaic power generation element 1 (light receiving region) that is at a diagonal position (distant side) with respect to the condenser lens 7 (projection 7p). The inclination angle θ is determined.

  In addition, four projections 7p (2 mm wide) are formed at the same inclination angle θ, but if the projections 7p having the same inclination angle θ are arranged too much, light in the short wavelength region is out of the solar cell element 1 (light receiving region). Since the protruding ratio increases, it is effective to make the width (inclination change pitch ph) of about 2 mm for the solar cell element 1 having a light receiving area of 7 mm square. With this configuration, the narrowing of the focus is alleviated, and more uniform light reception is possible over the entire surface of the light receiving region, and the power generation efficiency can be further increased.

  That is, the inclination angle θ of the protrusion 7p and the inclination change pitch ph, which is a pitch for changing the inclination angle θ, are shorter than the light in the short wavelength region (in other words, compared to the light in the other wavelength regions). The short-circuit current is limited and the light in the wavelength region that is more dominantly determined) is effectively refracted (condensed) toward the light receiving region. Therefore, the light collection efficiency for light in the short wavelength region is improved, and the photoelectric conversion efficiency (power generation efficiency) can be improved.

  In this embodiment, the optical design is such that light in the short wavelength region, which greatly contributes to the output current, is efficiently condensed in the light receiving region, and light of other wavelengths is condensed in the light receiving region at a certain ratio or more. As a whole, power generation can be performed efficiently. This example is an example of the characteristics of the solar cell element, and it is preferable to preferentially collect wavelengths that have a large contribution to the output current.

  8 to 10 are cross-sectional views illustrating a manufacturing method (manufacturing process) of the condensing lens structure according to the embodiment of the present invention.

  The positioning jig base 15 is formed with a planar positioning tool 15a that determines the position of the planar region 7sf (condensing lens 7) to be disposed corresponding to the position of the solar cell element 1 (light receiving region). The positioning jig base 15 is formed of, for example, an aluminum substrate, and the planar positioning tool 15a is, for example, a diameter inscribed in the diameter of the planar region 7sf (a stepped portion, that is, a vertical surface of the projection 7p adjacent to the planar region 7sf). A pin having a vertical position is provided. The positioning jig base 15 is further provided with a lens rotation preventing tool 15b for preventing the condensing lens 7 from rotating so that the condensing lens 7 can be juxtaposed and aligned. The lens rotation preventing tool 15b is configured by standing a pin in the same manner as the planar positioning tool 15a.

  By fitting the planar area 7sf of the condenser lens 7 to the planar positioning tool 15a using the boundary 7b, the condenser lens 7 (planar area 7sf) can be positioned with high accuracy. FIG. 8 shows a case where two condensing lenses 7 are juxtaposed, the left side in the figure shows the state after positioning, and the right side shows the state before positioning.

  The height of the planar positioning tool 15a is preferably equal to the outermost protrusion height hc (0.4 mm) in order to improve the flatness of the condenser lens 7. The tip of the planar positioning tool 15a is the boundary 7b, that is, a step between the planar region 7sf and the adjacent projection 7p (projection height ha (0.1 mm) defined by the plane of the planar region 7sf and the vertical surface of the projection 7p). It is fitted with. Since the step between the planar region 7sf and the projection 7p is constituted by a vertical surface, there is no displacement in the horizontal direction during positioning, so that the positioning can be performed with high accuracy.

  The positioning jig table 15 is further provided with a substrate end positioning tool 15c that determines the position of the end of the translucent substrate 6 corresponding to the position of the planar region 7sf. The substrate end positioning tool 15c is configured by erecting pins, for example, on an aluminum substrate.

  After the condenser lens 7 on the right side of FIG. 8 is moved and aligned in the direction of the arrow, a planar area fixing portion 8a is formed on the first surface 7f of the condenser lens 7 so as to correspond to the planar area 7sf. The peripheral edge fixing portion 8b is formed in correspondence with the peripheral edge portion of the protruding region 7sp (see FIG. 9). Either the planar region fixing portion 8a or the peripheral edge fixing portion 8b may be formed first, or may be formed simultaneously. The planar area fixing part 8a and the peripheral edge fixing part 8b can be easily formed by using, for example, a highly translucent double-sided adhesive tape, and workability can be improved.

  After the planar region fixing portion 8a and the peripheral edge fixing portion 8b are formed, the translucent substrate 6 is moved in the direction of the arrow in FIG. 9 and joined (temporarily fixed) to the condenser lens 7. At this time, the translucent substrate 6 can be accurately aligned by bringing the end of the translucent substrate 6 into contact with the substrate end positioning tool 15c.

  By aligning the translucent substrate 6, the condenser lens 7 is positioned on the translucent substrate 6 in a state where the center of the light receiving region (solar cell element 1) and the planar region 7sf (condenser lens 7) are accurately aligned. Will be combined. Therefore, the substrate frame alignment portion 6b provided in the substrate frame portion 6a of the light transmitting substrate 6 is accurately aligned between the end portion of the condenser lens 7 and the end portion of the light transmitting substrate 6. be able to.

  After condensing the condenser lens 7 and the translucent substrate 6 via the planar region fixing part 8a and the peripheral edge fixing part 8b, the air in the air layer between the condenser lens 7 and the translucent substrate 6 is exhausted. Thereafter, the space is filled with an adhesive having high translucency and fluidity, and the adhesive is cured at room temperature or baking to form a filling portion 8c (see FIG. 10). The condensing lens 7 and the translucent substrate 6 are fixed to each other over the entire surface by the filling portion 8c, and the condensing lens structure 8 having high mechanical strength and desired optical characteristics is obtained. As the adhesive, an adhesive having good translucency and weather resistance, for example, an acrylic resin adhesive or a silicone resin adhesive containing methyl methacrylate and an acrylic monomer is preferable.

  Since the air layer in the filling portion 8c is removed, the difference in refractive index between the surface of the translucent substrate 6 facing the condensing lens 7 and the first surface 7f of the condensing lens 7 is reduced, and loss due to reflection is reduced. Can be reduced.

  FIG. 11 is a plan view showing a plan view state in which the condensing lens structure according to the embodiment of the present invention is aligned using a positioning jig base.

  The planar region 7sf of the condenser lens 7 is aligned and fitted to the planar positioning tool 15a disposed on the positioning jig base 15. Since the planar area 7sf is circular, the lens rotation preventive tool 15b is disposed at an appropriate position in contact with the end of the condenser lens 7 so as not to rotate around the planar positioning tool 15a after alignment. is there. The lens rotation preventing tool 15b can be reliably prevented from rotating by being provided at two locations with respect to one plane positioning tool 15a. The planar positioning tool 15a is disposed at a total of 10 locations corresponding to the solar cell elements 1 (the transmission holes 4a of the frame bottom 4) mounted on the mounting plate 3, and has a total of 10 condenser lenses 7. A lens array can be constructed.

  The transparent substrate 6 is disposed so as to be superimposed on the positioned condenser lens 7 (lens array), and the transparent substrate 6 and the condenser lens 7 are joined to form a condenser lens structure 8. The end portion of the translucent substrate 6 is positioned in contact with the substrate end positioning tool 15c, and the substrate frame alignment portion 6b positioned at a predetermined position from the end portion is formed on the substrate frame portion 6a. It is. Therefore, the board frame alignment portion 6b can be positioned with respect to the planar area 7sf (planar positioning tool 15a).

  The substrate frame alignment portion 6b is formed at two locations in the longitudinal center of the translucent substrate 6 (substrate frame portion 6a), and the upper end of the frame side portion 5 is made to correspond to the substrate frame alignment portion 6b. By positioning and fixing to the hook protrusion 5c (see FIG. 12) formed on the hook 5a, the solar cell element 1 (transmission hole 4a) can be accurately aligned. Similarly to the above, it is possible to suppress the influence of the positional deviation due to thermal expansion to about 0.5 m, which is half of the length (about 1 m) in the longitudinal direction of the translucent substrate 6.

  FIG. 12 is a partial cross-sectional view illustrating a state in which the condensing lens structure according to the embodiment of the present invention is aligned with the solar cell element (frame side portion).

  A protrusion-like protrusion 5c is formed on the flange 5a at the upper end of the frame side part 5 so as to correspond to the central part in the longitudinal direction of the translucent substrate 6 (substrate frame part 6a). The ridge protrusion 5c is made to correspond to the position of the through hole formed as the substrate frame alignment portion 6b in the substrate frame portion 6a so as to align the condenser lens 7 with respect to the solar cell element 1 (transmission hole 4a). Formed.

  Therefore, if the translucent board | substrate 6 is moved to an arrow direction and the board | substrate frame alignment part 6b is fitted to the collar protrusion part 5c, it can align and position. Thereafter, the collar 5a and the translucent substrate 6 are fixed by an appropriate fixing member (not shown). Needless to say, the shape of the ridge protrusion 5c and the substrate frame alignment portion 6b is not limited to the above-described example, but may be other shapes. For example, when the board frame alignment portion 6b is a through hole, it is also possible to form a through hole in the flange 5c in the same manner and fasten both through holes with a bolt as a fixing member.

It is a disassembled perspective view which shows partially the arrangement | positioning relationship of the principal part of the concentrating solar power generation device which concerns on embodiment of this invention. It is a schematic side view which shows perspectively the arrangement | positioning relationship of the principal part seen from the side surface in the longitudinal direction of the concentrating solar power generation device which concerns on embodiment of this invention. It is an expanded sectional view which shows the cross-sectional outline | summary in the arrow AA of FIG. It is a top view which shows the arrangement | positioning state in the receiver of the solar cell element mounted in the concentrating solar power generation device which concerns on embodiment of this invention. It is explanatory drawing which shows the mounting state of the solar cell element mounted in the concentrating solar power generation device which concerns on embodiment of this invention, and the arrangement | positioning state of a permeation | transmission hole, (A) is a perspective view seen from the side surface (B) is a plan view of the light shielding plate (transmission hole) viewed from the condenser lens side. It is a top view of the condensing lens structure concerning an embodiment of the invention. It is an expansion schematic sectional drawing of the condensing lens structure of FIG. 6, and shows a partial schematic cross section from the plane center of the condensing lens structure to the arrow A. It is sectional drawing explaining the manufacturing method (manufacturing process) of the condensing lens structure which concerns on embodiment of this invention. It is sectional drawing explaining the manufacturing method (manufacturing process) of the condensing lens structure which concerns on embodiment of this invention. It is sectional drawing explaining the manufacturing method (manufacturing process) of the condensing lens structure which concerns on embodiment of this invention. It is a top view which shows the planar view state which aligned the condensing lens structure which concerns on embodiment of this invention using the positioning jig stand. It is a fragmentary sectional view explaining the state which aligns the condensing lens structure which concerns on embodiment of this invention with a solar cell element (frame side part). It is explanatory drawing explaining the concentrating solar power generation device as a prior art example, (A) is a top view which shows the outline | summary seen from the incident surface of sunlight, (B) is the arrow B of (A). It is sectional drawing which shows the cross section in -B.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solar cell element 2 Receiver 3 Mounting board 3a ４ 4 Frame bottom part 4a Transmission hole 4b Trapezoid part 5 Frame side part 5a ５ 5b Fitting groove 5c 鍔 Projection part 6 Translucent substrate 6a Substrate frame part 6b Substrate frame alignment part 7 Condensing lens 7b Boundary 7f First surface 7p Projection 7s Second surface 7sf Planar region 7sp Projection region 8 Condensing lens structure 8a Planar region fixing unit 8b Peripheral fixing unit 8c Filling unit 10 Concentrating solar power generation device 11 Frame 15 Positioning jig base 15a Planar positioning tool 15b Lens rotation preventing tool 15c Substrate edge positioning tool h Projection height Ls Sunlight ph Tilt change pitch pp Pitch θ Tilt angle

Claims (7)

A condensing lens having a planar first surface and a second surface formed with a protrusion having an inclined surface inclined with respect to the first surface and facing the first surface,
The second surface includes a planar region having a plane parallel to the first surface, and a projection region having the projections concentrically around the planar region, and the projection of the projections with respect to the pitch of the projections. It has an inclination change pitch that is a pitch for changing the inclination angle for each of a plurality of continuous protrusions, and the protrusion height of the protrusion is decreased from the end toward the center for each inclination change pitch. A condensing lens. A condensing lens having a planar first surface and a protrusion having an inclined surface inclined with respect to the first surface and having a second surface facing the first surface, and a plurality of the condensing lenses are fixed. A condensing lens structure comprising a translucent substrate to hold,
The second surface includes a planar region having a plane parallel to the first surface, and a projection region having the projections concentrically around the planar region, and the projection of the projections with respect to the pitch of the projections. An inclination change pitch that is a pitch for changing the inclination angle for each of a plurality of continuous protrusions, and the protrusion height of the protrusion is reduced from the end toward the center for each inclination change pitch,
A flat area fixing portion for fixing the translucent substrate and the condenser lens corresponding to the flat area between the translucent substrate and the first surface, and a peripheral edge of the protruding area A condensing lens structure characterized in that a peripheral edge fixing portion for fixing the translucent substrate and the condensing lens is formed. The condensing lens structure according to claim 2 , wherein the planar region fixing portion and the peripheral edge fixing portion are formed of a double-sided adhesive tape. The condensing lens structure according to claim 2 or 3 , wherein a filling portion filled with an adhesive is formed between the translucent substrate and the first surface. Condensing solar light comprising a condensing lens structure including a condensing lens and a translucent substrate that holds and fixes a plurality of condensing lenses, and a solar cell element disposed corresponding to the condensing lens A power generator,
The said condensing lens structure is a condensing lens structure as described in any one of Claim 2-4 , The said planar area | region is a circle | round | yen of the diameter surrounding the light-receiving area | region of the said solar cell element which opposes A concentrating solar power generation device defined by An inclination angle of the inclined surface with respect to the first surface and an inclination change pitch as a pitch for changing the inclination angle are such that light in a wavelength region that determines a short-circuit current of the solar cell element is condensed on the light receiving region. The concentrating solar power generation device according to claim 5 , wherein the concentrating solar power generation device is set. A condensing lens having a planar first surface and a protrusion having an inclined surface inclined with respect to the first surface and having a second surface facing the first surface, and a plurality of the condensing lenses are fixed. and a light-transmitting substrate that holds, the second surface comprises a planar region having a plane parallel to the first surface, the periphery of the flat surface area and a projection area having the projecting concentrically, wherein An inclination change pitch that is a pitch for changing the inclination angle of the protrusion for each of a plurality of continuous protrusions with respect to the protrusion pitch, and the protrusion height of the protrusion is changed from the end toward the center. A planar region fixing portion that is reduced for each pitch, and that fixes the light transmitting substrate and the condenser lens corresponding to the planar region between the light transmitting substrate and the first surface; The translucent substrate and the condensing lens corresponding to the peripheral edge of the protruding region A method of manufacturing a fixed to the peripheral fixing portion and is formed converging lens structure to,
The planar region is fitted and aligned with the planar positioning tool of a positioning jig base provided with a planar positioning tool that determines the position of the planar region and a substrate end positioning tool that determines the position of the end portion of the translucent substrate. And a process of
Forming the planar region fixing portion that fixes the translucent substrate and the condenser lens at a position corresponding to the planar region on the first surface;
Forming the peripheral edge fixing portion for fixing the translucent substrate and the condenser lens at a position corresponding to the peripheral edge portion of the protruding region on the first surface;
Contacting the end of the translucent substrate with the substrate end positioning tool and joining the translucent substrate to the planar region fixing portion and the peripheral edge fixing portion;
And a step of filling an adhesive between the translucent substrate and the condensing lens. A method for producing a condensing lens structure.

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