JP2010169981A - Solar lens and solar light utilizing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a necessary amount of a constituent material is increased to incur cost increase in a large solar lens due to its thick fundamental shape, a device is necessary for a structure such as a support for supporting the weight and it is difficult to apply a large solar lens to a light condensing device having a wide surface area even though the solar lens condensing incident rays on an light emission surface by total reflection is proposed by forming the solar lens of a reversed trapezoidal shape by using a transparent material as a method for condensing solar rays regardless of solar azimuth and height and to achieve constitution suitable for a large size, cost reduction and lightness in weight. <P>SOLUTION: Instead of the solar lens formed by using the transparent material such as glass and synthetic resin, a solar lens is formed by using a hollow body without using the transparent material and front and rear slopes are formed by using specular reflection plates to condense light by only specular reflection on the slopes. Thereby, cost reduction and lightness in weight are achieved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an improvement of a solar lens and a device for using the same, which aims to collect sunlight rays whose altitude and azimuth are constantly moving in a fixed range narrower than a light receiving area with a stationary lens. .

As a method for concentrating sunlight rays regardless of the direction and altitude of the sun, a condensing method using total reflection of light has been proposed.
Japanese Patent Application No. 2008-309186 Solar Lens JP-A-2001-189487 Concentrator and Concentrating Solar Cell Module

  The method of Patent Document 1 is a solar lens in which an inverted trapezoidal solar lens is formed of a transparent material and condenses incident light on a light exit surface by total reflection. Because the lens is so thick that the side length is not much different, the large solar lens requires a large amount of constituent material and the cost is high. There is a drawback that it is not possible to increase the size.

  The method of Patent Document 2 is a method of collecting light by a combination of specular reflection and total reflection by a reflection film. However, since the total reflection on the light incident surface is used, one of the light beams specularly reflected by the reflection film is used. There is a drawback in that the ratio of the light beam transmitted through and dissipated from the light incident surface, or the ratio of light rays that directly hit the opposite reflection film and reversely flow back and dissipate from the light incident surface. An object of the present invention is to eliminate these drawbacks and provide a solar lens with high light collecting performance.

  In contrast to the solar lens of Reference 1 and the concentrator of Reference 2 that are made of a transparent material such as glass or synthetic resin, the solar lens is formed of a hollow body without using a transparent material, and the front and rear slopes are formed. By forming the light with a specular reflector and collecting light only by specular reflection on a slope, the above-described problems are solved by reducing cost and weight.

  Since the lens body can be made hollow as compared with the solar lens of Document 1, the constituent material of the body is unnecessary, and the weight can be reduced and the cost can be reduced. Further, it becomes easy to manufacture a large-sized solar lens, and a large-scale solar power generation facility using, for example, an area of 100 square meters or more becomes possible. Although a specular reflector is required as the front and rear slopes, for example, in the case of photovoltaic power generation, the required area of the power generation panel is halved by concentrating, so that significant cost reduction can be expected as a whole. In addition, if a composite solar lens composed of a plurality of solar lenses arranged in a plane is used, there is a possibility that a solar-use facility with a larger area can be realized, and it can be applied to all devices that use solar energy. It can be done.

  FIG. 1 is a perspective view of a solar lens according to the present invention, and FIG. 2 shows a cross section of a solar lens 1 made of a hollow body having a rod shape and an inverted trapezoidal cross section. A front slope 4 that is in contact with the front end of the light surface at an acute angle of an inclination angle α1, and a virtual slope surrounded by a rear slope 5 that has a shape in which the inclination angle α2 decreases toward the light exit surface and is curved inward at the rear end of the light entrance surface. An inverted trapezoidal solar lens is formed in this space. Further, the front and rear slopes and the trapezoidal end faces 6 at both ends are made of a metal plate or the like, and the inside of the front slope and the trapezoidal end face is a flat surface, and the inside of the rear slope is formed as a curved surface so that it can be specularly reflected. .

  By tilting the light incident surface and light exit surface, the light collection magnification can be increased and the light collection performance can be finely adjusted, but the explanation is based on an inverted trapezoidal solar lens whose light exit surface is parallel to the light incident surface. To do. In addition, the inclination angle of the light entrance surface that is the sunlight collecting surface and the light exit surface from which the collected sunlight is extracted differs depending on the performance and installation conditions required by the light receiving device, but FIG. 2 shows that both the light entrance surface and the light exit surface are horizontal. The solar lens of the basic specification which condenses the sunlight beam of the maximum width | variety with an altitude of 0 degree to 90 degree | times with a state solar lens is shown. In the following description, the inclination angle of the slope and the inclination angle of the light beam are indicated by an inclination angle with respect to the vertical plane unless otherwise specified.

  In order to condense and extract all incident light rays incident from the light incident surface to the light exit surface, in addition to the incident light rays that directly reach the light exit surface, all light rays that are specularly reflected by the front and rear slopes are directed to the light exit surface. It is necessary to set it so that For this purpose, the maximum height of sunlight e1 incident from the front end of the light entrance surface is specularly reflected by the front slope and reaches the rear slope, and the light beam reaches the light exit surface again by specular reflection. The inclination angle α1 may be set.

  Specifically, when concentrating sunlight rays with an altitude of 0 to 90 degrees, the front slope is inclined 45 degrees in order to cause the incident light of the maximum altitude 90 degrees to travel horizontally toward the rear slope. Even at the highest altitude sun rays incident on any position on the slope, the sun rays at altitudes below that can be made to travel in the same way from the rear slope to the light exit surface by specular reflection.

  Further, the inclination angle α2 of the rear slope may be set so that the light beam reaching from the front slope by specular reflection or the minimum altitude sunlight ray e2 incident on the rear slope reaches the light exit surface after being specularly reflected by the rear slope. . Further, the inclination angle α2 is gradually reduced within a range in which the light beam specularly reflected by the rear slope reaches the light exit surface, and the rear slope is set to be curved inward. For example, by setting the inclination angle of the rear slope to 35 degrees at the upper end and forming it with a curved surface so that the inclination angle gradually becomes smaller, incident light rays that are specularly reflected on the side closer to the light entrance surface of the rear slope can also be emitted. Incident light that is specularly reflected on the side close to λ can also be collected in a narrow range.

  If it is set so that the light beam with the minimum altitude incident on the tip of the rear slope near the light entrance surface can be focused on the light exit surface by specular reflection, the sun rays of higher altitudes will also be reflected on the light output surface by specular reflection. It can be condensed. If the rear slope is a flat surface instead of a curved surface, the maximum slope of the light incident on the side closer to the entrance surface of the front slope and the light incident on the side closer to the exit surface should be specularly reflected on the rear slope at the same tilt angle. Therefore, it cannot converge and converge on the light exit surface.

  What is necessary is just to set the space | interval of a light emission surface and a light-incidence surface so that the light beam specularly reflected by the back slope may not hit a front slope again. Specifically, the thickness of the solar lens is the position where the light beam having the minimum altitude incident on the tip of the rear slope near the light incident surface is specularly reflected and reaches the front slope. If it is thicker than that, the light beam that has reached the front slope will be dissipated from the light incident surface by mirror reflection.

  By taking into account the latitude of the area where the solar lens is used, the variation range of the solar altitude, and the direction of installation, the solar lens can be made to have directivity and efficiently concentrate sunlight. For example, in the case of Tokyo, the maximum altitude is 78 degrees on the summer solstice and the minimum altitude is 31 degrees on the winter solstice, and sun rays exceeding this range do not enter the solar lens from the south.

  When the front slope of the sun lens is arranged southward, the altitude of the sun rays entering the light entrance surface from the front slope direction is a maximum of 78 degrees and a minimum of 31 degrees throughout the year. It is possible to collect light efficiently by setting the solar lens so that light can be collected. The altitude fluctuation range is 47 degrees regardless of the region or season because it is related to the inclination of the earth axis with respect to the public roads of the earth.

  The sun lens can be focused by placing the front slope southward, but if you try to focus sunlight from all directions at all altitudes without considering the direction of the sun, Since the inclination angle of the slope is 0 degree and the areas of the light incident surface and the light output surface are the same, it cannot be condensed.

  As described above, the solar lens of the present invention has directivity in the direction in which light can be collected, and light rays from the direction of the front slope inclined at an acute angle can be collected. Light rays other than the incident light beam that reaches can hardly be collected. Therefore, by limiting the range of the concentrated sunlight to the light beam with the maximum altitude to the minimum altitude according to the latitude, it is possible to secure more practical light condensing performance.

  Moreover, even if the performance is slightly reduced, it is possible to integrate products by setting specifications with a range in the latitude range that can be used. For example, considering the difference in latitude from Okinawa to Hokkaido, a solar lens that corresponds to the maximum altitude in Okinawa and the minimum altitude in Hokkaido can be used throughout Japan.

  When the sun lens is installed in consideration of the direction of the sun, light rays entering from an oblique direction, such as sunlight from the southeast, are rays of light traveling in the north-south direction from the front slope of the sun lens and rays traveling in the east-west axial direction. It can be considered in two parts.

  Sunlight shines from the direction of 30 degrees before and after the east-west axis at a time when the altitude close to sun rises is low, but for example, in the case of sun rays in the summer morning sun shining from the east direction, As shown in FIG. 3, the incident light beam travels with its front slope bent in the direction of the rear slope, and reaches the light exit surface after being specularly reflected by the rear slope and the trapezoidal end face. However, in the limited time zone where the sun appears before and after the summer solstice, the sun rays in the reverse direction from the east-northeast or west-southwest are incident on the solar lens. It is considered that some light beams such as the light beam are lost without being collected.

  FIG. 4 shows an example of a solar lens suitable for collecting sunlight rays having a maximum altitude of 78 degrees and a minimum altitude of 31 degrees. Since the inclination angle α1 of the front slope is set to about 51 degrees, the sunlight with the highest altitude is specularly reflected on the front slope and travels in a substantially horizontal direction to reach the rear slope. The rear slope is formed with a curved surface whose inclination angle is gradually reduced. However, if the uppermost inclination angle α2 is set to 38 degrees, the traveling light beam is specularly reflected on the rear slope and has an inclination angle of 14 degrees. It will reach the light exit surface. FIG. 4 also shows the light ray path, in which m1 to m4 are drawn with the highest altitude rays, and n1 to n3 are drawn with the lowest altitude rays according to the actual situation. If the ratio of the light incident surface to the light exit surface is the concentration concentration factor of light rays, the concentration factor of the solar lens in FIG.

  Various light receiving devices that collect and use solar energy, such as solar cell modules that use sunlight, light ducts that use natural light for indoor lighting, and heat receiving devices that use solar heat, are placed on the light exit surface. Can do. In the above description, the front slope is flat and the rear slope is curved. However, the performance can be adjusted more finely by gently curving the front slope.

  FIG. 5 shows a composite solar lens in which a plurality of rod-shaped solar lenses are connected with their light incident surfaces arranged in a direction perpendicular to the longitudinal direction. A sunlight utilization device can be configured by arranging a light receiving device such as a solar cell module on the light exit surface of each solar lens. The compound type solar lens can be formed by connecting the front and rear slopes adjacent to each other.

  As an application of the solar lens, when the light receiving device is a photovoltaic power generation battery module, a method in which the front slope and the rear slope are also used as the surface electrode of the cell is conceivable. In the case of a large-sized solar lens, a factory, warehouse, or office can be constructed directly under the front slope. Because the roof of the building can be used as a front slope, it is considered advantageous in terms of price and landscape

  In addition, for the sake of simplicity, the description has been made on the assumption that the solar lens is installed horizontally and the light incident surface and the light exit surface are parallel to each other, but the light incident surface and the light exit surface do not have to be parallel. In the case where the light receiving device attached to the light exit surface is a photovoltaic power generation panel, it is desirable to have an inclination so that the dirt on the panel surface is washed away by rainwater. However, in FIG. Even if the shape is inclined with respect to the surface, substantially the same concentration concentration factor can be secured.

  As described above, the solar lens of the present invention is a solar lens that collects light only by specular reflection, but it has an extremely simple shape by providing directivity with conditions set in consideration of latitude, solar orientation, and solar altitude. It has a feature that it can efficiently collect light and has high practicality. Although the solar lens according to the present invention can exhibit the maximum performance by arranging the front slope facing south, for example, there is a slight performance degradation even if it is installed tilted east and west such as south-southeast. The function is unchanged.

It is a perspective view of a solar lens. It is sectional drawing of a solar lens. It is explanatory drawing of the light ray path seen from the top. It is explanatory drawing of the light ray path seen from the side. It is a side view of a composite type solar lens.

1. Sun lens 2, light incident surface 3, light output surface 4, front slope 5, rear slope 6, trapezoidal end face

Claims (3)

  Incidence at the front edge of the light entrance surface when the solar lens is made of a hollow body with a reverse trapezoidal cross-section and the inside of the front and rear slopes of the solar lens is the reflective surface and sunlight is incident from the front slope direction. The angle of inclination of the front slope is set so that the highest altitude sunlight rays are specularly reflected on the front slope and reach the rear slope, and the light rays again reach the light exit surface by specular reflection, and the minimum incident on the rear slope The tilt angle of the rear slope is set so that high-level sunlight rays reach the light exit surface by specular reflection on the rear slope, and the rear slope is set inward within the range where the light beam specularly reflected by the rear slope reaches the light exit surface. A solar lens characterized in that, by bending, a light beam incident from a light incident surface is collected on a light exit surface by specular reflection.   A composite solar lens comprising a plurality of the solar lenses according to claim 1 arranged in a direction perpendicular to the longitudinal direction and connected by a light incident surface.   2. A solar light utilization device, wherein the solar lens according to claim 1 is disposed such that the front slope is substantially southward, and a light receiving device is disposed on a light exit surface.

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