JPH0743535A - Sunlight collection transmitter - Google Patents

Abstract

PURPOSE:To efficiently fetch sunlight, to remarkably reduce a cost and to increase safety, and to remarkably improve reliability by using a plastic optical fiber whose core and clad consist of plastic in a transmission line. CONSTITUTION:The plastic optical fiber 2 whose core and clad consist of the plastic is used in the transmission line in a sunlight collection transmitter 1 which collects sunlight and irradiates collected light by transmitting to a prescribed place. The sunlight is transmitted on an optical cable 4 in which optical fibers 2 are bundled, and is radiated from an exiting end 5. A light guide for the sunlight is provided by connecting to the entering end of the plastic optical fiber 2, and the sunlight is entered into the light guide with heat resistance. The heat of the sunlight is diffused on the light guide, and the sunlight is made incident on the plastic optical fiber 2, however, the heat can be remarkably reduced. As the light guide, it is desirable to employ a material with superior permeability and superior connection efficiency with the plastic optical fiber 2 such as a glass rod, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar concentrating and transmitting device.

[0002]

2. Description of the Related Art A solar light concentrating and transmitting device comprises a light condensing unit for concentrating sunlight, a transmitting unit for transmitting the concentrated sunlight to a predetermined place, and an emitting unit for irradiating the transmitted sunlight. The sunlight condensing unit is composed of an optical system such as a concave mirror or a lens and a drive system for controlling the mirror or the lens so as to always face the sunlight. The transmission section uses an optical duct or an optical fiber that makes the inside of the tube a highly efficient reflection surface and reflects the inside of the tube for transmission.

As the optical duct, a box-shaped mirror assembly or a tube with a mirror surface is used. The mirror reflection is not suitable for long-distance transmission because the transmission efficiency is poor because light loss occurs due to absorption and scattering of light every reflection. In addition, since the duct requires a large space, it is limited in the place of transmission. Further, there is a problem that it is difficult to easily change it once it is laid.

On the other hand, when an optical fiber is used for a transmission line, it is widely used because it has a good transmission efficiency and the facility is small so that it can be wired at any place and the wiring can be easily changed. The optical fiber used in the sunlight collecting and transmitting device needs to efficiently collect the collected sunlight. Since the sun has a finite size, the collected sun image does not become a point, but has a certain finite size. The converged diameter of the collected sunlight (solar image diameter) is represented by the focal length of the mirror or lens for condensing. The calculation formula is shown in Formula (1).

D = 0.0093 × f (1) f: mirror or lens focal length d: sun image diameter

From the formula (1), the focal length is 150 mm and the diameter is 1
The solar image diameter when using a 20 mm lens is about 1.
2 mm. In reality, due to lens aberrations, lens molding errors, etc., the sun image is blurred from the calculated value by about 1.5 m.
m. An optical fiber having a core diameter of 1.5 mm or more is required to take all the collected sunlight into the optical fiber. Conventionally, the optical fiber is made of glass, and the core diameter is limited to about 1 mm at the maximum due to the limitation of strength and flexibility of the optical fiber. Therefore, there has been a demand for an optical fiber capable of increasing the diameter of the core, rich in flexibility, and not broken even when bent.

[0007]

The diameter of the sun image collected by the solar light concentrating and transmitting device tends to increase as the size of the condensing lens increases, and the light with the glass currently used as the core is used. There is a problem in that the fiber cannot be used because it has poor flexibility and may be broken when bent.

[0008]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems, and condenses the sunlight, and transmits the condensed light to a predetermined place to irradiate it and irradiate it. In the device, a solar light concentrating and transmitting device is provided, in which a plastic optical fiber whose core and clad are made of plastic is used for a transmission line.

In the present invention, as a result of studying a fiber having a large core diameter, high flexibility, and not breaking, it was found that a plastic optical fiber made of plastic for both the core and the clad is most suitable. In order to capture all the sunlight, it is essential to use an optical fiber with a core diameter larger than that of the sun image.As an optical fiber with a sufficiently large core diameter and excellent flexibility, both core and clad are made of plastic. It was concluded that it was best to use a plastic optical fiber that Fig. 1 shows an outline of a solar light concentrating system using a plastic optical fiber.

It was confirmed that the efficiency of taking in sunlight into the optical fiber is good when the plastic optical fiber is used for the light concentrating device. However, since the plastic optical fiber has poor heat resistance, it is necessary to develop a plastic optical fiber having good heat resistance. became. At present, when using a plastic optical fiber having poor heat resistance, further improvement is needed.

The plastic optical fiber currently used has poor heat resistance, and there is a possibility that the optical fiber will be deteriorated by the heat of the condensing portion of sunlight. When sunlight is collected by a lens with a diameter of 100 mm, the image diameter of sunlight is approximately 1.5 m
It becomes m. A plastic optical fiber having a core diameter of 2 mm is installed at this image forming position, and sunlight is introduced into the optical fiber. When sunlight illuminance is 800 W / m ² , diameter is 1.5 m
It has been confirmed that the solar image of m has a high-density energy of about 6 W, and that it reaches a high temperature of several hundred degrees when irradiated on an opaque object.

When this optical energy is introduced into the optical fiber, there is no particular problem because the optical fiber is transparent and does not absorb the light, but in reality, due to distortion of the lens and inaccuracy of solar tracking, all The light is not introduced into the optical fiber and illuminates the surrounding connector ferrule. The irradiated light energy is converted into heat and the ferrule is heated to 80 ° C. or higher. It is conceivable that the plastic optical fiber is deteriorated by the heat of the ferrule and melts and burns in the worst case. Therefore, as a safety measure, it was necessary to prevent the heat at the incident end from reaching the optical fiber.

Further, when flammable substances such as dust and dirt or opaque substances (colored substances) adhere to the incident end face of the plastic optical fiber, the adhering substances absorb high-density sunlight and become high in temperature, and the combustible substances are absorbed. May cause combustion or heat may melt the plastic optical fiber. Another problem was how to prevent foreign matter from adhering to the incident end.

As a result of the study, it was found that a method in which a light guide path for sunlight is connected to the incident end of the plastic optical fiber and the sunlight is first incident on the heat-resistant light guide path is preferable.
The heat of sunlight is dissipated by the light guide, and sunlight is incident on the plastic fiber, but the heat can be greatly reduced. The light guide path is not particularly limited as long as it has excellent heat resistance, but it is desirable that the light guide path has good transmittance and good connection efficiency with a plastic optical fiber. Examples include quartz glass rods, glass rods, rods with core / cladding, optical fibers, glass blocks and the like. The light guide path also has an effect of preventing foreign matter from adhering to the plastic optical fiber.

[0015]

FIG. 1 shows a schematic view of a solar concentrating and transmitting device using the plastic fiber of the present invention. FIG. 1 shows a condenser lens 6
The manner in which the condensed image from is introduced into the plastic optical fiber 2 is shown. The optical fiber 2 is fixed in the connector ferrule 3. Even if a plastic optical fiber having a core diameter larger than the diameter of the sun image is used, it is flexible,
There is no disconnection. Since the core diameter is large, the efficiency of taking sunlight into the optical fiber 2 is excellent. The sunlight is transmitted by the optical cable 4 that bundles the optical fibers 2, and the output end 5
Emitted more.

FIGS. 2 and 3 schematically show a light guide path provided at the incident end of the plastic optical fiber of the present invention. FIG. 2 is a schematic diagram when a glass core optical fiber 8 having the same core diameter as the plastic optical fiber 2 is used as the light guide path. FIG. 3 is a schematic diagram when the glass rod 9 is used as the light guide path. Of the collected sunlight, sunlight that could not be introduced into the optical fiber is absorbed by the surroundings and converted into heat, but the heat-resistant light guide path is not deteriorated by the heat, and the heat is dissipated by this light guide path. Since heat is not applied to the plastic optical fiber, there is no need to worry about fire or melting of the fiber due to heat. Further, since the light guide path serves as a cover, there is no fear that dust, dust, etc. will adhere to the end surface of the plastic optical fiber.

[0017]

EFFECTS OF THE INVENTION By using a plastic optical fiber for a light concentrating device, an optical fiber having a large diameter is possible, and sunlight can be efficiently taken into the optical fiber. In addition, the cost of the optical fiber is significantly reduced. In addition, by installing a heat-resistant light guide, the safety and the reliability of the plastic fiber are significantly improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is an explanatory view of an embodiment using a glass core optical fiber as a light guide path.

FIG. 3 is an explanatory view of an embodiment using a glass rod as a light guide path.

[Explanation of symbols]

 1: Solar condensing transmission device 2: Plastic optical fiber 3: Connector ferrule 4: Optical cable 5: Emitting end 6: Condensing lens 8: Glass core optical fiber 9: Glass rod

Claims (3)

[Claims] 1. A solar light concentrating and transmitting device for concentrating sunlight, transmitting the condensed light to a predetermined place and irradiating it, and using a plastic optical fiber whose core and clad are made of plastic for a transmission line. A solar concentrating and transmitting device characterized by the above. 2. The sunlight concentrating and transmitting apparatus according to claim 1, wherein in the sunlight concentrating and transmitting apparatus, a heat resistant light guide path is provided at a sunlight incident portion of a plastic optical fiber. 3. A glass rod as the heat resistant light guide path,
The solar concentrating and transmitting device according to claim 2, wherein an optical fiber whose core is made of glass is used.