JP2008052229A - New collective mirror composed of annular parabolic mirror with different focal length - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collective mirror that is compact with an easily controllable optical system and comprises segment type parabolic mirrors. <P>SOLUTION: The optical system is configured in a small depth, long in the lateral direction and short in the vertical direction by combining segment type parabolic mirrors having different focal lengths. With this method, an azimuth and an elevation angle to a position of the sun can be determined with respect to one focus as the center, and the sunlight can be followed without using a heliostat mirror. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

Detailed Description of the Invention

  In the present invention, as a method of condensing light at one point, a parabolic mirror having a fixed length has been conventionally used. In combination with a parabolic mirror, a horizontally long and short optical system is used. For example, when used as an optical system for solar thermal power generation, the center of a high-pressure sphere that converges sunlight is used as the focal point of the parabolic mirror. It has a feature that can control the optical system so that it becomes, and a “shutter” that controls the amount of sunlight incident on the opposite side centered on the focal point is installed to balance the weight with respect to the position of the sun. All azimuths and elevation angles can be controlled, and it belongs to the technical field mainly related to solar power generation.

  In condensing light at one point, a method using a “lens” is generally performed as a conventional technique. However, the “lens” using glass has a drawback such as absorbing infrared rays, and a parabolic mirror has been used when handling infrared rays or the like or when handling a large area. In the case of huge solar furnaces, a method using a “segment type” parabolic mirror has been adopted. However, in such a method, a “heliostat mirror” for tracking the sun must be used, and the entire apparatus becomes large and its operation is difficult. On the other hand, this apparatus can be advantageous in that the entire apparatus becomes compact and the control of the optical system is simplified.

Problems to be solved by the invention

  As an optical system so far, a parabolic mirror having a fixed focal length has been mainly used as a method for condensing light from a distant place at one point. Here, by combining “segment type parabolic mirrors” with different focal lengths, the depth can be reduced (planar), and the optical system can be made longer and longer and shorter and longer. In this case, it is sufficient to increase the number of segment mirrors on the top, bottom, left, and right, and in implementing solar thermal power generation, the “segment-type paraboloid” is not required for tracking solar light. By combining it with a “mirror” and a “shutter” that controls the amount of sunlight, it is possible to easily control the azimuth and elevation with respect to the sun.

Means for solving the problem

  In this optical system, a parabolic mirror has been used to collect light from far away at one point. In this way, for example, when concentrating sunlight at a single point, the parabolic mirror becomes enormous, and a “heliostat mirror” must be used as a means of tracking sunlight, and the entire system is It becomes large and the operation becomes complicated. The first thing to solve such a problem is to focus on the optical axis and use a small segmented parabolic mirror with a focal length of a length on the optical axis. Next, place a “segmented parabolic mirror” with a slightly larger focal length than the previous mirror surface by shifting left and right from the mirror surface, and the focal length is also larger next to it. “Segmented parabolic mirror” is placed. If the optical system is configured in this way, the light reflected by each “segment parabolic mirror” will converge at a predetermined focal point, and the amount of light incident on the opposite side of the focal point will be controlled. If the "shutter" is installed and balanced with its weight, the control of the azimuth and elevation with respect to the sun will be simplified, and the need to use a "heliostat mirror" will be eliminated.

  As a background art regarding the present invention, as a first thing, first, for example, as a means for converging sunlight, a “heliostat type parabolic mirror” has been used. Without using a "mirror", the second thing is that the optical system can be a "segmented parabolic mirror" with a different focal length in a plane, a horizontally long and short condensing system, In addition, it has the feature that it can easily control the azimuth and elevation angle with respect to the position of the sun to track the sunlight. ”Is a device that obtains higher temperatures, and the fourth feature is that it can be laid down near the ground during a typhoon or other disaster.

    [In the present invention, a parabolic mirror with a small diameter is generally used for a small object and a “segment type parabolic mirror” is used for a large object as a method for converging light and sunlight from a distance. And when dealing with solar furnaces that track and use sunlight, see Figure. For example, if a parabolic mirror with a small circular area is placed on the optical axis, a large “segmented parabolic mirror” with a slightly longer focal length than the mirror on the optical axis is placed on the left and right. In such a manner, “segment-type parabolic mirrors are arranged vertically and horizontally one after another. The size of the“ segment-type parabolic mirror ”used here is appropriately determined as shown in the figure. In this way, if there is only one focal point, it is only necessary to determine the azimuth and elevation angle with respect to the position of the sun around this focal point, and there is no need to use a “heliostat mirror” as before. .

Also, when there are two focal points as in the case of solar power generation, etc. As shown in FIG. 2, it is only necessary to control the azimuth and the elevation angle so as to track the sun with respect to the respective mirror surfaces around the focal points of the left and right mirror surfaces.

The invention's effect

In the present invention, a parabolic mirror having a certain length has been used as a method for converging light from a long distance. In particular, in the case of a solar furnace that needs to track sunlight, the “heliostat mirror” for tracking the sun has been required, so that the sun can be tracked with only a parabolic mirror. Therefore, the effect is thought to be immeasurable.

Condenser mirror (single focus type) composed of "segmented parabolic mirrors" with different focal lengths Condenser mirror (sub-focal type) composed of "segmented parabolic mirrors" with different focal lengths

Explanation of symbols

A Light B Optical axis C Focus 1 Segment type parabolic mirror

Claims (1)

  As a method of concentrating light from a distance, a single parabolic mirror or a “segment type parabolic mirror” composed of a “segment mirror” has been used. Here, “segment type parabolic mirrors” with different focal lengths are combined to form an optical system with a small depth (in a plane), a long side, and a short length. This can be linked to a method that can track sunlight without using a “heliostat mirror”, for example, when converging sunlight.

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