JP2014163629A - Soar light concentrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar light concentrator in which the rotation of concentration spot on a receiver incident surface is properly suppressed.SOLUTION: The solar light concentrator follows the motion of sun on the celestial sphere by rotation around rotation shafts x, y which cross orthogonally each other and makes solar light reflected by a plane reflecting mirror 3 which is mounted incident to a receiver incident surface. Therein, when a straight line (a) which passes through a target point p, as one line of segment contained in a receiver incident surface is supposed and a flat surface Q containing the straight line (a) and an immobile point (e) are supposed, an inclination of the rotation shaft x with respect to a straight line which crosses orthogonally the flat surface Q is set to be 5° or less (containing 0°). Assembly of points at which light reflected on the position of the rotation shaft y of the plane reflecting mirror 3 intersects the receiver incident surface is always contained on the straight line (a) supposed on the receiver incident surface. Therein, the segment consisting of the assembly of points at which light rays reflected on the segments in parallel to the rotation shaft y on a mirror surface 30 of the plane reflecting mirror 3 intersect the receiver incident surface and the straight line (a) supposed on the receiver incident surface always get to parallel with each other and, therefore, the rotation of concentration spot is suppressed.

Description

  The present invention is a condensing facility for utilizing solar energy, which tracks the movement of the sun by rotation around two orthogonal rotation axes, and reflects the sunlight to the mounted flat reflector to condense it on the receiver. The present invention relates to a solar light collecting device.

  There are known facilities such as solar thermal power generation, solar power generation, and solar furnace that collect sunlight on a receiver installed on the top of the solar tower by a large number of solar concentrators (heliostats) and use the solar energy. The solar concentrator used here has the function of directing the mirror surface of the mounted reflector in any direction, and the direction of the mirror surface of the reflector is controlled appropriately according to the apparent sun direction. By doing so, the light incident from the sun and reflected by the mirror surface is condensed on the incident surface (light receiving surface) of the receiver.

  Conventionally, there are two types of solar light collecting devices that are generally used (for example, Patent Documents 1 and 2). Each includes a first rotating shaft whose position and direction are fixed with respect to the ground, and a second rotating shaft provided so as to be orthogonal thereto, and a reflecting mirror is attached to the latter. The case where the first axis of rotation is perpendicular to the ground is a graticule type, and the case where it is parallel to the axis is an equator ritual. When the reflecting mirror is rectangular, it is common that the two opposite sides of the rectangular side are perpendicular to the second rotation axis and the other two sides are parallel to the second rotation axis.

JP 2012-251755 A JP 2010-101591 A

  When the reflector is a parallelogram such as a rectangle, the shape of the condensing spot on the incident surface of the receiver installed on the top of the solar tower (the portion illuminated by the reflected light on the receiver incident surface) is also basically parallel. It becomes a quadrilateral. However, in the case of using a conventional graduation-type or equator-type sunlight condensing device, there is a problem that the shape of the condensing spot on the receiver incident surface changes as if rotating. When such a rotation of the condensed spot occurs, in order to utilize all of the solar energy that reaches the receiver, a sufficiently large receiver including the rotation range of the condensed spot must be prepared. On the other hand, if the entire incident surface of the receiver must be reflected as uniformly as possible, the receiver must be small enough to be included in the part that is always illuminated by the rotating focused spot. I must. In the former case, the receiver cannot be used effectively, and in the latter case, the collected solar energy cannot be used effectively, and it is difficult to say that both are efficient power generation systems.

Therefore, the object of the present invention is to solve the above-described problems of the prior art, and to suppress the rotation of the condensing spot on the receiver incident surface (change in shape as if rotating with time) appropriately. The object is to provide a light condensing device.
Another object of the present invention is to provide a method of installing a solar light collecting device in which the rotation of the condensing spot (the change in shape as if rotating with time) is suppressed.

  As a result of repeated studies to solve the above-described problems, the present inventors hypothesized an arbitrary straight line a passing through the target point p on the receiver incident surface, and this straight line a and a fixed point e (of the solar light collecting device). When the plane Q including the first rotation axis and the second rotation axis is hypothesized, by setting the first rotation axis of the solar light collecting device to be substantially orthogonal to the virtual plane Q, the receiver is incident. It has been found that the rotation of the condensing spot on the surface (the shape change as if rotating over time) can be appropriately suppressed.

The present invention has been made on the basis of such findings and has the following gist.
[1] A first rotating member (2x) rotatably supported by the fixed support portion (1), a second rotating member (2y) rotatably supported by the first rotating member (2x), A plane reflecting mirror (3) fixed to the second rotating member (2y);
The rotation axis (x) of the first rotation member (2x) and the rotation axis (y) of the second rotation member (2y) are orthogonal to each other, and the mirror surface (30) of the plane reflecting mirror (3) is the rotation axis (y ) Parallel to
A solar concentrator that tracks the movement of the sun on the celestial sphere by rotation around the rotation axes (x) and (y), and makes the sunlight reflected by the plane reflector (3) incident on the incident surface of the receiver. And
A line segment included in the incident surface of the receiver, which is assumed to be a straight line (a) passing through the target point (p), and a plane (Q) including the straight line (a) and the fixed point (e) is assumed to be virtual. In this case, the solar light collecting device is characterized in that the inclination of the rotation axis (x) with respect to a straight line orthogonal to the plane (Q) is 5 ° or less (including the case of 0 °).

[2] The solar light collecting device according to [1], wherein the mirror surface (30) of the planar reflecting mirror (3) is a parallelogram.
[3] In the solar light collecting apparatus of [1] or [2] above, the center of the incident surface of the receiver is the target point (p), and the straight line (a) passing through the target point (p) is horizontal. A solar concentrator characterized by.
[4] A plurality of solar light collecting devices according to any one of the above [1] to [3] are arranged around a receiver, and sunlight is condensed on the receiver by the plurality of solar light collecting devices. Concentrating power generation equipment.

[5] A first rotating member (2x) rotatably supported by the fixed support portion (1), a second rotating member (2y) rotatably supported by the first rotating member (2x), A plane reflecting mirror (3) fixed to the second rotating member (2y);
The rotation axis (x) of the first rotation member (2x) and the rotation axis (y) of the second rotation member (2y) are orthogonal to each other, and the mirror surface (30) of the plane reflecting mirror (3) is the rotation axis (y ) Parallel to
Installation of a solar concentrator that tracks the movement of the sun on the celestial sphere by rotation around the rotation axes (x) and (y) and makes the sunlight reflected by the flat reflector (3) incident on the incident surface of the receiver A method,
A line segment included in the incident surface of the receiver, which is assumed to be a straight line (a) passing through the target point (p), and a plane (Q) including the straight line (a) and the fixed point (e) is assumed to be virtual. In this case, the solar light collecting device is installed so that the inclination of the rotation axis (x) with respect to the straight line orthogonal to the plane (Q) is 5 ° or less (including the case of 0 °). To install a solar concentrator.

[6] The method of installing the solar light collecting device according to [5], wherein the mirror surface (30) of the planar reflecting mirror (3) is a parallelogram.
[7] The installation method of [5] or [6] above, wherein the center of the incident surface of the receiver is a target point (p), and the straight line (a) passing through the target point (p) is horizontal. To install a solar concentrator.

In the solar light collecting device of the present invention, a set of points where the light reflected at the position of the rotation axis (y) of the plane reflecting mirror (3) intersects the receiver incident surface is a straight line ( Always included in a). A line segment composed of a set of points on the mirror surface (30) of the plane reflecting mirror (3) and reflected on a line segment parallel to the rotation axis (y), and the receiver incident surface; Since the imaginary straight line (a) is always parallel to the incident surface, the rotation of the condensing spot (change in shape as if rotating with time) is suppressed. The effects of the present invention as described above are obtained when the inclination of the rotation axis (x) with respect to a straight line orthogonal to the plane (Q) is 0 °, that is, when the rotation axis (x) is orthogonal to the plane (Q). It can be obtained simply, but if the inclination of the rotation axis (x) with respect to the straight line orthogonal to the plane (Q) is 5 ° or less, the rotation axis (x) is almost orthogonal to the plane (Q). Therefore, in this case as well, a corresponding effect similar to the above can be obtained, and the rotation of the condensing spot (the shape change as if rotation has occurred over time) can be suppressed.
Moreover, according to the installation method of the solar concentrator of the present invention, it is possible to install the solar concentrator capable of suppressing the rotation of the condensing spot (the shape change as if rotating with time). it can.

BRIEF DESCRIPTION OF THE DRAWINGS It shows typically an example of the concentrating type power generation equipment with which the solar concentrating device of this invention is applied, FIG. 1 (a) is a top view, FIG. 1 (a) is a side view. The back view which shows one Embodiment of the sunlight condensing device of this invention typically, and shows the state in which the plane reflective mirror was partly notched Side view of the solar light collecting device shown in FIG. FIG. 4A schematically shows a change in shape of the focused spot on the receiver incident surface over time. FIG. 4A is a drawing showing a change in the shape of the focused spot when a conventional apparatus is used. ) Is a drawing showing the shape change of the focused spot when the apparatus of the present invention is used. Intensity distribution diagram of light showing the shape change of the condensing spot over time on the receiver incident surface obtained by numerical calculation when using a conventional graduation table type device Light intensity distribution diagram showing the shape change of the condensing spot over time on the receiver incident surface obtained by numerical calculation when using a conventional equator ritual device Intensity distribution diagram of light showing the shape change of the condensing spot over time on the receiver incident surface obtained by numerical calculation when using the apparatus of the present invention

The solar light collecting device of the present invention tracks the movement of the sun by rotation around two orthogonal rotation axes in a solar power generation or condensing type power generation facility that performs solar power generation, etc. It is a device that reflects sunlight and focuses it on a receiver, also called a heliostat.
FIG. 1 schematically shows an example of a concentrating power generation facility (concentrating power generating facility that performs solar thermal power generation or solar power generation) to which the solar light concentrating device of the present invention is applied. A) is a plan view, and FIG. 1 (a) is a side view. In the site, a solar tower 5 having a receiver 6 on the upper part and a plurality of solar concentrators 4 are installed, and a receiver on the upper part of the solar tower 5 using a plurality of solar concentrators 4 6 is condensed. The receiver 6 has a flat incident surface (light receiving surface).

Usually, hundreds to tens of thousands of solar concentrators 4 are installed around the solar tower 5 (receiver 6). Although the height of the solar tower 5 is arbitrary, it is usually about 50 to 100 m. In the case of a concentrating solar thermal power generation facility, the receiver 6 installed at the upper part of the solar tower 5 is constituted by a solar thermal receiver. Generally, in a solar receiver, heat transfer tubes are closely arranged on an incident surface (light receiving surface), and a heat medium flows through the heat transfer tubes. In the case of a concentrating solar power generation facility, the receiver 6 is a solar receiver. In this sunlight receiver, solar cells (for example, multi-junction solar cells) are arranged on the incident surface (light receiving surface).
When installing a concentrating power generation facility in the northern hemisphere, a solar tower 5 is usually installed at the south end of the site, and a receiver 6 is attached to the top of the solar tower 5 toward the north. In this case, the incident surface of the receiver 6 may be inclined forward to the north side. Then, a large number of solar light collectors 4 each equipped with a plane reflecting mirror (usually a rectangular plane reflecting mirror) are installed on the ground on the north side of the solar tower 5.

2 and 3 schematically show an embodiment of the solar light collecting device of the present invention. FIG. 2 is a rear view showing a state in which a plane reflecting mirror is partially cut away, and FIG. 3 is a side view. In any of the drawings, the receiver 6 installed on the top of the solar tower is shown.
This solar condensing device includes a fixed support portion 1 made up of a column or the like standing on an installation base such as the ground, a first rotating member 2x rotatably supported by the fixed support portion 1, and the first A second rotating member 2y that is rotatably supported by the rotating member 2x and a planar reflecting mirror 3 that is fixed to the second rotating member 2y are provided. Then, the rotation axis x of the first rotation member 2x (hereinafter sometimes referred to as “first rotation axis x”) and the rotation axis y of the second rotation member 2y (hereinafter referred to as “second rotation axis y”) And the mirror surface 30 of the planar reflecting mirror 3 is configured to be parallel to the rotation axis y. The first rotating member 2x and the second rotating member 2y are driven to rotate about the rotation axes x and y, respectively, by a driving device (both not shown) controlled by a control device.

Such a solar concentrator tracks the movement of the sun on the celestial sphere by rotation about the rotation axes x and y, and reflects the sunlight reflected by the planar reflecting mirror 3 on the incident surface 60 (light receiving surface) of the receiver 6. To enter.
The shape of the mirror surface 30 of the plane reflecting mirror 3 is arbitrary, but is usually a parallelogram such as a rectangle or a square. The rotation of the focused spot is particularly problematic when the shape of the mirror surface 30 is a parallelogram. In this case, the parallelogram (hereinafter referred to as “rectangular” as an example) plane reflecting mirror 3 may be a single unbroken mirror, or a single piece by bonding a plurality of plane mirrors. The rectangular reflector may be configured approximately. The rectangular plane reflecting mirror 3 is fixedly attached to the second rotating member 2y. Usually, of the four sides of the rectangle, two opposite sides are parallel to the second rotation axis y, and the remaining two sides are the second rotation axis. Make a right angle to y.

The solar light concentrator of the present invention is a line segment included in the incident surface 60 of the receiver 6 in the basic configuration as described above, and imaginary a straight line a passing through the target point p. When the plane Q including the straight line a and the fixed point e is assumed, the inclination of the first rotation axis x with respect to the straight line orthogonal to the plane Q is set to 5 ° or less (including the case of 0 °). That is, the first rotation axis x is set so that the inclination with respect to the straight line orthogonal to the plane Q is 5 ° or less (including the case of 0 °).
Here, the fixed point e is an intersection of the first rotation axis x and the second rotation axis y, and the target point p is such that light reflected at the position of the fixed point e is always incident. It is a point on the receiver entrance surface that is controlled by. The sunlight condensing device is controlled so that the target point p is defined on the incident surface 60 of the receiver 6 and the light reflected at the position of the fixed point e is always incident on the target point p.

  Most preferably, the first rotation axis x has an inclination of 0 ° with respect to a straight line orthogonal to the plane Q, that is, the first rotation axis x is orthogonal to the plane Q. If the inclination of the first rotation axis x with respect to is less than 5 °, it can be considered that the rotation axis x is substantially orthogonal to the plane Q. Further, the smaller the inclination of the first rotation axis x with respect to the straight line orthogonal to the plane Q, the better. For this reason, it is preferably 2 ° or less (including the case of 0 °), and preferably 1 ° or less (however, 0 (Including the case of °).

The position of the target point p set on the incident surface 60 of the receiver 6 is arbitrary, but is usually set at the center of the incident surface 60 of the receiver 6. In addition, a straight line a (straight line passing through the target point p) imaginary on the incident surface 60 of the receiver 6 can be arbitrarily set, and may be a straight line inclined with respect to the horizontal, but is usually composed of a horizontal straight line. Is done.
In the actual device, the fixed point e, which is the intersection of the second rotation axis y and the two rotation axes x, y, is not on the mirror surface 30 in a strict sense, but may be slightly away from the mirror surface 30. In many cases, the distance between the receiver 6 and the solar light collecting device is negligible so that it can be ignored. Therefore, even if the distance is considered to be on the mirror surface 30, the present invention is constituted. There is no problem.

  In the solar light collecting device of the present invention, the second rotation axis y itself is rotated by the rotation around the first rotation axis x when tracking the sun, but the second rotation axis y is the first rotation. Since it is orthogonal to the axis x, it is always included in a plane that passes through the fixed point e and is perpendicular to the first rotation axis x. That is, the second rotation axis y is always included in the plane Q including the straight line a and the fixed point e imaginary on the receiver incident surface 60. For this reason, the set of points where the light beam reflected at the position of the second rotation axis y of the plane reflecting mirror 3 intersects the receiver incident surface 60 is always included in the straight line a imaginary on the receiver incident surface 60. Become. And the line segment which consists of a set of points on the mirror surface 30 of the plane reflecting mirror 3 and reflected on the line segment parallel to the second rotation axis y intersects the receiver incident surface 60 is the receiver incident surface. 60 is always parallel to the imaginary straight line a. Therefore, a set of points where light beams reflected at two positions parallel to the second rotation axis y among the four sides of the mirror surface 30 of the rectangular plane reflecting mirror 3 intersect the receiver incident surface 60 is always the receiver incident surface. 60 is a line segment parallel to the straight line a on the line 60 (in this embodiment, the horizontal center line of the receiver 6). ) Will be suppressed.

  The operational effects of the present invention as described above are simply obtained when the inclination of the first rotation axis x with respect to the straight line orthogonal to the plane Q is 0 °, that is, when the first rotation axis x is orthogonal to the plane Q. If the inclination of the first rotation axis x with respect to the straight line orthogonal to the plane Q is 5 ° or less (preferably 2 ° or less, more preferably 1 ° or less), the first rotation axis is obtained. Since x can be considered to be substantially orthogonal to the plane Q, in this case as well, a corresponding effect similar to the above can be obtained, and the rotation of the focused spot (as if rotation has occurred over time) Change in shape).

  FIG. 4 schematically shows a change in shape of the focused spot on the receiver incident surface over time. FIG. 4A shows a case where a conventional apparatus is used, and FIG. The case where the device of the present invention is used is shown. Here, the condensing spot is a portion illuminated by the reflected light on the receiver incident surface 60, and more strictly, “when a straight line connecting the target point p and the fixed point e is L, plane reflection The contour of the mirror surface 30 of the mirror 3 is projected onto the receiver incident surface 60 along the straight line L ”. In the case of the conventional apparatus shown in FIG. 4A, the shape of the focused spot changes as if it has been rotated in one day. On the other hand, in the case of the device of the present invention shown in FIG. 4 (a), the shape of the parallelogram of the focused spot changes during one day (the upper and lower sides of the parallelogram shift to the left and right). However, the rotation as shown in FIG.

5 to 7 are light intensity distribution diagrams showing the shape change of the focused spot with time on the receiver incident surface obtained by numerical calculation. Among these, FIG. 5 shows the change in shape of the focused spot over time when the conventional pedestal device is used, and FIG. 6 shows the shape of the focused spot over time when the conventional equator apparatus is used. FIG. 7 shows changes in the shape of the focused spot over time when the apparatus of the present invention (the apparatus of the present invention in which the first rotation axis x is orthogonal to the plane Q) is used. The equipment configuration assumed for the calculation is the number of solar concentrators installed: 80, the height of the solar tower: 22 m, the height to the center of the condensing spot: 20 m, between the solar tower and each solar concentrator The horizontal distance was 15-60 m, and the angle between the first rotation axis x and the vertical line was about 51 degrees closest to the solar tower and about 18 degrees farthest from the solar tower.
According to FIGS. 5 to 7, when the conventional apparatus is used, the rotation of the focused spot is generated, whereas when the apparatus of the present invention is used, the rotation of the focused spot is not at all. It has not occurred.

In the installation method of the solar light collecting device of the present invention, when installing the solar light collecting device having the basic configuration as described above, it is one line segment included in the incident surface 60 of the receiver 6. When the straight line a passing through the target point p is hypothesized and the plane Q including the straight line a and the fixed point e is hypothesized, the inclination of the first rotation axis x with respect to the straight line orthogonal to the plane Q is 5 ° or less (however, , Including the case of 0 °). The details are as described above.
In a concentrating power generation facility (a concentrating power generating facility that performs solar thermal power generation or solar power generation) to which the solar light concentrating device of the present invention is applied, as shown in FIG. A plurality of solar light collecting devices 4 are arranged around the receiver), and the sunlight is condensed on the receiver 6 by the plurality of solar light collecting devices 4, and solar thermal power generation or solar power generation is performed.

DESCRIPTION OF SYMBOLS 1 Fixed support part 2x 1st rotation member 2y 2nd rotation member 3 Planar reflecting mirror 4 Sunlight condensing device 5 Solar tower 6 Receiver 30 Mirror surface 60 Incident surface x, y Rotation axis p Target point a Straight line
e Fixed point Q plane

Claims (7)

A first rotating member (2x) rotatably supported by the fixed support portion (1), a second rotating member (2y) rotatably supported by the first rotating member (2x), and the second rotation A plane reflector (3) fixed to the member (2y),
The rotation axis (x) of the first rotation member (2x) and the rotation axis (y) of the second rotation member (2y) are orthogonal to each other, and the mirror surface (30) of the plane reflecting mirror (3) is the rotation axis (y ) Parallel to
A solar concentrator that tracks the movement of the sun on the celestial sphere by rotation around the rotation axes (x) and (y), and makes the sunlight reflected by the plane reflector (3) incident on the incident surface of the receiver. And
A line segment included in the incident surface of the receiver, which is assumed to be a straight line (a) passing through the target point (p), and a plane (Q) including the straight line (a) and the fixed point (e) is assumed to be virtual. In this case, the solar light collecting device is characterized in that the inclination of the rotation axis (x) with respect to a straight line orthogonal to the plane (Q) is 5 ° or less (including the case of 0 °).   The solar light collecting device according to claim 1, wherein the mirror surface (30) of the plane reflecting mirror (3) is a parallelogram.   The solar light collecting apparatus according to claim 1, wherein a center of the incident surface of the receiver is a target point (p), and a straight line (a) passing through the target point (p) is horizontal.   A plurality of solar light collecting devices according to any one of claims 1 to 3 are arranged around a receiver, and the sunlight is condensed on the receiver by the plurality of solar light collecting devices. Type power generation equipment. A first rotating member (2x) rotatably supported by the fixed support portion (1), a second rotating member (2y) rotatably supported by the first rotating member (2x), and the second rotation A plane reflector (3) fixed to the member (2y),
The rotation axis (x) of the first rotation member (2x) and the rotation axis (y) of the second rotation member (2y) are orthogonal to each other, and the mirror surface (30) of the plane reflecting mirror (3) is the rotation axis (y ) Parallel to
Installation of a solar concentrator that tracks the movement of the sun on the celestial sphere by rotation around the rotation axes (x) and (y) and makes the sunlight reflected by the flat reflector (3) incident on the incident surface of the receiver A method,
A line segment included in the incident surface of the receiver, which is assumed to be a straight line (a) passing through the target point (p), and a plane (Q) including the straight line (a) and the fixed point (e) is assumed to be virtual. In this case, the solar light collecting device is installed so that the inclination of the rotation axis (x) with respect to the straight line orthogonal to the plane (Q) is 5 ° or less (including the case of 0 °). To install a solar concentrator.   The method of installing a solar light collecting device according to claim 5, wherein the mirror surface (30) of the plane reflecting mirror (3) is a parallelogram.   The center of the incident surface of the receiver is a target point (p), and the straight line (a) passing through the target point (p) is horizontal. Method.

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