WO2010119945A1

WO2010119945A1 - Solar light collection system

Info

Publication number: WO2010119945A1
Application number: PCT/JP2010/056835
Authority: WO
Inventors: 勝重中村
Original assignee: 三鷹光器株式会社
Priority date: 2009-04-16
Filing date: 2010-04-16
Publication date: 2010-10-21
Also published as: CN102362130A; US20120012102A1; JPWO2010119945A1

Abstract

Since the outer side of a receiver (3) is covered with a housing (5) and the receiver (3) is not exposed to the external air and heat is not taken due to contact with wind, thermal efficiency can be improved. Since the receiver (3) has an opening (4) on the lower side, the receiver (3) can introduce solar light (L) reflected by means of a heliostat (2) into the receiver from the opening (4) even the outer side is covered with the housing (5) and can reliably receive the solar light on the inner surface of the receiver (3).

Description

Sunlight collection system

The present invention relates to a solar light collecting system.

A solar condensing system in which a receiver is provided at the top of a tower standing on the ground and a plurality of heliostats for tracking the sun on the ground around the tower is known. The heliostat reflects the sunlight toward the receiver while tracking the sun. The sunlight reflected from the plurality of heliostats collects on the receiver, and the receiver becomes hot. There is a passage through which a heated fluid (for example, molten salt) flows inside the receiver, and the heated fluid becomes high temperature by passing through the inside of the receiver. Therefore, the heat of the receiver can be conveyed through the heating fluid by circulating the heated fluid that has become high temperature to a place where heat is required (for example, a steam generator). For example, US Pat. No. 4,227,513 is a related patent document.

However, in such a conventional technique, since the receiver is exposed to the outside air at a high position, much heat of the receiver is taken away by the wind. Further, heat is radiated as radiant heat from the receiver that has become high temperature. For this reason, the thermal efficiency is reduced.

The present invention has been made paying attention to such a conventional technique, and provides a solar light collecting system capable of improving the thermal efficiency.

Means for Solving the Problems According to the technical aspect of the present invention, a solar light collecting system includes a receiver installed at a predetermined height, and is installed on the ground around the receiver to direct sunlight to the receiver. And a heliostat for reflecting light, wherein the receiver has an inverted container shape having an opening for introducing sunlight on the lower side, and surrounds a portion other than the opening of the receiver outside the receiver, and A housing for forming a space for a heated fluid is provided between the receiver and the receiver.

The whole perspective view showing the sunlight condensing system concerning a 1st embodiment of the present invention. Sectional drawing which shows a sunlight condensing system. Sectional drawing which shows a receiver. Sectional drawing which shows the receiver which concerns on 2nd Embodiment of this invention. Sectional drawing which shows the receiver which concerns on 3rd Embodiment of this invention.

First Embodiment FIGS. 1 to 3 are views showing a first embodiment of the present invention. Four struts 1 having a predetermined height (about 10 m) are erected at the center of the solar light collecting system according to this embodiment. Around the support 1, a plurality of heliostats 2 that reflect the sunlight L toward a single target P while tracking the sun T are installed.

The receiver 3 is supported on the top of the four columns 1. The receiver 3 has an opening 4 on the lower side and has an inverted container shape (inverted bowl shape) that defines a predetermined internal space. The receiver 3 is entirely made of a black carbon material, and the inner surface is covered with a silicon carbide film (SiC). Therefore, the color of the inner surface of the receiver 3 is black, and the absorption rate of sunlight L is extremely high. The virtual target P of the heliostat 2 is located near the approximate center of the opening 4 of the receiver 3.

A cylindrical housing 5 having an upper surface is formed around the receiver 3. The housing 5 is made of metal, and a mirror coating 6 is formed on the inner surface by painting. The lower portion of the housing 5 and the receiver 3 are connected, and a space S through which air A as a heating fluid passes is defined between the housing 5 and the receiver 3.

A cylindrical smoke exhaust hole 7 is formed at the center of the upper surface of the housing 5. The lower end of the smoke exhaust hole 7 passes through the top of the receiver 3, and connects the interior of the receiver 3 and the outer space of the housing 5. Although the diameter of the smoke exhaust hole 7 is small and the smoke generated inside the receiver 3 can be discharged to the outside little by little, it is not enough to discharge a large amount of air inside the receiver 3 to the outside.

An inlet 8 for air A is formed at the lower part of the side surface of the housing 5, and an outlet 9 is formed at the upper part of the opposite position.

Sunlight L reflected by the heliostat 2 is introduced from the opening 4 into the receiver 3 having the above structure. The sunlight L is once condensed on the target P and then hits the inner surface of the receiver 3 in a diffused state. Since the inner surface of the receiver 3 is black and the absorption rate of sunlight L is high, the receiver 3 becomes high temperature. Even if the receiver 3 is heated to a high temperature, the receiver 3 is made of a solid carbon material whose inner surface is covered with a silicon carbide film, so that it has excellent heat resistance and the receiver 3 is not damaged by heat.

There is also sunlight L that is partially reflected on the inner surface of the receiver 3, but the diameter of the opening 4 of the receiver 3 is smaller than the diameter of the internal space, and the solid angle at which the opening 4 is desired from each incident position on the inner surface is small. Difficult to be discharged from the opening 4 to the outside. Therefore, most of the components scattered on the inner surface of the receiver 3 are further absorbed toward the inner surface toward the inner space. Smoke may be generated inside the receiver 3 due to the high temperature inside, but since it can be discharged outside from the smoke exhaust hole 7, there is smoke blocking the sunlight L inside the receiver 3. Without, the sunlight L reaches | attains the inner surface of the receiver 3 reliably.

The space S exists outside the receiver 3 that has become hot due to absorption of sunlight L, and air A as a heat medium flows there, so that the air A is heated in contact with the outer surface of the receiver 3. Air A is circulated from the outlet 9 to a place where heat is required.

According to this embodiment, the outside of the receiver 3 is covered with the housing 5, and the receiver 3 is not exposed to the outside air, and heat is not taken away by contact with the wind, so that the thermal efficiency is improved. Can do.

Even though the receiver 3 is covered with the housing 5, the receiver 3 has an opening 4 on the lower side. Therefore, sunlight L reflected by the heliostat 2 is introduced into the receiver 3 from the opening 4, and the inner surface of the receiver 3 is introduced. Can reliably absorb sunlight.

Since the receiver 3 has an inverted container shape having the opening 4 on the lower side, the air A heated inside the receiver 3 stays inside the receiver 3 and functions to maintain the high temperature of the receiver 3. In other words, since the heated air A is going to rise, if it has a reverse shape with the opening 4 on the upper side, the heated air A in the receiver 3 escapes as a rising air flow, and instead, cold air Since A enters the receiver 3, the receiver 3 is cooled, resulting in a decrease in thermal efficiency, but this is not the case in this embodiment.

Further, since the reflection surface by the mirror coating 6 is formed on the inner surface of the housing 5, the radiant heat from the receiver 3 that has become high temperature is reflected again to the receiver 3 side, and the radiation of heat from the receiver 3 can be prevented.

In the above embodiment, an example in which only the inner surface of the receiver 3 is formed of a silicon carbide film (SiC) has been shown, but the entire receiver 3 may be made of a silicon carbide film (SiC).

Further, in order to increase the contact area with the air A in the space S, the outer surface of the receiver 3 may be formed in an uneven shape.

Second Embodiment FIG. 4 is a diagram showing a second embodiment of the present invention. This embodiment includes the same components as those in the first embodiment. Therefore, common constituent elements are denoted by common reference numerals, and redundant description is omitted.

In this embodiment, the shape of the receiver 10 is a cylindrical shape having an upper surface similar to the housing 5. Since the receiver 10 has a cylindrical shape having an upper surface, the receiver 10 can be easily formed. Since the diameter of the opening 11 is larger than that of the previous embodiment, the component of the sunlight L that jumps to the outside due to reflection is slightly increased. However, the accuracy of collecting the sunlight L from the heliostat is increased by the size of the opening 11. Even if it drops, it can be taken into the opening 11. In addition, since the solid angle for which the opening 11 is desired from the incident position on the inner surface is reduced by increasing the height of the cylindrical shape of the receiver 10, the sunlight L scattered on the inner surface further goes to the inner space, The absorption efficiency of sunlight L improves.

Third Embodiment FIG. 5 is a diagram showing a third embodiment of the present invention. The present embodiment includes the same components as in the previous embodiment. Therefore, common constituent elements are denoted by common reference numerals, and redundant description is omitted.

In this embodiment, an example in which the receiver 12 is formed integrally with the housing 13 is shown. The housing 13 is divided into an upper member 14 and a lower member 15, which are welded to each other by

peripheral flanges

14f and 15f. As in the first embodiment, the receiver 12 has an inverted container shape with a narrow opening 16 and is integrally molded from the bottom surface of the lower member 15 with the same material. The smoke exhaust hole 7 is formed from the upper member 14 and is welded in a state of penetrating the upper part of the receiver 12.

In this embodiment, water W is allowed to flow as a heating fluid. While the water W is introduced from the inlet 8 and passes through the space S, the water W is heated in contact with the receiver 12 and becomes hot water W and is taken out from the outlet 9.

In this embodiment, since the receiver 12 is integrally formed from a part of the housing 13, there is no gap between them, which is suitable when a liquid such as water W is flowed as a heating fluid.

In this embodiment, the water W is taken as an example of the heating fluid, but a liquid such as oil may be used. Moreover, you may give the black coating which has heat resistance on the inner surface of the receiver 12. FIG.

Effects of the Invention According to the present invention, the outside of the receiver is covered with the housing, the receiver is not exposed to the outside air, and heat is not taken away by contact with the wind. it can. Even if the receiver is covered with a housing, the receiver has an opening on the lower side, so sunlight reflected by the heliostat is introduced into the receiver through the opening, and the receiver's inner surface reliably receives sunlight be able to. Since a heating fluid space is formed between the receiver and the housing, when the heating fluid is introduced into the space, the heating fluid is heated in contact with the outer surface of the receiver. Furthermore, since the receiver has an inverted container shape having an opening on the lower side, the air heated inside the receiver stays inside the receiver and serves to maintain the high temperature of the receiver.

According to another aspect of the present invention, since the opening diameter of the receiver is smaller than the inner diameter and the solid angle is small, even if sunlight introduced into the receiver is reflected by the inner surface of the receiver, There are few ingredients to go to.

In addition, since the receiver is made of solid silicon carbide or a solid carbon material whose entire surface is covered with a silicon carbide film, the inner surface of the receiver is black in the silicon carbide film, and the absorption rate of sunlight is high. In addition, since the receiver is formed at least on the surface with a silicon carbide film, it has excellent heat resistance.

Furthermore, because the mirror coating is formed on the inner surface of the housing, when the heated fluid is a transparent gas such as air, the radiant heat from the receiver that has become hot is reflected again to the receiver side, and the heat from the receiver is emitted. Can be prevented.

Furthermore, since the receiver is integrally formed from a part of the housing, there is no gap between them, which is suitable for flowing a liquid as a heating fluid.

(US designation)
This international patent application is based on US designation 119 (a) regarding Japanese Patent Application No. 2009-99980 (filed on Apr. 16, 2009) filed on Apr. 16, 2009 with respect to designation in the US Incorporate the interests of the right and cite the disclosure.

Claims

A solar light collecting system comprising a receiver installed at a predetermined height and a heliostat installed on the ground around the receiver and reflecting sunlight toward the receiver,
In the inverted container shape where the receiver has an opening for introducing sunlight on the lower side,
A solar condensing system comprising a housing surrounding a portion other than an opening of the receiver outside the receiver and defining a space for a heated fluid between the receiver and the receiver.
The solar light collecting system according to claim 1, wherein a diameter of an opening of the receiver is smaller than an inner diameter.
3. The solar light collecting system according to claim 1, wherein the receiver is made of solid silicon carbide or a solid carbon material whose entire surface is covered with a silicon carbide film.
The solar light collecting system according to any one of claims 1 to 3, wherein a mirror coating is formed on an inner surface of the housing.
The solar light collecting system according to any one of claims 1 to 4, wherein the receiver is integrally formed in a continuous state from the housing by the same material as the housing.