JPS5836260B2 - solar heat collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar heat collector having a reflecting mirror that collects sunlight, a heat collecting section that absorbs the solar heat, and a coolant flow path provided inside the heat collecting section. .

Conventionally, this type of solar heat collector uses a reflecting mirror 1 having a semicircular cross section as shown in FIG.

In this reflecting mirror 1, a line connecting an arbitrary point Q on the reflecting mirror 1 and the center P of the circle is the normal line of the circle at the point Q.

Therefore, sunlight directed toward point Q from outside the normal line PQ is always reflected toward the heat collecting section 2 from the normal line PQ, as shown in the figure.

1 and other sunlight directly enters the heat collecting section 2.

Therefore, all the sunlight is finally concentrated in the heat collecting section 2.

Note that in FIG. 1, reference numeral 3 indicates a coolant passage formed within the heat collecting section 2. As shown in FIG.

By the way, in order to improve the heat collection efficiency, it is necessary to make the surface area of the heat collection part smaller than the area of the reflecting mirror opening, and to reduce the heat loss from the surface of the heat collection part.

In other words, it is necessary to increase the light collection ratio, which is obtained by dividing the reflecting mirror opening area by the heat collecting part surface area.

However, in the reflecting mirror i shown in FIG. 1, which has a semicircular cross section, It is difficult to improve heat collection efficiency.

An object of the present invention is to provide a solar heat collector that can improve heat collection efficiency, and another object of the invention is to provide a solar heat collector that can further improve heat collection efficiency.

The feature of the present invention is that, when α is an arbitrary angle between the line of symmetry of the arc of the reflecting mirror and the sunlight, the reflecting mirror has a circular arc portion with a central angle of (90 + α) degrees, and a reflecting mirror from each end of the circular arc portion. and a straight line extending in the tangential direction of the center of the circle, the upper end of which has a height approximately equal to the center dimension of the circle. This solar heat collector has a large light ratio and high heat collection efficiency.

Another feature of the present invention is that the reflecting mirror has a central angle (90
+α) degrees, and a straight line portion extending from each end of the arc portion in a tangential direction to the center of the circle of the reflecting mirror, and whose upper end is approximately at the height of the center of the circle. The heat collecting section is formed in a panel shape and is installed in a plane determined by the center of the circle of the reflecting mirror and the line of symmetry of the arc, and the coolant flow path is formed in a gutter shape. With this configuration, the surface area of the heat collecting part can be reduced, and therefore a solar heat collector with even higher heat collecting efficiency can be obtained.

The present invention will be explained below based on the drawings.

FIG. 2 shows an embodiment of the present invention, in which a reflecting mirror 11,
In a device including a heat collecting section 12 and a coolant flow path 13, the reflecting mirror 11 is formed into a gutter shape having an arcuate portion 110 and linear portions 111, 112 extending from each end thereof.

The arcuate portion 110 of the reflecting mirror 11 has a central angle of (90+α) degrees, where α is the angle of pressure between the line of symmetry O of the reflecting mirror 11 and sunlight.

The arc portion 110 of the housing reflector 110 has a radius approximately equal to the height of the heat collecting portion 12 along the line of symmetry O.

Further, the lower end of the heat collecting section 12 is arranged so as to be in contact with the reflecting mirror 11 at the intersection of the line of symmetry O, or to be located close to it.

In the case of the reflecting mirror 1 having a semicircular cross section as shown in FIG.
All of the sunlight incident from the front was finally formed on the heat collecting part 2.

However, in reality, the altitude difference between the summer solstice and the winter solstice is 47 degrees, and it is approximately 3 degrees above and below the south center, which accounts for the majority of the daily solar radiation.
For practical purposes, it is sufficient to collect heat from the hours of sunlight.

Therefore, the reflecting mirror may be of any type as long as it allows all of the sunlight that is incident at an angle of 15 to 30 degrees with respect to the line of symmetry of the arc to be incident on the heat collecting section.

Therefore, in the present invention, the arc portion 110 of the reflecting mirror 11
The angle α at the central angle (90+α) is 15 degrees ≦ α<
Setting the angle to 30 degrees is sufficient for practical use.

The linear portions 111 and 112 of the reflecting mirror 11 are circular arc portions 1
It extends from each end Q, R of the mirror 10 in the tangential direction of the arc, and the upper end S, T has a height up to the center of the circle of the reflecting mirror 11.

The heat collecting section 12 is formed into a circular cross section with a radius r equal to half the length of a line segment connecting the line of symmetry 0 of the arc of the reflecting mirror 11 and the center P of the circle. The flow path 13 is formed inside the heat collecting section 12 .

In the solar heat collector having the above-mentioned configuration, sunlight incident on the upper end T of the reflecting mirror 11 is reflected as shown in the figure and enters the center P of the reflecting mirror 110, which is the upper end of the heat collecting part 12.

In the straight portion 111 of the reflecting mirror 11, the upper end T
Sunlight incident on the inner side is reflected in the same way and enters the heat collecting section 12.

In the past, sunlight incident at an angle smaller than the angle α shown in FIG.
The incident direction is inward from the line connecting the two.

Regardless of the direction of incidence, all sunlight that enters within the range of the arc portion 110 of the reflecting mirror 110 ultimately reaches the heat collecting section 12.
incident on .

The reason why the radius of the circular arc portion 1100 of the reflecting mirror 11 is set almost equal to the height of the heat collecting portion 12 is that the straight portion 11 of the reflecting mirror 11
When the heights of the upper ends S and T of 1,112 are higher than the height of the heat collecting part 12, even if sunlight enters the reflecting mirror 11 at α, some sunlight does not enter the heat collecting part 12. If the height of the upper ends S and T is lower than the height of the heat collecting part 12, all sunlight will enter the heat collecting part 12, but the light collection ratio will be small. This is to become.

The reason why the lower end of the heat collecting section 12 is placed in contact with or close to the reflecting mirror 11 is because if there is a gap between the two, light will escape and sunlight will not enter the heat collecting section 12. be.

From the above, all the sunlight that enters at an angle within the range of the pressure angle α1 between the line of symmetry O of the arc of the reflecting mirror 11 and the sunlight is collected on the heat collecting part 12.

The condensing ratio of the device of the present invention shown in Fig. 2 is becomes.

Therefore, when the angle α = 15 degrees, the condensing ratio = 0 from the above formula
．． 802, and when the angle α is 230 degrees, the condensing ratio = 0.
735, and the condensing ratio of the conventional device shown in Fig. 1 = 0.
．． Compared to 637, the device of the present invention is 15 to 26% larger.

The solar heat collected in the heat collecting section 12 is transferred to the coolant flow path 13.
It is absorbed by the coolant inside, and as a result, the coolant becomes humid.

Figure 3 shows another embodiment of the present invention, in which the reflecting mirror 11, the heat collecting section 22 and the coolant flow path 33 are shown.
It is composed of:

The reflecting mirror 11 is formed in a shape similar to that shown in FIG. 2 above.

The heat collecting section 22 is formed in a panel shape, is installed within a plane determined by the line of symmetry O of the arc of the reflecting mirror 11 and the center P of the circle, and has a surface area as small as possible.

The coolant flow path 33 is formed to have as small a diameter as possible, and is provided approximately in the middle of the heat collecting section 22 in the height direction.

In the solar heat collector with this configuration, the concentration ratio is as follows, and when the angle α = 15 degrees, the concentration ratio = 1.260
When the angle α=30 degrees, the condensing ratio is 1.155, and the condensing ratio is significantly improved.

Other effects of the invention shown in FIG.
Similar to that shown in the figure.

The present invention has the configuration and operation described above, and according to the present invention, the light condensing ratio is increased by forming the reflecting mirror into a gutter shape having a circular arc portion and a straight line portion extending to each end of the reflecting mirror. As a result, the heat collection efficiency can be improved.

Furthermore, in addition to forming the reflecting mirror in the above-mentioned shape, another invention of the present invention further improves the light collection ratio by forming the heat collecting part into a panel shape and making the surface area of the heat collecting part as small as possible. It has the remarkable effect of dramatically improving heat collection efficiency.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a conventional device, FIG. 2 is a vertical cross-sectional view showing an embodiment of the present invention, and FIG. 3 is a vertical cross-sectional view of an embodiment of another invention of the present invention. 11... Reflecting mirror, 110... Arc portion of the reflecting mirror, 1
1L112...Same straight line part, 12.22...Heat collecting part, 13.33...Coolant flow path, O...Line of symmetry of the arc of the reflector, P...The circle of the reflector Center, α... Any angle between the line of symmetry of the reflecting mirror and the sunlight.

Claims (1)

[Scope of Claims] 1. A device having a reflecting mirror, a heat collecting part, and a coolant flow path, wherein the reflecting mirror has a circular arc portion with a central angle of (90+α) degrees;
It is formed into a gutter shape consisting of a straight line portion extending from each end of the arc portion in a tangential direction to the center of the circle of the reflecting mirror, and whose upper end portion is approximately at the height of the center 1 of the circle. A solar heat collector featuring: However, α is an arbitrary angle between the line of symmetry of the arc of the reflecting mirror and the sunlight. 2. In claim 1, the radius of the arc portion of the reflecting mirror is set to be approximately equal to the height of the heat collecting part, and the lower end of the heat collecting part is in contact with or close to the reflecting mirror. A solar heat collector characterized by being arranged so as to be located at the same position. 3 In claim 1 or 2, the angle α
A solar heat collector characterized in that the temperature is 15 degrees≦α≦30 degrees. 4. For those having a reflector, a heat collecting part, and a coolant flow path.
The reflecting mirror has a circular arc portion having a central angle of (90+α) degrees, and an upper end portion extending from each end of the circular arc portion in a tangential direction to the center of the circle of the reflecting mirror, and an upper end portion having a height approximately at the center of the circle. The heat collecting part is formed in a panel shape and is installed in a plane determined by the center of the circle of the reflecting mirror and the line of symmetry of the arc. A solar heat collector characterized in that the coolant flow path is provided approximately in the middle of the heat collecting section in the height direction. However, α is the angle of pressure between the line of symmetry of the arc of the reflecting mirror and the sunlight. 5 In claim 4, the radius of the arc portion of the reflecting mirror is set to be approximately equal to the height of the heat collecting part along the line of symmetry, and the lower end of the heat collecting part is above the reflecting mirror. A solar heat collector characterized by being arranged so as to be in contact with or in close proximity to.