JP2006010292A - Waste incineration system using solar heat obtained by condensing sunlight - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To resolve a problem in incinerating "refuse" or the like by using solar heat wherein a temperature of an incineration part is affected by weather causing a large problem in an incineration condition of the incineration part, and consequently, there is a need to adjust incineration output in regard to the problem. <P>SOLUTION: Since the temperature of the incineration part is affected by weather, and there is a need to deviate a heating part of a device from a focal point of a parabolic mirror to adjust the incineration output, when it is almost cloudy weather, sunlight is condensed on the focal point or near the focal point of the parabolic mirror, and when it is fine weather, it is alright to condense the sunlight at a position separated from the focal point on an optical axis of the parabolic mirror. To that end, the parabolic mirror is composed of segment mirrors, orientations of the segment mirrors are controlled so as to separate away from the focal point, and the heating part of the device using solar heat is controlled. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a system that can always incinerate “dust” at a constant temperature by controlling the temperature of a light receiving part of a device that uses solar heat.

BACKGROUND ART When sunlight is condensed with a lens or the like, it has been known for a long time that a fairly high temperature is obtained in the vicinity of the light and a paper is ignited. In order to incinerate "garbage" etc. using this heat, it is necessary to take a large area to receive sunlight, but the lens absorbs infrared rays to obtain high temperature by the glass constituting the lens. Therefore, efficiency is bad. Therefore, in order to increase the light receiving area, a parabolic mirror with a wider aperture than the lens is used. However, it is difficult to create a large-diameter parabolic mirror as a unitary structure, and a practically used parabolic mirror is a small mirror, and many segmented mirrors are arranged on the parabolic surface. It is designed and manufactured so that the light reflected from each segment is focused at the focal point on the optical axis of the paraboloid, which is called a segmented parabolic mirror. So far, the sunlight has been collected at the focal point on the optical axis by the segmented parabolic mirror and the object placed near the focal point has been heated. It is possible to raise the temperature of the object to nearly 3500 ° C. Experiments have already been reported in which tungsten metal pieces are melted using this thermal energy, and application experiments to outdoor cookers have been attempted for practical application.

Problems to be solved by the invention

When sunlight is collected at the focal point on the optical axis by a parabolic mirror, the position of the focal point at which the highest temperature obtained from the sun is obtained is the ratio of the focal length (f) to the aperture (D) (f / D ) (Hereinafter referred to as the aperture ratio) is about 0.3, and the diameter of the converged solar image is 1/100 of the focal length f, the highest temperature can be obtained (for example, by Shishido [sealed cycle] Type solar thermal engine], solar energy, Vol. 29, No. 4, 2003, p.62)
The temperature obtained by actually collecting sunlight at the focal point of the parabolic mirror reaches about 3500 ° C when it is fine, but if it is cloudy, this temperature will be considerably lower, and the change in temperature obtained will be There is a problem that it is big. For example, when using this solar heat to incinerate “garbage” etc., the temperature of the incinerator will be affected by the weather, which will cause a major problem in the incineration situation of the incinerator. It is necessary to adjust the output for incineration, but there is no such device so far.

{Means for solving problems]
To solve the above problem, sunlight is collected near the focal point of the parabolic mirror when it is close to cloudy weather, while it is far from the focal point on the optical axis of the parabolic mirror when it is fine. Collect it at a location. Specifically, when the temperature of the solar heat is high, the direction of each segment constituting the segmented parabolic mirror is controlled so as to be away from the focal point, and an extremely high temperature is desired. If the focus of the parabolic mirror is gradually controlled to a position close to the incinerator, the temperature of the incinerator can be controlled arbitrarily and the purpose can be achieved.

{Embodiment of the Invention}
As an embodiment of the present invention, a parabolic mirror of a solar incinerator is fixed toward the north side, and sunlight is condensed by a parabolic mirror that guides sunlight parallel to the optical axis of the parabolic mirror by a heliostat mirror. Sunlight is poured into the incineration unit 2. High temperature heat is supplied to the incinerator 2 and the temperature of the incinerator rises. This high temperature promotes incineration of garbage.

  The present invention uses the parabolic mirror 1 and a segmented parabolic mirror having a structure as shown in FIG. 2, and the direction of the segment mirror 3 is variable. That is, the direction of the segmented parabolic mirrors is changed with respect to the intensity and distribution of sunlight collected on the incinerator 2, and the direction of the reflected light is directed to the focal point of each parabolic mirror. It is controlled by a temperature sensor 4 attached to the light receiving surface so that it can be separated and supplied with uniform heat energy from the light receiving surface to the incinerator.

  In the segment mirror variable system according to the present invention shown in FIG. 2, the intensity and distribution of sunlight and its vicinity can be controlled arbitrarily. The method for obtaining uniform incineration heat according to the present invention will be described below. As mentioned above. If the concave mirror of a segmented parabolic mirror is along the correct paraboloid, then the incoming sunlight along the optical axis will naturally converge at the focal point of the parabolic mirror. The temperature at this time is. Design the parabolic mirror so that it is sufficiently higher than the average temperature in fine weather. Of course, the parabolic mirror itself is an automatic control platform that maintains the relationship between the sun's direction and the incinerator using a mechanism similar to the automatic tracking system applied to ordinary large astronomical telescopes. It is installed above.

{The invention's effect}
The present invention. How can it be useful for incineration using solar heat? For example, taking FIG. 3 as an example, a in FIG. 3 is a sun image at the focal point with a parabolic mirror aperture ratio of 0.3, and depending on the same annular zone (zone), FIG. The solar image in the circle indicated by the dotted line b in FIG. 4 is obtained, that is, in this case, according to FIG. 4, if the solar image diameter is approximately twice the diameter of the solar image at the focal point of the parabolic mirror, The temperature is about 2400 ° C. This shows that when we consider what it means for solar thermal incineration, even if the weather at that time is not very good, the segment mirror can sufficiently incinerate "garbage".
Next, considering how much effect can be obtained by solar thermal incineration, it is assumed that the energy in fine weather is about 900 W per square meter for sunlight poured on the ground, 70% of which is effective. Considering this, the output obtained with a 10m diameter parabolic mirror is 50kW, and in order to avoid typhoons during daily use, the upper half of the parabolic mirror is used. In some cases, the output will be half of 25 kW if it is made to lie on the ground centering on its bottom. If a method using the upper half of such a parabolic mirror is taken, for example, if such a parabolic mirror is used, the output obtained thereby is about 100 kW.
Also, considering the effect of such incineration, the efficiency of solar power generation is generally said to be 10% to 13%, whereas the efficiency of this solar thermal power generation exceeds 25%, and at the time of production It can be said that the system can be evaluated as an extremely effective system because it can keep the temperature at incineration at 850 ° C, which is free from industrial waste and pollution during use, and also leads to the generation of dioxins.
As described above, according to the present invention, the position and shape of the sunlight image formed in the vicinity of the heat generating part of the device and the focal point of the parabolic mirror are simply controlled by controlling the inclination angle of the segment mirror. , The temperature of the heat generating part by sunlight can be kept constant. According to the present invention, for example, when “garbage” is incinerated by solar heat, an optimal heat source can be supplied to the incinerator regardless of whether the weather at the time of incineration is clear or cloudy. A stable and good incineration effect can always be obtained, and it can be provided as a solar thermal incineration system with extremely high practicality.

Solar incineration system using a parabolic mirror Example of sun image by segmented parabolic mirror (A) Sun image at the focal point (b) Sun image by one segment mirror at a position far from the focal point Temperature reached by a parabolic mirror when f / D = 0.3

Claims (3)

A light condensing method for controlling the temperature of the light receiving part of a device using solar heat. The parabolic mirror is a segmented parabolic mirror, the direction of the segment mirror is changed, and the reflected light is moved closer to or away from the focal point on the optical axis of each parabolic mirror. System that supplies uniform heat energy to the light receiving part. When sunlight is collected at the focal point on the optical axis by a parabolic mirror, the temperature obtained from the sun is the ratio (f / D) :( caliber ratio) between the focal length (f) and the aperture (D). When the diameter of the focused solar image is about 0.3 and the focal length is 1/100, the highest temperature is obtained, reaching 3500 ° C. If they are collected on the axis farther from the focal point, the diameter of the solar image becomes larger and the temperature becomes lower. Even if the diameter is six times that of the focal solar image, the temperature is about 1200 ° C. Therefore, a method for controlling the temperature reached by sunlight to drive a solar engine under such conditions.

Images