JP2013072578A - Solar furnace with heating temperature adjustment function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar furnace having a heating temperature adjustment function capable of ensuring safety during use, precisely and stably adjusting a heating temperature necessary for maintaining the heating temperature, and easily coping with the needs for a large scale lens or reflecting mirror without complicating the structure of the lens or reflecting mirror.SOLUTION: A solar furnace includes a light collection optical system 1 having a condensing lens 11 for collecting sunlight or a concave reflecting mirror 12 and a heating unit 2 provided at the focal position of light converged by the light collection optical system 1 or in the vicinity thereof. By providing a throttle mechanism 3 for varying the passing area of light converged by the size of an opening A surrounded by a shield between the light collection optical system 1 and heating unit 2, a dose of sunlight to an object T to be heated in the heating unit 2 is adjusted by the size of the opening A of the throttle mechanism 3 so as to adjust a heating temperature.

Description

  The present invention is an improvement of the solar furnace, specifically, the adjustment of the heating temperature can be accurately and stably performed, and can easily cope with the enlargement of the lens and the reflector. In addition, the present invention relates to a solar furnace having a heating temperature adjustment function that does not require complicated structures such as lenses and reflecting mirrors.

  As is well known, the `` solar furnace '' converts sunlight energy into heat energy by irradiating a target (object to be heated) placed near the focal point with sunlight collected by a convex lens or a concave reflector. In recent years, it has been widely used as a heat source for solar thermal power generation, cooking utensils (solar cookers), and materials melting experiments.

  However, conventional solar furnaces caused various dangers due to the heating temperature becoming higher than the assumed temperature (for example, when exceeding the ignition point of oil in heating during cooking, In the case of heating at a much higher temperature, etc.), it was necessary to adjust the heating temperature to ensure safety during use.

  In addition, the above adjustment of the heating temperature is essential not only for safety, but also for heating for a long time with the heating temperature kept constant (the amount of solar radiation depends on the weather and the altitude of the sun). If it is left as it is, the sky becomes cloudy and the heating temperature drops rapidly, or the heating temperature rises and falls violently from morning to evening).

  Therefore, in the past, a technique for adjusting the heating temperature by enlarging or reducing the effective area of a lens for collecting sunlight or a reflecting mirror has been proposed, and as one of the specific methods, light shielding is performed on the upper side of the reflecting mirror. A method of arranging a material and adjusting the amount of sunlight incident on a reflecting mirror with this light shielding material is known (see Patent Document 1).

  However, in the method of adjusting the amount of light incident on the light collecting member (reflecting mirror or lens), it is necessary to adjust the size of the light shielding material to the size of the light collecting member. If it was changed to a large one that was possible, the shading material had to be enlarged accordingly, and the temperature control device had to be replaced.

  In addition, as a method of enlarging / reducing the effective area of the lens and the reflecting mirror, the condensing member is composed of a plurality of divided parts (for example, Patent Documents 2 and 3), and the number of divided parts to be used. Although a method for changing the effective area by increasing / decreasing the value is known, this method not only makes the structure of the light collecting member complicated, but also makes it difficult to finely adjust the amount of light collected.

  On the other hand, as a method of adjusting the heating temperature of the solar furnace, a method of adjusting the amount of sunlight irradiated to the target by moving the target on the optical axis between the light collecting member and the focal point was also considered, In this method, since the amount of irradiation leakage varies depending on the size and shape of the target, the adjustment of the heating temperature tends to be unstable.

Japanese Utility Model Publication No.59-113169 JP 2003-279165 A JP 2009-257732 A

  Therefore, the present invention has been made in view of the problems as described above, and the purpose of the present invention is to accurately adjust the heating temperature necessary for ensuring safety during use and maintaining the heating temperature, and A solar that has a heating temperature adjustment function that can be performed stably, can easily handle the increase in size of lenses and reflectors, and does not require complicated structures such as lenses and reflectors. To provide a furnace.

  Means employed by the present inventor for solving the above-described problems will be described with reference to the accompanying drawings.

That is, the present invention relates to a condensing optical system 1 provided with a condensing lens 11 or a concave reflecting mirror 12 for condensing sunlight; and a focal position of light converged by the condensing optical system 1 or the vicinity thereof. In the solar furnace having the heating unit 2 provided in
By providing a diaphragm mechanism 3 between the condensing optical system 1 and the heating unit 2 to increase or decrease the passage area of the converged light according to the size of the opening A surrounded by the shield,
It is characterized in that the heating temperature can be adjusted by adjusting the amount of sunlight irradiated to the article T to be heated arranged in the heating unit 2 by the size of the opening A of the aperture mechanism 3.

  The diaphragm mechanism 3 is configured by mounting two light shielding curtains 32 and 32 in a double-opening manner inside a rectangular base frame 31 in which slide guides 31a and 31a are arranged in parallel on two opposite sides. Thus, the size of the opening can be adjusted with a simple structure.

  Furthermore, in the aperture mechanism 3, if the two light shielding curtains 32, 32 mounted on the slide guides 31 a, 31 a are connected to the manual linear actuator 33, only the handle portion 33 c of the linear actuator 33 is operated. The two light shielding curtains 32 and 32 can be easily opened and closed symmetrically.

  On the other hand, in the present invention, in the diaphragm mechanism 3, the two light shielding curtains 32 and 32 mounted on the slide guides 31a and 31a can be connected to the electric linear actuator 33. In this case, Since the drive motor 33b of the linear actuator 33 can be operated to open and close the two light-shielding curtains 32 and 32, labor for opening and closing can be saved.

  The “linear actuator” used in the present specification refers to all mechanisms for reciprocating linear movement of connected objects, including those using a feed screw, gas pressure, and hydraulic pressure. Fluid pressure cylinders, electromagnetic linear motors, etc. are included.

  When the feed screw 33a is used for the linear actuator 33 of the diaphragm mechanism 3, the nut portion N that moves on the screw shaft of the feed screw 33a and the inside of the light shielding curtains 32 and 32 are connected by a connecting member 32b. The linear actuator 33 can be configured with a simple structure.

  In addition, in the present invention, an automatic adjustment device 4 for automatically adjusting the heating temperature can be attached to the heating unit 2 and the diaphragm mechanism 3. For the automatic adjustment device 4, The temperature sensor 41 for detecting the temperature of the heating unit 2, the information detected by the temperature sensor 41 and the set temperature are compared, and the linear actuator 33 is controlled so that the heating temperature approaches the set temperature, thereby the light shielding curtains 32 and 32. And an open / close control unit 42 that opens and closes.

  As the diaphragm mechanism 3, a camera-type diaphragm mechanism 3 (for example, an iris diaphragm or the like) can be used in order to adjust the condensed light amount more accurately. A plurality of diaphragm blades 36, 36 are attached to the peripheral edge of the hole provided in the hole so as to be rotatable and overlap with adjacent blades. Alternatively, the size of the opening A can be adjusted by rotating outward.

  In the present invention, an aperture mechanism is provided between the condensing member and the heating unit of the solar furnace so that sunlight can be condensed through the opening of the aperture mechanism, thereby reducing the passage area of the converged light. Since it can be adjusted according to the size of the opening, it is possible to adjust the heating temperature by increasing or decreasing the amount of sunlight irradiated to the target using this diaphragm mechanism.

  In addition, if the target is placed so that all the collected light beams are irradiated with the aperture mechanism fully opened, the adjustment of the heating temperature can be performed accurately and stably without causing irradiation leakage. Therefore, it is possible to ensure safety during use and maintain a heating temperature that is not affected by the weather or the like.

  The above-mentioned “state in which the aperture mechanism is fully opened” refers to a state in which the aperture is opened so that the heating temperature for the target is maximized during use, and all the sunlight condensed by the light collecting member. When the heating temperature to be set is low, the half-open state can be maximized.

  Furthermore, in the present invention, even when the condensing member of the solar furnace is enlarged by using the above-mentioned diaphragm mechanism, it can be easily dealt with only by arranging the diaphragm mechanism close to the heating part side. In addition, since it is not necessary to divide the lens and the reflecting mirror into a plurality of parts, the structure of the solar furnace is not complicated.

  Therefore, according to the present invention, it is possible not only to effectively use natural energy, but also to provide a solar furnace with a heating temperature adjustment function that is very convenient in terms of safety during use, manufacturing cost, and ease of handling. The practical utility value of the present invention is very high.

It is a whole perspective view showing the solar furnace in Example 1 of this invention. It is the schematic showing the structure of the solar furnace in Example 1 of this invention. It is a front view showing the aperture mechanism of the solar furnace in Example 1 of this invention. It is an expansion perspective view showing the structure of the aperture mechanism of the solar furnace in Example 1 of this invention. It is the schematic showing the structure of the linear actuator of the aperture mechanism in Example 1 of this invention. It is a state explanatory drawing showing the state which opens an aperture mechanism in the solar furnace of Example 1 of this invention. It is a state explanatory drawing showing the state where a diaphragm mechanism is closed in the solar furnace of Example 1 of the present invention. It is a state explanatory view showing the relation between the diaphragm mechanism and the amount of sunlight irradiated in Example 1 of the present invention. It is the schematic showing the automatic adjustment apparatus of the heating temperature in Example 1 of this invention. It is a whole perspective view showing the aperture mechanism of the solar furnace in Example 2 of this invention. It is the schematic showing the solar furnace in the modification of this invention.

“Example 1”
A first embodiment of the present invention will be described with reference to FIGS. In the figure, what is indicated by reference numeral 1 is a condensing optical system, and what is indicated by reference numeral 2 is a heating unit. What is indicated by reference numeral 3 is an aperture mechanism, and what is indicated by reference numeral 4 is an automatic adjustment device.

[Configuration of solar furnace]
First, in the first embodiment, a large condensing lens 11 (Fresnel lens) is used for the condensing optical system 1 for condensing sunlight, and two support frames extended from the base B of the solar furnace. The condenser lens 11 is fixed to the tips of S and S to constitute a large-scale solar furnace for melting experiments capable of ultra-high temperature heating (see FIG. 1).

  Further, with respect to the solar furnace, the base B is configured to be able to turn in the horizontal direction, while the support frames S and S can be tilted / stand up with respect to the base B, thereby The direction and angle can be adjusted by tracking the sun moving in orbit. As the angle adjustment mechanism of the condenser lens 11, the technology according to Japanese Patent Application No. 2006-261778 is adopted.

  Further, on the base B of the solar furnace, a metal box 21 (material: stainless steel) in which the object to be heated T is accommodated is arranged, and the light converged by the condensing optical system 1 as shown in FIG. The heating unit 2 is provided at the focal position. Further, in this embodiment, a crucible 23 in which an object to be heated T is placed is arranged and used in the center of a metal box 21 filled with a heat insulating material 22.

  Incidentally, if it is desired to adjust the atmosphere during the melting experiment, the inside of the metal box 21 can be sealed by covering the upper side of the metal box 21 with a glass material or the like. In addition, since a link type expansion / contraction mechanism is attached to the fixing portion of the metal box 21, the position of the metal box 21 can be moved on the optical axis if necessary.

  On the other hand, a diaphragm mechanism 3 is provided between the condensing optical system 1 and the heating unit 2 to increase or decrease the passing area of the converged light depending on the size of the opening A surrounded by the shield. In the example, inner frames F and F are disposed inside the support frames S and S, and a base frame 31 of the diaphragm mechanism 3 is fixed to the inner frames F and F in parallel with the condenser lens 11.

  In addition, the diaphragm mechanism 3 has two light shielding curtains 32 and 32 on the inner side of a rectangular base frame 31 in which slide guides 31a and 31a (slide poles) are arranged in parallel on two opposite sides. It is configured to be mounted in a double-open manner through 32a, 32a... (See FIG. 3). In this embodiment, flameproof sheets are used for the light shielding curtains 32 and 32 in consideration of safety.

  Further, the upper and lower corners of the two light shielding curtains 32 and 32 are connected to the linear actuator 33. Specifically, in this embodiment, as shown in FIG. 4, the light shielding curtain 32 is connected to the nut portion N of the feed screw 33a (ball screw) via the connecting member 32b, and is interlocked with the nut portion N moving on the screw shaft. The shading curtains 32 and 32 can be opened and closed.

  Further, as shown in FIG. 5, the linear actuator 33 is disposed so as to be shifted forward and backward on the upper and lower sides of the light-shielding curtains 32 and 32 to be mounted, and the front and rear feed screws 33a and 33a are connected via a gear 34. So that the direction of rotation is reversed. In addition, the upper and lower feed screws 33a and 33a are also coupled to each other via a gear 34 and a longitudinal shaft 35.

  Further, in this embodiment, one of the upper feed screws 33a is connected to a drive motor 33b with a speed reducer, and one of the lower feed screws 33a is connected to the handle portion 33c, so that The actuator 33 can be operated electrically by the drive motor 33b or manually operated by the handle portion 33c.

  Since the diaphragm mechanism 3 is configured using the linear actuator 33, the light shielding curtains 32 and 32 can be opened symmetrically simultaneously when the feed screw 33a is rotated in a predetermined direction by the drive motor 33b or the handle portion 33c. On the contrary, if the feed screw 33a is rotated in the opposite direction, the light-shielding curtains 32 and 32 can be closed at the same time (see FIG. 7).

  As described above, when the diaphragm mechanism 3 is used, the size of the opening A is adjusted by opening and closing the light shielding curtains 32 and 32, and the amount of sunlight irradiated to the heating unit 2 is shown in FIGS. 8 (a) to 8 (c). Since it can increase / decrease as shown, the heating temperature to the to-be-heated object T arrange | positioned at the heating part 2 can be adjusted accurately.

  Furthermore, in this embodiment, as shown in FIG. 9, since the automatic adjustment device 4 for automatically adjusting the heating temperature is attached to the solar furnace, if this automatic adjustment device 4 is activated, it will take a long time. Even when this heating experiment is performed in a state where it is left as it is, the heating temperature for the non-heated object T can be maintained at the set temperature.

  The automatic adjustment device 4 includes a temperature sensor 41 (thermocouple) that detects the temperature of the heating unit 2 and a drive motor 32b of the linear actuator 33 of the aperture mechanism 3 based on information detected by the temperature sensor 41. An open / close control unit 42 that controls to open and close the light-shielding curtains 32 and 32 is configured by connecting each with a wire.

  The control process of the automatic adjustment device 4 will be briefly described. First, the temperature sensor 41 detects the temperature of the heating unit 2, and then the temperature information detected by the open / close control unit 42 and the preset temperature input in advance. In comparison, the drive motor 33b of the linear actuator 33 is PID controlled so as to eliminate the temperature difference, and the light shielding curtains 32 and 32 are opened and closed.

  Then, after a predetermined time (in this embodiment, “5 second interval”) has elapsed since the detection by the temperature sensor 41, the temperature of the heating unit 2 is detected again by the temperature sensor 41, and the light shielding curtain 32 · By repeatedly performing the open / close control of 32, the heating temperature is adjusted so as not to greatly deviate from the set temperature.

  Further, in this embodiment, in the operation panel of the opening / closing control unit 42, the input of the set temperature, the setting of the interval for detecting the temperature of the heating unit 2 (the interval for performing the opening / closing control of the light shielding curtains 32, 32), the drive motor 33b Speed setting (setting of the opening / closing speed of the light shielding curtains 32, 32), automatic / manual switching of the linear actuator 33, and opening / closing operation of the light shielding curtains 32, 32 by the drive motor 33b can be performed.

“Example 2”
Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, in a relatively small solar furnace such as a solar heat cooker, a camera-type diaphragm that can adjust the amount of collected light more accurately without using the light-shielding curtain type diaphragm mechanism 3 as in the first embodiment. The mechanism 3 can be used to adjust the heating temperature.

  The camera-type diaphragm mechanism 3 is attached to a peripheral edge of a hole provided in the base frame 31 so that a plurality of diaphragm blades 36, 36,... Can rotate freely and overlap with adjacent blades. .. Is a mechanism for adjusting the size of the opening A by rotating the diaphragm blades 36, 36...

  The present invention is generally configured as described above. However, the present invention is not limited to the described embodiments, and various modifications can be made within the description of “Claims”. The optical system 1 can use a convex lens instead of a Fresnel lens as the condensing lens 11, can also use a concave reflecting mirror 12 as shown in FIG. 11, and adopts a combination of lenses and reflecting mirrors. You can also.

  Further, with respect to the diaphragm mechanism 3, a slide rail is used for the slide guide 31 a of the base frame 31 instead of a pole type, and the light-shielding curtains 32 and 32 are attached via runners 32 a that are mounted while being hooked in the rail. You can also. The linear actuator 33 can be a gas pressure, hydraulic fluid pressure cylinder, electromagnetic linear motor, or the like.

  Furthermore, when using the feed screw 33a for the linear actuator 33, it is possible to unify the front and rear feed screws 33a by setting half of the feed screw 33a to the right screw and the other half to the left screw. Further, the upper and lower feed screws 33a and 33a can be connected by a roller chain or a timing belt.

  The diaphragm mechanism 3 only needs to have a structure capable of adjusting the size of the opening A to adjust the amount of light passing therethrough. For example, the mechanism for sliding the light shielding plate from four directions and the angle of the base frame are adjusted. Thus, all the mechanisms for changing the size of the opening as viewed from the optical axis are included, all of which belong to the technical scope of the present invention.

In recent years, research on energy systems using solar energy has been promoted due to the problems of global warming due to depletion of fossil fuels and CO ₂ emissions. Solar furnaces that convert sunlight into thermal energy are also Research and development for practical application is underway as one of the energy systems.

  Under such circumstances, the solar furnace equipped with the heating temperature adjustment function of the present invention not only enhances safety during use by adjusting the temperature of the solar furnace, but also enables long-time heating in a specific temperature range. Therefore, it is a useful technique that can widen the application range of heating experiments and cooking, and its industrial utility value is very high.

1 Condensing optical system
11 Condensing lens
12 Concave reflector 2 Heating part
21 Metal box
22 Insulation
23 Crucible 3 Drawing mechanism
31 Base frame
31a Slide guide
32 Shading curtain
32a Lanna
32b Connecting member
33 Linear actuator
33a Lead screw
33b Drive motor
33c Handle
34 Gear
35 shaft
36 Aperture blade 4 Automatic adjustment device
41 Temperature sensor
42 Opening / closing control part B Base S Support frame T Object to be heated A Opening part F Inner frame N Nut part

Claims (7)

A condensing optical system (1) having a condensing lens (11) or a concave reflecting mirror (12) for condensing sunlight; and a focal position of light converged by the condensing optical system (1), or In a solar furnace having a heating section (2) provided in the vicinity thereof,
A diaphragm mechanism (3) is provided between the condensing optical system (1) and the heating unit (2) to increase or decrease the light passing area that converges depending on the size of the opening (A) surrounded by the shield. By configuring
The heating temperature can be adjusted by adjusting the amount of sunlight irradiated to the object to be heated (T) disposed in the heating unit (2) by the size of the opening (A) of the aperture mechanism (3). A solar furnace with a characteristic heating temperature control function.   The aperture mechanism (3) is mounted in a double-opening manner on the inside of a square base frame (31) with slide guides (31a, 31a) arranged in parallel on opposite sides. A solar furnace having a heating temperature adjusting function according to claim 1, wherein the solar furnace is configured as described above.   In the diaphragm mechanism (3), the two light-shielding curtains (32, 32) mounted on the slide guides (31a, 31a) are connected to the manual linear actuator (33), and the handle portion of the linear actuator (33) is connected. The solar furnace having a heating temperature adjusting function according to claim 2, wherein the two light shielding curtains (32, 32) can be opened and closed by operating (33c).   In the diaphragm mechanism (3), the two light shielding curtains (32, 32) mounted on the slide guides (31a, 31a) are connected to the electric linear actuator (33), and the drive motor of the linear actuator (33) is connected. The solar furnace having a heating temperature adjusting function according to claim 2, wherein the two light shielding curtains (32, 32) can be opened and closed by operating (33b).   In the diaphragm mechanism (3), a feed screw (33a) is used for the linear actuator (33), and the nut portion (N) moving on the screw shaft of the feed screw (33a) and the light shielding curtain (32, 32) The solar furnace having the heating temperature adjusting function according to any one of claims 2 to 4, wherein the inner side is connected by a connecting member (32b).   An automatic adjustment device (4) for heating temperature is attached to the heating unit (2) and the throttle mechanism (3), and the automatic adjustment device (4) is used to detect the temperature of the heating unit (2). Open / close control that compares the information detected by the temperature sensor (41) with the set temperature and controls the linear actuator (33) to open and close the light-shielding curtain (32/32) so that the heating temperature approaches the set temperature. A solar furnace having a heating temperature adjusting function according to claim 4 or 5, characterized in that the solar furnace is constituted by a section (42).   The diaphragm mechanism (3) is attached to the peripheral edge of the hole provided in the base frame (31) so that a plurality of diaphragm blades (36, 36...) Can rotate freely and overlap with adjacent blades. 2. The heating temperature adjustment according to claim 1, wherein the size of the opening (A) can be adjusted by rotating the diaphragm blades (36, 36...) Inward or outward of the hole. Solar furnace with functions.