A sample heating device using sunlight

Abstract

The application discloses a device for heating samples by using sunlight, which is composed of a black body furnace, a converging lens, a black body furnace support and a converging lens support, and is provided with a light transmission opening switch; the surface of the black body furnace is provided with a light transmission opening and a material loading and taking opening; the light transmission opening enables the converging sunlight to enter the black body furnace; the material loading and taking opening is used for loading and taking samples; the converging lens is composed of a plano-convex lens and a Fresnel zone plate made on the plane side of the plano-convex lens, and is used for converging the sunlight to the sample in the black body furnace; the sunlight is reflected or scattered by the sample, is reflected in the black body furnace for multiple times and is finally absorbed by the sample, so that the sample is heated; the black body furnace support is connected with the black body furnace, and plays a fixing and supporting role; the converging lens support is used for connecting the converging lens and the black body furnace, and fixing the converging lens above the light transmission opening of the black body furnace; and the light transmission opening switch is installed on the converging lens support, and is opened during heating and closed during non-heating. The device uses the solar energy to heat the sample, is environment-friendly and green, can be used in all places with sunlight, has high energy utilization rate and wide application.

Description

Technical Field

[0001] This invention relates to concentrating sunlight and heating blackbody furnaces, belonging to the field of solar thermal collection and energy. Technical Background

[0002] Currently, the main methods of solar thermal collection include flat-plate collectors, vacuum tube collectors, and concentrating collectors. Flat-plate collectors are suitable for medium- and low-temperature heating, generally reaching 100°C to 200°C; vacuum tube collectors can provide medium- and high-temperature heating, generally reaching 300°C to 400°C; and concentrating collectors are typically used for high-temperature heating applications, reaching nearly 1000°C. To obtain even higher heating temperatures, new devices need to be invented.

[0003] This invention provides a device for heating samples using sunlight. The device comprises a blackbody furnace, a converging lens, a blackbody furnace support, and a converging lens support. It uses the converging lens to focus sunlight onto the sample inside the blackbody furnace, where it is absorbed and heated. Scattered and reflected sunlight is also absorbed by the sample after reflection from the furnace wall, further increasing the sample temperature. This heating device has high energy efficiency and can be used anywhere with sunlight for high-temperature sample heating. Summary of the Invention

[0004] The purpose of this invention is to provide a sample heating device that utilizes sunlight, which can solve the problem of low temperature in current solar thermal collectors.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The heating device consists of a blackbody furnace, a converging lens, a blackbody furnace support, a converging lens support, and a light-transmitting port switch. The blackbody furnace has a light-transmitting port and a sample loading / unloading port on its surface. The light-transmitting port allows focused sunlight to enter the blackbody furnace, while the sample loading / unloading port is used for sample insertion and removal. The converging lens consists of a plano-convex lens and a Fresnel zone plate (referred to as a "zone plate") fabricated on one side of its plane. It is used to focus sunlight onto the sample inside the blackbody furnace. After transmission, reflection, or scattering by the sample, the sunlight undergoes multiple reflections within the blackbody furnace before being absorbed by the sample, achieving the purpose of heating the sample. The blackbody furnace support is connected to the blackbody furnace, providing fixation and support. The converging lens support connects the converging lens to the blackbody furnace and fixes the converging lens above the light-transmitting port of the blackbody furnace. The light-transmitting port switch is installed on the converging lens support; it is opened during heating and closed when heating is not required, preventing the blackbody furnace from being continuously heated.

[0007] The blackbody furnace has a three-layer structure. The inner layer is a spherical shell made of quartz or microcrystalline material. A total reflection silver film is deposited on the outer surface of the inner shell, and a SiO2 hard film is applied over the silver film. The purpose of the coating is to reflect visible and infrared light. The second layer is asbestos, which is used to wrap the inner shell and provides insulation and protection. The third layer is a spherical shell structure made up of two edged metal (such as aluminum alloy, titanium, or stainless steel) hemispheres joined together. The two hemispheres are fixed together along the edges with screws. In the three-layer structure, the inner layer is thicker to avoid damage during material loading and unloading, and the inner diameter of the cavity is smaller, so that the sample falls close to the center of the sphere.

[0008] One side of the converging lens is fabricated with a zone plate by bonding or photolithography. The width of each zone on the zone plate is determined by the peak wavelength of the sample absorption and the focal length of the zone plate. The focal length of the zone plate depends on the focal length of the converging lens and the focal length of the plano lens. The focal length of the converging lens should be the distance from the converging lens to the sample.

[0009] The blackbody furnace support consists of three metal pillars with boots at the bottom. The three pillars are of the same length, are distributed at equal angles to each other, and are fixedly connected to the outer shell of the blackbody furnace.

[0010] The converging lens support consists of three metal pillars fixed above the light-transmitting opening of the blackbody furnace, allowing the converging lens to focus sunlight onto the sample inside the blackbody furnace to heat the sample through the light-transmitting opening. The three pillars are extendable and retractable, making it easy to adjust the position of the converging point.

[0011] The light-transmitting switch is a metal (such as aluminum alloy, titanium, or stainless steel) disc, which is mounted on a pillar of the converging lens bracket and can rotate around the pillar. When rotated above the light-transmitting opening, the disc completely covers the light-transmitting opening. At this time, the other side of the disc contacts another pillar, and the light-transmitting switch is in a closed state. When the disc is rotated in the opposite direction to expose the light-transmitting opening, the light-transmitting switch is in an open state.

[0012] The metal support can be a metal tube, wherein the blackbody furnace support has a thicker wall, a larger diameter, and is longer than the converging lens support, and they are made of aluminum alloy, titanium, or stainless steel.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. A zone plate and a plano-convex lens together form a converging lens. Using a plano-convex lens is beneficial for creating the zone at the edge of the zone plate.

[0015] 2. The combination of converging lens and blackbody furnace can effectively improve the energy utilization rate of sunlight and facilitate obtaining higher heating temperatures;

[0016] 3. The focusing position is not a physical point, which facilitates three-dimensional heating of the sample;

[0017] 4. Using solar energy to heat samples is green and environmentally friendly. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 Here is an example diagram of the sample heating device;

[0020] Figure 2 This is an example diagram of the internal structure of the blackbody furnace of the sample heating device;

[0021] Figure 3 An example diagram of the photolithographic zone plate converging lens of the sample heating device;

[0022] In the attached diagram, the components represented by each number are: 1-blackbody furnace, 2-blackbody furnace support, 3-converging lens, 4-converging lens support, 5-light transmission port, 6-material loading / unloading port, 7-light transmission port switch. Detailed Implementation

[0023] To make the technical content of the present invention clearer, the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0024] like Figure 1 As shown, the posture of the heating device is adjusted so that the converging lens 3 can focus sunlight into the blackbody furnace 1 through the light-transmitting port 5. The sample is placed into the blackbody furnace 1 through the feeding port 6. The light-transmitting port switch 7 is opened, and the length of the converging lens support 4 is adjusted so that the focal point of the converging lens 3 is located on the sample, thereby converging sunlight onto the sample for heating. When heating is finished, the remaining sample in the furnace is removed through the feeding port 6, and the light-transmitting port switch 7 is closed.

[0025] The blackbody furnace 1 has a three-layer structure. The inner layer is a spherical shell made of quartz or microcrystalline blown glass. A total internal reflection silver film is deposited on the outer surface of the inner shell to reflect visible and infrared light back onto the sample. SiO2 is used to harden the silver film. The second layer, made of asbestos, is close to and wraps around the outer surface of the inner shell, providing insulation and protection. The third layer is a spherical shell structure made of two edged hemispherical shells (e.g., aluminum alloy, titanium, or stainless steel) joined together to protect, secure, and support the two inner layers. During assembly, the asbestos-wrapped inner shell is first placed into one hemispherical shell, and then the other hemispherical shell is joined on top. The two hemispherical shells have screw holes along their edges. Screws are passed through these screw holes to fix the two hemispherical shells together, forming a third spherical shell. The inner spherical shell and the third metal spherical shell clamp the middle asbestos layer, thus combining the three spherical shells into one.

[0026] The internal structure of the blackbody furnace 1 is as follows Figure 2 As shown, in its three-layer structure, adjacent spherical shells are in close contact. The innermost spherical shell is thicker, and its mechanical properties are sufficient to prevent damage during sample insertion and removal. At the same time, its inner diameter is small, allowing the sample to be positioned close to the center of the sphere. Both the light-transmitting port 5 and the material loading / unloading port 6 pass through the three-layer structure. The position of the material loading / unloading port 6 on the blackbody furnace 1 is determined by the ease of sample loading and unloading. Its shape is funnel-shaped, facilitating sample loading and unloading and preventing the sample from falling outside the blackbody furnace 1. It also has screw holes inside, through which screws are used to fix the material loading / unloading port 6 and the third spherical shell together, thereby preventing damage caused by scratching during sample loading and unloading.

[0027] The converging lens 3 consists of a zone plate and a plano-convex lens. The zone plate can be fabricated on one side of the plano-convex lens by gluing or photolithography. Gluing can be done with either an amplitude-type or a phase-type zone plate, while photolithography can fabricate a phase-type zone plate. A phase-type zone plate significantly improves the utilization rate of solar energy during focusing compared to an amplitude-type zone plate. The convex side of the plano-convex lens faces the light-transmitting aperture 5. The focal length F of the converging lens 3 is:

[0028]

[0029] In the formula, f1 is the focal length of the convex surface of the plano-convex lens, d is the distance between the zone plate and the principal plane of the plano-convex lens, and f is the focal length of the zone plate, which can be written as:

[0030]

[0031] In the formula, r1 is Figure 3 The radius of the first waveband in the zone plate, λ pLet be the peak wavelength of sunlight absorbed by the sample. Generally, d≈0. F is the distance from the sample to the converging lens 3. f1 is known. Substituting equation (2) into equation (1), r1 can be calculated. Consider the radius of the j-th waveband:

[0032]

[0033] The radius of each band of the zone plate can be calculated according to equation (3), and the width of each band can be calculated accordingly. The zone plate can then be fabricated.

[0034] The converging lens support 4 consists of three metal pillars, which are fixed to the light-transmitting opening 5 of the outer shell of the blackbody furnace 1. The converging lens 3 is fixed above the light-transmitting opening 5 by the converging lens support 4. Figure 1 (As shown), it is used to focus sunlight onto the sample inside the blackbody furnace to heat the sample. The length of each converging lens support can be adjusted by telescoping, making it easy to adjust the position of the converging point.

[0035] The light-transmitting switch 7 is a metal disc, which is mounted on a pillar of the converging lens bracket 4 and can rotate around the pillar. When closed, the metal disc is rotated to above the light-transmitting opening 5, and the disc area can completely cover the light-transmitting opening 5. The other side of the disc contacts another pillar, preventing the disc from continuing to rotate. When heated, the metal disc is rotated in the opposite direction to expose the light-transmitting opening 5. At this time, the light-transmitting switch 7 is in the open state.

[0036] The blackbody furnace support 2 used to support and fix the blackbody furnace 1 is as follows: Figure 1 As shown, it consists of three metal supports with boots at the bottom. One end of the support with a boot is in contact with the supporting surface, and the other end without a boot is fixedly connected to the outer shell of the blackbody furnace 1. The three supports are of the same length and are distributed at equal angles to each other.

[0037] The metal support can be a metal tube. The outer diameter of the blackbody furnace support is larger, thicker, and longer than that of the converging lens support. They can be made of aluminum alloy, titanium, or stainless steel.

[0038] The present invention describes a sample heating device using sunlight, which can be summarized as follows: 1) A blackbody furnace is used to reflect the sunlight reflected and scattered by the sample multiple times, so that the sample can fully absorb the sunlight and heat the sample; 2) A plano-convex lens with a zone plate on one side is used as a converging lens, and the focal length of the converging lens is the distance from the converging lens to the sample; 3) A bracket is used to support and fix the blackbody furnace and the converging lens; 4) This heating device has high energy utilization and can heat the sample at high temperatures.

[0039] The above embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A device for heating a sample using sunlight, characterized in that: The heating device consists of a blackbody furnace, a converging lens, a blackbody furnace support, a converging lens support, and a light-transmitting port switch. The blackbody furnace has a light-transmitting port and a material loading / unloading port on its surface. The light-transmitting port allows focused sunlight to enter the interior of the blackbody furnace, while the material loading / unloading port is used for inserting and removing samples. The converging lens consists of a plano-convex lens and a Fresnel zone plate fabricated on one side of its plane. It is used to focus sunlight onto the sample inside the blackbody furnace. After transmission, reflection, or scattering by the sample, the sunlight is absorbed by the sample after multiple reflections inside the blackbody furnace, achieving the purpose of heating the sample. The blackbody furnace support is connected to the blackbody furnace and serves to fix and support the blackbody furnace. The converging lens support is used to connect the converging lens and the blackbody furnace and fix the converging lens above the light-transmitting port of the blackbody furnace. The light-transmitting port switch is installed on the converging lens support. It is opened when heating is needed and closed when heating is not needed to prevent the blackbody furnace from being in a constantly heated state. The blackbody furnace has a three-layer structure. The inner layer is a spherical shell made of quartz or microcrystalline material. A total reflection silver film is deposited on the outer surface of the inner shell, and a SiO2 hard film is applied over the silver film. The purpose of the coating is to reflect visible and infrared light. The second layer is asbestos, which is used to wrap the inner shell and provides insulation and protection. The third layer is a spherical shell structure made up of two edged metal hemispheres joined together. The two hemispheres are fixed together along the edges with screws. In the three-layer structure, the inner layer is thicker to avoid damage during material loading and unloading, and the inner diameter of the cavity is smaller, so that the sample falls close to the center of the sphere. One side of the converging lens is fabricated with a zone plate by bonding or photolithography. The width of each zone on the zone plate is determined by the peak wavelength of the sample absorption and the focal length of the zone plate. The focal length of the zone plate depends on the focal length of the converging lens and the focal length of the plano lens. The focal length of the converging lens should be the distance from the converging lens to the sample.

2. The sample heating device using sunlight according to claim 1, characterized in that: The blackbody furnace support consists of three metal pillars with boots at the bottom. The three pillars are of the same length, are distributed at equal angles to each other, and are fixedly connected to the outer shell of the blackbody furnace.

3. The sample heating device using sunlight according to claim 1, characterized in that: The converging lens support consists of three metal pillars fixed above the light-transmitting opening of the blackbody furnace. The converging lens is fixed above the light-transmitting opening by the converging lens support, which focuses sunlight onto the sample inside the blackbody furnace to heat the sample. The three pillars are retractable, making it easy to adjust the position of the converging point.

4. The sample heating device using sunlight according to claim 1, characterized in that: The light-transmitting switch is a metal disc, mounted on a support pillar of the converging lens bracket, and can rotate around the support pillar. When rotated above the light-transmitting opening, the disc completely covers the opening. At this time, the other side of the disc contacts another support pillar, and the light-transmitting switch is in a closed state. When the disc is rotated in the opposite direction to expose the light-transmitting opening, the light-transmitting switch is in an open state.

5. A sample heating device using sunlight according to claim 2 or 3, characterized in that: The metal supports can be metal tubes, with the blackbody furnace support having thicker walls, larger diameters, and longer lengths than the converging lens support. They are made of aluminum alloy, titanium, or stainless steel.

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