A radiation cooling test device

Abstract

The present invention relates to the field of radiation cooling technology, and in particular to a radiation cooling test device, including a test device body, a temperature measuring device, and a bracket, wherein the test device body includes a top support rod and a plurality of vertical rods, wherein the top support rod and the plurality of vertical rods together form a cavity, wherein a transparent mesh layer for placing a test sample is provided at the bottom of the cavity, and the periphery of the cavity is covered with a transparent film, wherein the temperature measuring device is provided below the cavity, and wherein the bracket includes a plurality of support rods connected to the vertical rods. The present invention has a simple structure, an ingenious construction, a low manufacturing cost, a low solar radiation absorption rate, a high light transmittance, good sealing, and good test accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of radiation cooling, and in particular to a radiation cooling testing device. Background Art

[0002] As global warming becomes more and more serious, people need to invest more energy in the field of refrigeration to achieve the expected cooling effect. On the one hand, this aggravates the energy crisis. On the other hand, due to the large-scale use of refrigeration and air conditioning, more Freon emissions will also lead to further deterioration of people's living environment. In this context, reducing energy consumption or developing new methods and technologies for refrigeration and cooling is an urgent task. At this time, radiant refrigeration, as a zero-energy, safe, efficient and clean refrigeration technology, has shown practical application value.

[0003] Radiative cooling is a passive cooling method in which an object radiates its own heat to the outer space, a huge cold source, through the atmospheric window in the form of infrared emission to achieve self-cooling. For the atmosphere, electromagnetic waves in different bands have different transmittances. The so-called "atmospheric window" is the band with higher transmittance, such as 0.3-2.5μm, 3.2-4.8μm, and 8-13μm. Among the many bands, the 8-13μm band is the most noteworthy band because blackbody radiation at room temperature is mainly concentrated in this band.

[0004] For a long time, experiments on radiation cooling were mainly conducted at night. This is because the radiator absorbs a large amount of solar radiation energy during the day, causing its own temperature to rise continuously, making the effect of radiation cooling impossible to show. Until recently, scientists have developed a variety of materials that can achieve daytime radiation cooling. The common characteristics of these materials are that the material surface has a high reflectivity to solar radiation (wavelength between 0.3-2.5 microns) and a high infrared emissivity to the transparent atmospheric window spectrum (8-13 microns). As a result, a new chapter in the field of radiation cooling research has been opened, and a number of excellent research works have emerged. In these works, many new radiation cooling test devices have emerged. For example, in the device designed by the scientific research team of Stanford University in the United States in 2017, the radiation cooling material was placed on the inside of a transparent glass culture dish, which was supported by three glass rods about 20 cm high and placed above the roof. The top of the culture dish is covered with a polyethylene film that is transparent to all radiated electromagnetic waves, acting as a convection shield. Although the device is simple, it has the following two significant problems that affect the accuracy of the measurement: 1. The thicker glass culture dish easily absorbs solar radiation and generates heat; 2. The culture dish is only 20 centimeters above the ground, and the higher temperature of the ground easily heats the sample in the culture dish through short-distance radiation heat transfer. For example, in 2018, a research team at the University of New Mexico in the United States designed a relatively complex device for radiative cooling research, but the outer surface of the device is covered with aluminum foil, and the inner surface is white opaque polystyrene foam material. The aluminum foil and polystyrene foam material will absorb a certain amount of heat when exposed to sunlight, which will affect the accuracy of the experimental measurement, especially during long-term testing.

[0005] At present, the test equipment for radiative cooling is still being improved to minimize the impact of the device's absorption of solar radiation energy and high-temperature ground radiation heat transfer on the test. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a simple radiation cooling test device, which improves the test accuracy by reducing the absorption of solar radiation energy by the test device itself and reducing the influence of high-temperature ground radiation heat transfer on the test sample.

[0007] To achieve the above-mentioned purpose, the technical solution of the present invention is: a radiation refrigeration test device, including a test device body, a temperature measuring device, and a bracket. The test device body includes a top support rod and a plurality of vertical rods. The top support rod and the plurality of vertical rods together constitute a cavity. The bottom of the cavity is provided with a transparent mesh layer for placing the test sample. The transparent mesh layer is woven from high-strength nylon wire. The periphery of the cavity is covered with a transparent film to isolate the heat transfer caused by air convection, and the film has high light transmittance and good sealing. The temperature measuring device is arranged below the cavity, and the bracket includes a plurality of support rods connected to the vertical rods.

[0008] Preferably, the thickness of the transparent film is 10-25 μm, so that the cavity is not easy to absorb heat, thereby increasing the accuracy of the test.

[0009] Preferably, the top support rod and the vertical rod are both made of transparent organic glass. By using transparent organic glass to make the rod, the absorption of solar radiation is reduced, and the influence of the temperature rise of the rod on the test results is reduced.

[0010] Preferably, the top support rod and the vertical rod are both made of transparent polystyrene. By using transparent polystyrene to make the rod, the absorption of solar radiation is reduced, and the influence of the temperature rise of the rod on the test results is reduced.

[0011] Preferably, the height of the support rod is 1-2 m. Such a height range can significantly reduce the heat radiation of the high-temperature ground to the test sample.

[0012] Preferably, the outer surface of the support rod is affixed with a silver film to reduce solar radiation absorption and reduce the influence of the rod on the test results.

[0013] Preferably, the outer surface of the support rod is painted with white paint to reduce solar radiation absorption and reduce the influence of the rod on the test results.

[0014] Preferably, it also includes a plurality of transparent fixings, which are in a convex shape, and the first and second ends of the top support rod and the vertical rod are provided with grooves for the transparent fixings to be inserted. While covering the transparent film, the transparent fixings are used to further fix the transparent film, so that while ensuring good light transmittance, the transparent film is made tighter, has a strong sealing performance, isolates air convection, and improves the accuracy of the test results.

[0015] Preferably, the transparent film is made of transparent polyethylene. By selecting a transparent polyethylene film to cover the cavity, it not only has a very low absorption rate in the solar radiation band, but also has a high transparency in the atmospheric radiation window of 8-13μm, so that the test device itself is not significantly heated by solar radiation, and does not affect the energy radiation release of the test sample to the outside world, thereby improving the accuracy of the test results.

[0016] Preferably, the cavity is provided with a door that can be opened and closed freely, so as to facilitate sample loading and sampling.

[0017] By adopting the above technical solution, the beneficial effects of the present invention are as follows: the present invention adopts transparent rods, transparent films and transparent mesh layers to form a cavity for placing test samples, and the cavity has low solar radiation absorption rate, good transparency, strong sealing performance, and isolates air convection, which greatly improves the accuracy of the test results. The present invention also provides a bracket 1 to 2 meters above the ground at the bottom of the main body of the test device, and the bracket is affixed with a silver film or painted with white paint to reduce solar radiation absorption and reduce the radiant heat effect of the high temperature ground on the test product, which greatly increases the accuracy of the test results. The present invention has a simple structure, ingenious construction, low production cost, low solar radiation absorption rate, high light transmittance, good sealing, and good test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention;

[0019] Figure 2 It is the front view of the present invention;

[0020] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0021] Explanation of main figure markings: (1. test device body; 11. top support rod; 12. vertical rod; 13. cavity; 14. transparent mesh layer; 15. transparent film; 16. door; 2. temperature measuring device; 3. bracket; 31. support rod; 4. transparent fixing piece; 41. groove). DETAILED DESCRIPTION

[0022] The present invention is further described below with reference to specific embodiments.

[0023] like Figure 1 As shown, a radiation cooling test device includes a test device body 1, a temperature measuring device 2, and a bracket 3. The test device body 1 includes a top support rod 11 and a plurality of vertical rods 12. The top support rod 11 and the plurality of vertical rods 12 together constitute a cavity 13. A transparent mesh layer 14 for placing a test sample is provided at the bottom of the cavity 13. The transparent mesh layer 14 is woven from high-strength nylon wire. The periphery of the cavity 13 is coated with a transparent film 15 to isolate heat transfer caused by air convection, and the film has high light transmittance and good sealing. The temperature measuring device 2 is provided below the cavity 13. The bracket 3 includes a plurality of support rods 31 connected to the vertical rods 12.

[0024] The thickness of the transparent film 15 is 10-25 μm, so that the cavity 13 is not easy to absorb heat, thereby increasing the accuracy of the test.

[0025] The top support rod 11 and the vertical rod 12 are both made of transparent organic glass. By using transparent organic glass to make the rod, the absorption of solar radiation is reduced, and the influence of the temperature rise of the rod on the test result is reduced.

[0026] The top support rod 11 and the vertical rod 12 are both made of transparent polystyrene. By using transparent polystyrene to make the rod, the absorption of solar radiation is reduced, and the influence of the temperature rise of the rod on the test result is reduced.

[0027] The support rod 31 has a height of 1 m to reduce the heat radiation from the high-temperature ground to the test sample.

[0028] The outer surface of the support rod 31 is covered with a silver film to reduce the absorption of solar radiation and reduce the influence of the rod on the test results.

[0029] The outer surface of the support rod 31 is painted white to reduce the absorption of solar radiation and reduce the influence of the rod on the test results.

[0030] like Figure 2-3 As shown, it also includes a plurality of transparent fixing members 4, which are in a convex shape, and the first and second ends of the top support rod 11 and the vertical rod 12 are both provided with grooves 41 for the transparent fixing members 4 to be inserted. While covering the transparent film, the transparent fixing members 4 are used to further fix the transparent film, so that the transparent film is more tight and has a strong sealing performance while ensuring good light transmittance, isolating air convection, and improving the accuracy of the test results.

[0031] The transparent film 15 is made of transparent polyethylene. By selecting a transparent polyethylene film to cover the cavity, it not only has a very low absorption rate in the solar radiation band, but also has a high transparency in the atmospheric radiation window of 8-13μm, so that the test device itself is not significantly heated by solar radiation, and does not affect the energy radiation release of the test sample to the outside world, thereby improving the accuracy of the test results.

[0032] The cavity 13 is provided with a door 16 that can be opened and closed freely, so as to facilitate sample loading and sampling.

[0033] Comparative example: A radiation refrigeration testing device comprises a testing device body, a temperature measuring device and a glass support rod. The testing device body is a transparent glass dish and a transparent polyethylene film covering it. The temperature measuring device is arranged below the transparent glass dish. The height of the glass support rod is 20 cm.

[0034] The accuracy of the radiant cooling performance test can be judged in the following way. The accuracy is characterized by testing the temperature difference between the temperature in the embodiment and the comparative example device and the natural environment temperature under the same natural environment. The larger the temperature difference, the less the device is affected by the external environment, and the higher the test accuracy. The test results are shown in Table 1.

[0035] Table 1: Temperature of commercial refrigeration film samples under two test conditions

[0036] Refrigeration sample temperature (℃) Natural environment temperature (℃) Temperature difference (℃) Example 20.2 26.1 -5.9 Comparative Example 21.5 26.1 -4.6

[0037] It can be concluded from Table 1 that the temperature difference (absolute value) between the temperature in the embodiment and the natural environment temperature is greater than that in the comparative example, indicating that the accuracy of the test result of the embodiment is higher than that of the comparative example, that is, the embodiment is less affected by the external environment than the comparative example.

[0038] The above-mentioned are only preferred embodiments of the present invention and cannot limit the scope of the present invention. All equivalent changes and decorations made according to the scope of the patent application of the present invention should still fall within the scope of the present invention.

Claims

1. A radiation cooling test device, characterized in that: The device comprises a test device body, a temperature measuring device, and a bracket. The test device body comprises a top support rod and a plurality of vertical rods. The top support rod and the plurality of vertical rods together constitute a cavity. A transparent mesh layer for placing a test sample is provided at the bottom of the cavity. The periphery of the cavity is covered with a transparent film. The temperature measuring device is provided below the cavity. The bracket comprises a plurality of support rods connected to the vertical rods. The transparent film is made of transparent polyethylene and has a thickness of 10 to 25 μm; The top support rod and the vertical rod are both made of transparent organic glass or transparent polystyrene; The outer surface of the support rod is silver film or white paint, and the height is 1 to 2 meters.

2. A radiation cooling test device according to claim 1, characterized in that: It also includes a plurality of transparent fixing members, which are in a convex shape. The first and last ends of the top support rods and the first and last ends of the vertical rods are both provided with grooves for the transparent fixing members to be inserted into.

3. A radiation cooling test device according to claim 1, characterized in that: The cavity is provided with a door which can be opened and closed freely.

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