Novel radiation refrigeration device based on broadband absorber with metasurface

A technology of radiative cooling and metasurface, applied in instruments, optical components, optics, etc., can solve the problems of unstable cooling effect, low cooling effect, easy damage of film, etc., achieve easy mass production of large area, reduce preparation cost, The effect of improving production efficiency

Pending Publication Date: 2022-03-01
XIAMEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In 2017, Professor Yin Xiaobo from the University of Colorado randomly embedded resonant polar dielectric microspheres into a polymer matrix, resulting in a metamaterial that is completely transparent to the solar spectrum, while having an infrared emissivity greater than 0.93 in the atmospheric window, cooling Power over 110W / m 2 , although this radiative cooling film has a high emission, but this film is easily damaged, and the cooling effect is unstable
The advantage of the third method is that the absorption spectrum range can be precisely adjusted, but there are obvious disadvantages of low refrigeration effect and complicated preparation

Method used

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  • Novel radiation refrigeration device based on broadband absorber with metasurface
  • Novel radiation refrigeration device based on broadband absorber with metasurface
  • Novel radiation refrigeration device based on broadband absorber with metasurface

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Under the incidence of TE wave, the material used in the reflective film with uniform optical thickness in the absorber is metal titanium with a thickness of 100nm, and the intermediate dielectric layer covering the bottom metal film is germanium with a thickness of 480nm. The periodic array is formed by stacking plasmonic metal titanium discs and dielectric germanium cylinders with the same radius. The period of 1 μm is spread out in a two-dimensional planar tetragonal lattice on the upper surface of the intermediate dielectric layer. The thickness of the titanium disc is 20nm, and the germanium cylinder The thickness is 500nm. The spectra of the above absorbers are shown in figure 2 As shown by the black solid line, it can be seen that it basically coincides with the atmospheric infrared transparent window (gray solid line), and the average absorption rate in the 8-13 μm working band is 0.94.

[0035] The radiation cooling power of the absorber of embodiment 1 under...

Embodiment 2

[0037]On the basis of Embodiment 1, modify the thickness of the intermediate germanium dielectric layer to 400nm, 430nm, 450nm, 480nm, and 500nm respectively. The spectra of the above absorbers are shown in Figure 4 It can be seen that modifying the thickness of the intermediate dielectric layer of the absorber will affect the absorptivity, but within a certain range of modification, the absorptivity has little effect, and the device can still maintain a high broadband average absorptivity, thereby reducing the Accuracy requirements for absorber preparation.

Embodiment 3

[0039] On the basis of Example 1, modify the period of the plasmonic titanium metal disc and the dielectric germanium cylinder array to be 0.8 μm, 1 μm, 1.2 μm, and 1.4 μm, respectively. The spectra of the above absorbers are shown in Figure 5 As shown, it can be seen that if the period is too large, the absorption bandwidth will be reduced, so that it is impossible to maintain a high average absorption rate in the working band of 8 μm to 13 μm, and if the period is too small, the absorption rate in the working band will be reduced, which will also reduce the average absorption rate. . However, the array period changes within a certain range, and the device can still maintain a high absorption rate in the working band.

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Abstract

The invention discloses a novel radiation refrigeration device based on a metamaterial surface broadband absorber, and relates to a radiation refrigeration device. A supporting substrate, a uniform light thickness reflective film, an intermediate dielectric layer and a periodic array are sequentially arranged from bottom to top; the periodic array is an array formed by columnar units which are periodically distributed in a square shape, and the columnar units are formed by stacking and combining plasmon metal discs and dielectric cylinders; through interaction of local plasmon resonance of the periodic array and other parts, the infrared broadband absorption characteristic is formed, and therefore the passive radiation refrigeration function is achieved for a heat source. Bottom metal with the thickness larger than the skin depth is used for blocking light transmission; strong absorption is generated by exciting plasmon resonance to reduce reflections. The structure is simple, the requirement for preparation precision is lowered, the preparation efficiency is improved, and the preparation cost is lowered. The broadband high emissivity is achieved, large-area batch manufacturing is easy, and the device can be used for radiation refrigeration to achieve the energy-saving and environment-friendly effects.

Description

technical field [0001] The invention relates to a radiation cooling device, in particular to a novel radiation cooling device based on a metasurface broadband absorber, which has broadband high emissivity in the atmospheric infrared transparent window and high reflectivity in other wave bands. Background technique [0002] Radiant cooling is a passive, energy-free cooling technology. The atmosphere has an optically transparent window at 8-13 μm, and the object radiates heat to the low-temperature universe through the transparent window of the atmosphere in the form of thermal radiation, thereby reducing its own temperature and realizing passive cooling. In recent years, radiation cooling, as a passive, green and renewable cooling method, has attracted widespread attention in the field of energy conservation. [0003] Thermal radiation is the process of heat transfer between hot and cold objects relying on the electromagnetic wave radiation of objects. It is a non-contact he...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G02B5/00
CPCG02B5/003G02B5/008
Inventor 蔡国雄祝涵魏斌刘娜柳清伙
Owner XIAMEN UNIV
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