Journal of Quantitative Spectroscopy and Radiative Transfer ( IF 2.3 ) Pub Date : 2021-05-31 , DOI: 10.1016/j.jqsrt.2021.107774 Zafrin Ferdous Mira , Se-Yeon Heo , Do Hyeon Kim , Gil Ju Lee , Young Min Song
Passive Daytime Radiative Cooling (PDRC) process radiates excess heat by dumping heat into space through Transparent Atmospheric Windows (TAWs). Many structures are proposed for the PDRC but their main constraint is achieving near unity selective emission over 8–13 µm (first TAW, i.e., TAW 1) and 16–26 µm (second TAW, i.e., TAW 2) wavelength regions. In this paper, we have presented two Passive Daytime Radiative Coolers (PDRCs) referred as Design 1 and Design 2 which have respectively maximum 99% and 98% emissivity in TAW 1. While Design 1 is simulated considering only TAW 1, Design 2 is found acknowledging both TAW 1 and TAW 2. Both the models consist of three dielectric layers (i.e., SiN, SiC and SiO2) and a metal (i.e., Ag) back reflector. A genetic algorithm named” Memetic Algorithm” (MA) is utilized to identify the dielectric materials and determine their optimum thickness. The dielectric materials are selected by MA in such a way that their absorption peaks in the TAW 1 do not overlap and destructively interfere with each other, which in turn helps to obtain a high selective emission in that particular window with minimum thickness. This technique can be a new paradigm in designing PDRCs via tailoring material configuration. Additionally, the selective emitters are capable of providing a cooling temperature of 49.8 K and 44 K with a cooling power of 100.72 Wm−2 and 112.27 Wm−2 at equilibrium respectively for Design 1 and 2 when non-radiative heat exchange coefficient hc is 0 Wm−2K−1 and the studied wavelength range is in between 0.3 to 30 µm. The proposed emitters have only 1D planar layers. Therefore, they can be fabricated with promptly accessible materials which make them a better candidate for large scale fabrication.
中文翻译:
使用模因算法的多层选择性被动日间辐射冷却器优化
被动日间辐射冷却 (PDRC) 过程通过透明大气窗 (TAW) 将热量排放到太空中,从而散发出多余的热量。为 PDRC 提出了许多结构,但它们的主要限制是在 8–13 µm(第一个 TAW,即TAW 1)和 16–26 µm(第二个 TAW,即TAW 2)波长区域上实现接近统一的选择性发射。在本文中,我们介绍了两个被动日间辐射冷却器 (PDRC),称为设计 1 和设计 2,它们在 TAW 1 中分别具有最大 99% 和 98% 的发射率。虽然设计 1 仅考虑 TAW 1 进行仿真,但发现设计 2承认 TAW 1 和 TAW 2。这两个模型都由三个介电层(即SiN、SiC 和 SiO 2)和一个金属(即,Ag)背反射器。一种名为“模因算法”(MA) 的遗传算法用于识别介电材料并确定其最佳厚度。MA 以这样一种方式选择介电材料,即它们在 TAW 1 中的吸收峰不会相互重叠和相消干涉,这反过来有助于在具有最小厚度的特定窗口中获得高选择性发射。这种技术可以成为通过定制材料配置来设计 PDRC 的新范式。此外,该选择性发射极能够提供49.8 K和44 K的冷却温度与100.72了Wm的冷却功率的-2和112.27了Wm -2在平衡分别为设计1和2时的非辐射的热交换系数hc是 0 Wm -2 K -1并且研究的波长范围在 0.3 到 30 µm 之间。提议的发射器只有一维平面层。因此,它们可以用可快速获取的材料制造,这使它们成为大规模制造的更好选择。