Abstract The silica sphere embedded hybrid system is a promising emitter for radiative cooling in construction applications. Optimization of its cooling performance requires a thorough understanding of how the fabrication parameters influence its cooling performance. The objective of this study was to explore the influence of the silica sphere radius, sphere volume fraction, and layer thickness on a material’s optical properties and cooling efficiency through theoretical prediction. Using OptiFDTD and Mie theory, the optical property of eight different silica sphere radii, five different silica sphere volume fractions, and five different silica-TPX layer thicknesses were simulated and analyzed. A well-validated thermal model predicted the cooling power of these scenarios under various climatic inputs. These inputs covered the common range of the related parameters in most middle and low latitude areas. The 0.3 μm and 0.5 μm radii had higher emissivity in the atmospheric window and higher cooling power under various climatic conditions. Emissivity in the atmospheric window and other infrared wavelengths increased as the silica sphere volume fraction or silica-TPX layer thickness increased. The best cooling performance was balanced between high emissivity in the 8–13 μm range and low emissivity in other infrared ranges.

中文翻译：

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硅球嵌入聚甲基戊烯 (TPX) 系统的辐射冷却效率

摘要 硅球嵌入式混合系统是一种很有前途的建筑应用辐射冷却发射器。其冷却性能的优化需要彻底了解制造参数如何影响其冷却性能。本研究的目的是通过理论预测探索二氧化硅球半径、球体积分数和层厚度对材料光学性能和冷却效率的影响。使用 OptiFDTD 和 Mie 理论，对八种不同的二氧化硅球半径、五种不同的二氧化硅球体积分数和五种不同的二氧化硅-TPX 层厚度的光学性质进行了模拟和分析。一个经过充分验证的热模型预测了这些情景在各种气候输入下的冷却能力。这些输入覆盖了大部分中低纬度地区相关参数的共同范围。在各种气候条件下，0.3 μm 和 0.5 μm 半径在大气窗口中具有更高的发射率和更高的冷却能力。随着二氧化硅球体体积分数或二氧化硅-TPX 层厚度的增加，大气窗口和其他红外波长的发射率增加。最佳冷却性能在 8-13 μm 范围内的高发射率和其他红外范围内的低发射率之间取得平衡。随着二氧化硅球体体积分数或二氧化硅-TPX 层厚度的增加，大气窗口和其他红外波长的发射率增加。最佳冷却性能在 8-13 μm 范围内的高发射率和其他红外范围内的低发射率之间取得平衡。随着二氧化硅球体体积分数或二氧化硅-TPX 层厚度的增加，大气窗口和其他红外波长的发射率增加。最佳冷却性能在 8-13 μm 范围内的高发射率和其他红外范围内的低发射率之间取得平衡。