Chen Qixiang, Huang Xuemei, Lu Yuehui, Xu Hua, Zhao Dongliang
School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China.
Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China.
ACS Appl Mater Interfaces. 2024 May 1;16(17):21807-21817. doi: 10.1021/acsami.4c00825. Epub 2024 Apr 18.
Radiative cooling is the process to dissipate heat to the outer space through an atmospheric window (8-13 μm), which has great potential for energy savings in buildings. However, the traditional "static" spectral characteristics of radiative cooling materials may result in overcooling during the cold season or at night, necessitating the development of dynamic spectral radiative cooling for enhanced energy saving potential. In this study, we showcase the realization of dynamic radiative cooling by modulating the heat transfer process using a tunable transmittance convection shield (TTCS). The transmittance of the TTCS in both solar spectrum and atmospheric window can be dynamically adjusted within ranges of 28.8-72.9 and 27.0-80.5%, with modulation capabilities of Δ = 44.1% and Δ = 53.5%, respectively. Field measurements demonstrate that through the modulation, the steady-state temperature of the TTCS architecture is 0.3 °C lower than that of a traditional radiative cooling architecture during the daytime and 3.3 °C higher at nighttime, indicating that the modulation strategy can effectively address the overcooling issue, offering an efficient way of energy saving through dynamic radiative cooling.
辐射冷却是通过大气窗口（8 - 13μm）将热量散发到外层空间的过程，这在建筑节能方面具有巨大潜力。然而，传统辐射冷却材料的“静态”光谱特性可能导致在寒冷季节或夜间出现过冷现象，因此需要开发动态光谱辐射冷却技术以增强节能潜力。在本研究中，我们展示了通过使用可调透射率对流屏蔽（TTCS）来调节传热过程实现动态辐射冷却。TTCS在太阳光谱和大气窗口中的透射率可分别在28.8 - 72.9%和27.0 - 80.5%的范围内动态调节，调制能力分别为Δ = 44.1%和Δ = 53.5%。现场测量表明，通过这种调制，TTCS结构在白天的稳态温度比传统辐射冷却结构低0.3°C，在夜间高3.3°C，这表明该调制策略可以有效解决过冷问题，为通过动态辐射冷却实现节能提供了一种有效方法。
