A polydimethylsiloxane-coated metal structure for all-day radiative cooling
A polydimethylsiloxane-coated metal structure for all-day radiative cooling
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DOI：
10.1038/s41893-019-0348-5
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发表时间：
2019-08
影响因子：
27.6
通讯作者：
Lyu Zhou;Haomin Song;Jian-Wei Liang;Matthew H. Singer;Ming Zhou;Edgars Stegenburgs;N. Zhang;
中科院分区：
文献类型：
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作者：
Lyu Zhou;Haomin Song;Jian-Wei Liang;Matthew H. Singer;Ming Zhou;Edgars Stegenburgs;N. Zhang;
辐射冷却是一种零耗电的被动冷却策略，可用于辐射建筑物的热量，以减少空调需求。虽然这项技术可以在夜间最佳大气条件下工作，但在白天制冷需求高峰时实现高效制冷至关重要。在这里，我们报告了一种廉价的平面聚二甲基硅氧烷（PDMS）/金属热发射器薄膜结构，这是使用快速的解决方案涂层工艺，可扩展的大面积制造。通过在不同的环境条件下进行测试，在实验室和外部环境中分别证明了9.5 °C和11.0 °C的温度降低，薄膜热发射器的平均冷却功率约为120 W m-2。此外，设计并实现了一种光谱选择性结构，以抑制太阳能输入并控制热发射光束的发散。这增强了热发射的方向性，因此发射器的冷却性能较少依赖于周围环境。室外实验在纽约的布法罗进行，在美国北方纬度典型的晴朗天气实现了约2-9 °C的持续全天冷却。这种无需电力输入即可冷却的实用策略可能会对全球能源消耗产生重大影响。
Radiative cooling is a passive cooling strategy with zero consumption of electricity that can be used to radiate heat from buildings to reduce air-conditioning requirements. Although this technology can work well during optimal atmospheric conditions at night, it is essential to achieve efficient cooling during the daytime when peak cooling demand actually occurs. Here we report an inexpensive planar polydimethylsiloxane (PDMS)/metal thermal emitter thin film structure, which was fabricated using a fast solution coating process that is scalable for large-area manufacturing. By performing tests under different environmental conditions, temperature reductions of 9.5 °C and 11.0 °C were demonstrated in the laboratory and an outside environment, respectively, with an average cooling power of ~120 W m–2for the thin film thermal emitter. In addition, a spectral-selective structure was designed and implemented to suppress the solar input and control the divergence of the thermal emission beam. This enhanced the directionality of the thermal emissions, so the emitter’s cooling performance was less dependent on the surrounding environment. Outside experiments were performed in Buffalo, New York, realizing continuous all-day cooling of ~2–9 °C on a typical clear sunny day at Northern United States latitudes. This practical strategy that cools without electricity input could have a significant impact on global energy consumption.