Meijie Chen, Shuang Li, Dan Pang, Yanwei Zhao, Yuan Yang, Hong-jie Yan
{"title":"Numerically enhancing daytime radiative cooling performance of random dielectric microsphere coatings by hollow structures","authors":"Meijie Chen, Shuang Li, Dan Pang, Yanwei Zhao, Yuan Yang, Hong-jie Yan","doi":"10.1117/1.JPE.11.042108","DOIUrl":null,"url":null,"abstract":"Abstract. Dielectric microsphere coatings for passive daytime radiative cooling (PDRC) are gaining attention owing to their low cost and potential for mass production. The cooling performance could be further enhanced to effectively reflect solar radiation and emit thermal radiation to the cold sky by designing microspheres suitable for PDRC applications. Hollow dielectric structures were numerically designed to enhance the PDRC performance of dielectric microsphere coatings. The maximum solar reflectance (R¯solar = 0.96) was obtained with a fill rate f = 0.6, outer radius rout = 0.5 μm, core–shell rate φ = rin / rout = 0.3, thickness t = 300 μm, and thermal infrared emittance ε¯LWIR = 0.90. Furthermore, by controlling the multisize sphere distribution within φ = 0.1 to 0.5, the cooling performance at t = 300 μm was enhanced to R¯solar = 0.98, ε¯LWIR = 0.95, and a net cooling power of 77 W / m2 was achieved at a temperature of 25°C, which was ∼38 % higher than that achieved with the single-size sphere coating (φ = 0.3) and ∼64 % higher than that of the solid SiO2 sphere coating (φ = 0). These results indicate that hollow structures can effectively enhance the cooling performance of dielectric microsphere coatings by increasing the number of interfaces between the air and dielectric materials.","PeriodicalId":16781,"journal":{"name":"Journal of Photonics for Energy","volume":"11 1","pages":"042108 - 042108"},"PeriodicalIF":1.5000,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Photonics for Energy","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1117/1.JPE.11.042108","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 5
Abstract
Abstract. Dielectric microsphere coatings for passive daytime radiative cooling (PDRC) are gaining attention owing to their low cost and potential for mass production. The cooling performance could be further enhanced to effectively reflect solar radiation and emit thermal radiation to the cold sky by designing microspheres suitable for PDRC applications. Hollow dielectric structures were numerically designed to enhance the PDRC performance of dielectric microsphere coatings. The maximum solar reflectance (R¯solar = 0.96) was obtained with a fill rate f = 0.6, outer radius rout = 0.5 μm, core–shell rate φ = rin / rout = 0.3, thickness t = 300 μm, and thermal infrared emittance ε¯LWIR = 0.90. Furthermore, by controlling the multisize sphere distribution within φ = 0.1 to 0.5, the cooling performance at t = 300 μm was enhanced to R¯solar = 0.98, ε¯LWIR = 0.95, and a net cooling power of 77 W / m2 was achieved at a temperature of 25°C, which was ∼38 % higher than that achieved with the single-size sphere coating (φ = 0.3) and ∼64 % higher than that of the solid SiO2 sphere coating (φ = 0). These results indicate that hollow structures can effectively enhance the cooling performance of dielectric microsphere coatings by increasing the number of interfaces between the air and dielectric materials.
期刊介绍:
The Journal of Photonics for Energy publishes peer-reviewed papers covering fundamental and applied research areas focused on the applications of photonics for renewable energy harvesting, conversion, storage, distribution, monitoring, consumption, and efficient usage.