技术中心

【摘要】 针对辐射致冷进行了可行性研究。首先介绍了辐射致冷的原理和实现方法,然后利用红外发射率测定仪测定了碳黑、TiO2、NaCl晶体、聚酯(PET)薄膜与聚四氟乙烯(PTFE)薄膜的红外发射率,并间接测定了低密度聚乙烯薄膜(LDPE)对于不同材料的透过率。最后研制了利用空气为冷媒介质的辐射致冷实验装置,进行了夜间静态和连续抽气实验。实验结果表明:分别用PET薄膜和PTFE薄膜作为辐射体,静态实验时,可获得与环境的最大温差分别为11℃和9℃;连续抽气实验时,装置出口处冷空气与环境的最大温差分别为4.7℃和5.4℃。通过计算,装置的有效致冷功率为74.5W/m2,故该装置可实现节能型建筑夏季夜间的连续降温。 【Abstract】 In this study,the principle and the method of radiative cooling were stated.The emissivities of black carbon powder,NaCl crystal,TiO2 powder,PET film and PTFE film were measured using an infrared emission detector.The transmittance of LDPE film to several materials was obtained by using theoretical derivation combined with experimental measurement.The experiment for static and continuous airflow was conducted.The results show that by using PET film and PTFE film as the radiators,the temperature difference between the cooling space and the surroundings reached 11℃ and 9℃,respectively,in the static airflow while air temperature difference between the device outlet and the surroundings was 4.7℃ and 5.4℃,respectively,in the continuous airflow.From the calculation,the effective cooling power of the device is 74.5W/m2.It seems that the device could realize the continuous cooling for energy-saving buildings at night in summer. 【关键词】 热工学; 辐射致冷; 发射率; 透射率; PET薄膜; PTFE薄膜 【Key words】 Pyrology; Radiative cooling; Emissivity; Transmissivity; PET film; PTFE film