直接吸收式太阳能集热纳米流体光热特性研究  

Photothermal Properties of Nanofluid in Direct Absorption Solar Collectors

作　　者：郑兆志[1] 何钦波[1] 

机构地区：[1]顺德职业技术学院广东高校热泵工程技术开发中心,佛山528333

出　　处：《真空科学与技术学报》2015年第1期84-88,共5页Chinese Journal of Vacuum Science and Technology

基　　金：2012国家自然科学基金项目(51246006)

摘　　要：采用两步法配制了Co-H2O纳米流体,针对不同粒径、不同质量分数、不同pH值的纳米流体,与去离子水一起同步测试了其光热转换特性。实验结果表明:纳米流体的温升速率及集热量明显优于去离子水的。纳米流体质量分数有一最佳值,实验中质量分数为0.1%时效果最好,其最高温度要比纯水高出30.3%。30 nm Co-H2O纳米流体的光吸收能力要强于50 nm Co-H2O纳米流体的。pH值对光热特性有较大影响,实验中p H=8效果最佳。Co-H2O纳米流体优异的光吸收性能表明其有望运用在直接吸收式太阳能系统中。The Co-H2O nano-fluid was prepared via two-step chemical route. The impact of the nano-fluid proper- ties, including but not limited to the Co nano-particle size, mass fraction and pH-value, on its photo-thermal characteristics was experimentally evaluated. The nano-fluid filled in the solar thermal collector was tested and compared with de-ionized （DI） water. The test results show that the Co nano-particle size,rnass fraction and pH-value all have a major impact on the photo-thermal properties. For example, the photo-absorption coefficient of 30 nm Co nano-particle is higher than that ~ff the 50 nm one.The optimized mass fraction and pH value were found to be 0. l%（wt） and 8,respectively.The Co-H20 nano-fluid has much higher temperature rising-rate and larger heat capacity than DI-water. The peak temperature of the nano-fluid with a mass fraction of 0.1% was 30.3 % higher than that of DI water.

关 键 词：纳米流体 太阳能 辐射 光热特性 直接吸收式 

分 类 号：TK121[动力工程及工程热物理—工程热物理]