环腔流道太阳能空气吸热器的光-热转换特性研究  

Study of optical-thermal conversion characteristics of solar air receiver with an annular cavity flow channel receiver

作　　者：谢欣旖 颜健[1] 彭佑多[1] Xie Xinyi;Yan Jian;Peng Youduo(School of Mechanical Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学机电工程学院,湖南湘潭411201

出　　处：《可再生能源》2023年第9期1174-1180,共7页Renewable Energy Resources

基　　金：国家自然科学基金(52105097);湖南省自然科学基金(2019JJ40085)。

摘　　要：吸热器是太阳能聚光热利用系统中光-热能量转换的核心部件,文章针对一种简单结构的环腔流道吸热器,采用光线跟踪方法和计算流体力学方法实现光热耦合,建立了含石英窗环腔流道空气吸热器的耦合传热数值模型,探讨了碟式聚光器焦距、太阳直接辐射强度、质量流量、入口温度以及能流分布形式(非均匀与均匀能流分布)对光热转换性能的影响。研究表明:吸热器热效率和出口温度受焦距影响不大,但壁面峰值温度随焦距增大而急剧上升;热效率与质量流量呈正相关而与太阳直接辐射强度(Direct Normal Irradiance,DNI)呈负相关,出口温度反之,当DNI=800 W/m^(2),质量流量m=0.0166 kg/s时,吸热器综合热性能最优,热效率和出口温度分别为74.70%和478.74 K;出口温度受入口温度直接影响以几乎相同的差值变化,入口温度每升高50 K,热效率下降7.3%左右,该吸热器结构适用于中低温空气;能流分布均匀与否对出口温度及热效率影响不大,均匀能流分布下的吸热器壁面峰值温度反而略高于非均匀能流分布的。The receiver is the core component of the optical-thermal energy conversion in a solar concentrating utilization system.For a simple air receiver with an annular cavity flow channel,a numerical model study on coupling heat transfer of the air receiver with a quartz window is developed by using ray-tracing method and computational fluid dynamics method to realize photothermal coupling.The influence of disc concentrator focal length,solar irradiation intensity,mass flow rate,inlet temperature,and the form of solar flux distribution(non-uniform versus uniform solar flux distribution)on the optical-thermal conversion performance of receiver is investigated.The thermal efficiency and outlet temperature of the receiver are not significantly influenced by the focal length,but the peak wall temperature increases sharply with the increase of focal length.The thermal efficiency is positively correlated with the mass flow rate and inversely correlated with DNI,and the outlet temperature has the opposite correlations.When DNI=800 W/m^(2) and the flow rate=0.0166 kg/s,the comprehensive thermal performance of the recever is optimal,which are found respectively 74.70%and 478.74 K.The outlet temperature is directly influenced by the inlet temperature with almost the same difference change,and the thermal efficiency decreases about 7.3%for every 50 K increase in the inlet temperature,indicating that the structure of receiver is suitable for medium and low temperature air applications.The uniform solar flux distribution has little effect on the outlet temperature and thermal efficiency,and the peak wall temperature of the receiver under uniform solar flux distribution is slightly higher than that under non-uniform solar flux distribution.

关 键 词：太阳能聚光热利用 环腔流道吸热器 光线跟踪方法 光-热转换 耦合模型 

分 类 号：TK513[动力工程及工程热物理—热能工程]