小槽式集热系统热性能测试和理论研究

Thermal performance testing and theory study of small parabolic trough collector system

为拓宽太阳能应用领域,基于新研发的小型槽式太阳能聚光集热器,定义当量采光面积参数概念,建立吸热和散热数学模型。以广州地区为例,给出东西向放置的槽式聚光集热器在典型日期跟踪状态下太阳光入射角和直射光利用率的变化规律。通过散热数学模型计算,分析系统各项热损失的变化规律,提出改善系统热性能的有效解决方案并通过测试进行验证。实验测试表明,所开发小槽式聚光集热器在中温段有高热效率,在工质150℃时系统热效率在50%左右。

To broaden the application field of solar energy,a small solar parabolic trough collector system has been developed. In this paper,with the concept of equivalent aperture area for the collector system defined,a mathematical model for heat absorption and heat loss of the system is established. The variation tendency of solar incident angle and beam radiation availability is summarized for the collector system rotated about a horizontal east-west axis in Guangzhou at a typical date. With the mathematical model,the variation of the collector system heat loss is analyzed,and a method validated against test for improving its thermal performance is presented. The experiment shows that the collector system has high thermal efficiency in mid-temperature ranges,and at 150 ℃,the system thermal efficiency reaches about 50%.