小型菲涅尔定焦线聚光系统关键参数影响特性研究

基于线性菲涅尔透镜聚光特性和极轴式跟踪原理,提出一种采用圆弧腔体吸收器的小型菲涅尔定焦线聚光系统。采用蒙特卡洛光线追迹方法与数理统计原理,详细研究太阳赤纬角、太阳时角和腔体内表面吸收率等关键参数对聚光系统光学性能的影响。结果表明,腔体内表面吸收率对光学效率因子的影响最显著,其次为太阳赤纬角、太阳时角。腔体内表面吸收率分别为1.00、0.85、0.75时,系统平均光学效率因子分别为0.950、0.865、0.799。太阳赤纬角对能流均匀性影响最显著,其次为太阳时角、腔体内表面吸收率。在太阳赤纬角分别为0°、8°、16°、23.45°时的平均均匀因子分别为0.507、0.519、0.561、0.612。该系统可减少余弦损失、降低焦线偏移对端部损失的影响。

ANALYSIS ON INFLUENCE CHARACTERISTICS OF KEY PARAMETERS OF SMALL-SCALE FIXED-FOCUS LINEAR FRESNEL LENS CONCENTRATOR

A small-scale Fresnel fixed-focus linear concentrating system using arc-cavity absorber is proposed based on the concentrating characteristics of linear Fresnel lens and the principle of polar tracking. The influence of key parameters such as solar declination angle, solar time angle and internal surface absorptivity of absorber on the optical properties of the concentrating system is studied in detail by using Monte Carlo ray tracing method and the principle of mathematical statistics. The results indicate that the internal surface absorptivity of absorber has the most significant effect on the optical efficiency factor. When the absorptivity is 1.00, 0.85 and 0.75 respectively, the average optical efficiency factor of the system is 0.950, 0.865 and 0.799 respectively. When the sun declination angle is 0°, 8°, 16° and 23.45°, the average uniformity factors are 0.507, 0.519, 0.561 and 0.612, respectively. The system is highly effective on the reduction of the cosine loss as well as the impact of focal line offset on the end loss.