以單軸追跡的高效能平面式日光集光器

Abstract

本論文提出一款以單軸追跡的高效能平面式日光集光器，使用具有拋物線截面輪廓的圓弧狀微結構以及複合拋物面集光器(Compound Parabolic Concentrator, CPC)分別作為第一段與第二段集光結構。第一段集光結構利用全內反射將入射的太陽光耦合到下方的導光板並在導光板內藉由內部全反射行進並且在導光板末端端面上聚焦。第二段集光結構則在端面聚焦處將光線導引到末端處並對光線做進一步集中。第二段集光結構具有三種不同尺寸的CPC與設計參數，分別對應不同入射條件的光線，根據入射光角度變化而平移。除了能取代一轉動軸的追跡外，還能夠有效提高集光倍率。 最後，將集光部分做多層堆疊後搭配單一轉動軸追跡裝置構成此平面式日光集光器。由模擬結果顯示：以裝置在台北為例，總長度為88公分、考慮太陽光譜為AM1.5，在全年維持單軸追跡的情況下，最高與最低效率分別為56.7%與33.1%，最高與最低的集光倍率分別為623與134。

The paper proposes a high-performance planar solar concentrator using single-axis tracking, using arc-shaped microstructure with parabolic cross-section and compound parabolic concentrator as the first and the second collecting structure. The first collecting structure uses total internal reflection to couple the incident sunlight into the underlying light guide plate and travel within the light guide plate by total internal reflection and focus on the end of it. The second collecting structure directs the incident sunlight to the end at the end spot focusing and further concentrates the incident sunlight. And the second collecting structures are constituted of three different sizes of CPC and design parameters, respectively corresponding to the sunlight of different incident conditions, and shifted according to the change of the incident angle. In addition to being able to replace the trace of a rotating shaft, it can also increase the concentration ratio effectively. Finally, the light collecting sections are stacked into multi-layer and assemble with a single rotating shaft tracking device to form the planar solar concentrator. The simulation results show that taking the installation in Taipei as an example, the total length is 88 cm, considering solar spectrum AM1.5, maintaining single-axis tracing through whole year, the maximum and minimum efficiency are 56.7% and 33.1% respectively, and the maximum and minimum concentration ratio are 623 and 134 respectively.