本研究主要是針對太陽能加熱系統中的集光器,探討其加熱均勻度,並提出一種改善加熱均勻度的變焦拋物面。再利用歪斜光線追蹤法對其作光學建模,進而利用最佳化設計理論,獲得最佳化的變焦拋物面參數,而達到加熱效率之提升。最後利用ZEMAX光學分析軟體與SolidWorks Flow Simulation熱流分析軟體模擬,加以比較驗證。 本研究以柱狀曲面的一次反射面為主,提出一種改善加熱均勻度的變焦拋物面。由於收集到加熱管的光線為部分一次反射後再接收,部分直接接收,因此在數學建模上有一定的困難度。而本研究乃是以純解析的歪斜光線追蹤法,對此變焦拋物面的集光器進行數學建模。再套用最佳化設計理論,獲得一組最佳化的變焦拋物面參數。之後,我們再利用ZEMAX光學分析軟體與SolidWorks Flow Simulation熱流分析軟體,模擬現有的二種最常見的反射面(即圓柱面及標準拋物面),並與本研究所提出的變焦拋物面進行比較。本研究得到以下結果:(1)圓柱面雖然有其加工容易上的優點,而加熱均勻度比標準拋物面好約15%,但卻有能量無法百分之百到達加熱管的缺點。(2)標準拋物面相對於圓柱面加工上雖然難一點,能量能百分之百到達加熱管,不過加熱上並不均勻。(3)本研究所提出的變焦拋物面集光器,除了能量卻能百分之百到達加熱管之外,加熱均勻度上比標準拋物面改善約83%。(4)在加熱的效率方面,若以完全均勻加熱的效率為指標(100%),則變焦拋物面集光器的加熱的效率可高達99.7%。
The purpose of this project is to design a solar-heating-system concentrator which can give more uniform heating on the heat pipe. In this study, we provide a specific reflector, i.e., variable-focus-paraboloid (VFP) reflector, and use the skew ray tracing method to model the solar-heating-system comprising the VFP reflector. After that we find out the optimum solution by using the optimum method. Next, we use the softwares of ZEMAX and SolidWorks-Flow-Simulation to simulate four types of reflectors (i.e., ideal, circular, standard paraboloid (SP), and VFP reflectors). Consequently, the final results are obtained as follows: (1) although the circular reflector has the benefit of easy manufacturing and the heating uniformity on heat pipe is 15% better than SP reflector, the solar energy can not fully reach the heat pipe; (2) although the SP reflector has low heating uniformity on heat pipe, the solar energy can fully reach the heat pipe; (3) the VFP reflector not only can lead all the solar energy to reach the heat pipe, but also give a better heating uniformity on heat pipe (83% better than SP reflector); (4) the VFP reflector can provide more efficient heating of a solar-heating-system (99.7% of the fully uniform heating).