Test of the Efficiency of the Concentrator with Different Types of Optical Fiber

• Main Authors: Yen-kai Peng, 彭彥凱
• Other Authors: 吳俊諆
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/61974826914820460618

碩士 === 國立中央大學 === 能源工程研究所 === 95 === Solar concentrator is an important device in the application of solar energy, and one of its applications is utilize the optical fiber to transport the concentrated light into the indoor for converting the solar energy to other form of energy. Such arrangement provides flexibility and yet its practical implementation remains to be investigated. Thus, this work is a feasibility study of transmitting the concentrated light from a concentrator through the optical fiber. Present arrangement of the fiber-concentrator consisted of a parabolic dish (the primary mirror) and a flat secondary mirror, and various forms of optical fiber (plastic and quartz) up to the length of 150 cm. There is some mismatch between the optical and material characteristics of fibers and the mirrors used in the concentrator, especially the diameter and the curvature of primary mirror, and the numerical aperture of the fiber. In addition, the operating temperature will affect the output power from the fiber. This study uses two types of primary mirror, three types of single fiber and two modes of quartz-fiber bundle. The transmitting efficiency is calculated from both the measured and predicted light power through the light path of the concentrator-fiber. In the case of single fiber, the quartz-fiber with the buffer layer has best efficiency; it’s efficient is 77-80% for a 120-cm length of transmitting length. Due to imperfect fabrication of the fiber bundle, the light intensity of the fiber bundle drop significantly compare with that of the single fiber. Finally, the measured light power was stable in the range of low operating temperature (25oC - 95oC).