| Summary: | 碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 97 === ABSTRACT
A Study of Aerodynamic effects of Water tank installed on Solar Water Heater
Student: Chin-Cheng Chou
Advisor: Keh-Chin Chang、Kung-Ming Chung
The Renewable Development Energy Bill was activated recently in Taiwan. This is the milestone in the development and application of renewable energy, in which solar energy is one of the major resources. During the past two decades, solar water heaters have been proved to be reliable and economical in cases of hot water production in Taiwan. However, tens of typhoons may occur over the western North Pacific and South China Sea each year, and some affect Taiwan. The safety of solar water heaters under severe wind load during typhoon season is thus a critical issue in promotion of solar water heaters in Taiwan. Previous studies on solar water heaters have mainly focused on the thermal efficiency of various types of solar collectors, and there has been limited work done on the aerodynamic characteristics of solar collectors or their supporting structure. In this study, an experimental program was conducted to examine the aerodynamic characteristics of a solar collector model (a tilt flat panel) with or without a guide plate. With a guide plate, less wind load and increasing uniformity of spanwise pressure distributions are associated with larger projected area of a guide plate on the lower surface of a tilt flat panel. This is essentially attributed to the attenuation of corner vortices. From the measurements by load cells and x-y force sensors, the uplift force increases with tile angle and decreases with increasing projected area of a guide plate. In comparison with a tilt flat panel with a horizontal cylinder, the data show the presence of a horizontal cylinder tends to reduce the suction force on the lower surface within the first half of the tilt flat panel. Stronger positive longitudinal differential pressure is observed for the test case of a tilt flat panel only, which corresponds to strong wind load. Further, the blockage effect is significant for both test models at higher tilt angles.
Keywords : Solar water heater, guide plate , uplift force , blockage effect
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