The study of improving the performance of a all-glass vacuum tube solar energy collector

• Main Authors: Ming-Je Huang, 黃明哲
• Other Authors: Ming-Chiou Shen
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/08684002882793037140

碩士 === 遠東科技大學 === 機械研究所 === 97 === This study is to improve the performance of a forced circulation solar collector with components of all-glass evacuated tubes by applying both numerical and experimental methods. First, the thermal performance of a commercial solar collector was tested outdoor according to the ANSI/ASHRAE93-1986 Standard and to be as a reference. Then, the flow field and thermal performance simulation associate with this collector is performed by applying the numerical method. Furthermore, the accuracy and feasibility of the numerical system can be verified by comparing the numerical with experiment result. In addition, the effect of the performance improvement and the influences on the flow filed due to installing flow-guide tubes inside the evacuated tube and vortex generators upon the surface of flow-guide tubes will be investigated by executing a series of numerical simulation and comparison. Also, the optimum design parameters of both flow-guide tubes and vortex generators will be found respectively. In addition, the new type solar collector with highest thermal performance will be manufactured and tested to validate the design result. Besides, the influences of the thermal performance due to the variation of system circulation flow rate will investigate and compare for both original and new type solar collector. The results indicate that the new type solar collector, in comparison with the original solar collector, can increase the thermal performance by 7~9%. In additional, the more evacuated tubes with flow-guide tubes installation, the better performance enhancement effect. Furthermore, the performance enhancement by installing the vortex generators is indistinctive. Besides, the higher circulation flow rate, the higher thermal performance for the new type solar collector. However, the thermal performance decreases with the increasing of circulation flow rate for the original one. From the above, we can see that the new type solar collector improving by this study can indeed achieve the design requirement and the effect of performance improvement. It also extents a superior characteristic with broad and efficient circulation flow rate with high efficiency.