碩士 / 國立中山大學 / 海洋環境及工程學系研究所 / 103 / The aim of this research is to use the FLOW-3D Computational Fluid Dynamics (CFD) software to simulate the raceway style microalgae cultivation system, which is built at Microalgae Biotechnology and Engineering Laboratory, located in Annan Campus, and conducted by the University Center of Bioscience and Biotechnology of National Cheng Kung University.
The content of research is mainly divided into two parts, i.e., field test and numerical simulation: The field test is to verify the accuracy of numerical simulation of FLOW-3D and to adjust the settings of CFD parameters. The numerical simulation is to conduct a series of analysis for the system, such as the pathlines of fluid particles, average energy losses for up- and down-streams’ ross-sections, mean velocity of flow field and energy conversion efficiency of waterwheel and so on. Based on the results of the flow patterns in the raceway channel and the efficiency of energy conversion of waterwheel, it could provide suggestions of the optimal design of the microalgae cultivation system and the direction of research.
The results of this research indicate that the curve of the raceway style microalgae cultivation system, due to poor design of channels, tends to have large areas of low-speed dead zones which cause the accumulation of algae. After conducting the design optimization of channels, it is expected to significantly reduce the coverage rate of dead zone and improve circulation efficiency of algae.
The waterwheel commonly used in the microalgae cultivation system is originated from the aeration waterwheel for fish pond, and the energy conversion rate is about 19% only. This research has reduced the gap between the lowest waterwheel blade and bottom of channel from present 7 cm to 2 cm and changed the blade angle from 0 degree to 45 degree. The result of the energy conversion efficiency of waterwheel increases to 26%. Although the effects of the phenomenon of flow patterns and the reduction of dead zone are significant, the waterwheel energy conversion efficiency is still relatively low.
Finally, this research suggests that if it wants to build a new microalgae cultivation system, the numerical simulation model should be carried out first to find the optimal design of system under the environment conditions and equipment limitations. For further studies, it recommends to explore other flow-making equipments or other style waterwheels for the raceway system to improve the energy conversion efficiency.
| Identifer | oai:union.ndltd.org:TW/103NSYS5282003 |
| Date | January 2014 |
| Creators | Yu-heng Lin, 林裕恆 |
| Contributors | Chai-Cheug Huang, 黃材成 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 95 |
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