管道式光生物反应器的混合特性及藻细胞受光特性的CFD模拟研究

发布时间：2018-05-14 20:48

本文选题：管道式光生物反应器 + 静态混合器　；参考：《华东理工大学》2015年硕士论文

【摘要】：管道式光生物反应器作为目前能源微藻大规模培养中应用最广泛的一类光生物反应器,迫切需要对其进行结构优化以提高微藻的混合效果和受光特性。本文对一种新型管道式光生物反应器进行了系统研究,开展了PIV流场测试、CFD模拟、内部静态混合器优化以及管道式光生物反应器中藻细胞受光特性分析等研究。首先,采用粒子图像测速技术(PIV)和CFD数值模拟方法,分别对有新型静态混合器与不含静态混合器的两种管道式光生物反应器的流场进行测量,得出新型静态混合器能显著增强管内流体的混合。将PIV测试结果与CFD模拟结果进行对比,显示基于标准κ-ε模型的数值计算方法能很好应用于管道式光生物反应器的流场模拟,验证了CFD数值模拟的适用性及可靠性。其次,运用计算流体力学方法(CFD)对管道式光生物反应器中多种静态混合器的混合特性进行模拟和计算,优选出了具有最佳混合效果的新型静态混合器。接下来以平均光照方向速度(Uy)、湍动能(TKE)、压强损失和平均流体剪切力等混合特性参数对新型静态混合器的结构进行了模拟优化,得到最优化的新型静态混合器结构参数为：静态混合器两叶片交叉角度α=90°,相邻静态混合器的间距s=80 mm,静态混合器开孔率为16%以及开孔半径ro=2 mm。最后,结合粒子追踪模型和光衰减模型,通过模拟藻细胞在管道式光生物反应器中的运动轨迹,进而对藻细胞在管道式光生物反应器中的受光特性进行分析。结果显示,添加新型静态混合器后,在0.3 m/s和0.4 m/s两种进口流速下,藻细胞光暗交替频率分别增加了85.21%和95.77%,证明了新型静态混合器能够促进藻细胞在光区和暗区之间的交替循环,增强藻细胞“闪光效应”的实现。
[Abstract]:Tubular photobioreactor is the most widely used photobioreactor in the large-scale cultivation of energy microalgae. It is urgent to optimize its structure in order to improve the mixing effect and light-receiving characteristics of microalgae. In this paper, a new type of tubular photobioreactor is studied systematically. The simulation of PIV flow field test, the optimization of internal static mixer and the analysis of the photoresponse characteristics of algal cells in the tubular photobioreactor are carried out. Firstly, particle image velocimetry (PIV) and CFD numerical simulation were used to measure the flow field of two kinds of tubular photobioreactor with and without static mixer, respectively. It is concluded that the new static mixer can significantly enhance the mixing of fluid in the tube. The comparison between the PIV test results and the CFD simulation results shows that the numerical method based on the standard 魏-蔚 model can be applied to the flow field simulation of the tubular photobioreactor. The applicability and reliability of the CFD numerical simulation are verified. Secondly, the mixing characteristics of many static mixers in a tubular photobioreactor are simulated and calculated by using computational fluid dynamics (CFD) method, and a new type of static mixer with the best mixing effect is selected. Then the structure of the new static mixer is simulated and optimized by the mixing characteristic parameters such as the average illumination direction velocity, the turbulent kinetic energy, the pressure loss and the average fluid shear force. The optimized structural parameters of the new static mixer are as follows: the cross angle of the two blades of the static mixer is 90 掳, the spacing of the adjacent static mixer is 80 mm, the opening rate of the static mixer is 16% and the opening radius of the static mixer is ro=2 m. Finally, combining the particle tracing model and the light attenuation model, the characteristics of the algae cells in the tubular photobioreactor were analyzed by simulating the trajectory of the algal cells in the tubular photobioreactor. The results show that after adding a new static mixer, at the inlet velocity of 0.3 m / s and 0.4 m / s, The alternating frequency of light and dark increased by 85.21% and 95.7777%, respectively, which proved that the new static mixer could promote the alternating cycle between the light and dark areas of algal cells and enhance the realization of "flash effect" of algal cells.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q945;TQ033

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