Study Of Experiments And CFD Simulation Of Circular Pond Photo-bioreactors For Microalgae

With a series of methods, such as PIV technology,CFD technology and experiments, Different mixing systems in circular pond PBRs were systematic studied in this paper.First of all, Particle Image Velocimetry experiments were conduct before CFD simulations were done. This paper focused on properties of flow field and contours of axial velocity of different impellers, such as grid plate, hydrofoil impeller and PBT. In addition, simulations were done under the same conditions as PIV experiments. After simulation results with different turbulence models were compared with PIV results, standard κ-ε model was refered as the best turbulence model for simulation of circular pond PBRs. It can accurately capture the instantaneous characteristics and turbulent characteristics of flow field. The simulation results with standard κ-ε model agreed well with PIV results.Then simulations in industrial scale were done after standard κ-ε model was chosen. This paper focused on a serial of parameters, such as velocity in direction of light(Uz),rate of low speed area(Dz), turbulent kinetic energy (TKE) and turbulent kinetic energy dissipation rate(TKEDR).It was found that hydrofoil impellers performed best in aspect of mixing for micro algae cultivation.In addition, culture experiments of microalgae were also conduct under the same conditions as the simulations. In the process of experiments, a serial of biological indicators were investigated,such as optical density(OD680) and dry cell weight(DCW).It showed that results of culture experiments agreed well with simulation results and hydrofoil impellers performed best in aspect of mixing for microalgae cultivation.