| Summary: | 碩士 === 國立中正大學 === 機械工程學系暨研究所 === 102 === A vanadium redox flow battery (VRFB) is used for energy storeage and integrated with renewable energy, such as solar and wind power energies. A VRFB plays the role of peaking shaving and load leveling because it can quickly switch between charing and discharging processes. During discharging process, the concentration of reaction ions in the electrolyte will decrease, enhancing the effect mass transfer overpotential on cell performance.
In this study, the effects of vanadium ion concentration and electrolyte flow rate on the mass transfer coefficient are experimentally study. The normal VRFB is operated with recirculated electrolytes, causing variation of electrolytle concentration. In order to fix the electrolyte concentration during experiment, the electrolyte is not recirculated. Firstly, electrolyte solutions with different state of charges (SOCs) prepared and used for a single cell to obtain the polarization curves. Then, the polarization curves of overpotential are analyzed for limiting current density.
Experimental results show that the limiting current density and mass transfer coefficient increases with increasing state of charge and stoichiometric ratio. At the end of this study, the relationship between the transfer coefficient and electrolyte velocity is established. The result helps predict the effect of operating condition on the cell performance in a mathematical model.
|
|---|
