全钒液流电池双螺旋流道顺流与逆流性能分析OA

In order to improve the energy efficiency of vanadium redox flow battery,the pressure,velocity and concentration distribution inside the battery were analyzed by numerical simulation when the electrolyte in the double spiral flow channel was in co-current and counter-current flow.The results show that,when the flow rate is the same,the pressure gradient and flow velocity of the counter-current flow are relatively high only at the inlet and outlet sections,which in turn triggers flow"short-circuiting".This phenomenon causes the electrolyte that should fully participate in mass transfer to be diverted,with a portion of it prematurely exiting the flow channel and discharging out of the electrode,leading to insufficient reactants in the regions beyond the inlet and outlet sections and significant concentration polarization.However,the electrolyte pressure drop is significantly lower than that of the co-current flow.When the pump power is the same,the electrolyte flow rate of the counter-current flow is larger,which enhances the electrolyte flow velocity and the uniformity of reactant concentration distribution inside the battery.Consequently,the uniformity factor of the counter-current flow is 0.40％-1.40％higher than that of the co-current flow,with a 0.16％-2.52％improvement in energy efficiency.Meanwhile,the superiority of counter-current flow is more pronounced under low pumping power conditions,which indicates that the performance improvement resulting from the increased flow rate outweighs the performance degradation caused by flow"short-circuiting".This design idea provides a reference for the flow channel design of flow battery.