Chemical looping hydrogen generation technology has the advantages of low energy consumption,high purity of hydrogen production,cleanness and efficiency,etc.,and is receiving more and more attention in the field of hydrogen energy.However,the complex flow and mass transfer mechanisms inherent in the system pose significant challenges to its technological development.Therefore,conducting comprehensive research aimed at elucidating the operational characteristics of the chemical looping hydrogen generation reactor is of significant importance.This study performs a three-dimensional numerical simulation of a dual fluidized bed reactor for chemical looping hydrogen generation utilizing the two-fluid model(TFM)to examine the impacts of various operating conditions and oxygen carrier properties on system performance.The particle quantity and pressure drop in the riser obtained from the simulation agree well with experimental results,which suggests that the current model is capable for the simulation.The numerical results show that increasing the bed material reduces the pressure fluctuation amplitudes in the riser,leading to enhanced operational stability.The distribution of the solid phase in the radial direction of the riser is non-uniform,attributed to the arrangement of the inlet.And non-uniformity distribution of solid becomes more pronounced at higher gas velocities and results in severe operating conditions.Under the current operating conditions,the reactor operates most steadily when the inlet gas velocity of the riser is 7 m/s,and an increase in fluidization gas velocity leads to a significant fluctuation in solid circulation.The flow characteristics of reactor,derived from numerical simulation,provide insights into the operation and optimization of the dual fluidized bed in chemical looping hydrogen generation.
关键词
化学链制氢/载氧体/循环流化床/多相流/计算流体力学
Key words
chemical looping hydrogen generation/oxygen carrier/circulating fluidized bed/multiphase flow/computational fluid dynamics
维普
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