微凸台阵列型重整微反应器的传热传质特性

Heat and mass transfer characteristics in reforming micro-reactor with micro-pin-fin arrays

针对带微凸台阵列结构的重整制氢微反应器的流体传热传质问题,建立微通道传热传质理论模型.采用计算流体力学软件Fluent对不同微凸台阵列结构和排布方式微通道的流体传热传质进行数值模拟,并研究在低雷诺数条件下不同微通道结构对微通道摩擦系数和努塞尔数的影响.结果表明,随着气体入口速度增大,通道摩擦系数减小,努塞尔数增加;当气体入口速度相对较小时,反应器微凸台阵列高度及横向中心间距的差异对努塞尔数影响不大;当气体入口速度相对较大时,随着微凸台阵列纵向和横向中心间距的增加,摩擦系数减小,随着微凸台高度的增加(除1.3mm以外),摩擦系数和努塞尔数均先增后降.研究成果为带微凸台阵列结构重整制氢微通道反应器的设计和制造提供理论依据.

Aiming at fluid heat and mass transfer in micro-reactor with micro-pin-fin arrays for hydrogen production by reforming,a theoretical model about the heat and mass transfer in micro-channel was established.A CFD software Fluent was used to calculate the heat and mass transfer of different structure and arrangement mode of micro-pin-fin arrays in micro-channel,and the effect of different micro-channel structure on the friction coefficient and Nusselt number of micro-channel was analyzed under lower Reynolds number condition.The results indicate that,with the increase of the inlet velocity,the friction coefficient decreases while the Nusselt number increases.When the inlet velocity is lower,the height and transverse center-to-center distance of micro-pin-fin arrays have little effect on Nusselt number.When the inlet velocity is higher,with the increase of longitudinal and transverse center-to-center distance of micro-pin-fin arrays,the friction coefficient decreases,with the increase of the height of micro-pin-fins（except 1.3 mm）,both friction coefficient and Nusselt number increase firstly and then decrease.The analysis results provide the theoretical basis for the design and fabrication of micro-channel reactor with micro-pin-fin arrays for hydrogen production by reforming.