颗粒堆积床内两相流动阻力及相间摩擦力

Two-Phase Flow Resistance and Interfacial Drag in Packed Beds

为了探究颗粒堆积多孔介质通道内两相流动阻力特性,使用不同尺寸的球形颗粒构建实验床,在碎片床冷却性实验装置(DEBECO)上进行了气-水两相流动实验.基于实验数据,对比验证了多孔介质内两相流动阻力压降预测模型,重点分析了颗粒床内气液两相相间摩擦力对阻力压降的影响.结果表明:对小尺寸(如d=1.5mm)颗粒堆积床,气液两相相间摩擦力对其两相流动阻力压降影响微弱,两相流动阻力压降随气速增大呈逐渐上升的趋势;对大尺寸(如d=6mm)颗粒堆积床,在低速下气液两相相间摩擦力对阻力压降影响显著,随气速增大,其阻力压降出现先下降后上升的趋势.

In order to investigate the characteristics of two-phase flow resistance in packed porous media, the experiments of air water two-phase flow in packed beds with spherical particles of different sizes are performed by the test facility of DEBECO （Debris Bed Coolability）. Based on the experimental data, the calculative results by different predictive models are compared and verified, and the influence of interracial drag on pressure drop for two-phase flow is analyzed emphatically. The results show that the effects of the interracial drag on two-phase flow pressure drop are negligible for packed beds with small size （e. g. d 1.5 mm） particles, and the two-phase flow pressure drop curves show an increasing tendency with the in- crease of air flowrates. The interracial drag has significant influence on two-phase flow pressure drop for packed beds with large-size （e. g. d=6.0 mm） particles at low liquid velocities , and has a descent-ascent tendency in the pressure drop curve.