气液两相并流向下通过筛板孔口单元的压降特性

针对堆叠筛板填料的基本单元，采用12种不同规格的孔板，研究了气液两相并流向下通过孔口的压降特性，阐明了气液流量、孔板结构对压降的影响规律。结果表明：压降随气液流量的增加而增大；随孔径的增大而减小；在筛板常用厚度范围内，孔口锐缘效应使得压降随板厚减小而增大。根据孔口压降行为不同，以气相雷诺数Re_G=5000分界，建立了单一气相向下通过孔口的压降预测关联式；然后利用气相折算因子对关联式进行修正，得到了Re_G>5000时气液并流向下通过孔口的压降预测关联式；当Re_G<5000时，通过直接对单一气相阻力系数进行修正，得到了相应气相雷诺数范围内的气液两相压降预测关联式。

Pressure drop of gas-liquid two phase co-current flowing down through the orifice unit of sieve plate

For the basic unit of stacked sieve plate packing, 12 orifice plates were used to study the pressure drop characteristics of gas-liquid two-phase co-current flowing down through the orifice, and the influence of flowrates and the orifice plate structure was clarified. The experimental results showed that the pressure drop increases with the increase of gas-liquid flow rate, decreases with the increase of orifice diameter. In the usual thickness range of the sieve plate, the pressure drop increases with the decrease of plate thickness due to the sharp edge effect of the orifice. According to the different behaviors of the pressure, the pressure drop prediction correlation of a single gas phase downward through the orifice was established with the Reynolds number of 5000 as the demarcation. When the gas Reynolds number is greater than 5000, the correlation is modified by using the gas phase conversion factor, and the pressure drop prediction correlation of gas-liquid two phases flowing down through the orifice was obtained. When the gas Reynolds number is less than 5000, the prediction correlation of gas-liquid two-phase pressure drop in the corresponding range of gas Reynolds number was obtained by directly modifying the single gas resistance coefficient.