错排降膜阵列气液交叉流界面捕集PM2.5的传质类比模型

根据气溶胶颗粒拟流体性质提出了气液交叉流界面捕集PM2.5的传质类比模型.分析了颗粒Schmidt数及其指数m对气溶胶流体传热传质类比的影响机理.以常用的横掠错排管束对流传热Nu方程为基础,导出了横掠错排降膜阵列PM2.5传质Sherwood数方程,由此建立了以m为模型参数的PM2.5捕集效率预测模型.用横掠20列×90排ø3 mm降膜阵列PM2.5捕集效率实测数据回归获得m值为0.808.在Reynolds数50～650的范围内,模型预测传质Sh与实测值误差在±20%之内.

Mass transfer analogy model of PM2.5 collection on interface of gas-liquid cross-flow through staggered falling film array

According to the pseudo-homogeneous fluid performance of aerosol particles, a mass transfer analogy model was proposed for PM2.5 collection on the interface of gas-liquid cross flow. With the mechanism analysis on the particle transport behavior analogized to fluid convective heat transfer, which is mainly affected by the Schmidt number (Sc) and its exponent m, an analogous equation of Sherwood number (Sh) of particle transfer was derived for PM2.5 collection through a staggered falling film array (SFFA), based on a widely used equation of Nusselt number (Nu) of convective heat transfer over the staggered tube bundles. From the analogous equation of Sh, a model for prediction of PM2.5 collection efficiency was deduced with the exponent m as the model parameter. The value of m was obtained to be 0.808 via regression analysis of experimental data of PM2.5 collection efficiencies measured in a SFFA consisting of 20 (line)×90 (row) falling film cylinders with diameter of 3 mm. In the range of Reynolds number from 50 to 650, the deviation between the model prediction of PM2.5 mass transfer Sh and the experimental data is within ±20%.