入口角度对氨法烟气脱硫塔内气液流场影响的数值模拟

Influence of Entrance Angle on Gas-Liquid Flow Field in Ammonia Flue Gas Desulphurization Tower

利用CFD方法进行了烟气入口角度对双循环脱硫单塔内气液流场影响的数值模拟,分别用标准k-ε模型和DPM模型对其进行了求解,并在气液离散相的求解中运用了非定常二阶隐式时间推进法,分别选取不同的烟气入口角度(6°、9°、12°和15°)进行了比较和分析.结果表明:考虑到能量损失和气液混合程度,烟气入口角度为9°和12°较合适;当烟气入口角度为12°和15°时,烟气分布较均匀,有利于气液两相混合和脱硫塔内空间的充分利用;综合考虑烟气流场的均匀性、塔内阻力、气液混合程度以及液膜覆盖范围等因素,12°是脱硫塔最佳烟气入口角度.

The influence of flue gas entrance angle on gas-liquid flow field in an ammonia desulphurization tower has been simulated numerically by Computational Fluid Dynamics（CFD） algorithm.To solve the governing equations for gas-liquid two phases,standard k-ε model and DPM model are separately used,and during the solution of discrete phase,unsteady second-order implicit time scheme is applied,of which the results are compared and analyzed at different entrance angles（6°,9°,12° and 15°）.Results show that the entrance angles of 9° and 12° are believed to be appropriate considering of energy loss and mixing degree of gas-liquid;uniform flue gas distribution forms at entrance angles of 12°and 15°,in which cases adequate mixing of gas-liquid two phases can be achieved while the space in desulphurization tower completely used.Taking into account the influence of the uniformity of gas flow field,the resistance in desulphurization tower,the mixing degree of gas-liquid two phases and the coverage range of liquid film,the optimal entrance angle is determined to be 12°.