离子风对ESP气流分布和除尘效率影响的数值模拟

Numerical Simulation of the Effect of Ion Wind on ESP Air Flow Distribution and Dust Removal Efficiency

针对离子风对静电除尘器内气流分布均匀性和除尘效率影响的问题,基于计算流体力学,以ANSYS软件中的FLUENT模块为平台,应用动力风模拟离子风,以数值模拟的方式进行研究。研究表明离子风会在静电除尘器内形成涡流,严重影响气流分布的均匀性;并且离子风会通过冲刷收尘极板造成二次扬尘,进一步降低除尘效率。研究还发现,在不同的烟气流速、粉尘直径、烟气含尘浓度和电晕极电压条件下,离子风对除尘效率的影响程度不同:烟气流速由0.1 m/s增加0.5 m/s,影响程度由24%降到1%;粉尘直径由1μm增加5μm、电晕极电压由35 k V增加到55 k V,影响程度分别由4%增加到18%、由0增加到27%;烟气含尘浓度由1 g/m^3增加到5 g/m^3,影响程度由18%降低到7%;超过5 g/m^3影响程度开始上升,由5 g/m^3增加到8 g/m^3,影响程度由7%增加到17%。

Based on computational fluid dynamics and FLUENT software platform, application of dynamic wind to simulate ion wind, the influence of ion wind on the distribution uniformity and dust removal efficiency of the electrostatic precipitator were simulated. From the results, many large and small vortices formed by ion wind in electrostatic precipitator will seriously affect the uniformity of airflow distribution. And the ion wind will be through the dust collector to cause the secondary dust effect, further reduce the dust removal efficiency. The study also found that the effect of ion wind on the dust removal effi-ciency is different in different flue gas velocity, dust diameter, dust concentration and corona electrode voltage, that is, flue gas flow rate increased from 0.1 m/s to 0.5 m/s, and the influence degree reduced from 24 % to 1%; when dust diameter increased from 1 μm to 5 μm, the corona electrode voltage increased from 35 k V to 55 k V, the influence degree increased re-spectively from 4% to 18%, from 0 to 27%; The flue gas dust concentration increased from 1 g/m^3 to 5 g/m^3, the influence degree reduced from 18% to 7%; when the dust concentration more than 5 g/m^3, the influence degree began to rise; the dust concentration increased from 5 g/m^3 to 8 g/m^3, and the influence degree increased from 7% to 17%.