To improve the dust removal performance of the wet electrostatic precipitator(WESP), a flow field optimization scheme was proposed via CFD simulation in different scales. The simplified models of perforated and collec...To improve the dust removal performance of the wet electrostatic precipitator(WESP), a flow field optimization scheme was proposed via CFD simulation in different scales. The simplified models of perforated and collection plates were determined firstly. Then the model parameters for the resistance of perforated and collection plates, obtained by small-scale flow simulation, were validated by medium-scale experiments. Through the comparison of the resistance and velocity distribution between simulation results and experimental data, the simplified model is proved to present the resistance characteristics of perforated and collection plates accurately. Numerical results show that after optimization, both the flow rate and the pressure drop in the upper room of electric field regions are basically equivalent to those of the lower room, and the velocity distribution in flue inlet of WESP becomes more uniform. Through the application in practice, the effectiveness and reliability of the optimization scheme are proved, which can provide valuable reference for further optimization of WESP.展开更多
目的改善精密/超精密成形磨削中砂轮存在磨粒分布不均匀的问题。方法仿真分析针-环电极空间电场强度的分布特性,以及喷嘴轴线上场强随喷嘴直径、环状电极直径、电极间距的变化规律。金刚石磨粒均匀分散在静电喷雾溶液中,在高压电场和压...目的改善精密/超精密成形磨削中砂轮存在磨粒分布不均匀的问题。方法仿真分析针-环电极空间电场强度的分布特性,以及喷嘴轴线上场强随喷嘴直径、环状电极直径、电极间距的变化规律。金刚石磨粒均匀分散在静电喷雾溶液中,在高压电场和压力泵的作用下将喷出形成微表面。通过网格分析法和截距法定量分析金刚石颗粒微表面分布的均匀性。结果针-环电极产生的空间电场是对称分布的,电场线集中分布在喷嘴附近,其电场强度沿轴线向外急剧降低。由于尖端效应,喷嘴直径减小,其尖端处的电场强度明显增大;电极间距增大,喷嘴处的场强降低。网格计数法中,网格划分得越细,微表面颗粒分布偏差越大,即分布均匀性越差,但更能反映真实的颗粒整体分布情况,且各偏差曲线分布的趋势基本相同,仅在液体流量20 m L/h处出现了与理论的变化规律不符合的情况。截距法中,当液体流量增大时,颗粒间距离偏差值逐渐降低,且在液体流量20 m L/h处明显下降。结论在金刚石颗粒微表面分布的定量化分析中,网格计数法只能体现区域分布的均匀性,而对某块区域内颗粒的距离不敏感,无法区分颗粒聚集的情况,导致计算结果出现偏差。截距法则对颗粒的间距比较敏感,因此有效地结合网格计算法和截距法可以对金刚石磨粒的分布情况做出准确分析。展开更多
文摘To improve the dust removal performance of the wet electrostatic precipitator(WESP), a flow field optimization scheme was proposed via CFD simulation in different scales. The simplified models of perforated and collection plates were determined firstly. Then the model parameters for the resistance of perforated and collection plates, obtained by small-scale flow simulation, were validated by medium-scale experiments. Through the comparison of the resistance and velocity distribution between simulation results and experimental data, the simplified model is proved to present the resistance characteristics of perforated and collection plates accurately. Numerical results show that after optimization, both the flow rate and the pressure drop in the upper room of electric field regions are basically equivalent to those of the lower room, and the velocity distribution in flue inlet of WESP becomes more uniform. Through the application in practice, the effectiveness and reliability of the optimization scheme are proved, which can provide valuable reference for further optimization of WESP.
文摘目的改善精密/超精密成形磨削中砂轮存在磨粒分布不均匀的问题。方法仿真分析针-环电极空间电场强度的分布特性,以及喷嘴轴线上场强随喷嘴直径、环状电极直径、电极间距的变化规律。金刚石磨粒均匀分散在静电喷雾溶液中,在高压电场和压力泵的作用下将喷出形成微表面。通过网格分析法和截距法定量分析金刚石颗粒微表面分布的均匀性。结果针-环电极产生的空间电场是对称分布的,电场线集中分布在喷嘴附近,其电场强度沿轴线向外急剧降低。由于尖端效应,喷嘴直径减小,其尖端处的电场强度明显增大;电极间距增大,喷嘴处的场强降低。网格计数法中,网格划分得越细,微表面颗粒分布偏差越大,即分布均匀性越差,但更能反映真实的颗粒整体分布情况,且各偏差曲线分布的趋势基本相同,仅在液体流量20 m L/h处出现了与理论的变化规律不符合的情况。截距法中,当液体流量增大时,颗粒间距离偏差值逐渐降低,且在液体流量20 m L/h处明显下降。结论在金刚石颗粒微表面分布的定量化分析中,网格计数法只能体现区域分布的均匀性,而对某块区域内颗粒的距离不敏感,无法区分颗粒聚集的情况,导致计算结果出现偏差。截距法则对颗粒的间距比较敏感,因此有效地结合网格计算法和截距法可以对金刚石磨粒的分布情况做出准确分析。
