燃煤细微颗粒声波团聚的机理研究

SIMULATION OF ACOUSTIC AGGLOMERATION OF FINE PARTICLES EMITTED FROM COAL FIRED PLANTS

采用声波团聚方法促使燃煤电厂产生的细微烟尘颗粒在较高强度下的声场中团聚为较大颗粒,以此提高除尘器对细微颗粒的脱除效率。建立了以同向凝聚和流体力学作用为机理的烟尘气溶胶声波团聚动力学模型,经过数值模拟求解得到烟尘粒子团聚后的再分布曲线.模拟计算结果与声压(SPL)为130～150 dB,频率为1000～4000 Hz,烟尘浓度为2～10 g/m^3条件下的团聚实验相比较,得到较好的吻合.当声压SPL增加时,PM_(10)和PM_(2.5)质量百分比相对于初始分布均有明显下降,表明细微颗粒的团聚效果明显。

One possible way to increase the efficiency of traditional separators is to agglomerate fine particles emitted from coal fired plants to form larger ones in a high acoustic fieid. Aerosol dynamics equation of flue gas in acoustic agglomeration, which is based on the orthokinetic and hydrodynamic interaction as main mechanisms, is derived and numerically solved to get the particle size distribution. The results of numerical simulation are compared with the experiments and have a good agreement at SPL=130-150 dB, Freq=1000-4000 Hz, and dust loading concentration 2-10 g/m^3 conditions. When SPL increases, the fraction of PM10 and PM2.5 in particle size distribution decreases compared with initial particle size distribution without agglomeration.