双流体雾化液滴荷电特性分析

本文通过理论分析,提出了双流体荷电雾化过程中,增大电场强度或减小液滴粒径均能提高荷电效果的论点。针对不同的电极布置情况建立了数值模拟模型,计算结果表明,双流体喷嘴接地时,喷嘴与环状电极之间的电场强度比喷嘴不接地时大很多。通过实验,验证了电场强度、液滴粒径等参数对荷电效果的影响规律,在环状电极荷电情况下,双流体喷嘴接地时,液体荷质比高于双流体喷嘴不接地时的荷质比;电场强度增大,荷质比增加;液滴粒径越小,荷质比越大;在一定的电导率范围内,电导率越大,荷质比越小。实际喷雾中,运动液滴发生二次破碎的临界荷电量小于Rayleigh极限。

Analysis of Droplet Charged Characteristics for Twin-fluid Atomization

An argument is put forward in this paper based on theoretical analysis, that is increasing electric field intensity or decreasing droplet diameter are able to improve the charging effect in twin-fluid charging atomization. Taking into account different electrode arrangement, a numerical simulation model was established. Calculation results show that when twin-fluid nozzle is grounded, the electric field intensity between nozzle and annular electrode is much larger than that of ungrounded nozzle. The influence of electric field intensity and droplet diameter on charging effect is verified by experiment. Experimental results indicate that when annular electrode is charged, the charge-mass ratio of twin-fluid grounded nozzle is higher than that of twin-fluid ungrounded nozzle. The charge-mass ratio increases with the increase of electric field intensity and with the decrease of droplet diameter. Within a certain electrical conductivity range, the greater the electrical conductivity is, the smaller the charge-mass ratio. In practical atomizing, the critical charge quantity due to moving droplet second crushing is less than Rayleigh limit.