新型旋流喷射式真空泵及其工作特性的研究

摘要

In view of the existing problems of the poor suction performance,low ejector efficiency,etc. of the jet vacuum pump,a novel swirl jet nozzle was proposed and a novel swirl jet vacuum pump was obtained. Two methods,i.e.,the tangential rotation and the top guide element were employed at the inlet of the working fluid to intensify the swirling,and the swirl ejection intensity of the jet nozzle can be adjusted through the top guide element.The change rule of flow fields within the proposed swirl jet vacuum pump was analyzed by numerical simulations. Compared with the common free jet nozzle,the proposed swirl nozzle has the characteristics of high turbulence degree and stronger entrainment ability;the swirl ejection is better than the common free jet,and this advantage is more obvious with the increase of working fluid pressure.%针对喷射式真空泵工作过程存在吸入性能差、引射效率低等问题,提出了一种新型旋流喷嘴,进而得到新型旋流喷射式真空泵.该喷嘴在工作流体入口处采用切向入旋和顶部导向元件加旋,可以通过顶部导向元件来微调喷嘴的旋流引射强度;利用数值模拟分析了新型旋流喷射式真空泵内部的流场变化规律.相比于常用的自由射流,所提出的旋流喷嘴具有出口紊流程度高,卷吸能力更强的特点;旋流引射优于普通自由射流,并且随着工作流体压力的增大这种优势更明显.