压力喷嘴常温下雾化特性实验研究

Experimental study of spray characteristics of pressure nozzle at room temperature

为了满足工程中对喷嘴雾化特性测量的高精度、低成本要求,建立了喷嘴雾化特性实验系统,以自来水为雾化工质,对蒸发冷却压力喷嘴在常温、常压下的雾化特性进行了实验研究。用容积法测量了喷嘴的流量,用最小二乘法对测量数据进行回归分析,得到了喷嘴流量、雾化压力和喷孔直径之间的关联式与流量系数;用机器视觉方法测量了喷嘴的雾化锥角与雾滴尺寸,得到了雾化锥角与雾滴尺寸随雾化压力变化的规律。结果表明:随着雾化压力的增大,喷嘴雾化锥角不断增加,雾滴尺寸不断减小;随轴向距离的增大,D0.632、D0.5、D32有不同幅度的增大,而D0.9则基本不变。

In order to meet the demand of high precision and low cost in measuring the nozzle spray characteristics, an experimental system of nozzle spray characteristics was established for an experi- mental study of spray characteristics of a evaporative cooling by using the running water as the wor king fluid under normal temperature and pressure. The flow rate was measured with the volumetric method and the measurement data was analyzed regressively with the least square method to obtain the relationship between the flow rate, the atomizing pressure and the nozzle orifice diameter as well as the flow coefficient. The spray angle and the droplet size were measured by the machine vision tech- nique to reveal the effect of the atomizing pressure on the spray angle and the droplet size. Results show that with the enhancement of the atomizing pressure, the spray angle increases and the droplet size reduces constantly. Along the axial spray direction, the characteristic size such as D0.632. D0.5. D32 all increases in various degrees, while D0.9 keeps nearly constant.