带膨胀腔喷嘴制冷剂R134a闪蒸喷雾可视化研究

• 作 者: 周致富 白飞龙 王锐 钞睿 陈斌 王国祥
• 机 构: 西安交通大学动力工程多相流国家重点实验室,美国Akron大学机械工程系,
• 出 处: 工程热物理学报
• 发表日期: 2015年12期
• 关键词: flashing spray expansion-chamber nozzle internal flow pattern spray angle

闪蒸喷雾由于存在特殊的气泡爆裂使得其在较小压力下即能够实现较好的雾化效果。为了探索制冷剂R134a的闪蒸喷雾机理,本文利用高速摄像机对直管石英玻璃喷嘴内部流型以及不同膨胀腔喷嘴的外部喷雾特性进行了可视化观察及量化比较。发现随喷雾压力增大,制冷剂R134a在直管喷嘴内部表现出对称空化、非对称空化和类弹状空化等不同的空化流型,其中对称空化流型对应的雾化锥角基本相同。膨胀腔型喷嘴达到较小喷雾锥角所对应的膨胀腔长径比为1:2~2:1,最佳外部喷雾锥角稳定在70°左右。

Flash spray due to the presence of a special burst of bubbles so that it is less pressure to achieve a better atomization effect. In order to explore the flash spray mechanism of refrigerant R134a, this paper uses a high-speed camera to visualize and quantify the internal flow patterns of straight-tube quartz glass nozzles and the external spray characteristics of different expansion chamber nozzles. It was found that with the increase of spray pressure, the refrigerant R134a showed different cavitation flow patterns, such as symmetric cavitation, asymmetric cavitation and cavitation-like cavitation, in the straight pipe nozzle. The symmetrical cavitation cone The same angle. Expansion cavity nozzle to achieve a smaller spray cone angle corresponding to the expansion of the cavity length to diameter ratio of 1: 2 ~ 2: 1, the best external spray cone angle stabilized at about 70 °.