一、引言 在核反应堆、重力辅助热管等装置中,在过冷沸腾工况下,器内液体经常会产生激烈的压力脉动,在有关文献中,这种现象常被称为间歇效应、间歇沸腾或冲击沸腾。在我们开发的真空相变热水器中也经常出现这种不稳定现象。显然这种不稳定对设备的安全性和传热特性等会产生不良影响,所以有必要对振动的产生条件和机理进行研究。近年来,我们针对真空相变热水器中的这类现象进行了理论研究和可视化实验,并得到了 I. INTRODUCTION In nuclear reactors and gravity-assisted heat pipes and other devices, under the conditions of subcooled boiling, the liquid in the device often produces intense pressure pulsations. In the literature, this phenomenon is often referred to as batch effect, intermittent boiling or Impact boiling. This instability often occurs in our vacuum phase change water heaters. Obviously, this instability will adversely affect the safety and heat transfer characteristics of the equipment. Therefore, it is necessary to study the conditions and mechanism of vibration generation. In recent years, we have conducted theoretical research and visualization experiments for such phenomena in vacuum phase change water heaters, and obtained