欠热沸腾诱发自然循环不稳定性的研究

以最佳估算程序RELAP5为基本分析工具，对自然循环系统进行数值分析，得出了不同条件下系统的不稳定性边界。研究发现自然循环对过冷沸腾有一定的承受能力，不稳定性一般发生在低欠热沸腾区，气泡脱离壁面和凝结时的扰动可能是自然循环系统不稳定性的诱因，系统驱动力、阻力和流量之间的相位差使振荡得以维持和发展。

Study on Instability of Natural Circulation Induced by Subcooled Boiling

The best estimate system analysis code RELAP5 was used to analyze the natural circulation systems. The instability boundaries of one natural circulation system were obtained under different conditions. According to present results, most of the boundary points were found in the low subcooled boiling zone. The natural circulation systems can tolerate high subcooled boiling, and the disturbance of bubbles departing from the wall and condensing in the subcooled boiling region may be the inherent source to induce the instability, then the flow oscillations can become self-sustained and evolve because of the phase differences among system driving force, resistance and flow rate.