Abstract: This article regards U-bend tube natural-circuit steam generator of Daya Bay Nuclear Power Station as the research target. Drift-flux dynamic model is established for the engineering application according to the characteristics of rising channel boiling section of steam generator. Based on the verification accuracy of steady state characteristic and the key parameters involved in drift-flux theory, the dynamic characteristics of steam generator are simulated and analyzed. The results suggest that the drift-flux theory can be used to predict and reflect the flow and heat transfer characteristics of two-phase flow in the steam generator. With the add of the disturbance, all parameters of steam generator show a reasonable variable trend. And the “false water level” phenomenon is accurately simulated. Meanwhile, the response speed and degree of the water level to disturbance is greater as the load increases.

Key words: steam generator, drift flow model, dynamic characteristics, two-phase flow

摘要： 以大亚湾核电站U型管自然循环蒸汽发生器为研究对象，根据蒸汽发生器上升通道沸腾段特点，建立了适合工程应用的漂移流模型动态方程。在验证稳态工作特性及与漂移流理论所涉及的关键参数准确性的基础上,进行了蒸汽发生器动态特性仿真与分析。结果表明，所建立的漂移流模型能够较准确地反映蒸汽发生器两相流的流动与换热特性。随着扰动的添加蒸汽发生器各参数都表现出合理的变化趋势，并准确地模拟出“虚假水位”现象，且负荷越高水位对扰动的响应速度与程度越大。

关键词: 蒸汽发生器, 漂移流模型, 动态特性, 两相流