海洋条件（摇摆）下竖直通道临界热流密度（CHF）发生机理与变化特性研究

海上浮动核电站是解决海洋开发能源供给问题的重要途径，具有广阔的应用前景。海洋条件下堆内燃料组件的临界热流密度（CHF）变化特性与静止时存在显著区别。各国学者以倾斜、起伏和摇摆三种基本运动模拟海洋条件，但摇摆条件下CHF研究不够深入，摇摆条件对CHF的影响机理尚不明确，缺乏摇摆条件下CHF机理模型。本项目拟搭建氟利昂临界热流密度可视化实验平台，以参数可控的摇摆平台模拟海洋条件，研究摇摆条件下竖直通道内CHF变化特性。采用高速摄像和高频光纤探针相结合的实验手段，定量分析摇摆条件对宏观流态演变及局部汽泡行为的影响。以近壁面微层内气泡运动特征为突破口，深入研究摇摆条件下CHF的发生机理。本项目通过基础研究形成摇摆条件下CHF的变化特性及影响机制的系统性和规律性认识，开发摇摆条件下CHF机理模型，为我国海上浮动核电站燃料组件设计和性能分析提供理论支撑，具有重要的理论意义和实用价值。

Offshore floating nuclear plant is one of the most important approaches to supply power for ocean exploitation, which has tremendous potential in the future. The critical heat flux (CHF) of the fuel bundle in a nuclear reactor under ocean condition is far different from that on land. Scholars from various countries have studied and simulated ocean conditions by using three basic motions instead, i.e. heeling, heaving and rolling. However, the mechanism and characteristics investigation of CHF under rolling motion is not enough, and the CHF mechanism model appropriate for rolling condition is required. In this project, a visual Freon experimental facility will be built to study CHF under rolling motion. An electrically-controllable rolling platform for simulating actual oceanic motion will be used to study the variation characteristics of CHF in a vertical channel. Meanwhile, both high-speed camera and optical probes will be employed to obtain the macroscopic flow evolution and local two-phase behavior on the effect of rolling motion. The trigger mechanism of CHF is investigated and analyzed with the characteristics of bubble motion in microlayer near the heating surface as a breakthrough. The aim of this project is to systematically and regularly understand the CHF mechanism and characteristics in a vertical channel under rolling condition, and develop a CHF mechanism model appropriate for rolling condition. This study has great pharmacody point and practical value, which contributes to improving the design and performance analysis skills of offshore floating nuclear plant in our country.