快堆钠-水直流蒸汽发生器七管样机热工水力特性分析

钠-水直流蒸汽发生器是钠冷快堆主热传输系统的关键设备之一，其结构及内部的传热现象是十分复杂的。管内外侧的介质及压力不同，管内侧为高温高压的水/蒸汽，存在复杂的两相流动传热传质现象；管外侧为高温液态金属钠，沿换热管高度方向存在较大的钠温变化。本文以钠-水直流蒸汽发生器七管样机为研究对象，对其热工水力特性进行了CFD分析和实验研究，CFD分析结果和实验结果吻合较好，验证了CFD分析所采用的数学模型和数值方法的可靠性。结果表明，钠-水直流蒸汽发生器七管样机的传热面积是足够的，达到了设计指标要求，其界限质量含汽率约为0.42，临界热流密度约为451.98 kW/m²，从而确定了蒸干点的位置。

Thermal Hydraulic Characteristic Analysis for Sodium-water Once-through Steam Generator Seven-tube Prototype of Fast Reactor

Sodium-water once-through steam generator is one of the most important components for removing heat from the main heat transfer system of fast reactor, and its structure and internal heat transfer phenomenon are very complex. Medium and pressure inside and outside of the steam generator heat transfer tubes are different. Water/steam with high temperature and pressure is on the tube side and where the complicated heat and mass transfer of two-phase flow occurs. Liquid sodium is on the shell side, and there is a great change in temperature along the height of heat transfer tubes. In this paper, the thermal hydraulic characteristics of sodium-water once-through steam generator seven-tube prototype were studied using CFD software and experiment method. The CFD analysis results and experimental results are in good agreement, and the reliability of the mathematical models and numerical methods used in CFD analysis is verified. The results show that there is sufficient heat transfer area to meet the design requirements for the steam generator, the critical mass vapor fraction is about 0.42, the critical heat flux is about 451.98 kW/m², thus the location of dry-out is determined.