铅铋快堆SGTR事故下高压过冷水注入高温铅铋合金流动传热数值模拟研究

Numerical Study on Flow and Heat Transfer of High-pressure Sub-cooled Water Injection into High-temperature Lead-bismuth Alloy under Lead-bismuth Cooled Fast Reactor SGTR Accident

铅铋快堆内蒸汽发生器传热管两侧为高压过冷水和高温铅铋冷却剂,传热管两侧较大的压差和温差以及液态铅铋合金(LBE)的腐蚀效应可能造成蒸汽发生器传热管破裂(SGTR)事故。深入研究事故后高压过冷水冲击高温液态LBE的射流沸腾和相变产物蒸汽扩散的特征,具有十分重要的学术意义和工程应用价值。为揭示事故工况下液态LBE与水相互作用的传热传质机理,基于流体体积(VOF)方法,结合LES湍流模型和Lee相变模型,建立了水/蒸汽-液态铅铋多相流动与传热的三维数值计算模型,系统研究了高压过冷水注入高温LBE内发生的相变传热过程。结合注入压力及过冷水温度等因素,分析了射流沸腾过程中不同工况对射流形态、迁移深度以及沸腾行为的影响,研究结果可为SGTR事故工况下堆芯安全性预测提供指导。

There are high-pressure sub-cooled water and high-temperature lead-bismuth coolant on both sides of the heat transfer tube of the steam generator in the lead-bismuth fast reactor.The large pressure difference and temperature difference on both sides of the heat transfer tube and the corrosion effect of Lead-bismuth eutectic(LBE)may cause the steam generator heat transfer tube rupture(SGTR)accident.It is of great academic significance and engineering application value to deeply study the characteristics of jet boiling and phase change product steam diffusion of highpressure sub-cooled water impacting LBE after the accident.In order to reveal the heat and mass transfer mechanism of the interaction between LBE and water under accident conditions,this paper establishes a three-dimensional numerical calculation model of water/steam-liquid lead-bismuth multiphase flow and heat transfer based on the volume of fluid(VOF)method,combined with LES turbulence model and Lee phase change model.The phase change and heat transfer process occurred during the high-pressure sub-cooled water injection into the high-temperature LBE is systematically studied.Combined with the factors such as injection pressure and sub-cooled water temperature,the effects of different conditions on the jet shape,migration depth and boiling behavior during the jet boiling process are analyzed.The research results can provide guidance for the prediction of core safety under SGTR accident conditions.