高温气冷堆螺旋管直流蒸汽发生器时域模型

螺旋管直流蒸汽发生器(SG)是高温气冷堆核电站的关键部件。为研究SG内氦气、水/蒸汽流动和换热的动态过程,该文建立了SG时域模型并编制了计算程序。其中,水/蒸汽两相流采用一维漂移流模型描述;氦气采用一维、可压缩流动模型描述;两侧流体与管壁的换热系数和流动阻力系数采用经验关系式计算。求解方法采用适用于动态、低速、可压缩流动的压力修正算法,以克服低Mach数造成的数值不稳定。采用此模型计算了THTR-300SG温度分布,计算结果与实验结果相比平均温度误差小于10℃。动态计算结果表明,此模型可以捕捉到规律的两相流脉动。利用此模型可以进行SG热工设计、不稳定性分析以及电站系统的工艺设计。

Time domain model for once-through helical coil steam generator for high-temperature gas-cooled reactors

The once-through helical coil steam generator(SG) is one of the key parts of high-temperature gas-cooled reactor systems.A time domain model was developed for the steam generator to investigate the dynamic heat transfer and flow processes in both the helium and water/steam sides.A drift-flux model was used for the water/steam two-phase flow,while the helium flow was described by a one-dimensional compressible flow model.The heat transfer and flow resistance were computed by correlations.To improve convergence,a pressure-correction method capable of solving low-speed compressible flows was used for both the helium and water/steam flows.The predicted steady state temperature fields in the steam generator agree well with THTR-300 SG experiments.Typical two-phase flow oscillations can also be captured.