Abstract:

For the complexity of flow and heat transfer in the once-through steam generator secondary side, the secondary side is divided into preheating section, subcooled boiling section, saturated nucleate boiling section, forced convective evaporation section, lacking of liquid section and superheated section in order to accurately research the internal thermal parameters of spatial distribution rules. The one-dimensional homogeneous flow mathematics model of once-through steam generator is built base on the distribution parameter method. The independent developed MATLAB simulation program can be used to automatically piecewise calculate for once-through steam generator. The results show that the model can accurately predict the wall temperature soaring amplitude and location and the length of heat transfer areas in different conditions based on partition. The poor working area of once through steam generator can be forecasted. The results can provide theoretical support for preventing tube burst accident of once through steam generator.

Key words: once-through steam generator, homogeneous flow model, heat transfer, wall temperature soar, numerical simulation, steady state

摘要：

针对直流蒸汽发生器二次侧复杂的流动与换热过程, 为准确研究其内热力参数空间分布规律, 将其分为预热段、过冷沸腾段、饱和核态沸腾段、强制对流蒸发段、缺液段、过热段, 基于分布参数法建立了直流蒸汽发生器一维均相流数学模型, 并自主开发了可实现自动分段计算的直流蒸汽发生器MATLAB仿真程序。仿真结果表明, 基于传热分区的模型能准确预测不同工况下壁温飞升的幅度、位置及各传热区域传热管的长度, 得到直流蒸汽发生器工作恶劣区域。所得结果可为预防直流蒸汽发生器超温爆管等事故提供理论支持。

关键词: 直流蒸汽发生器, 均相流模型, 传热, 壁温飞升, 数值模拟, 稳态