Abstract: Taken the steam generator of nuclear power plant as the prototype, the vapor-liquid two-phase flow and the boiling heat transfer were simulated by two-fluid model. The coupled flow and heat transfer process between the fluid of the primary and secondary sides and the heat transfer tubes with support plates was numerically simulated using CFX software. Based on the flow and heat transfer calculation, the pressure of fluid in the primary and secondary sides was extracted. The pressure load was transferred to the structure model in Workbench. And the structural stress of tube was calculated. The fluid-structure interaction results show that there is an abrupt increase in secondary velocity at the positions of support plates. The fluid pressure loss of secondary side increases because of the increase of fluid turbulence dissipation. The pressure stress of the heat transfer tube depends on the pressure difference between the primary side and the secondary side. The overall average of the pressure stress is about 58 MPa, which is consistent with the actual measured parameter.

Key words: steam generator, vapor-liquid two-phase flow, pressure stress, fluid-structure interaction

摘要： 以核电站蒸汽发生器为研究对象，采用两流体模型描述二次侧汽液两相流动及沸腾换热，利用CFX对一、二次侧流体与换热管及支撑板的耦合流动换热进行三维数值模拟，在此基础上提取一、二次侧流体压力载荷，在Workbench平台中实现载荷向结构模型的传递，计算换热管结构应力。流固耦合计算结果表明：支撑板位置处二次侧流体流速迅速增大又快速减小，并且流体湍流耗散急剧增大造成二次侧流体压力损失增大；换热管压力应力取决于一、二次侧流体压差，整体平均压力应力约为58 MPa，与实际测量参数相符。

关键词: 蒸汽发生器, 汽液两相流, 压力应力, 流固耦合