核电厂蒸汽发生器二次侧三维流场分析

Three- dimensional Flow Field Analysis on Secondary Side of Nuclear Power Plant Steam Generators

为弄清核电厂蒸汽发生器二次侧的流动和传热特性机理,以确保蒸汽发生器的稳定性,文章采用数值软件根据蒸汽发生器的结构特点和运行模式进行简化建模,利用相似原理,使用相变模块模拟了蒸汽发生器的二次侧汽液两相流的流场分布情况。研究了相同结构下不同给水比例对二次侧流场分布的影响,尤其是对空泡份额分布特性的影响。研究发现,不同的给水工况对直管段的空泡份额分布和流体流速分布都有明显的影响,但对传热管上部区域的空泡份额和速度分布的影响不大。

Steam generator is one of the key equipments of nuclear power plants. It is not only an important part of the second safety barrier to prevent the leakage of radioactive,but also the primary loop heat trap. Its stability is closely related to nuclear power plant safety. The flow and heat transfer characteristic of the secondary side of steam generators was analyzed using computational fluid dynamics software. According to the structure characteristics and operation pattern of steam generators,simple model was built using similarity principle. The flow field distribution characteristic of the steam generator＇s secondary side was simulated by RPI module and phase change module. Different feed water ratio effect on flow field distribution characteristic in the secondary side was studied,especially the distribution characteristic of volume fraction. The analysis showed that the way of homogeneous and inhomogeneous feed water have obvious effect on velocity distribution and the volume fraction distribution during the straight pipe area,but have little effect on the distribution of velocity and volume fraction at the region near the model exit.