The reverse flow is an important phenomenon occurring in inverted U-tube steam generator under natural circulation, which may result the heat accumulating in the first loop and cause serious accident. Thus, researching the flow performance and its influence factors in steam generator is necessary for the safety of nuclear reactor. In this paper, the criterion of reverse flow judgement and flow distribution program are developed firstly. Based on the model of PCATEL (Parallel Channel Test Loop) pressurized water reactor, program validation and calculation of flow distribution of steam generator is carried out. As last, sensitive analyses of parameters on both steam generator flow distribution and performance of inverted U-tubes are carried out. From the result, the requirement of heat transferring can be satisfied in the condition of PACTEL facility design. In addition, different kinds of parameters have significant influence to the performance of steam generator flow distribution and fluid in single inverted U-tube.

逆流是自然循环下倒置U型管蒸汽发生器中发生的重要现象，可能导致热量在第一回路中积聚，并引起严重事故。因此，研究蒸汽发生器的流动性能及其影响因素对于核反应堆的安全是必要的。本文首先建立了逆流判断准则和流分配程序。基于PCATEL（并联通道试验回路）压水堆模型，对蒸汽发生器的流量分配进行了程序验证和计算。最后，对蒸汽发生器流量分布和倒置U型管性能的参数进行了灵敏的分析。从结果来看 在PACTEL设施设计的条件下可以满足传热的要求。此外，不同种类的参数对单个倒U型管中蒸汽发生器的流量分布和流体的性能也有重要影响。