Flow distribution investigation and sensitive analyses on reverse flow in U-tubes of steam generator under natural circulation

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. © 2021 Elsevier Ltd.