In order to meet the needs of offshore platform reactor design, the flow characteristics of the integrated natural circulation reactor under the rolling condition coupling power increase was analyzed and a typical three-dimensional analysis model of natural circulation was established. Computational fluid dynamics methods were used to numerically simulate natural circulation under swing conditions, and the velocity and temperature distribution characteristics during different power changes were analyzed.

The results indicated that there is a more pronounced “overshoot” phenomenon in temperature and flow rate corresponding to the condition of significantly increasing power. The swinging could enhance the internal wall heat transfer flux of the rising heat transfer component. Under conditions of severe oscillation, the descending flow channel has a significant reheating effect on the cold fluid at the outlet of the heat exchanger. For different oscillation cycle conditions, the temperature changing process during the transient process is smoother under the condition of significantly increased power.