01. Experimental/Computational Fluid Dynamics

Heat pipe-cooled reactors (HPRs) is increasingly favored in the energy field due to its excellent reliability and adaptability. High-temperature heat pipes, as a key component of HPRs, mastering the internal phase change process and heat transfer characteristics are crucial for optimizing the overall design of the reactor. This study constructed a numerical model of high-temperature heat pipe with liquid potassium metal, and deeply analyzed the effects of inclination angle and filling ratio (FR) on the heat transfer performance of the heat pipe. The accuracy of the heat pipe model is validated by relevant experiments. The results indicate that the thermal resistance decreases with the increase of the inclination angle. As the FR increases, the thermal resistance shows a decreasing trend. Notably, at high FR conditions, there exists a critical inclination angle that significantly affects heat transfer performance. Based on CFD method visualization analysis, the processes of bubble generation and aggregation are clearly captured, revealing the formation mechanism of Geyser boiling phenomenon (GBP). The inclination angle has a mitigating effect on GBP, and under low FR conditions, the GBP is not obvious due to the smaller size of generated bubbles.