Numerical study of subcooled flow boiling in dual-elbow cooling structure for fusion applications

Subcooled flow boiling is crucial in heat dissipation for fusion devices, a promising clean energy technology. The dual-elbow cooling structure enhances energy efficiency by reducing pressure drop while maintaining effective heat transfer. This study investigated the subcooled flow boiling characteristics of a dual-elbow cooling structure under high heat flux conditions using the RPI wall boiling model in Fluent. By modifying bubble characteristic parameters, a numerical simulation approach suitable for dual-elbow cooling systems was proposed. Simulations were conducted over a heat flux range of 1.5-8.1 MW/m 2 to analyze the heat transfer performance, with particular attention to liquid temperature distribution, bubble behavior, and heat flux partitioning. The results indicate a significant increase in the proportion of quenching heat flux at high heat flux conditions, which effectively mitigates the rise in wall temperature and enhances overall heat transfer efficiency.