Experimental study of minimum film boiling temperature and quench front propagation velocity characteristics during the reflooding process

The plate-type fuel assembly stands as a prevalent choice in research reactors and naval power reactors, owing to its expansive heat transfer area and high heat transfer efficiency. Examining the flow heat transfer during the reflooding process and conducting safety analyses pertaining to this configuration emerge as a matter of great significance. Within the confines of this study, the ramifications brought by distinct reflooding velocity, coolant subcooling, heat flux, and initial wall temperature on the minimum film boiling temperature (MFBT) and quench front propagation velocity (QFPV) is delved. By employing a meticulous analysis of the standard regression coefficients, we discern the sensitivity of MFBT and QFPV under each individual condition. The results indicate that reflooding velocity and subcooling meet a significantly positive effect on MFBT and QFPV. The reflooding velocity has the most significant impact on the two key parameters, with an SRC of 0.603 for MFBT and 0.577 for QFPV, respectively. However, the initial wall temperature has a negative effect, while the heat flux does not play a critical role, as indicated by an SRC of only 0.135 for MFBT. The findings presented in this paper offer valuable data support for the safety design of nuclear reactors, and the conclusions drawn from the sensitivity analysis provide refined guidance for future research direction.