Database construction and prediction model development of CHF in narrow rectangular channel under low pressure conditions

Abstract

Research reactors serve as radioisotopes and neutron sources for research fields, including non-destructive testing and radioisotope treatment. This study was conducted on the critical heat flux (CHF), which is one of the design basis criteria of research reactors which use plate-type fuel. The stable CHF database for rectangular channel was constructed excluding the flow instability data and prediction performance of existing correlations were evaluated. Among them, to improve the applicability of CHF LUT to rectangular channel, correction factor was developed and Sudo and Kaminaga correlation was improved as well. In addition, for deep understanding on CHF phenomena and further applicability to outside of applicable range for subcooled flow boiling condition, mechanistic approach has been conducted based on liquid sublayer dryout model. The suggested model showed good prediction performance among existing liquid sublayer dryout models which were developed for tube condition.