A detailed review on critical flow experiments and models

Abstract

Critical flow is a significant phenomenon in reactor safety analysis, which has remained a research focus for several decades. The critical flow rate determines the rate of coolant loss in the reactor and the rate of pressure relief in the primary loop. Owing to the multiplicity of parameters influencing critical flow and the complexity of the flow phenomenon, there exists an incomplete cognition of the critical flow phenomenon at present, and precisely calculating the critical flow rate under various working conditions is extremely challenging. Consequently, this paper presents a comprehensive review of the experimental and theoretical studies on critical flow carried out in various thermodynamic regions. It summarizes the current progress and deficiencies in experimental research and concurrently compiles the experimental research data to offer database support for other researchers engaged in theoretical studies of critical flow. A brief but comprehensive overview of the existing theoretical models and general modeling framework for critical flow phenomena is provided. It is conducive to the further understanding and investigation of the critical flow phenomenon.