Interaction characteristics of subcooled water jet with high-pressure upward into high-temperature oil in a confined space

During the Steam Generator Tube Rupture (SGTR) accident of Lead-cooled Fast Reactors (LFR), liquid metals come into direct contact with water, resulting in a multiphase flow phenomenon involving liquid metal, water and vapor. Studying the corresponding mechanisms of the interaction process between subcooled water jet and liquid metal is crucial with the pressure impact and temperature drastic changes during the phenomenon may damage the structural components of the reactors. The simulation experiments were conducted to investigate the interaction characteristics of subcooled water jet with high-pressure upward into high-temperature thermal oil in a confined space, studying the effect of experimental parameters (such as injection time and pressure, oil and water temperature, nozzle shape and diameter) on the oil temperature drop and pressure variation. Three pressurization modes were distinguished, including two overall vapor productions and one local vapor production. The evolution path of water/vapor in oil was inferred based on transient temperature changes. Finally, the oil temperature drop model was established by four dimensionless thermophysical parameters, and the model was validated with experimental values at an average error of 12.05%.