Experimental study of BLEVE mechanism and pressure response characteristics of high initial pressure and temperature superheated water under multi-scale vessels

This study designed and built a multi-scale high-temperature and high-pressure (T > 140 °C, P > 2 MPa) superheated water experimental platform, and systematically investigated the BLEVE pressure characteristic parameters and their variation trends under different sizes of vessels, different release diameters, different initial temperatures, and different initial pressures. The results indicate that three distinct pressure-peak regions appear during the pressure rebound stage. Pressure peaks typically occur within the first two regions, where the energy released from the first peak significantly attenuates the second. Distinct critical relief diameters were identified for vessels of different sizes, with larger vessel volumes corresponding to larger critical diameters. Both excessive and insufficient vent diameters can suppress the occurrence of BLEVE. An increase in initial temperature and pressure shows a positive correlation with the BLEVE peak pressure, while the initial pressure exhibits an exponential influence on the peak value. In addition, the larger the volume, the larger the pressure peak generated after venting, and the maximum pressure peak occurs in Vessel I, which is 4.14 times the initial pressure. Overall, this study elucidates the formation mechanism of the multimodal pressure response during BLEVE, providing experimental evidence to support the safe design, operation, and risk mitigation of high-temperature and high-pressure vessels.