Experimental and simulation study on internal explosions in vented confined spaces based on scaled models

This study addresses the explosion hazards and leakage risks associated with Liquefied Petroleum Gas (LPG) in nuclear chemical facilities by proposing a venting design validation methodology that integrates reduced-scale experiments with numerical simulations. A 1:10 scaled experimental facility and a corresponding CFD simulation model representing interconnected semi-confined spaces were constructed. Utilizing the calibrated model, a 1:1 full-scale model was employed to characterize the overpressure and temperature distributions under varying vent panel sizes and venting space heights. The results indicate that the edge length of the vent panel is the dominant factor controlling explosion suppression effectiveness, whereas the height of the venting space has a negligible influence. Increasing the vent panel edge length to 5 m reduces the peak overpressure by 94.3% (from 821.4 kPa to 47.1 kPa) and the flame temperature by 62% (from 1028 K to 347 K). From the perspectives of venting efficiency and engineering economics, a panel edge length of 3 m is identified as the optimal configuration. A 3 m vent panel effectively mitigates structural collapse risks, ensuring structural integrity and personnel survivability (overpressure < 50 kPa). Ultimately, this work establishes a coupled geometry-explosion protection framework. Beyond theoretical insights, the study offers actionable design guidelines for preventing domino effects in complex facility layouts, providing safety engineers with a cost-effective strategy to enhance the intrinsic safety and resilience of high-risk nuclear chemical facilities.