Quasi-Static Pressure Characteristics of Explosion Venting Vessel Under Confined Explosion

Abstract

To study the quasi-static pressure characteristics inside the explosion venting vessels, 3 numerical models for cylindrical explosion venting vessels were established with the AUTODYN software, including a one-end-opening explosion venting vessel, an explosion venting vessel with an ejectable venting cover, and an explosion venting vessel with a shear pinned venting cover. Based on the Bernoulli equation, a theoretical simplified model was established to simulate the quasi-static pressure inside the opening explosion venting vessel. A theoretical simplified model based on the energy conservation equation was established to simulate the quasi-static pressure in the vessel with a venting cover under different charge weights. In the end, the effects of the shear pin on the pressure of the explosion venting vessel were discussed in the cases of cutoff or non-cutoff. The numerical models in previous literatures were established. The theoretical quasi-static pressure results are in good agreement with the experimental results in the literatures, which verifies the reliability of the proposed theoretical calculation method. The results show that, the internal pressure of the open explosion venting vessel decays rapidly, and the quasi-static stage lasts for a short time. The theoretical simplified model based on the Bernoulli equation can better predict the time when the internal pressure in the explosion venting vessel decays to the atmospheric pressure. The shock wave in the vessel with a venting cover propagates reciprocally along the axial direction. The theoretical model based on the energy conservation equation can better predict the quasi-static pressure during the pressure decaying process. In the case of the non-cutoff shear pin, the quasi-static pressure inside the vessel exhibits an obvious platform effect. Compared with the case without a shear pin, the internal pressure in the vessel with a shear pin will decay basically in the same way after the shear pin with a diameter of 18 mm is cut off, and the venting cover will reach the opening in advance by 0.25 ms. This work mainly provides a theoretical basis and applicable reference for the structural design of explosion venting vessels.