Effect of Multiple Vent Parameters on an External Explosion Induced by an Indoor Premixed Methane-Air Explosion
L. Pang1,2, Q.-R. Hu1, K. Yang1,2
1School of Safety Engineering, Beijing Institute of Petrochemical Technology, Beijing, 102617 China
2Beijing Academy of Safety Engineering and Technology, Beijing, 102617 China
Keywords: gas explosion, vented explosion, external explosion, flow field, venting hazard
Abstract
To reveal the influence of vent parameters on the dynamic mechanism of an external explosion induced by a vented premixed methane-air explosion, the evolution process of an outdoor flow field under different vent opening pressures ( pv ), opening times ( tv ), and scaled vent size ( Kv = Av / V 2/3) is studied by methods of computational fluid dynamics. With an increase in Kv , the shape of the unburned gas cloud and vented flame gradually changes from a jet shape to a depression toward the vent. The outdoor peak specific turbulent kinetic energy increases by 36.5 and 4 times with an increase in pv and tv , respectively. At tv = 0.1 s, the peak specific turbulent kinetic energy reaches 1 411 m2/s2 and the turbulence range reaches 3 times the length of the room. With an increase in pv , tv , and Kv , the occurrence time interval of the external explosion exhibits a decreasing trend. The external explosion is located at a distance of less than 1.4 times the length of the room. At Kv = 0.05, the external explosion occurs at the furthest location.
|
