Research On The Fire And Explosion Endangerment Of The Lpg Tank

LPG has flammable and explosive characteristics. Fire and explosion can easily be caused in the process of LPG production,stockpiling and use. Especially in the LPG storage tank area, severe property damage and human casualties may be induced in case of an accident. Therefore,it is very necessary to study the hazardous consequences of fire and explosion of LPG tank. Setting up relevant physicals models and mathematical models and modeling by computer imitate technique which will predict, prevent and control accidents and ensure the production safety are of great theoretical value and practical significance. The detail research contents are as follows:(1)The fire and explosion hazards of LPG tank area were analyzed. According to the three types of hazards theory, hazards were identified in LPG storage tank area. The forms,causes and interaction of three types of hazards in the LPG tank area were summarized. The main dangerous substance was LPG which was the lst class hazard; LPG reaches to a flammable concentration was the 2nd class hazard; management bug was the 3rd class hazard. The common modes of fire and explosion consequences in LPG storage tank area were analyzed.(2)Numerical simulation for the thermal radiation of LPG pool fire was studied. Combustion characteristics, relational model and radiation damage criteria of pool fire were introduced. Based on the previous study, the flame shape of pool fire was theoretically analyzed; physical and geometrical models were established according to the reasonable assumption. Appropriate radiation models were selected and the initial and boundary conditions were determined; the thermal radiation to environment from the pool fire (D=12m)was numerically simulated using Fluent software and the contour of incident heat flux around the flame was obtained. Simulation results showed that the pool fire heat radiation decreased rapidly along with increase of the distance from the target point to the flame center. The damage range of pool fire was calculated combining with radiation damage criteria: death radius21m, second degree burn radius35m, critical safety radius55m. The thermal radiation affected by pool size and wind was analysed which showed that: flame length and radius of the injuries increased approximatel linearly as the pool diameter increases. Because of the influence of wind, the heat radiation of downwind direction increased while reducing against the wind direction, hazard areas moved to the downwind direction.(3)LPG hazardous areas of explosive gas were analyzed. After LPG diffusing into the atmosphere,mixing with air and forming explosive gas,it is likely to initiate explosion if meeting ignition sources. Explosive gas diffusion was studied using numerical simulation method based on Fluent software; the diffusion laws of explosive gas were simulated under different wind conditions and initial conditions; the scope of explosion was calculated combining with LPG explosion limit; the range of hazardous area was more intuitive and specific using the graphical display capability of Fluent software so as to provide valuable reference data for LPG tank area safety assessment and emergency plans.The study in the paper was a valid attempt to study the danger of flammable gas using CFD method,which offered a new thought way to study the other style disaster about storage tank.