Cause Analysis And Accident Inversion Of Explosion In Tank Region

The primary task in addition to the rescue is searching the cause of the accidents when the combustion and explosion accidents occurred in petrochemical industry. In this paper, a major explosion accident occurred in a tank region in a factory was set as an example. A detailed study of the causes of the accident and the accident morphology was conducted. The strength and failure mode of the accident tank was analyzed. The entire accident process was inversed ultimately.The main contents and conclusions are as follows:(1) The process of the accident and the morphology of the post-accident tanks were systematically described. The two possible reasons for the accident investigation were analyzed and recognized. The direction of the causes of accidents was determined.(2) The burst experimental process and devices of the glass plate of the foam generator were designed. It was found that the blasting burst pressure of the glass plate of the foam generator is much higher than the explosion pressure that the combustible gas can achieve. When explosion occurs on the top of the tank, the pressure wave cannot make the glass break, so the foam generator is not the reason of the flame tempering from out space to the inner tank.(3) The experimental program and devices of the flame transmission of the contact surface of the oil-measuring hole were designed. It was found that the flame can be spread by the gap of the contact surface of oil-measuring hole. Therefore, the gap of the contact surface of oil-measuring oil is the reason that flame spread from the top of the tank to the inner space of the tank. Meanwhile, the gap of the contact surface of oil-measuring hole is the channel of the combustible medium leakage.(4) The numerical simulation software Fluent was used to simulate the flammable gas cloud range when gas leaks through the gap of the oil-measuring hole to the outer space. The results show that when the leak channel is2mm, the leakage gas moves in the horizontal direction due to the influence of the leakage speed, while the downward movement under the action of gravity. The maximum range of the flammable gas cloud is1.5m and2m in the horizontal and vertical direction when the diffusion of the combustible gas reaches a steady state. The shape of the flammable gas changes with the change of the leakage pressure. The range of flammable gas cloud in the horizontal direction increases obviously with the increase of the leakage pressure.(5) The destruction pressure and the buckling pressure of the accident tank B were calculated. The results show that the destruction pressure of tank B is4037Pa, and the buckling pressure of the same tank is2241Pa. There are two main forms of the overpressure strength failure of tanks:first is the split of the parts of the dome. Second is the split of the part in the bottom of the tank. Tank intends to be instability when ruptured because of the overpressure.(6) The inversion process of the explosion accident in the tank region is conducted abased on the above findings.