Accident Consequence Simulation Application In Trichlorosilane Production Device Safety Evaluation

The method of accident consequences simulation has been widely used in safety evaluation of chemical production devices.This method is targeted in evaluation process and the results obtained are intuitive.Thus,this method is widely applied in evaluation of dangerous accidents about production devices,such as fire,explosion,poisoning and so on.Production process of trichlorosilane involves a lot of flammable toxic chemicals,extremely casualties,property damage and environmental disruption will be caused once a link goes wrong.Therefore,conducting simulation of accident consequences and putting forward relative precautionary measures for production devices of thichlorosilane are of great importance for further improving intrinsic safety of construction projects.The main contents and conclusions of this paper are as follows.1.We concluded the progresses made at this stage through study of accident consequences simulation and safety evaluation of trichlorosilane at home and abroad in this field.Besides,we also gave further analysis on problems about idealization of domestic accident consequences simulation model,lacking in applied formula on domino accidents simulation and safety evaluation about trichlorosilane and lacking in analysis on environmental factors.2.Firstly,we calculated the death radius,serious injury radius and minor injury radius of pool fire caused by storage tank of trichlorosilane through pool fire formula and ALOHA software,respectively.According to comparison of the two kinds of simulated result deviation,we employed wind speed correction coefficient to modify formula,and the error was less than 1% with modified formula,which means that the range of application for formula was expanded.Secondly,we conducted a simulation aimed at lacking in flammable vapor cloud area in safety evaluation reports.Damage range of shock waves produced by vapor cloud explosion was simulated at first.Then the calculation of combustible area was added.The results showed that damage range caused by combustible area is larger than shock waves and both of the two kinds of damage range would decrease with increasing of wind speed.Finally,diffusion of chlorine was simulated by a simplified heavy gas atmospheric diffusion model DEGADIS.The results indicated that tendency of maximum distance fromthe wind was increasing first and then decreasing.The diffusion distance of chlorine was affected by multi-factors.The influence of wind speed,temperature,moisture and ground roughness on diffusion distance of chlorine was investigated,respectively.The results showed that wind speed and ground roughness were main influence factors.3.Domino accidents of trichlorosilane production equipment were simulated with CASST-QRA software.The damage range of domino accidents was obtained.The probability of single accident such as valve leakage or pipeline leakage and probability of domino accident at different accidental patterns on devices were also obtained.Besides,probability of damage of target equipment in area of storage tanks as well as probability of personal and social risks were obtained.The result indicated that domino damage range caused by trichlorosilane storage tanks or pressure swing adsorption towers was larger than damage range caused by single device about 24.90 m and 12.20 m,respectively.Therefore,it is of great importance to simulate domino accidents with simulation devices.Through the work of this paper,a more comprehensive safety distance is proposed for the trichlorosilane production device,and the specific location of the safety management device and the damage probability of the target equipment in the trichlorosilane storage tank area are obtained,so as to provide a basis for the factory to reduce production risk in an all-round way,which promotes the comprehensiveness and completeness of safety evaluation of trichlorosilane production device.The pool fire correction coefficient and the simulation of the domino accident improve the accuracy of the accident consequence simulation model,which makes the chemical enterprise get the more realistic result in the application of the accident consequence simulation,and provides the scientific basis for the enterprise safety accident prevention work.