At assessment of the accidents consequences at hazardous production facilities, one of the most complicated tasks is the calculations of hazardous substances accidental release from the process systems. In such cases, it is required to take into account the inflows of hazardous substances to the area of accident from the tanks connected with emergency equipment. Consequences assessment of accidents can also be used to substantiate the layout diagrams and the normative response time of process units shut-off valves. However, in the native and foreign scientific works, as well as in the existing software products, the required methods are either absent or have significant limitations. The article suggests the method for calculating emergency emissions of hazardous substances implemented as a computer program. It allows to consider emergency situations with complete or partial destruction of the equipment, including with guillotine pipeline rupture in the process systems of various configurations, taking into account the availability of accident-prevention control systems. These methods are used to estimate the emergency flow rate and the time for hazardous substances expiration in gas or liquid state, as well as to calculate the total mass of their release at various stages of the accident. The example is considered concerning the effect of the shut-off valves layout on the consequences of release and the risk indicators. With the help of the developed methodology, the masses of emergency leaks for each equipment of the process system for transferring hazardous substances from one tank to another were determined, the fields of hazardous factors were calculated, and the risk indicators were estimated.
A.S. Sofyin, Cand. Sci. (Eng.), Department Head, toxi@safety.ru S.V. Prokudin, Lead Specialist A.A. Agapov, Cand. Sci. (Eng.), Director of the Computational Analysis Center STC «Industrial Safety» CJSC, Moscow, Russia S.I. Sumskoi, Cand. Sci. (Eng.), Senior Lector NIYAU MEPhI, Moscow, Russia
At assessment of the accidents consequences at hazardous production facilities, one of the most complicated tasks is the calculations of hazardous substances accidental release from the process systems. In such cases, it is required to take into account the inflows of hazardous substances to the area of accident from the tanks connected with emergency equipment. Consequences assessment of accidents can also be used to substantiate the layout diagrams and the normative response time of process units shut-off valves. However, in the native and foreign scientific works, as well as in the existing software products, the required methods are either absent or have significant limitations. The article suggests the method for calculating emergency emissions of hazardous substances implemented as a computer program. It allows to consider emergency situations with complete or partial destruction of the equipment, including with guillotine pipeline rupture in the process systems of various configurations, taking into account the availability of accident-prevention control systems. These methods are used to estimate the emergency flow rate and the time for hazardous substances expiration in gas or liquid state, as well as to calculate the total mass of their release at various stages of the accident. The example is considered concerning the effect of the shut-off valves layout on the consequences of release and the risk indicators. With the help of the developed methodology, the masses of emergency leaks for each equipment of the process system for transferring hazardous substances from one tank to another were determined, the fields of hazardous factors were calculated, and the risk indicators were estimated.
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