Calculation of the Parameters of Hazardous Substances Accidental Release from the Process Units Taking into Account Inflows from Adjacent Equipment

A.S. Sofyin, Cand. Sci. (Eng.), Department Head, 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.


1. Methods for Modeling Dispersion of Hazardous Substances Accidental Releases: Safety Guide. Ser. 27. Iss. 11. Moscow: ZAO NTTs PB, 2016. 130 p. (In Russ.).
2. Methods for Assessment of Accidents Risk at the Process Pipelines Associated with the Movement of Explosive and Fire Hazardous Liquids: Safety Guide. Ser. 27. Iss. 12. Moscow: ZAO NTTs PB, 2016. 52 p. (In Russ.).
3. Methods for Assessment of Accidents Risk at the Process Pipelines Associated with the Movement of Explosive and Hazardous Gases: Safety Guide. Ser. 27. Iss. 10. Moscow: ZAO NTTs PB, 2016. 48 p. (In Russ.).
4. Declaration of Fire Safety and Assessment of Fire Risk. In 4 parts. Part 4. Normative Legal Documents on Fire Risk Assessment, Methods and Examples. 5-e izd., ispr. Ser. 19. Iss. 2. Moscow: ZAO NTTs PB, 2016. 196 p. (In Russ.).
5. General Rules of Explosion Safety for Explosive and Fire Hazardous Chemical, Petrochemical and Oil Refining Plants: Federal Norms and Rules in the Field of Industrial Safety. 3-e izd., ispr. i dop. Ser. 09. Iss. 37. Moscow: ZAO NTTs PB, 2018. 132 p. (In Russ.).
6. Rules of Industrial Safety for Oil and Oil Products Warehouses: Federal Norms and Rules in the Field of Industrial Safety. Ser. 09. Iss. 46. Moscow: ZAO NTTs PB, 2017. 60 p. (In Russ.).
7. Kozlitin A.M., Kozlitin P.A. Risk analysis of process systems using Monte Carlo method. Tekhnicheskie nauki — ot teorii k praktike = Engineering Sciences — from Theory to Practice. 2016. № 7 (55). pp. 11–20. (In Russ.).
8. Sitenkov V.T. Calculation of the amount of hazardous substance in the accidental release. Bezopasnost truda v promyshlennosti = Occupational Safety in Industry. 2003. № 12. pp. 33–38. (In Russ.).
9. ALOHA Software. Available at: (accessed: November 27, 2017).
10. Stene J., Harper M., Witlox H.W.M. Modelling Transient Leaks of Multi-Component Fluids Including Time-Varying Phase Composition. Chemical Engineering Transactions. 2016. Vol. 48. pp. 169–174. DOI: 10.3303/CET1648029.
11. Agapova E.A., Degtyarev D.V., Lisanov M.V., Kryukov A.S., Kulberg S.B., Sumskoy S.I. Comparative analysis of the Russian and foreign methods and computer programs on modeling of accidental release and risk assessment. Bezopasnost truda v promyshlennosti = Occupational Safety in Industry. 2015. № 9. pp. 71–78. (In Russ.).
12. Sirotin S.A. Universal method for calculating the process of three-phase rectification. Khimicheskaya promyshlennost segodnya = Chemical Industry Today. 2008. № 12. pp. 44–48. (In Russ.).
13. Haydary J., Pavlík T. Steady-state and dynamic simulation of crude oil distillation using aspen plus and aspen dynamics. Petroleum & Coal. 2009. № 51 (2). pp. 100–109.
14. Methods for Accidents Risk Analysis at Hazardous Production Facilities of the Offshore Oil and Gas Complex: Safety Guide. Ser. 08. Iss. 27. Moscow: ZAO NTTs PB, 2016. 94 p. (In Russ.).
15. TOXI+Risk 5 software package. Available at: programmnyi-kompleks-toxirisk-5 (accessed: November 27, 2017. (In Russ.).

DOI: 10.24000/0409-2961-2018-3-5-13
Year: 2018
Issue num: March
Keywords : software package accidental release hazardous substances process systems shut-off valves accident consequences assessment quantitative risk analysis