关键词: 量化风险评估, 火炬系统, 装置改扩建, 泄放负荷管理, 数值模拟

Abstract:

Flare system is a necessary auxiliary production facility for large-scale petrochemical plant. It is also an important safety and environmental protection measure. However, flare design standard SH 3009—2013 “Design specifications for combustible gas discharge system in petrochemical engineering” and the international standard API 521 “Pressure-relieving and Depressuring Systems” are mainly based on industry practices and engineering experience currently. Therefore, when the flare system needs installation or extension, there will be higher risk, especially when the diameter and layout of pipe line cannot be changed. This paper presented a general method for the risk assessment of the flare system for the renovation or expansion of combined petrochemical plant. The key parameters of the flare system were obtained by the superposition algorithm of simultaneous discharge of multiple discharge sources before and after the reconstruction and expansion. This paper used Aspen flare-net software for numerical simulation and case study. The numerical results of the back pressure and noise of the safety valve of flare system caused by the newly installed device in the plant, the corresponding safety risks, and the release combinations that may lead to safety risks of flare system were obtained. The results provided quantitative decision basis for discharge load management, and the application effect and effectiveness of the proposed method were illustrated.

Key words: quantitative risk assessment, flare system, plant reconstruction or expansion, discharge load management, numerical simulation