Risk Analysis And Assessment Of Fire Explosion For Catalytic Cracking Device

The catalytic cracking is the most important kind of secondary processing technology in oil refining industry, occupies an important position in the industrial production of oil refining. In this thesis, according to the development tendency and safe situation of the domestic and international catalytic cracking device in recent years, analyzes the typical accidents of catalytic cracking equipments and clarifies the necessity of carrying out analysis and assessment of the fire explosion risk of catalytic cracking device. And the risk analysis and assessment technique have been summarized, includes the development history and classification of risk analysis and assessment technique.According to the production characteristic of the catalytic cracking device, this paper chooses both the qualitative and the quantitative method. First, the fire explosion hazard of the material and product has been analyzed. At the same time, the technology deviation and reason leading to the runaway type fire explosion accident in production process have been discussed with the method of hazard and operability analysis (HAZOP), and countermeasure has been presented. Second, failure modes and effects analysis (FMEA) has been used to analyze hazard of the installations. The analysis result indicates the fault grade of the 3 sub systems, which is an important reference for establishing precautionary measures. According to the result of the qualitative analysis, the installations which have the great fire explosion risk are reactor, regenerator, heating-furnace, exhaust-heat boiler, fractionator, oil and gas separator, absorption column, stabilizer, and pressure machine. Using the relatively well-known DOW's index fire explosion hazard method, carries out fire explosion risk assessment for the nine units of the reaction-regeneration system, cracking equipment and assimilation stabilization system in the production process, and determines the fire explosion hazard grade of each unit. In addition, weight coefficients of various systems of the catalytic cracking devices are calculated. The system which has the maximum weight coefficient is analyzed with the linked function model, and dissociation and control models are established. At the same time, establishes the dissociation and control models for the fire explosion accident resulting from management, which can be used for safety management. Last, carries out the quantity assessment for three kinds of important calamity accident—pool fire, vapor explosion (VCE) and boiling liquid expanding vapor explosion (BLEVE)—with simulation assessment technique at catalytic cracking farm, computes the injury and loss scope, and puts forward the defend measure.