Research Of System Quantitative Risk Based On SDG-HAZOP

Petrol-chemical industry has complicated process, many parameters and dangerous points. Analyzing risk of process system need follow standard procedure and international standard. By SDG-HAZOP risk inference, we can identify accident consequences, dangerous reasons and paths. By layer of protection analysis (LOPA), we can decide whether the system safe or not. If it doesn't satisfy demand of standard, risk reduction, which is safety integrity level (SIL), will be assigned. It can direct layer of protection design and provide data to support its design. Getting accident consequence risk and SIL is aim of mine.How to get main dangerous source, accident consequence, risk level from data by SDG-HAZOP, and quantitative risk calculation in execution face the same problem: in present period, consequence quantitative risk calculation mainly depends on experts asserts, need high quality of them, lack of automation method and in low efficiency.On the basis of IEC-61508 directive suggestion, this thesis compares several general methods and comes into a result: assignment of SIL by system model's risk. In consideration of process industrial characteristics, the thesis presents a method of computing accidental probability and risk value by computer on the basis of SDG-HAZOP systematic dangerous paths analysis and inference. It also can be a tool of assigning SIL. Preliminarily constructs a rule library of SDG probability calculation, designs methods of SDG paths probability calculating and SDG tree analysis. Related program is designed. In order to store, search and abstract data from SDG paths, related database architecture has been established. This software module can work closely with SDG-HAZOP software and become a part of Safety Analyze Platform. Make a discussion on designing and realizing process, basic structures and components of SIL assignment, which is based on SDG-HAZOP. Finally, this thesis elaborates advantage and disadvantage of method and technology used now. Put forward some advice on future development of assignment on SIL.