Risk Analysis In Chemical Concept Design Phase Risk Indexes And Calculation Of Risk Degree

Petrochemical industry provides immensely convenience for people in varies aspects including production and life, at the same time it bring us some bedeviled problem. Frequent dangerous accidents in recent years make people realize that it is no time to delay to evaluate the risk in the petrochemical industry.There are three kinds of methods we know commonly:qualitative analysis,quantitative analysis and semi-quantitative analysis. Hazardous and operational analysis,risk graph,improved risk graph,fault-tree analysis and risk matrix are the most commonly used and basic analytical methods. Although these methods are easy to be operated, there are many problems. In view of the recent development tendency, this paper improves traditional risk matrix and fault tree analysis, proposing improving strategy in order to overcome its shortcoming.Traditional risk matrix is a qualitative analysis method which bases on expert Subjective evaluation. Well fuzzy mathematics is suitable method to solve this problem which is used to quantify the risk indexes. At the same time the risk indexes are incomplete. Therefor this paper proposes comprehensive fuzzified risk index. And then human factor, which is added into fuzzy matrix, is taken as an example and to be analysised and explained. At last the result of the multiple indexes on fuzzy risk matrix is compared with the result got from the two indexes on fuzzy risk matrix and the result got from the traditional risk matrix, proving that fuzzy mathematics is suitable to process data uncertain problems.There exists uncertainty in basic events' probability data in traditional fault tree. Well fuzzy mathematics can dispose the uncertainty effectively and then this paper uses this strategy in the propylene transportation line to explain this strategy in order to calculate the probability of risk event. As well Failure mode and effect analysis method is combined to calculate the severity of consequence. Therefore the risk degree is got according to comprehensive index factors risk evaluation. Layer of protection is added according to the risk degree until the risk is accepted.Comparison is made between fuzzy risk matrix and fuzzy fault tree, and summarize is made according to the respective suiting case,emphasis and the research degree.