Application Study On Performance Evaluation Of Safety Barriers In Risk Control To Chemical Plant

With the continuous development of chemical technology,chemical plant is developing toward large-scale,highly automated and continuity,if an accident occurs,the consequences can not be estimated.It has become an important issue in the field of chemical safety about how to prevent accidents,or how to control the situation and reduce the consequences of the accident as soon as the accident occurs.At present,the research on the methods of accident prevention is mostly based on the accident probability and accident consequences,ignoring the influence of the existing safety measures to prevent and control the accident.In view of the current research deficiencies and limitations,and from the site of the existence of security measures of risk reducing effect,we propose a new chemical equipment risk control method based on the accident scenario determined and safety barrier performance evaluation method of industrial accident risk analyse method(ARAMIS,Accidental Risk Assessment Methodology for Industries),and a polypropylene equipment is used to be an example.First of all,we shouid analyse the safety barrier and the definition,classification and identification of its function,a clear assessment of the safety barrier performance of three indicators: E(effectiveness),RT(response time)and LC(level of confidence),and on the basis,we can use risk graph method to determine the risk control targets of the system to complete the construction of risk control methods for performance evaluation of safety barrier device,then certify the principle,process and optimization measures and so on.Secondly,we should construct a suitable accident scenario.Accorfing to the characteristics of the present dangerous substances and devices in the scence,we should definate the type of dangerous equipment,analysis the accident that the equipment risk may occur,establish the bow tie diagrams that can reflect evolution process of the accident scene,and fully consider the effert of safety barrier performance to the accident scene risk control,analysis the critical events in the bow-tie diagrams and the probabilaty of leading to dangerous phenomenon,determine the accident scenario which is needed for risk control.Finally,the method is applied to a loop polypropylene installations,we can identify the present safety barrier and its function,identify all the accident scenario we should analyse for the equipment,We should determine whether the present safety barrier meet the risk control target based on the risk analysis of every present accident sencario.For the scenario which is not meet the risk control target,we should put forward reasonable safety barrier to optimize the measures.From the site of the security barrier performance,we can certify whether additional security measures need to be taken according to whether the analysis of risk control level is up to the standard,to allow decision makers to clearly understand the weak links in the site safety measures and provide decision makers a theoretical basis to make rational decisions.