Optimization Design And Evaluation Research Of Safety Instrumented System Schemes Under Different Demand Modes

With the development of industry and the advancement of technology,the situation of global industrial safety production is becoming increasingly severe,and people are paying more and more attention to safety issues.As one of the risk control measures,the safety instrumented system is an important means to ensure the safe and reliable long-term operation of the enterprise.In conjunction with the requirements of Document 116 of the State Administration of Safety Supervision,optimization design and evaluation research of the safety instrumented system is very important.At present,quite a lot of research and discussions have been made on safety instrumented systems at home and abroad,but more attention has been focused on the reliability and maintainability modeling of safety instrumented systems in low demand mode.Relatively speaking,few discussions have been conducted on safety instrumented systems for optimization design and evaluation studies from the perspective of economics.From an economic point of view,this paper takes the cost factor into consideration in the process of designing,feasibility evaluation and maintenance optimization of the safety instrumented system under different demand modes,in order to achieve a better balance between safety and economy.First,determine the safety integrity level based on the expected utility theory.The utility function is used to express the safety integrity level,and the optimal target safety integrity level is determined by maximizing the expected utility,thereby minimizing the risk of violation design and over-design.According to the determined target safety integrity level,the configuration and rectification investment schemes of the safety instrumented system are proposed.Perform costbenefit analysis on different investment schemes based on the principle of as low as reasonably practicable,thereby evaluating the feasibility of the schemes.It realizes the selection of the most economical investment decision without violating the reliability requirements.Combining the safety functions of the safety instrumented system,two more realistic cost-benefit analysis methods are proposed to provide further technical support for investment decisions.For the safety instrumented system scheme with the determined structure,maintenance optimization can be carried out.This article proposes a method of online preventive maintenance for the safety instrumented systems with a redundant structure.The optimal maintenance interval of the safety instrumented system scheme is determined through the costbenefit analysis,so as to optimize the maintenance strategy.