Duelist algorithm for optimisation of safety instrumented system at distillation column based on RAMS + C

Abstract

This paper describes the optimisation of safety instrumented system at distillation column based on reliability, availability, maintenance, safety, plus cost using duelist algorithm. Safety instrumented system maintain operating condition in the safe regime when normal operation over the allowable limits. Diversity redundancy was implemented as allocation redundancy. The requirement of safety instrumented system has been appointed by international standard, International Electrotechnical Commission 61508. The objective of this study is to achieve the lowest value of lifecycle cost that affected by average probability of failure on demand and spurious trip rate value. Average probability of failure on demand is involved by failure rate danger that has an effect on safety instrumented level value; meanwhile, spurious trip rate is influenced by failure rate safe that has an effect to the product losses caused unscheduled shutdown. The field instruments subsystems are provided by utilising one of or all different technologies. The best optimisation solution utilises vote 1 out of 1 for all subsystem with smart transmitter technology and air-operated actuator. Its solution obtained lifecycle cost 1,139,898 USD, average probability of failure on demand 7181 × 10−02/h and spurious trip rate 4844 × 10−05/h.