关键词: SIL验证, 优化设计, 测量元件, 逻辑控制器, 执行元件, 辅助元件, 经验架构

Abstract: Safety instrumented function (SIF) loop is set to reduce the safety risk of specific scenes. The functional description of SIF loop in the grading report is the complete logic requirement of process design, including key actions and accessory actions. Safety integrity level (SIL) verification belongs to the research field of probability, and there are many and complex factors affecting the failure rate. If it fails to pass SIL verification, a large amount of engineering changes will be caused, engineering cost will be wasted, and engineering schedule will be delayed. Designers should focus on the identification of key action, average probability of failure on demand (PFDavg) and the constraints of SIF loop structure in SIL grading report. Based on the method of this article to optimize the design of measuring components, logic controllers, executing components and supplemental components, the probability to pass the SIL verification will be increased. When pre verification and safety requirement specification are not available, designers can refer to the typical proven structures of SIF loop to pass SIL verification listed in this article to minimize the engineering change.

Key words: SIL verification, optimization design, measuring component, logic controller, executing component, supplemental components, proven structure