摘要
HAZOP分析和SIL评估后可以通过可靠性框图等方法进行SIL验证计算。根据IEC 61508平均失效概率的计算公式可以分别计算出传感器、逻辑控制器、最终元件的平均失效概率PFD,求其和,从而得出安全仪表功能的平均失效概率。根据平均失效概率值所落入的SIL等级的区间,可以判定其对应的SIL等级,从而实现SIL等级的验证。
After HAZOP analysis and SIL evaluation, the method by using reliability block diagram can be applied in SIL verifying calculation. Based on average fallure probability equation in IEC61508, the values of probability of fallure on demand for sensor subsystem, logic subsystem and final element subsystem can be calculated, respectively. With the sum from these values, the probability of fallure on demand for safe instrument can be calculated. Then, from the fact that the value obtalned is within which group of SIL, the SIL level can be determined and SIL veriifcation is realized.
出处
《化工与医药工程》
2015年第2期53-57,共5页
Chemical and Pharmaceutical Engineering
关键词
安全完整性等级
可靠性框图
平均失效概率
硬件故障裕度
safety integrity level
reliability block diagram
probability of failure on demand
hardware fault tolerance
