融合误跳车的安全仪表系统测试周期优化流程

Optimization process of proof test cycle of safety instrumented system integrating spurious trip

安全仪表系统(SIS)的验证测试周期对油气生产安全具有重大影响,目前IEC标准推荐的方法仅限于考虑平均需求失效概率的需要,且采用的名义失效率与现场实际不一致。为此提出一种基于贝叶斯估计的融合误跳车影响的测试周期优化流程(PTIST),可以综合考虑SIS运行阶段的误动作和拒动作损失,并通过获取更精确的SIS失效率,实现SIS具体失效数据和数据库信息的结合。将PTIST应用于某加氢裂化装置的液位联锁控制回路中,结果表明:相较于IEC标准,PTIST中的前两个测试周期均缩短,测试周期内的总损失成本平均降低了17.57%,单位损失率平均降低了10.25%,且能有效地利用SIS误跳车信息;PTIST不仅提高了测试周期内SIS的可靠度,而且能大幅降低SIS运行损失成本。

The proof test cycle of safety instrumented system(SIS)has a significant impact on the safety of oil and gas pro-duction.However,the recommended method in the IEC standard is only limited to considering the needs of the average prob-ability of failure on demand,and the nominal failure rate adopted is often inconsistent with the actual situation on site.Therefore,the optimization process of proof test cycle integrating the spurious trip(PTIST)was proposed based on the Bayesian estimation,which could comprehensively consider the spurious trip and failure action loss in the SIS operation stage and by obtaining more accurate SIS failure rate,the combination of SIS specific failure data and database information was re-alized.The PTIST was applied to the liquid level interlock control circuit of a hydrocracking unit.The results show that,compared with the IEC standard,the first two test cycles in the PTIST are shortened,the total loss cost in the test cycle is re-duced by 17.57%on average,the unit loss rate decreased by 10.25%on average,and the spurious trip information can be effectively utilized.The PTIST can not only improve the reliability of SIS during the proof test,but also greatly reduce the SIS operation loss cost.