Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8068129 | Annals of Nuclear Energy | 2016 | 4 Pages |
Abstract
Imperfection of proof test can result in the safety function failure of safety instrumented system (SIS) at any time in its life period. IEC61508 and other references ignored or only elementarily analyzed the imperfection of proof test. In order to further study the impact of the imperfection of proof test on the probability of failure for safety instrumented function (SIF), the necessity of proof test and influence of its imperfection on system performance was first analyzed theoretically. The probability of failure for safety instrumented function resulted from the imperfection of proof test was defined as probability of test independent failures (PTIF), and PTIF was separately calculated by introducing proof test coverage and adopting reliability block diagram, with reference to the simplified calculation formula of average probability of failure on demand (PFDavg). Research results show that: the shorter proof test period and the higher proof test coverage indicate the smaller probability of failure for safety instrumented function. The probability of failure for safety instrumented function which is calculated by introducing proof test coverage will be more accurate.
Keywords
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Physical Sciences and Engineering
Energy
Energy Engineering and Power Technology
Authors
Jianghong Jin, Lei Pang, Bin Hu, Xiaodong Wang,