Research And Application Of Functional Safety Assessment For Chemical Plant Safety Instrumented System

With the continuous development of modern industry, people pay more and more attention on the safety in production of chemical industry. The safety instrumented system (SIS) for chemical plants is the key to ensure production safety. How to assess the functional safety of safety instrumented system accurately and timely has attracted much attention. Concept of functional safety has not been spreaded or popularized all around China by now. Also, there is no standard or specification for functional safety assessment. So, we should make a countribution to help establish the assessment system for functional safety of SIS.To help Shanghai Bureau of Quality Supervision assess a set of SIS’s functional safety for chemical plants, we do some research on this issue. The works we do are as follows:Study the functional safety relevant international standards and related literatures, compare different kinds of models for functional safety assessment. Developed a software to calculate parameters of functional safety using MFC and Matlab based on Markov model. This software can calculate PFD, PFS, and SIL of a system accurately. As a result, the accuracy of functional safety assessment can be improved with the help of this software. We assess the functional safety of an Overvoltage protection system for Evonik Degussa and give advices to optimize the system. Improve the method to build Markov model, calculate and analysis the results of the new model.