Method for evaluating functional safety of safety instrument system

Abstract

The invention relates to a method for evaluating the functional safety of a safety instrument system, belonging to the technical field of functional safety of safety instrument systems. The invention aims at reliably simulating and monitoring the safety instrument system, evaluating the functional safety and studying the variation condition of common cause failure of the safety instrument system. The method comprises the following steps of: controlling the functional safety of a controlled system by a safety instrument system; analyzing the initial risk of the safety instrument system and determining the grade of safety integrity; verifying whether the safety instrument system reaches the determined grade of safety integrity; changing the constituting structures or devices of the safety instrument system; and repeating the above steps. In the technical scheme, the constituting structures or devices of the safety instrument system can be changed according to the studied specific condition to adapt for different application environments and requirements, and the variation condition of the common cause failure characteristic of the safety instrument system can be analyzed under different circumferences so as to provide important basis for studying the topic of common cause failure.

Description

technical field [0001] The invention relates to the technical field of functional safety of safety instrumented systems, in particular to a method for evaluating the functional safety of safety instrumented systems. Background technique [0002] The safety instrumented system (Safety Instrumented System-SIS) is responsible for monitoring safety-related state parameters in the production process, and taking timely measures to prevent accidents when dangerous conditions such as faults or abnormalities are found. Used in petroleum, chemical and other process industries. Therefore, the safety performance of the safety instrumented system is directly related to the safety control and safety protection level of various hazard sources and complete equipment, and then directly related to the safety production level. For example: when the boiler pressure reaches a certain value, the valve will automatically open, when the dangerous gas in the mine reaches a certain level, it will al...

AI Technical Summary

Problems solved by technology

The safety instrumented system designed in this way may be over-protected or under-protected. Over-protection will cause waste of cost, and under-protection will make the risk unacceptable. In addition, due to its own structure, hardware, software and surrounding environment, etc., the safety instrumented system will Inevitably there are security issues; moreover, whether the safety instrumented system can still meet the requirements of safety and economical rationality after installation or operation for many years and after modification, these issues have become restrictions on modern important industrial fields, especially safety The bottleneck of large-scale application in related fields, therefore, there is an urgent need to study the functional safety related technologies of safety instrumented systems, especially the change characteristics of common cause effects of safety instrumented systems, as a key factor affecting system performance, common cause effects The change characteristics of is a very important topic in the field of functional safety research

Images