Justification of choice of the technical means of automation for safety systems
The paper deals with the design of the technical means of automation (TMA) for industrial safety systems, in particular emergency shutdown systems (ESS). The article analyzes the scientific literature and technical documentation in the field of industrial safety and automation of the process control system. The scientific and technical documentation has requires to indicators of reliability of technical means of automation, which are part of the safety system (SS), but these requirements are defined on an interval scale, and not specific enough. Due to the lack of clarity of the existing performance requirements of reliability it is necessary to develop a methodical basis to justify the selection of the automation system safety technical means that takes into account the required safety integrity level facility, the requirements of scientific and technical documentation, reliability of technological devices, technical and economic parameters of procedures implementation and maintenance of automation hardware. The paper presents a conceptual framework for solving this problem and methods of implementation the automatic protection circuit technological equipment. The idea of the method consists in the fact that from a variety of software and hardware of the SS, on which you can build circuits automatic protection, select system, for which the probability of failure (or uptime) regulatory requirements and, in addition, low costs of implementation and maintenance. The example of use of the developed methodology in selecting SS capacity in one of the processing units is did. Based on these results it is concluded that the proposed method enables the choice of the hardware part of security systems to meet the scientific and technical documentation requirements for the reliability indicators of devices, performance and reliability the technical and economic efficiency of the implementation and maintenance the automation hardware. This technique allows you to take into account the preferences of the customer in selecting the manufacturer if they are submitted in the technical specifications for the design.