The Design Of ESD System In 76,000,000 Nm~3/a Liquefied Natural Gas Project

With the development of modern industry and the "people oriented" ideas are slowly filtering into people's minds, production equipment and personnel security requirements are also stepping up. Emergency Shut Down System (ESD) now has been widely used in petrochemical industry, metallurgy, electric power and other industries. ESD system started from the 70s of last century. At first, ESD used conventional instruments and relays to generate interlock logic, now it is based on integrated circuits and it is mature, reliable, completely independent from control system. Many foreign manufacturers, such as the USA companies TRICONEX and ICS, Germany HIMA and Siemens had developed their own ESD system.ESD system is independent from distributed control system (DCS) and has a higher security level. Usually, ESD system automatically monitor the produc-tion process in real-time. Whenever the device is in an emergency situation, the ESD can directly generate a protection interlock signal to protect the craft process or emergency stop without DCS , so that the production facilities can response and be protected in time and the craft process can stop in a predeter-mined condition, the risk can be reduced to an acceptable level. It has become an important part of automation in Chemical industry.This paper describes the characteristic of ESD system, illustrate the neces-sary of ESD system in the petrochemical industry. Comparing several kinds of fault-tolerant and vote ways,probing into design methods and principle of ESD, introducing main foreign ESD standard and producers and their system. Proceed from angle of craft, decide the amount of analog and digital quantity, finish the systematic type select and interlock logic, using Germany HIMA Company's ESD system-HIMatrix system, introducing their technology from hardware con-figuration, logic programming, configuration of software and debug in detail separately.This system finishes designing tentatively at the end of June of 2009, en-tering the stage of taking a trial run at the end of December. The systematic op-eration conditions are good at present, it can finish realizing the apparatus of craft is required, playing a role in protecting the production equipment and pro-duction technology.At present, ESD system have been applied in all chemical big aircrew in-terlock or craft of enterprise extensively. This project find a new way to utilize the coke oven gas,the successful design of ESD system in this project can offer reference and guidance for design and transformation of similar project.