The DCS Control System Is Designed For LNG Pretreatment Processes

In recent years, Chinese energy shortages are worsening. How to improve the efficient use of energy is much more important. However, the current efficiency in the use of coke exhaust gas is low, it is a waste of non-renewable energy, LNG liquefied natural gas project which is one of the demonstrations of Shanxi Province projects as an attempt is the efficient use of coke exhaust gas, its successful operation provides a new way for the efficient utilization of coke exhaust gas.In china, it is also a new technology that making liquefied natural gas from coke oven exhaust gas, so when designing the control systems of the project, there is not the similar project that can be referred to.DCS control system is a kind of distributed computer control system,incorporating computer application technology, network communication and course control technology. Adopted in LNG project, DCS control system can control and monitor the whole process of technology, meanwhile, complete system diagnosed, the function of maintaining and control. Make production more convenient and efficient.Based on the analysis of process of this technology and the current state of process control system, completed the design of control scheme and the selection of control system. After analyzing the traditional control scheme of pretreatment, finds out the defect of scheme and proposes an improved feedback control scheme. Then complete the design of hardware, especially the design of control station, communication network, configuration of control cabinet and profibus-dp. And then realizes the design of software program, including single device programs and process procedures programs. Ultimately through the installation and commissioning the project is put into operation successfully.Under the production technique and the security and reliability of premise which in the process of the liquefied natural gas project, the goal of the paper is to put the Distributed Control System with mature thought of controlling and advanced controlling theory into the produced process which from the selecting of the controlling systems to the success operation, ensure the liquefied natural gas project control system is safe, reliable and stable operation, and then the project is successful. Also a new method is provided for the design of control system in the similar coal chemical products.