Application Research Of DCS Control System In MEG Regeneration And Recovery Process

Oil and gas is the basic raw material guarantee for industrial production.In order to guarantee the safe and steady operation of oil and gas pipelines,the anti-blocking technology of pipeline has been paid extensive attention around the world.Currently,as hydrate inhibitor,the Mono Ethylene Glycol(MEG)solution is injected into oil and gas pipelines and associated equipments,which helps to ease and suppress the congestion in the pipelines.However,the huge dissipation of the MEG can easily cause unnecessary waste.For the sake of economic and environment factors,the regeneration and recovery of MEG is of great value and significance.As the core technology of the MEG regeneration and recovery equipment is controlled by most foreign companies,it is badly in need that the domestic academic institutions and the relative enterprises research and develop the internal key structures of the equipment,and improve and perfect the process together,thus improving efficiency of the regeneration and recovery of MEG.In this paper,based on the Cameron MEG desalination system,an entire dynamic desalination system of MEG has been built indoors,which can realize the separation,recovery and reuse of MEG and salt in the MEG solution.Under the premise that the technical indicators of the field experiment equipments are sought to attain,the requirements of the corresponding instruments and equipments of the experimental facility have been analyzed,the whole technical process of the system has been designed,the control schemes of the relative equipments have been determined,and the DCS automatic control system has been constructed.The main contents of this article include the following aspects:(1)According to the characteristics and the research status of MEG regeneration and recovery system,the existing problems and the developing directions of experimental facilities have been summarized,and the research and design of technology have been completed on the basis of practical working conditions.(2)Under the premise of looking into the correlation theory and technology of MEG regeneration and recovery,the technical process designation of the experiment device system has been accomplished,and each link of the technical process has been elaborated.(3)Based on working conditions of each subsystem,the selection,verification and installation of the instruments have been fulfilled,and the specific control points and control parameters have been confirmed.What's more,the electrical safety analysis and design of the instrument wiring and system control cabinet has been carried out.(4)According to the requirements of system technical process,the detailed control scheme of the system has been determined.In addition,though the research on the speed control strategy of SRM,the modeling and simulation of SRM under Matlab/Simulink environment have been realized utilizing PID algorithm.While regulating the opening of valve,the valve flow characteristic curve under the condition that the valve and the pipeline are in series are obtained firstly according to the formula,then the best opening value of the valve can be found though observing the curve,thus achieving the control of flow rate and flow velocity.(5)Aiming at the overall control requirements of the experimental device,a DCS control system composed of monitor layer,system layer,communication layer and operation stations is built.The monitoring system,configured by configuration software,has been designed,which can realize local and remote monitoring.In order to ensure orderly and stable operation of the DCS system,real-time measurement and monitoring of the experiment system,the security design for configuration software and serial communication has been proposed.Since the elaborated DCS based MEG regeneration and recovery system was put into operation,it runs stably and has low failure rate,it's safe and reliable and has obvious overall effect,which satisfies the technological requirements of MEG regeneration and recovery completely.Furthermore,its control system is very easy to operate and maintain,which shortens the training time of the operators.This system realizes the closed and automatic control during the MEG regeneration and recovery process,and improves the recovery efficiency of MEG effectively.Because of this,the system can not only save cost,but also increase the economic benefits.