The Exploitation Of Control System For Air Separation Equipment

Air separation equipment is a key auxiliary equipment of North China Petrochemical Branch Company of PetroChina (NCPBC). It supplies nitrogen gas for all equipments of NCPBC. The PLC control system of the air separation equipment supplied by Schneider-electric Company has been equipped for decades by now, so the control system has many problems, such as communication failure, computer fault and so on. These problems lead the air separation equipment to shut down frequently, and its safety and stability are threatened directly.The control software adopts 984 Ladder Diagram. Its complicated logic is difficult to understand, and it doesn't accord with IEC programming language. In this project we choose the Industrial IT distributed control system of ABB Company which is advanced, open, stable and reliable as the developing platform of software and hardware to build the air separate equipment control system, and make the control scheme more perfect than before by applying the IEC 61131-3 programming language. This paper implements the automatic process of the adsorption/regeneration recirculation of 15 control valve groups by using Sequential Function Chart (SFC) program and the program is clear and easy to understand. It implements the design of the normal monitor and control loop and the design of the safe interlocks loop of the whole equipment by using Function block diagram (FBD) program, and then completely solves the problems in the air separation equipment which have been introduced above. The application of the new control system improves the automatization level and ensures the safety of the air separation equipment.