Design And Implement Of Flare Monitoring System Based On PLC

In the petrochemical enterprises, lots of inflammable and explosive gases would be produced in normal operation, accidents and emergencies. Flare system is aimed to deal with these dangerous gases. On one hand, the gases generally can be recycled by the flare system, to reduce energy consumption and emissions. On the other hand, in order to ensure the process unit safety in the whole plant, the gases produced in accidents or can not be recycled, can be burned by the flare system.In this thesis, PLC is applied in the flare system of a petrochemical plant. The design of flare system is given to monitor the external gases and recycling. Hardware design of the system involves the selection of PLC and control cabinet, types of hardwares, quantity of the cards, network building and computers configuration etc. Most hardwares of the system are the products of Siemens, for example, PLC of the series of S7-400H, distributed I/O of ET200iSP and ET200M. Layout drawings and schematic diagrams of control cabinets are completed and all the cabinets have be installed and tested. Besides, the entire network architecture of the whole control system is constructed with the hardware and network configuration. System software is developed using the PCS 7 of Siemens, where the graphical programming of all monitor points is implemented with the CFC configuration tool and the monitor screen of all supervisory computers with the WinCC configuration tool.The whole control system have already been constructed smoothly and put into operation. The master station in control room and all sub-stations in the field run stably. The function requirements of real-time monitoring and control of flare system in control room, is totally satisfied, and the safety of production equipments is ensured in whole plant.