Engineering Design Of Automatic Control System Of 1000x10～4t/a Atmospheric Distillation And High Vacuum Unit Of Dalian Petrochemical Corp.

Comparing demestic crude distillation units and high vacuum units with the same units of overseas big refineries,the scale is smaller, the process technology is more behindhand,the control strategies is simplier,the automatic level is more behind, and the energy wastage is more.The basic design package of the 1000X104t/a crude distillation unit and high vacuum unit of petrochina dalian petrochemical co.was bought from Shell Global Solution International, and the engineering design had finished by luoyang petrochemical engineering corporation. It is the largest in scale and the best advanced in automation around china. The paper introduces the process principle , process flow and technical characteristics of the unit. The author had established perfect control strategies and emergency shutdown strategies for the first time by applying the correlative knowledge and as well as the requirement of the package. These advanced control strategies include: the selected control formed by the balanced control of heat exchange of branch flows and the pressure control and pretection of the desalting vessel; the temperture and flow balanced control formed by the outlet temperture control and inlet flow control of no.1 pumparound oil exchanger of the atmospheric distillation unit; the automatic balanced control of the branch flows of the atmospheric furnace inlet; the temperture control of the atmospheric furnace outlet;the difference pressure control of fuel oil and atomized steam and flow control of fuel oil;the automatic backward-wash of desalting vessel etc. The emergency shutdown strategies include: the interlock exhaust of the dry gas from the top of drying tower; the interlock exhaust of the dry gas from the top of high vaccum tower ; the interlock of the important levels etc. The automatic ignition and interlock pretection strategies of the furnaces include:the blowing of the furnace hearth;automatic ignition;startup of burner;the interlock of blower and burner etc. The author drawn the piping and instrument diagrams (ab. P&ID) and instruments cables layouts diagrams and signals conection diagrams of all control systems by AutoCAD; calculated and chose all measurement instruments and control valves and shutdown valves. chose installation and tracing and insulating schemes of field instruments, participated in the configuration of DCS and SIS and BMS and F&GS. Instructed the installation of field instruments and start of the unit. By application of this automatic control system, The unit runs well. It not only reduces the operator's burden, but also increases the equipment's stability. The unit had successfully put into production in march 2006,the unit is all right.All parameters achieved the requirement of design.It keeps ahead in china and the automatic level is advanced in world.