Applying Of Cascade-control To Vacuum Tower Of Distillation And Vacuum Unit

Control of industry process of Refinery develops rapidly; Common control becomes complicated and advanced to meet the market demand for high quality of oil products. Pneumatic instruments develop into electric instruments or intelligent digital instruments.The thesis introduces development of control system of distillation and vacuum unit of TPCC Refinery. First it analyzes the process of distillation and vacuum unit and its development of control system,second analyzes the structure and control principle of ABB Advant 500 control system,discusses how to do in ABB Advant 500 by cascade-system;such as the cascade-system of tower top temperature and top back-flow of vacuum unit of distillation and vacuum unit of TPCC refinery,study the model of its control system by SIMULINK imitator,and by comparing the imitating data and the unit data,the advantages are revealed:1. By the rapid action of auxiliary circuit, the disturbance in auxiliary circuit is corrected by auxiliary controller before affects the main parameter.2. The cascade-system has better Robust for changes of auxiliary parameter and character of controller.Cascade-system is used in the temperature control of distillation and vacuum unit, the result is very clear, the yield rate develops 1.92%.