DMC Algorithm And GPC Decoupling Design’s Application In Three Benzene Distillation Units Of The Continuous Reforming Device

This issue is based on catalytic reforming device technology project from apetrochemical enterprise. Along with our country’s petro-chemical ability increasingceaselessly, oil resources has become the main factor in restricting the development ofprocessing industry. So how to obtain better quality products and greater benefit fromthe limited resources is to become areas of focus in petrochemical industry, and to usereasonable process control technology and advanced equipment to monitor catalyticreforming process in refinery is an effective means.This paper introduces the technological process of catalytic reforming unit,giving a detailed analysis for unit relation among variables of three benzene distillation,putting forward the improvement scheme for technology problems of existing unit, andtest the modified and control effect for the unit with the help of model predictive controlalgorithm.Because three benzene distillation units is a non minimum phase systemcharacteristic of interfering with complex, frequent disturbance, and difficult to controland build direct process model.This paper use petrochemical process control algorithm--DMC predictive controlalgorithm, the algorithm takes the object unit step response as process model, use theforecast, rolling optimization and feedback correction to implement optimization controlfor control object, solves the contradiction between the feedback and optimization, andrealize the union of open-loop control and closed-loop control, enhances the robustnessof the system, and can achieve the real-time solution to matrix model. The datameasured in the actual process is simulated in the DMCplus environment, verifyingthe validity of the algorithm. Since three benzene distillation units is a multiple input multiple output, andvariable strong coupling relation of the unit system. The paper gives GPC design forunit based on CARIMA. In order to simple calculation, prevent decentralized control,cumbersome and defects of decoupling control, the paper uses unique decouplingfunction of implicit algorithm GPC, reaching the intermediate calculation of lessparameters, on-line short calculation effect through the performance index to controlweight restrictions and the introduce of control weight matrix. The data obtained in thepractical process is simulated in the MATLAB environment, verifying the validity of thealgorithm.