Study And Application Of The DCS Supervision System For The Gas Fractionation Device

Since the 1970s, the main goal of refining and petrochemical industry is stability and safety of production. Based on classical control theory, PID convention control has been widely used because it is simple and easy to understand and master. Although Optimization Control is applied in many fields at present, more than 80 percents of control circuits are implemented by PID conventional control. But this kind of production method and control level can't make the plants meet the optimum status. A plenty of latent power isn't tapped out.The production quality and the output of an enterprise of the refining and chemical industries are usually determined by fractionation process, a physical separate process that is the mostly frequently used in these industries. The fractionation device is the most energy-consuming plant in the refining industry and the fractionation process consumes about 40 percents of the whole energy consumed by the industry. What is more, the distillation will consume more and more energy along with the higher requirement of separation. Presently, the control of many industry fractionation towers is still at a level of single-loop with several parameters. However, the regular single-loop control is difficult to meet the expected control object in the case that there are obviously load change or material and energy disturbance in the process. With the fierce market competition and rapid development of the computer optimization control technology, shall tap the latent power and increase the profits. Optimization control has become an important way to modify available equipments and guarantee long term operation. An enterprise will benefit more from the improvement of the operation of fractionation tower and the decrease of the quantity of consumed production, the increase of target production energy by exploiting the distribute control system and optimization control technology.The paper discusses a gas fractionation device and JX-300XP developed by ZHEJIANG SUPCON is used for rebuilding. Some optimization control technology is applied after experimenting. Integration of Management and Control is achieved by OPC.