Mixing Process Of Intelligent Decoupling Control Algorithm Research And Application

In the iron and steel factories, it is a common process that several kinds of gases which have different calorific value are mixed and then pressurized to be sent to the subsequent gas user. Whether the calorific value and pressure of the mixed gas is steady is one of the most important factors that affect the subsequent gas user's production.The control target of the mixing and pressurizing of the gas is to ensure the stability of the calorific value and pressure of the gas. To solve the coupling problem that exists between the calorific value control and pressure control, this paper presents a hybrid intelligent control strategy. This strategy partitions the whole control system into calorific value and mixing pressure decoupling control loop and gas-pressurized machine's post pressure control loop. In the former decoupling control loop, the fuzzy control and the expert control is combined to design a decoupling controller to realize the stability of the calorific value and restrain the fluctuation of the mixing pressure. In the latter pressure control loop, a two-degree-of-freedom expert control method is introduced to realize the stability of the gas-pressurized machine's post pressure.To solve the problem that the complex intelligent control strategy is very difficult to be applied in the DCS system, this paper presents a new OPC-based design method. According to this method, the intelligent control algorithm implemented by programming language seamlessly connects to the DCS software through OPC interface and access the process data. To make the OPC programming easier, this paper uses ATL to encapsulate an ActiveX control that can exchange data with any DCS system supporting the OPC specification in the world.The system has been applied in the factory. The result of real-time control shows the method obviously enhances the control accuracy, reduces the undulation of pressure and calorific value and fulfills the control target.