Design And Implementation Of Advanced Control Strategy For Cement Calcination Process

The cement calcination process is the most important processes in the cement factory.It turns raw materials into clinker by means of preheating,decomposing,calcinating and cooling.Due to multivariable strong-coupled nature and big pure time delay of the cement calcination process,it is difficult to obtain satisfactory control effect by using conventional control strategy.In order to improve the control quality of the cement calcination process and the efficiency of energy saving,an advanced control strategy for the cement calcination process based on field research is designed and implemented in this dissertation.The main work of this dissertation is as follows:1.According to multivariable strong-coupled nature of the cement calcination process,an advanced control structure which includes the parameter optimization module and a two-layer control scheme:the basic advanced control layer and the parameter adjusting layer,has been designed.The basic advanced control layer is designed for the purpose of improving control performance of key variables.The parameter adjusting layer is designed for optimization of benchmark set points and comprehensive adjustment of set points.2.The basic advanced control layer has been desighed and implemented.The great cooler clinker thickness control loop,whose controlled plant is selected between 2nd wind chamber pressure and current of G11 fan,has been implemented by using PID control algorithm.The decomposing furnace temperature control loop,whose controlled plant is selected between decomposing furnace outlet temperature and 5th preheater outlet temperature,has been implemented by using stair-like generalized predictive control algorithm.The rotary kiln coal feeding control loop has been implemented by using PID control algorithm.3.A rotary kiln current model has been established by using neural network.Then benchmark set points of the basic advanced control layer have been obtained by the parameter optimization module which is implemented by particle swarm optimization algorithm,and adjusted by parameter adjusting layer which is designed and implemented by using adaptive fuzzy control algorithm.4.An advanced control system for the cement calcination process has been designed and implemented.A hardware platform of the advanced control system has been establishen.The graph user interface,the data communication module and the core function module of the advanced control system software has completed.Then the system has been applied.Implement result has shown that control performance of key variables and efficiency of energy saving is clearly improved.