Application Of Predictive Control In The Boiler Control System

The boiler system is a complicated time-varying and dynamic process. It has many control loops, with obvious non-linearity, tight coupling, long time lags and strong interference. So it's hard to achieve ideal control performance and higher rater of auto-control in operation with conventional control algorithms. Based on analysis of the present situation and development trend of boiler control domestic and overseas and long-time situ experiments, application of advanced control for boiler is researched profoundly in this paper and it is proved that this method can get good regulation quality, enhance combustion efficiency and realize energy-saving, which not only has value on academic study but also has remarkable economic benefits and social benefits.In this paper, weighing generalize predictive self-tuning controller (GPC) and generalized predictive self-tuning controller with proportion and integration structure (GPPIC) are used to realize simulation of some loops in boiler system and the adaptation and robustness of two type of controller are proved. Based on the analysis of the boiler system, water level control is regarded as one loop, combustion control is divided into two loops, each is described by controlled auto-regressive integration average moving (CARIMA) model and make measurable disturbance feed-forward to eliminate its effect on controlled parameter and to reduce the interaction among loops. GPC and GPPIC are compared by simulation, which is actualized by matlab language.Simulations results have demonstrated that controllers can better realize the control for boiler and overcome to some the shortcomings of conventional algorithms. These results provide helpful experimental support for the situ realization of the two types of controller; the DCS system used in the field boiler control guarantee for safe and operation of the control system.