The decoupling multivariable control for the paper drying section

Abstract

In the line of PMs paper, the control of the paper moisture content undertaken by the drying system is an important indicator of the paper quality. The control of the drying system has four main control loops: The loop controlling hot air entering the drying section and combining with the paper moisture content control loop using saturated steam for drying paper, the dew point temperature control loop ensuring the air environment in the drying section so that the water in the paper gets enough conditions to evaporate and the air input- out put balance control loop ensuring less heat loss. In four loops, the air heating loop is relatively independent, but the three remaining loops interact with each other and affects the paper moisture content, the capacity of thermal consumption when drying. In [2],[3],[4] the authors have studied three loops separately: the moisture control, the air input – output balance control and the dew point temperature control and in [5], having studied and designed the decoupling multivariable control structure, made the reciprocal impact survey. In this paper, the authors design the decoupling control for the multivariable system to improve the quality of the paper drying system. The paper content consists of three parts: The first one summarizes the dynamics of each loop in [2],[3],[4]; The second one summarizes the decoupling multivariable control structure as well as the demand satisfaction of the system; The third one designs the decoupling control for the multivariable system.