Application of the method of structural-parametric identification to determine the mathematical model of a multidimensional object with distributed parameters and delay

Abstract

Drying is one of the most responsible and energy-intensive post-harvest grain processing operations. The constant rise in heat prices has led to the search for new designs of grain dryers, or improvements to existing ones. Studies of well-known scientists such as Romankov, Rezchikov, Rashkovskaya have proven the potential effectiveness of using a fluidized bed for drying grain. The degree to which this drying efficiency approaches the potential is determined by how much the change in the actual humidity of the material during drying approaches the theoretical drying curve at the same resource consumption and the same initial state of the material to be dried. Taking into account the provisions of the theory of optimal control indicates that max-imizing the accuracy of stabilization of a given value of the height of the fluidized bed should be achieved by developing an optimal multidimensional stabilization system of the specified height. The basis for solving the first of these is the study of the design of a fluidized bed grain dryer. The decomposition of the grain dryer allows to present it in the form of a set of multidi-mensional objects with pure delay. The size of this set is determined by the number of cascades, and the dynamic characteristics of its elements depend on the distance of the cascade to the gate Δ. Automation of control and management of processes of processing and storage of grain opens wide opportunities for increase of efficiency of use, increase of productivity of current lines, further reduction of labor costs and improvement of quality of processing of grain. If today most of the known dryers have their own mathematical model, this fluidized bed dryer is new, incompletely studied and therefore needs its own mathematical description in order to develop a system of automatic control of its parameters. Therefore, this paper shows the practical application of the technique of identification of signals "input-output" of the dryer for the dispersed material of the cascade type. According to the spectral and mutual spectral densities of the signals, using the technology of structural-parametric identification, a matrix of transfer functions of the dryer was found, which is a multidimensional dynamic object with distributed parameters with delay, which is affected by various perturbing factors.