Output fiber form distribution PDF modeling method for high consistency refining system

Abstract

The invention relates to an output fiber form distribution PDF modeling method for a random dynamic system of a high consistency disc refiner in the pulping process and based on a random distribution theory and a wavelet neural network, and belongs to the field of modeling and control of the random dynamic system of the high consistency disc refiner in the pulping and papermaking process. According to the method, the partial time domain and the frequency domain characteristics and the powerful nonlinear function approximation performance of an intelligent wavelet neural network modeling method are utilized, the random distribution B-spline basic function approximation probability density function theory is also considered, and therefore a nonlinear dynamic model between the output fiber form distribution PDF of the high consistency refining system and the main input variable of a disc refiner is established. Compared with a prior modeling method, the method is more vivid and stable, the error precision is high, and the defects that a mechanism model is high in theoretisch and poor in universality are overcome. Meanwhile, the prediction of the output PDF of the high consistency refining system is achieved, a theoretical basis and reference value are laid for online real-time soft measurement of output pulp fiber form parameters of the high consistency refiner, and a model fo0undation is also provided for tracking control and operation optimization of the output fiber form distribution PDF.

Description

technical field [0001] The invention belongs to the technical field of high-consistency refining stochastic dynamic system modeling and control in the pulping and papermaking process, and in particular relates to a PDF (probability density function) modeling method for output fiber form distribution of a high-consistency refining system. Background technique [0002] The paper industry is closely related to the development of the national economy and social civilization. The consumption level of paper and cardboard is one of the important symbols to measure the degree of modernization and civilization of a country. The whole papermaking process consists of two major links: pulping and papermaking. The main function of the pulping link is to produce fibers with specific shapes from plant fiber raw materials; the main function of the papermaking link is to use fibers of specific shapes as raw materials to produce various paper products. Pulping and papermaking both need to co...

AI Technical Summary

Problems solved by technology

However, the shape distribution of the beating output fiber of the disc refiner does not conform to the Gaussian distribution, which is random, and the probability density function of its distribution cannot be modeled and controlled by the variance and mean.

The main reason is that the fiber bundles are gradually dissociated into single fibers through the horizontal extrusion and longitudinal brooming of the grinding disc, and the output fiber shape is very random and uncertain. Characterized by a single variable, which makes modeling and controlling fiber morphology extremely difficult

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