A pdf modeling method for output fiber morphology distribution of high consistency refining system

Abstract

The invention relates to a PDF modeling method for the output fiber form of the stochastic dynamic system of a high-consistency disc refiner in the pulping process based on random distribution theory and wavelet neural network, and belongs to the field of modeling and control of the stochastic dynamic system of high-consistency refining pulping in the pulping and papermaking process . The method uses the local time domain and frequency domain characteristics of the wavelet neural network intelligent modeling method and the powerful nonlinear function approximation ability, and combines the random distribution B-spline basis function approximation probability density function theory to establish the output of the high consistency refining system. A nonlinear dynamic model between the fiber morphology distribution PDF and the main input variables of the disc refiner. Compared with the previous modeling method, the method of the invention is more intuitive and stable, has high error precision, and avoids the drawbacks of strong hypothesis and poor universality of the mechanism model. At the same time, the prediction of the output PDF of the high-consistency refining system is realized, which lays a theoretical foundation and reference value for the online real-time soft measurement of the output pulp fiber form parameters of the high-consistency refiner, and also provides a basis for the tracking control and operation optimization of the output fiber form distribution PDF. Model basis.

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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