Structural and parametric identification of the model for the process of obtaining hop extract at the rotary pulsation machine

摘要

Wort hopping in a traditional way requires large energy, time, and raw material expenditure. The authors suggest a new way of beer wort hopping which allows using raw plant material more effectively, intensifying the process, and reducing power consumption. The method entails beer wort hopping with hop extract obtained in the rotary pulsation machine (RPM). Hop extract has a higher content of isohumulone- the main component of bitter substances in the hopped wort. Mathematical modeling of technological processes in RPM will allow obtaining the best results of isohumulone extraction. Despite the existing research, reliable measurement of the processes in RPM kinetics remains vague and understudied; therefore, the issues of dynamic processes modeling in RPM are of current interest. This paper introduces the unconventional algorithmic apparatus of continued fractions in the structural and parametric identification of the technological process, which allowed building a dynamic model of obtaining hop extract with a minimum amount of experimental data and no a priori information. The experimental data for the process of obtaining hop extract were found to approximate with acceleration characteristics of the aperiodic link of the first order with variable coefficients. The models allowed choosing the optimal technological parameters within the given limits for the treated medium, at which the isohumulone output is maximum. Modeling errors are 0.6%-6%, which is acceptable for engineering calculations (＜10%). The suggested approach does not require selecting trial models or making numerous measurements.