Математичне моделювання нестаціонарних теплових режимів біореактора безперервної і періодичної дії

Abstract

Abstract. The article considers the issues of increasing the efficiency of processing of livestock and crop residues for the purpose of obtaining biogas and organic fertilizers, which reduces the dependence of agricultural production from energy supply companies and enhances the environmental state of the environment. The analysis of the quality of the biogas production process is given depending on the state of methane bacteria which is very sensitive to changes in the temperature of the substrate. To control thermal processes, it is necessary to use automation systems, but for the synthesis of control systems, it is necessary to determine the dynamic characteristics of the object of automation. To develop a mathematical model, it is proposed to use a generalized structural and technological scheme of a bioreactor. The object of simulation consists of the following elements which can be represented by heat-accumulation capacities: a housing, a heat exchange tube, a substrate, a heat-carrier (in the volume of a heat-exchange tube); the capacity of the loading and unloading devices is not taken into account. An improved mathematical model of non-stationary temperature processes of a bioreactor from a substrate heating system, which consists of four differential equations in partial derivatives, and takes into account the distribution of the temperature of the flows of substrate and coolant in the direction of motion. To identify model parameters and simplified analytical research, simplified dynamics models are presented and analytical dependences of transient processes in a bioreactor are obtained. Key words: bioreactor, mathematical models, coolant, heat balance, heat exchanger