Thermal Processes in a Biogas Plant for the Disposal of Agricultural Waste

Abstract

The article discusses the thermal processes occurring in a biogas plant in which the mixing device and the heating element are combined into one node, which allows to heat and maintain a given temperature regime more evenly due to the rotation of the heat exchanger and heat transfer to the biomass throughout the entire bioreactor. Required to operate the unit in a thermophilic mode, after its withdrawal to the working state, the heat output is determined by the heat loss of the plant itself and flow with increasing litter temperature to the temperature of the thermophilic mode, which can be described by thermodynamic equations. As a result of theoretical studies, factors have been identified that allow determining the distribution of biomass temperature over the entire volume of the digester. Studies were conducted to obtain data on the impact of the main parameters (design, kinematic and geometric) of a biogas plant and a heat exchanger-agitator on the quality indicators of its work, as well as the thermal processes occurring in it. The theoretical temperature homogeneity of the mixed medium is achieved by combining the heat exchanger and the mixing device into one node, the design and technological parameters of which characterize the intensity of the forced movement of fermented waste, changing the value of thermal conductivity, and finding the temperature field is the main task of the analytical theory of thermal conductivity applicable to the processes occurring in the bioreactor installation.