Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Temperature Stabilization System in the Methane Tanks of Biogas Plants E.V. LUBENTSOVA, E.V. OZHOGOVA, V.F. LUBENTSOV The article presents the results of a study of an automatic control system (ACS) for the temperature of the biogas production process with a linear PID controller and a pulse width modulator. It is noted that the creation of the required temperature conditions and their preservation at an optimal level for the process of obtaining biogas is impossible without providing heat in the bioreactors-methane tanks of the biogas plant. When designing the ACS, the scheme of substrate heating based on equipping the bioreactor with a water jacket with hot water is considered, which is the simplest heat exchange device that does not require additional measures to prepare steam under pressure and complicate the design of the bioreactor when placing heat exchange devices inside or outside the bioreactor. In the course of research, it was found that the ACS works similarly to a multi-position system with the implementation of maximum exposure at the beginning of the transition process and the implementation of a moderate pulse effect of the regulator after entering the steady state, while maintaining a set temperature value with permissible fluctuations. The practical signifi cance of the results obtained is that the constructed ACS can be used in all modes of the thermal fermentation process of the biogas plant: mesophilic, psychrophilic and thermophilic. Keywords: biogas plant, automatic temperature control system, PID controller, pulse width modulator. DOI: 10.25791/pribor.10.2023.1444 Pp. 01-07.