Energy-saving automated system for microclimate in agricultural premises with utilization of ventilation air

Abstract

Agricultural production is a large consumer of thermal energy for various processes. Heat is necessary to maintain the microclimate on livestock farms in the cold season. Previous studies have reported that heat recovery of ventilation air can reduce thermal energy consumption by up to 40–60%. However, most of these studies were retrospective and descriptive in nature and they did not take into account the peculiarities of agricultural production technologies. The energy-saving method of microclimate support for livestock farms of a decentralized type is described. It is based on the principles of exhaust air heat recovery, ozonation and deep air recirculation. The article deals with the structural and technological schemes of the ventilation-heating device implementing this method. The main statements of calculation methods including the thermal-power, electrical and structural calculations are described. Polyethylene terephthalate film is used as heat exchange surface. The design constant of the heat exchanger is 180 W/°C. Exergy efficiency for the heat exchanger equal to 0.48 relative units. An expression was obtained to determine the convective heat transfer coefficient in the electric supply air heater. Corona discharge ozonator is used for purification and disinfection of circulating air. The experimental stand is used for automated registration, transfer, processing and storage of data. The results of experiments confirming the energy efficiency of the electrothermal installation are reflected on the charts. The implementation of the described method provides reduction of energy consumption up to 55%.