THERMAL BALANCE OF THE AIR SOLAR COLLECTOR IN THE NATURAL VENTILATION SYSTEM OF THE COWSHED

Abstract

The urgency of the problem is due to the need to form the required microclimate in livestock premises in the conditions of import substitution of expensive and quickly worn-out curtain systems of natural ventilation. One of the ways to improve such systems for cattle premises is the use of air solar collectors in the form of ventilation and heating panels instead of curtains. Such a system provides not only ventilation of the livestock premises, but also heating of the supply air entering it. The assessment of the thermal characteristics of an air solar collector, taking into account the variables of external environmental factors, is based on taking into account the temperature of its heat-receiving surface during the day. This dependence connects variable external environmental factors with the design and technological parameters of an air solar collector, which allows modeling its heating capacity depending on various external conditions. Based on the thermal balance of the air solar collector, a first-order differential equation in the form of the Cauchy problem is obtained. As a result of its solution, the dependence of the temperature of the heat-receiving surface of the air solar collector on the time of its operation under conditions of variable external factors is found. At the same time, assumptions are made that the density of the solar energy flow has a quadratic dependence on the time of day, and the temperature of the heated air is directly proportional to the temperature of the heat-receiving surface of the air solar collector. The resulting expression makes it possible to predict the output thermal characteristics of the natural ventilation system.