APPROACH TO DETERMINING BOUNDARY CONDITIONS ON THE EXTERNAL SURFACE OF THE HEIGHT CASE OF THE ADMINISTRATIVE BUILDING

Abstract

Problem statement. The influence of the external climate on the thermal regime of the enclosures of premises and buildings is complex. The calculated values and combinations of parameters are determined, as a rule, taking into account the security factor of the calculated conditions. The main indicators of the cold season are the outdoor temperature and wind speed. As you know, an increase in wind speed with a constant outside air temperature causes an increase in pressure on the windward facade of the building, as a result of which the heat loss of the room, associated with heating of the incoming air, increases. Wind speed and direction have a stronger influence on the distribution of air flows in the ventilation system and on the infiltration costs than the outside temperature. A change in the outside air temperature from −15 to −30 °С leads to the same increase in air exchange in the apartment as an increase in wind speed from 3 to 6 m/s. The purpose of the article is to determine the heat transfer coefficients on the outside of an office building. Results. The basic principles of calculating heat transfer coefficients are presented. The zoning of the premises of the Institute is proposed, taking into account their thermal regime and boundary conditions on external surfaces. Scientific novelty and practical significance. The original values of the heat transfer coefficients, which are considered on the example of the climatic conditions of the city of Kharkov for the IP Mash complex of the NAS of Ukraine. On the basis of the presented methodology for determining the heat transfer coefficients, it is planned to present this building as a single energy system with three main energetically interconnected subsystems: the energy effect of the external climate on the building envelope; energy that is contained in the building envelope, that is, in the external building envelope; energy, which is contained within the volume of the building, that is, in the internal air, internal equipment, internal structures, etc. Then the mathematical model of the building as a unified energy system will consist of three submodels: the mathematical model of the influence of the external climate on the building envelope; mathematical model of heat transfer through the building envelope; mathematical model of radiant and convective heat transfer in the premises of the building.