Similarity in numerical and experimental study of heat transfer in a model of a residential building with variable heating load

The problems related to increasing the energy efficiency of heating of premises in the construction industry are considered, which can have a tangible effect in moving towards low-carbon production. Most of the heating systems of completed construction sites in Russia have a "weather regulation" level. To ensure its correctness, it is first of all necessary to create correct digital information models (DIM) of buildings, which are created mostly on the basis of a software package (SP) — Revit, and recently — on the basis of the domestic product Renga. At the same time, the modeling results of both SPs require verification and validation. The heat engineering calculations integrated into them are performed for stationary modes of heat flow passage, whereas the heat flows of heating systems of most objects operating in automatic weather regulation mode can change several times during the day. Since at present, when the structure of enclosures is designed, their thermal inertia is not taken into account, temperature fluctuations can have a noticeable effect on the results of heat loss calculations. An expression for comparing the Fourier criterion and the thermal inertia of the enclosure of premises has been obtained, which allows for adequate assessment of the similarity of heat flows through enclosures of various designs and selection of the parameters of the characteristics of the simulated enclosures to maintain the similarity. To validate the results of the SP modeling, a full-scale model of a fragment of the building subject to numerical modeling was created and tested. The geometric and thermal characteristics of the models are given; a description of their designs and measurement methods is given. The results of full-scale studies has shown good similarity with the numerical studies. The obtained results will allow adjustments to be made to the calculations of heating systems and thermal protection of buildings, taking into account the nonstationarity of heat losses in premises due to weather regulation or climatic instability.