Study of the influence of the configuration of a small-dimensioned fire installation on the uniformity of heating of the surface of a steel-reinforced concrete slab

Abstract

 During the design of buildings, important aspects are the guarantee of fire safety and fire resistance of building structures, which must meet today's requirements. The limits of fire resistance of reinforced concrete building structures are usually investigated by conducting tests using a standard method in special test facilities. However, the set of certain norms, rules and methods designed to ensure the reliability of measurements and the designs themselves are not perfect, so they need to be improved.The purpose of the work was to check the possibility of simulating heat and mass transfer inside the furnace chamber and analyzing the quality of the computer model during heating of steel-reinforced concrete slabs with a corrugated profile. The results were compared with experimental data.CAD software was used to create geometric models. Next, the 3-D model was imported into the CFD software package. Mathematical methods based on systems of differential equations which use continuous media of the Navier-Stokes type, heat conduction equations, under conditions of heating during a fire and Fourier heat conduction equations are used to reproduce the process of heat and mass transfer in a fire furnace. A calculation grid has been created in the computer model of the furnace chamber. The size of the cells is determined based on the principle of reasonable sufficiency.According to the obtained results, the outer surface of the corrugated ceiling profile of the steel-reinforced concrete structure was heated relatively uniformly. The higher temperature was observed in the flat parts, the lower temperature was observed in the bends. The maximum temperature on the heating surface of the load-bearing wall at the last minute of the simulation reached 840 ºС, and the average temperature at this time over the entire surface of the structure was 820 ºС. The temperature distribution on the surface of the structure is uniform, the deviation in different places of the surface does not exceed 5%.A comparison of temperature regimes in the furnace chamber during experimental studies and modeling was carried out. The results showed a sufficiently high reproducibility of the results.