PSI - Issue 36

Anatolii Pavlenko et al. / Procedia Structural Integrity 36 (2022) 3–9 Anatolii Pavlenko, Andrii Cheilytko, Serhii Ilin, et al. / Structural Integrity Procedia 00 (2021) 000 – 000

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permeability for common thermal insulation materials was found. To measure the thermal conductivity of granular and powder materials, it is best to use finite element method.

Fig. 2. Composite insulation material of flexible ceramic fabric and thin basalt sheet.

After the experiments, the geometric characteristics of the porous structure and the thermal permeability of the porous insulation materials were determined. The results of the experiments are listed in Table 1. The use of these characteristics allows to determine the effective thermal conductivity of any porous structure knowing the material thermal conductivity and geometric characteristics of the porous structure. The results for the materials that were not introduced here are the model results. The research results shown in the table (G 0 C 1 and G 0 C 2 ) differ from each other by integration constants. Thus, the developed technique allows to reduce the complexity of work in determining the effective coefficient of thermal conductivity of porous structures. The error of the method is less than 8.5 % (according to the results in the table).

Table 1. Porous constructions characteristics and thermal permeability of porous thermal insulation materials Porous material   G   1 O G C , W/(m 2 ·К) 2 O G C , W/(m 2 ·К) Composite material developed П=70% 0.402 0.235 104.71 Composite material developed П=50% 0.402 0.158 68.75 Composite material developed П=30% 0.402 0.057 24.89 Foam concrete 0.434 0 0 Foam-pumice concrete 0.388 0.011 17.35 Aerated concrete 0.681 0 0 Empty brick 0.824 0 0 Empty brick void 22% 0.824 0,189 81.24 Empty brick void 40% 0.824 0.273 116.18 Shellfish Chamotte brick Thermal insulation ISOVER Mineral wool 0.712 0.871 0.482 0.473 0 0 0.162 0.188 0 0 68.24 72.39

The geometric characteristics of the porous structure and the thermal permeability of fourteen porous materials widely used in construction were found. Therefore, a calculated model of thermal energy transfer through porous constructions was developed, which allowed to reduce the complexity of work in determining the effective coefficient of thermal conductivity of porous structures.