Moscow, Russian Federation
The paper considers the depth of penetration of electromagnetic fields into materials as a function of frequency. The author discusses the works on mathematical modelling of electromagnetic heating and drying of materials in the infrared and ultra-high frequency ranges. The article indicates the advantages and disadvantages of analytical and numerical methods for solving problems of electromagnetic product heating. It is noted that the electromagnetic heating of moist building materials is often accompanied by evaporation of moisture. It should be taken into account in the mathematical modelling of their electromagnetic heating process. Futher the article highlights the role of heat treatment of concrete, which has become an important stage of the technological process of building materials production. The electro-thermal treatment of reinforced concrete products and electromagnetic heating methods in different frequency ranges are relevant. The article presents the analytical mathematical model of electromagnetic heating of a plate under the influence of a radiation flux penetrating the body according to Booger's law. It takes into account the heat flow to the evaporation of moisture occurring at the surface of the plate, and its convective heat and mass exchange with the external gas medium. We analyse the model for consistency with the real process under infra - red heating conditions by comparing calculated and experimental thermograms. Its relevance to the real process is shown. The author shows the possibility of selecting the required electromagnetic heating process mode by means of numerical computer analysis. The mathematical model considered is recommended for practical application in building technology.
electromagnetic heating, building mate rials, mathematical modeling, heating dynamics
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