Solution of the Heat and Mass Transfer Problem for Soil Radiant Heating Conditions Using the Method of Finite Integral Fourier Transform

Abstract

To achieve high agricultural yields, it is essential to predict the soil temperature and moisture regime, considering the heating technology employed. The research object is soil heated by a ceiling-mounted infrared emitter. The research subject encompasses one-dimensional unsteady fields of soil moisture content and temperature. The research goal is to forecast the soil temperature and moisture regime under radiant heating conditions. The research methods involve the analytical solution of heat and mass transfer differential equations using the method of finite integral Fourier transforms. Research results indicate that the top layer of milled peat, with an initial moisture content of 3.7 kg/kg, will reach a final moisture content of 1.0 kg/kg in approximately 6 hours during infrared drying. As a result of radiant heating, the soil temperature will rise from an initial 5 ℃ to a final 22.6 ℃ in approximately 3 hours. The analytical solution of the mass transfer differential equation can be utilized for theoretical studies of drying capillary-porous materials, such as determining the drying period or the thickness of the material layer that will dry to a specified final moisture content. The analytical solution of the heat transfer differential equation, accounting for both thermal conductivity and the Dufour effect, can be employed to manage the operation of the infrared radiation source, such as determining its operational and shutdown periods when the soil surface temperature reaches its maximum (critical) value. The mathematical solutions discussed in the article do not consider thermodiffusion processes in the soil layer (Soret effect), which presents a promising direction for further scientific research.