Solution of heat and mass transfer boundary problem using the method of sources for soil radiant heating conditions

Abstract

The purpose of the research is to find, predict and regulate the temperature and humidity regime of the soil for the conditions of radiant heating of cultivation facilities using dark-type ceiling infrared emitters. A system of differential equations (in dimensional and dimensionless forms) is presented, reflecting the relationship of thermal and mass transfer processes in colloidal capillary-porous bodies in the case of surface radiant heating. A partial analytical solution of this system of differential equations for a semi-bounded body is considered with the exclusion of the phenomenon of thermal and thermal conductivity and period diffusion processes. On the example of milling peat, taking into account the initial data, the solution of the boundary value problem of heat and mass transfer by the method of sources is obtained, which is one-dimensional non-stationary fields of moisture content and temperature. It is established that under the given initial and boundary conditions, as well as taking into account the thermophysical properties of milling peat, the required moisture content will be achieved in six hours, the temperature in three hours. By adjusting the thermal power of the infrared radiation source, and, therefore, the intensity of moisture evaporation from the soil surface into the environment, it is possible to control the rate of heating and drying of the layer (for example, to determine the time or frequency of watering the soil). To clarify the values of moisture content and soil temperature by coordinate and over time, it seems expedient to consider analytical solutions that took into account not only basic, but also conjugate processes of heat and mass diffusion.