Two-layer approximated approach to heat exchange between the feed air and ventilation shaft lining

The article describes the mathematical solution of the problem on the unsteady heat exchange between the feed air, ventilation shaft lining and rock mass. The integral relations, obtained using the Laplace transforms, allow the calculation of the fed air temperature as the function of time, as well as the analyzing of the temperature variations lengthwise the tubing, concrete lining and annular space.