This paper describes fundamental studies on numerical prediction system related to air temperature and humidity of underground airways and shafts that are in dry and wet conditions.
The mathematical model including angle of inclined airways, heat and mass transfer at rock surface of airway and phase change of water vapor to fog is presented. The quasi three dimensional finite difference model was used for numerical calculations of rock temperature. The wetness was used to express the degree of wet condition of the rock surface.
The prediction calculations about the variations of air flow temperature and humidity along the dry and wet airways have been carried out. The air flow temperature of inlet side is affected by the wet condition and inclined angle of airway. The air temperature in the exhaust shaft has tendency to be kept a constant temperature by the latent heat released by the phase change of water vapor. The amount of fog in airflow of the exhaust shaft is presented.
Finally, the practical equations (33) and (37) to predict air temperature of the dry airways and shafts are presented on the basis of results by the finite difference calculations.
