Temperature and humidity of cooled air in mining galleries with direct ventilation

Taking into account the possibilities of condensation of water vapour contained in air during its flow through a series of spot coolers as well as formation of eventual fog, a mathematical model of dynamic temperature, specific humidity and degree of fogging of cooled air in underground mining galleries with direct ventilation is developed. In the gallery, there situated various heat and moisture sources both of distributive and of concentrated types. The model is represented by three partial differential equations of first order. The cases of cooling with full as well as with partial air stream flowing through the gallery are distinguished. Owing to the fact that in practical designing, more important is the knowledge of the variation process of temperature, specific humidity and fogging of cooled mine air at steady state conditions, the model is modified to a set of three nonlinear ordinary differential equations. Based on the presented algorithm, the obtained set of ordinary differential equations is numerically solved which enables to: specify the distribution of temperature, specific humidity, relative humidity and degree of fogging of cooled air in mining galleries; determine the cooling powers of air coolers for their known locations; indicate the locations of the coolers of known cooling powers. Exemplary calculations of temperature and relative humidity of cooled air are presented graphically in a number of diagrams.