The Principles of Ventilation Analysis of an Operating Underground Mine Investigated Using the Thermodynamic and the Compressible Gravimetric Approaches

The principles of ventilation analysis have been based on the thermodynamic and compressible gravimetric approaches to ventilation system of an operating underground mine. Making use of this system by keeping the fields of elevation above datum, absolute static pressure, dry bulb and wet bulb temperature measured in it, and mass streams of pure dry air determined for the branches/airways - an object of investigation was developed. Ventilating air turbulent flows were treated as the one-dimensional steady ones. At both the approaches, the mentioned fields of measured ventilating air parameters as well as determined mass streams of pure dry air were used. By means of the adequate formulae and relations the calculated parameters of ventilating air in nodes/survey stations and the quantities concerning branches/airways, at thermodynamic approach refer to a mass unit of pure dry air, and at compressible gravimetric approach - to a unit of this air volume. At the first approach, ventilating air was treated as a mixture of pure dry air, water vapour and liquid water droplets and at the second one - as moist air. For both approaches the characteristics of fan station, main natural ventilating energy/pressure and resistance of ventilation system, as well as the parameters of operating points of ventilation system operation and standstill of the fan station - were presented. The paper analyses the results and gives the conclusions.