| A mine ventilation system is a complex network of airways in which natural ventilation drafts of a certain strength are usually present. A thermal disturbance such as a mine fire can significantly change the distribution of natural ventilation pressures and affect the ventilation in the whole system accordingly, causing fumes to propagate in a pattern difficult to predict, especially when a quantitative analysis is pursued.;The goal of the dissertation is to perform a theoretical analysis on transient mine ventilation under the influence of thermal disturbances. Mathematical models of heat transfer are set up for the energy balance of airflow along airways. The processes of water evaporation and vapor condensation are also analytically evaluated. Together with suitable ventilation network calculation techniques, they are integrated into computer simulation program MFIRE, which can predict temperature, airflow, fume/methane concentration, humidity distributions throughout a mining system at any moment of time based on a set of user specified initial conditions. A theoretical model for mine fires is also completed, leading to the development of computer program PIPEFIRE that reveals effect of the interactions among significant factors in mine fires.;The achievement from this research showed its practical significance. The resulted computer programs are powerful tools for emergency planning of mine ventilation, fire fighting and ventilation analyses on difficult problems. |
