The Thermodynamic Approach to Safety State Assessment of a Complex Diagonal Ventilation System of a Deep Colliery During the Phase of Self-Heating of Coal Called the Point of Fire Hazard

摘要

Mine air was treated as pure dry air (a pure substance), while its slow turbulent flows - as one-dimensional steady ones with heat exchange. Input data were presented pertaining to nodes, airways and meshes of a diagonal complex ventilation system of a deep colliery. Output data were determined pertaining to resultant airways, outer and inner meshes of three topological structures of this ventilation system. Significant properties of these structures were determined using two-mesh closed canonical diagrams of the ventilation system. The main mesh of these diagrams contains outer and inner meshes having common resultant airway b. For each of the topological structures mesh equations were presented. Starting from these equations the following was derived: the condition for preservation of original (straight) direction of air stream flow in the mentioned resultant airway b, the safety degree and its value; the streams mass of pure dry air in closed canonical diagrams of ventilation system. Starting from the obtained aerodynamic resistances of airways of the ventilation system, the total resistances and equivalent orifices of the topological structures were calculated. The discussion of the results was given.