Авторы: Trofimov V.O., Kavera O.L., Zemlianska L.V.
Перевод с русского: Zemlianska L.V.
Источник: Статья былы написана для IV Международной конференции студентов факультета геохтехнологий и управления производством 16 апреля 2009 г.

Ventilation (aerodynamic) parameters of mining enterprise underground part have a hierarchical structure. Its determination allows to set priority of calculation and control of aerodynamic parameters of separate parts of a mine ventilation network.

Most general are ventilation parameters of main fan network, because a fan is disposed (in most cases) on a "border" between the underground part of mine and the ground surface.
The fan discharge duct, ways of air inleakage from the ground surface to the discharge duct (external offence) and mine ventilation network can be referred to main component parts of fan network(in the case of suction method of mine ventilation).

Mine ventilation network consists of all underground ways of air motion,i.e. workings, ways of inner venting and workings connections. It is reputed that the places of "connection" of shafts with the ground surface on the one side and connection of a venting shaft with fan duct belong to the "borders" of mine network.

The further division of mine ventilation network into separate parts (structure of network underground part) depends on mine ventilation scheme. These can be mine-take wings, sections, dip-working panels or incline districts. Within the boundaries of these parts of mine ventilation network it is possible to distinguish separate areas with drift ways or development headings.
The concept "ventilation district" is sometimes used during measurements or calculations. It differs from the abovementioned structural units of a ventilation network. Ventilation district is a separate part of mine ventilation network , which is connected with a network only in two points (joints).
Ways of air motion (branches-workings) between the two nearest connections and connections(joints-connections) belong to elementary (such, that are not divided farther) parts of a ventilation network. So, a mine ventilation system, presented in the form of ventilation network, consists only of branches-workings and joints-connections.
Ventilation connections appertain to the normalized units of a ventilation network. Sequential, parallel, diagonal and combined connections can consist both of the separate workings and of separate ventilation sites.

In accordance with the enumerated parts of a mine ventilation network, each of them is characterized by aerodynamic parameters: static pressure (h), air rate (Q) and resistance to air motion (R). These three parameters are united by the law of aerodynamic resistance [1]

h = RQ² (1)

R parameter requires clarification. A general concept "resistance" showed be distinguished from a concept "aerodynamic resistance". Aerodynamic resistance includes: resistance of air friction on walls of workings, local resistance (turns of workings, narrowing and widening of working cross section, connections of workings) and head resistances (equipment and transport vehicles which partially pack working cross section).

However dynamic factors(natural ventilating pressure, water and coal falling in inclined workings and drift way, traffic flow) influence air distribution along workings. In emergency for mitigation of the incident different devices are used which also influence air distribution in a ventilating network. The term "active" means that these factors not only influence air distributing, but can change direction of ventilation stream in the separate workings or parts of mine network.

Active factors do not influence directly aerodynamic resistance, i.e. coefficient of working aerodynamic resistance, but their action can look as decrease or increase of resistance of a separate working or a part of a ventilation network. In theory activity of separate factors can be showed (if it is necessary to detach influence of separate factors on air distributing in a network) by dint of special activated characteristics [2]. Such characteristic takes into account the action of a separate draught source in a working or a ventilation connection.

Thus, a concept "aerodynamic resistance" can be used only for the separate workings, their parts and ventilation connections, which do not contain the "active" initiator of air motion. If in the aggregate of workings which are considered, some initiator of air motion (except the main fan) operates, more general concept of resistance shoud be used working resistance, network resistance, resistance of ventilation area, et cetera. Such division enables to separate and show (visualize by means of graphical method) the influence of a separate initiator of air motion on air distributing, in the cases when a few artificial and natural initiators of air motion operate in the network. Accordingly,aerodynamic and activated characteristics of working ought to be distinguished(those of ventilation area, ventilation connection, network).

Thus, every separate part of a ventilation network can be characterized by corresponding parameters,which enables to generalize recommendations on increasing ventilation efficiency in these parts of mine and to understand the picularities of mine ventilation network construction.