The abstract on a theme of final work

Goals and tasks of the master's work

The purpose of master's work is a study of local reversing the ventilation during the fires in mines in the conditions of mine Yuzhnodonbasskaya № 1.

In this work the following tasks are solved:

development of a computer model of a mine ventilation network;
calculation of normal and emergency air distribution;
determination of the places for possible tipping air flow (change of direction of air movement in the making);
allocation of zones of carbonating and cover the order of closing the doors open and the path of movement of people;
an assessment is made of the sustainability of the upward and downward ventilation ventilation workings in the fires;
development of measures to improve the sustainability of airing of mines;
determination of the places where the most effective use of local illumination.

Relevance of the work of

In accordance with the Rules of safety in coal mines [1] in the mines of Ukraine provides for the use of local illumination by fires in individual mines is mines.

The purpose of the local reversing - the shortest way to withdraw fire gases from the burning of development in outgoing flow, without violating the regime airing of the other sections of mines; to create conditions for the miners to exit emergency workings, and горноспасателям for intelligence; to prevent the spread of fire on the mountain manufactures by establishing water curtain, the construction of bridges, etc.; to ensure the possibility of approach rescuers to the site of fire and to create conditions for the effective application of various means of fire fighting.

Local reversing the ventilation jets are invited to apply in the plans of liquidation of accidents to create the most favorable conditions of exit of people, caught in a mine fire and to extinguish fires [2].

Procedure for determining the capacity of local reversing the ventilation jets

To determine the capacity of local reversing the ventilation stream should:

identify whether the branch (division of developing between the two nodes of the network), in which there was a fire, or branches, in which are the products of combustion, diagonals (generation, for which the air when you change the resistance certain branches of the network can change the direction of motion in the opposite direction);
determine the branches, of which you want to change;
set the minimum required flow rate of air in mines (if there is a need for safety);
calculate how should change the resistance of the branches, to ensure the rollover air jet with the necessary flow;
to determine the sequence of change of resistance of the branches network, which ensures the safety of the people performing the ventilation maneuver;
check experimentally in terms of mine scheduled ventilation mode.

The definition of the fundamental possibility of local illumination

Local reversing possible in the presence of mine network diagonals. When their presence is recommended to be guided by the following rule: if the traffic from the network to the end you can go to any branch, is not going twice in one and the same unit, in the direction opposite to the movement of air, the production is diagonal. For example, from the beginning of the network (point 1, see figure 1) to the end (point 6) you can go the route 1–2–3–4–5–6. In the first case, the motion is carried out in the direction opposite to the movement of air, through the branches of 4–5 and 2–4, is not going twice in one and the same unit, in other cases - by the branches of 4–3. Then the branches 2–4, 4–5 and 4–2 are diagonals. Thus, presented on Fig.1 scheme allows local reversing ventilation streams only in three branches: 2–4, 4–5 and 4–3.

Fig.1. Scheme of the excavation of the site: 1–6 – the number of the units of the scheme

The greatest influence on the direction of movement of the air in the diagonal, for example, 4–5, have branches, forming together with her two circuits (Fig.1). The contour of the first forms together with a diagonal of 4–5 branches 1–2, 2–4, 1–5, the second – branches 4–3, 3–6, 5–6. Both circuits are diagonal connections. Point 1 is the starting point of connection, point 6 – the final.

For measurement of direction of air movement in the diagonal 4–5 need to vent pressure at point 5 was more than in point 4. Depression diagonal is equal to 4–5

where h₀ – general depression diagonal connections, PA;
h₁ – depression branches of 1–5, included in the outline of one, PA;
h₂ – depression branches 4–3 and 3–6, included in the contour of the two, PA.

The implementation of the local reverse may hinder the natural bent or thermal depression fire. Therefore, it is necessary to strive to ensure that depression diagonal maximum, which is achieved by reduction of values of h1 and h2. Depression h1 is determined by the equation:

where R_1–5 – resistance branches of 1–5, N*C2/M8;
, – air consumption respectively in the diagonal 4–5 and in the branches of 5–6, m3/c.

Out of the equation shows that the reduction of depression should be maximally reduce the aerodynamic resistance of the branches of 1–5 and air consumption in branches of 5–6. Decrease of the resistance is achieved, as a rule, the ventilation opening of the doors, the reduction of air flow – installation of jumpers or the closing of fire doors.

Similarly, the factors that determine the depression h₂. In order to reduce its value, should be reduced resistance branches 4–3 and 3–6, as well as the flow of air in them. The latter is achieved jumper in the branches of 2–4 and 2–3.

From the formula h_д of definition it is clear that depression diagonal can be no more depression diagonal connections. Therefore, in all cases, you should strive to increase the latter. This is achieved by increasing the depression of the fan of the main airing or restriction of the supply of air to the other panel.

In carrying out local reversing ventilation streams should also take into account the magnitude and direction of natural draught and heat depression fire, as well as methane abundance workings.

The requirements of the Rules of Safety (SGS) for air handling units

The requirements of the Rules of Safety (SGS) for ventilation devices:

to prevent short-circuit ventilation streams and ensure the reversal must be installed gateways and deaf jumpers. The design of gateways must prevent the simultaneous opening of the door.
gateways, installed in mines, which connects the trunks, as well as designed to prevent shorting of ventilation streams entering the wing, a panel, a group of excavation sites, should be constructed of non-combustible materials. Allowed on the wing, panel, sites of construction of wooden doors, with the fire-retardant coating.
jumpers with Windows for regulation of the air flow can be wooden. At the erection of bridges, designed for insulation of ventilation streams, should be made fringe отслоившейся breed.
with depression gateways 50 PA and more ventilation doors should be equipped with a device to facilitate their opening.
all ventilation doors (including reversible) should be self-closing and constantly closed (fig. 2). In the mines with intensive откаткой (six or more trains per shift) they should be opened and closed automatically or remotely.
do not install ventilation doors in the areas inclined workings, equipped with rail transport, as well as монорельсовыми and teleferics. The ventilation of the door, set out below plots the workings, which are removal, should be protected by barriers.

Fig. 2. The self-closing ventilation door

Scientific novelty

For the first time for the plan of liquidation of the accident will be a preliminary assessment of the possible implementation of the local emergency ventilation regime in the entire mine. In advance will identify all the possible places where you can topple the vent stream and place of the installation of the necessary ventilation controls. Research will be carried out for the conditions of mine Yuzhnodonbasskaya № 1.

A summary of the results of the master's work

The master's work is based on a computer model created in the program the IRS Ventilation ЭПЛА (the plan of liquidation of the accident) (Fig.3). For research in computer scheme of mine ventilation network, the database was created consisting of 444 units and 677 of the branches, and was introduced 9780 units of data.

Fig. 3. Computer model of SOEs mine administrations have Yuzhnodonbasskaya № 1

And also it was the simulation of the fire and defined areas of the spread of fire gases (fig. 4) and the generation, in which there was a rollover air flow.

Fig. 4. Modeling of fire on the computer model

The color red – alarm output. Yellow – area of distribution of fire gases to the overturning of the air flow.

Animation 1. Zone of reversing the computer model

Conclusion

At the present time in the master's work developed a computer model of a mine ventilation network, prepared database, and conducted a study of the sustainability of airing of mines with the descending and ascending airing in the fires. In the future, will be carried out modeling of local illumination, ventilation and study of stability of ventilation in the emergency ventilation mode.

Literature

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Bolbat I.E., Lebedev V.I., Trofimov V.A. Emergency ventilation modes in the coal mines – M.: Nedra, 1992, – 204 c.
Guidelines for the design of ventilation of coal mines, Kiev, 1994.
Trofimov V.A., Bulgakov Y.F., Kavera O.L., Kharkov M.V. Aerology of mine ventilation network. – Donetsk, 2009. – 87 с.
Lebedev V.I. The study of ventilation modes during the fires in уклонних the fields of mines in Donbass: Avtoref. dis. candidate of technical Sciences, Donetsk, 1974. – 19 с.
Recommendations on selection of effective mode of airing of mines in case of accidents – Donetsk. – 1995. – 165 with.
Kaledin I.A., Romanchenko S.B., Trofimov V.A. Computer simulation of mine ventilation network: Methodical instructions. – M.: Publishing house of mshu. 2004 – 72 с.
Kaledin I.A., Romanchenko S.B., Trofimov V.A., V.A. Gorbatov Computer simulation of the tasks of the emergency protection mines: Methodical instructions. – M.: Publishing house of mshu. 2004 – Part 1. – 45 с.