Goals and objectives of master's work

Purpose of master's work – the development of potential measures to improve the safety of the people spread area of fire gases in fires in inclined workings with upward ventilation, developed through the use of a virtual model of mine ventilation network of the mine to them.Xolodna balka.

To achieve this goal it is necessary to solve the following problems: to analyze the ventilation circuit, air distribution, to develop a computer model of the mine using the «IRS Ventilation – PLA», to assess the stability of ventilation at fires in inclined workings of the mine, and develop measures to improve the sustainability of ventilation; explore the area spread of fire gases from fires in inclined workings and explore the exit routes of miners from the area gassing.

1. Relevance of topic

Analysis of coal mine accidents shows that the underground fires are one of the most common types of accidents. Fires in inclined workings are characterized by the rapid spread of flame, and fire them due to the much greater difficulties, than other workings.

The simplest and most effective way to increase the stability of the network airing in case of fire in the development of the ascending movement of the air is closing fire doors in front of the hearth fire, that not only increases the stability of ventilation, but at the same time reduces the intensity of a fire. Therefore, the appropriate emergency response plans include closing fire doors following the fire, and in those cases, when you do not want to increase the resilience of ventilation. However, if a fire broke out in a branch without a fire door, closing fire doors (for example, at the top or bottom of the slope) may violate the (worsening) the stability of other ventilation openings [1].

The action of heat in the development of depression fire with upward ventilation same direction as the main fan depression. As a result, the air flow in other mines (usually in a nearby fire branch) can change direction (tip). Rollover air flow leads to an expansion zone zagazirovaniya, poses a threat to the appearance of fire gases on evacuation routes, which can lead to more victims [2]. Therefore, place rollover vent stream you need to know in advance and to provide for measures to ensure the stability of the ventilation openings, and such a calculation is possible only by using specialized software.

Thus, the urgent task is to develop possible measures to improve the sustainability of mining ventilation at fires in inclined workings with upward ventilation, developed through the use of virtual model of the mine ventilation network of the mine to them.Xolodna balka.

2. Probable scientific novelty

First assess the stability of mine workings ventilation at fires in inclined workings with upward ventilation, using a computer model of the mine ventilation network of the mine to them. Xolodna Balka.

Technology problem solving mine ventilation with complex software «IRS Ventilation – PLA», is defined by a sequence of actions, including the stage of preparing the initial information. At this early stage, it is necessary to prepare a scheme of ventilation shafts before putting it into the computer. The peculiarity of this training is to apply the scheme of ventilation in the form of a sequence (network) connected between each other, branches. Each node of the network links between them, two or more output (branches), or part of production, as a rule, the coding schemes of ventilation is carried out in preparing the mine to the depression survey. In this case each node and branches in the diagram is assigned a certain number (Fig. 1).

Figure 1 – Simplified diagram of the field gradient
(1 – vozduhopodayuschy drift; 2 – upper sboyka ; 3 – walker; 4 – bias)

Stability of air flow in mines is estimated at a fire after the introduction of the production ramp source of thrust, simulating the thermal depression fire. Destabilization of ventilation in case of fire is possible in those mines, where, after the introduction of the thermal depression stop or change the direction of air flow.[3].

This numbering allows the identification of all the production of the mine, or portions thereof, and to determine the actual direction of movement of air in them. In preparing the scheme of ventilation shafts, to represent it in electronic form, is unacceptable to simplify it. Under the simplification means joining a ventilation network nodes to one or the schematic representation of ventilation, the series connection of several workings of one branch (Fig. 2).

Figure 2. Computer sample piece of a ventilating web of shaft № 22 Xolodna Balka

In operation the estimation of stability of ventilating flows in developments with descending airing has been spent at fires in 12 branches, in 11 from them airing in 1 at fire origin it will appear not steady (Fig. 2).

Figure 3.Simulation of a fire in 333 branches. Red colour – development in which the fire is simulated; Yellow colour – a zone of spreading of fire gases before overturning of a ventilating stream (a zone 1); Turquoise colour –zone of spreading of fire gases after overturning of a ventilating stream (a zone 2);

At fire origin in this development, it is possible in 2 minutes, after a kickoff of ardent combustion, there will be an overturning of a ventilating stream at thermal depression 5,17 daPa. It is necessary to provide actions for stability security.

In 1 zone, that is in a zone of spreading of fire gases before overturning of a ventilating stream, 57 branches have got: 497, 522, 219, 228, 124, 810, 67, 69, 133, 70, 354, 349, 536, 512, 513, 138, 342, 89, 809, 127, 520, 537, 2011, 215, 538, 2013, 2015, 470, 167, 2021, 535, 617, 2023, 615, 136, 534, 430, 286, 66, 327, 495, 542, 2017, 2019, 400, 321, 616, 482, 52, 508, 2012, 2014, 2016, 2018, 2020, 2022, 2024. After overturning the zone is in addition spreaded to 31 branch: 424, 414, 57, 218, 141, 776, 229, 862, 777, 861, 234, 451, 351, 387, 166, 137, 471, 201, 472, 474, 744, 294, 447, 232, 483, 455, 898, 135, 322, 963, 134. To be saved from an additional zone gazing it is necessary to ensure stability of airing of 235 branches, using function airing reinforcement, this problem is doubled in a branch window. Having clicked the cursor on any branch (an adjusting plant), it is possible to define development (branch-regulator) adjuster installation in which, will ensure the maximum increase in an air-flow rate in an adjusting plant. If, for any reasons, in the first branch adjuster installation is impossible, other branch is offered. A problem of double assignment - for fast searching of an installation site of an adjuster, in an emergency, and for adjusting problem solving, ensuring master schedules [2].

Parametres of a branch before airing reinforcement: an air-flow rate 4,14 m3/s, aerodynamic resistance 0,0059 kMurg. We select the first offered variant a branch 229 (Fig. 3).[4].

Figure 4. Reinforcement of airing of a branch 333.

In 333 branches we augment resistance on 1 kMurg (was 0,00090 kMurg, became 1,00090 kMurg). It has not given expected result (fig. 4), therefore it is necessary to iterate a command «airing Reinforcement», an installation site of the second adjuster is 463 branch.

Aerodynamic resistance of a branch 319 made 0,00127 kMurg, after increase on 1 kMurg, it has made 1,00127 kMurg. After that we iterate fire simulation in a branch 235. Apparently from fig. 5, overturning of a ventilating stream does not occur and consequently the zone of spreading of fire gases after overturning of a ventilating stream is absent.[6 – 8].

Figure 5. A zone after airing reinforcement . Red colour – development in which the fire is simulated; Yellow colour – a zone of spreading of fire gases before overturning of a ventilating stream (a zone gazing 1);

References

1. Трофимов В. А., Кавера А. Л., Калинич Н. М., Негрей А. Г. Влияние увеличения сопротивления наклонной выработки на устойчивость ее проветривания при пожаре ⁄⁄ Материалы Международной научно-практической конференции «Промышленная безопасность и вентиляция подземных сооружений в XXI столетии» – Донецьк. – 2012. – С. 16-18.
2. Болбат И. Е., Лебедев В. И., Трофимов В. А. Аварийные вентиляционные режимы в угольных шахтах. – М.: Недра, 1992. – 206 с.
3. Булгаков Ю. Ф., Трофимов В. О., Кавєра О. Л., Харьковий М. В. Аерологія шахтних вентиляційних мереж – Донецьк, ДонНТУ. – 2009. – 88 с.
4. Руководство по проектированию вентиляции угольных шахт – Киев. – 1994.
5. Правила безопасности в угольных шахтах. – К.– 2010. – 422 с.
6. Рекомендації по вибору ефективних режимів провітрювання шахт при аваріях ⁄⁄ НДИІД. – Донецьк.–1995. – 165 с.
7. Каледіна І. О., Романченко С. Б., Трофимов В. О. Комп’ютерне моделювання шахтних вентиляційних мереж: Методичні вказівки. – М.: Видавництво МГГУ. – 2004. – 72 с.
8. Каледіна І. О., Романченко С. Б., Трофімов В. О., Горбатов В. А. Комп’ютерне моделювання задач протиаварійного захисту шахт: Методичні вказівки. – М.: Видавництво МДГУ. 2004. – Частина 1. – 45 с.
9. Борзых А. Ф. Содержание, ремонт и ликвидация выработок угольных шахт – Алчевск: ДонГТУ, 2004. – 614 с.