Purposes and problems of the student work
Conclusions and future research
Purpose - develop possible measures to improve safety of people entering the zone of distribution of fire gases in fires in inclined workings of top-down ventilation, developed through the use of a virtual model of mine ventilation network of mine named. SM Kirov. Make an analysis of air distribution and ventilation schemes. Develop a computer model of the mine with the software "IRS ventilation - planning".
The results obtained allow to predict conditions for rescue during emergencies and develop activities to increase the safety of miners.
In practice, the sustainability assessment of ventilation flow is provided only for mines with downward ventilation and in those caseswhen ventilation is not stable, these include the development of the zone of general mine ventilation flow reversal. Under modern conditions in some coal mines in Ukraine reversal zone extends to excavation uchastkov.
Analysis of general conditions of use of underground coal fires in the reversal shows that in some cases there is a risk transfer and air flow in the reverse mode provitryuvannya. Calculations of air flow resistance in fires in the mine workings sloping, carried on all coal mines in the preparation of plans for the elimination of accidents.
The basis of these calculations is the definition of thermal depression fire modeling and its actions in the mine ventilation merezhi
The assessment of resistance first conducted with the use of four different determination methods of path resistance shorting:
— resistance decrease of typy branches in 100 times;
— determination of resistance the way of shorting as amount of working resistance and doorway resistance;
— use the value of middle resistance of shorting way, which is 0,69;
— resistance calculation of shorting ways, on a formula for a air-passage.
On the basis of the results got during master's degree work comparison will be conducted and a conclusion is done about what from the above-stated methods is most exact.
OP Kirov mine established on the basis of the same name mine office, in which two of mine - mine is number 1 and the Kirov Kirov mine-West. Mine is number 1 Kirov was commissioned in 1947 with a designed production capacity of 90 thousand tons per year. Kirov Mine West was commissioned in 1948. Plast l1, are threatened with a depth of 320 m and a depth stratum h10v 230 m. with a capacity of 100 thousand tons in god.
Production capacity at the mine 1. 01. 2007g. - 600 tys. tonn.
Category mine methane - a dangerous surprise for vybrosam.
Mine is working out seams and h10v. l1. Plast l1 is a dangerous explosion of coal dust. Plast h10v not dangerous. Plast l1, are threatened with a depth of 320 m and a depth stratum h10v 230 m.
Former mine field number 1 Kirov opened by three vertical shafts (cage, vent to bed K42n, vent to g. 475 m), tilting barrel to a layer l8-1 and for supplying fresh air to the jet gor. 475m drilled vozduhopodayuschaya hole d = 3. 2 m. Former mine field Kirov West opened by three vertical shafts (cage, skip, ventilation) pits "0" and three inclined shafts in the stratum h10v: italic vozduhopodayuschim trunk inclined conveyor and tilting barrel vent stvolom..
Industry stocks of coal on the mine, the 1. 01. 2009 up 16. 445 million tons. Prepared stock - 814 tys. tonn. Stocks of coal grades: K - 0. 103 million tonnes T - 13. 983 million tons OS - 2. 359 mln. t.
In 2011, coal production is planned in two grades: grades K in the amount of 190 thousand tons. shipped to the CCM "Kolosnikovskaya" for coking coal and in the amount of 265 thousandt T brand for energy needs. The total volume of production - 455 tys. tonn.
Technology problem solving mine ventilation using software package "IRS Ventilation - PLA" is a particular sequence of actions, including the preparation phase of the initial information. At this early stage, it is necessary to prepare a scheme of ventilation shaft to enter it into the computer. In this case each node and branches in the diagram is assigned a number.
A feature of this training is to feed the ventilation system in the form of a sequence of (network) connected between themselves, the branches. Each node of the network links among themselves the production of two or more (branches), or part of production, usually coding schemes ventilation shaft is held in preparation for depressive shooting. In this case each node and branches in the diagram is assigned a number. This numbering allows identification of all the development of the mine or part thereof and determine the actual direction of movement of air in them. In preparing the mine ventilation system, to be submitted in electronic form, is unacceptable to simplify it.
Under the simplification means the union of several nodes in a network of ventilation or a view on the scheme of ventilation, the serial connection of several workings of one branch. The need for such a detailed representation of ventilation system in a computer because of the connection, the workings may be the site with different angles and geometrical parameters that form the different conditions of fire and movement of people. In simplifying the ventilation system, where multiple nodes, which are sites of interface (connection) mining, are replaced by one ("shrink to one"), are also possible errors in the construction of the zone of fire gases, the best routes of movement of people and modeling of thermal sources of traction (natural draft, the thermal depression of fire).
The stability of ventilation is calculated on a PC using the software package "IRS Ventilation PLA. " We first determine the normal air distribution in the mine ventilation network. The source of background information appear depressed shooting.
The main feature of the calculation is the consideration of the natural draft. Natural draft operating shafts, inclined workings excavation of fields and areas defined by the data contained in the reports of depressive shooting. In the first case, the value of the natural draft is introduced into the branch and the trunk area simulates the output streams adjacent to the main ventilation fan channel, the second - at the top of the slope of the outgoing flow of the excavation of the field and in the third - in the slope the excavation site.
In the excavation field, where output is given by several slope, natural draft is introduced into the upper part of each of these developments. The value of the natural draft in all cases take the maximum calculated from measurements of temperature for the coldest season of the year. The stability of ventilation flow in mines in case of fire was assessed after the introduction of slope thrust source, which simulates the thermal depression fire.Violation of the fire resistance of ventilation possible in those mines, And, in case of fire in the development of the downward flow of ventilation, the magnitude of the thermal depression and the branch will be introduced to the source of thrust should be determined taking into account the normal direction of flow vozduha. where after the introduction of thermal depression stop or change the direction of the ventilation flow.
Thermal depression fire is determined by taking into account the possible place of its occurrence. And, in case of fire in development of the downward flow of ventilation, the magnitude of the thermal depression and the branch will be introduced to the source of thrust should be determined taking into account the normal direction of airflow.
If the calculation results revealed that under the influence of thermal depression may occur rollover vent stream, you must include activities to improve the sustainability of ventilation. Increase the stability of ventilation slope in a fire in two ways: a decrease or increase in the critical thermal depression.
However, the influence of thermal changes in depression can be a very limited extent. Therefore, practical importance is the second way - increase the critical depression. Develop recommendations to improve the sustainability of ventilation should be started with an analysis of emergency ventilation circuit area. Allocate the circuit, which in case of a rollover vent stream will re circulate the products of combustion. Figure 4 shows a circuit for recycling the case of a fire in the slope (see Fig. . 2 )This circuit consists of two parts connected in parallel. Fire includes several branches, connected in series and parallel. After tilting the air flow under the influence of thermal depression in the direction of air flow path of the fire is reversed.
Current status of coal mines in Ukraine is characterized by complex economic and geological conditions. Increased depth of mining operations, which leads to an increase in air temperature, declining terms of maintenance and mining. Security schemes of ventilation is reduced by increasing the length of the mine workings. In these circumstances, the question of ventilation of coal mines acquire special weight. They have a direct connection with occupational safety and their solutions at the present level is the key to improving safety. In the past two years has spread the use of simulation software of ventilation network of coal mines. These software packages allow you to automate a number of issues related to the prediction and control of air distribution in mine ventilation networksand preparing and maintaining emergency response plan.
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