Lukashova Lidiya Sergeevna
Discriminatory Mine Fire Source Detection
The Individual Task
"The computerised subsystem of diagnostics and monitoring
of a condition of the mountain machine
(on an example of coal-mining combine 1KDK500)"
CONCLUSION
The
method of filling sealed goaf and headings with methane has been used
in the mines of Jastrz?bie Mining District many times. The experimental
studies have revealed that by using this method it is possible to:
1. regulate, within a certain range,
the composition of gases, in particular methane and oxygen,
2. change the composition of the
methane-air mixture to reduce its explosivity in a controlled way,
3. reduce oxygen concentration,
and as a result, significantly limit the possibility of or the speed of
the process of spontaneous combustion of coal or endogenic fire.
In the "Pni?wek" mines, experimental research was undertaken,
enabling a very precise monitoring of gaseous dynamic changes in the sealed
goaf and headings during the process of methane application. Selected
measuring equipment allowed us to determine the time taken for changes
in methane and oxygen concentrations as well as the velocity of gas flowing,
and in particular, it confirmed that:
1. filling goaf with methane results
in a considerable growth in methane concentration and a drop in the oxygen
concentration,
2. the dynamics of the course of
changes in methane and oxygen concentration is dependent on:
3. the capacity of the machine to
pump methane from the methane drainage pipeline,
4. the composition of the methane-air
mixture that is supplied to goaf, and recovered from the methane drainage
network,
5. the topological structure and
the gas permeability of the sealed goaf and headings,
6. the effect of external factors,
chiefly mine ventilation and methane drainage.
The article contains selected results of experimental studies that have
been carried out in actual conditions of mine operation. They created
a basis for a mathematical model of the phenomena occurring. To achieve
the aim of the research, a simple mathematical model was developed, and
appropriate boundary conditions and numerical methods made it possible
to create computer simulation software. The computer programme allowed
us to perform a number of simulations of the distribution of methane and
oxygen concentrations in the cases of methane loading into the goaf of
N-6 longwall in the "Pni?wek" mine.
The simulation calculations obtained revealed a considerable convergence
of results between experimental and modelling studies, which enables an
analysis of quality and time courses.
The developed simulation programme is useful for mining practice. A number
of alternative simulation tests on the effect of methane supplied into
the sealed spaces enable us to:
1. determine the distribution of
methane and oxygen concentrations in the sealed area,
2. observe the effect of the concentration
and expenditure of the supplied methane on gas parameters, and above all
to discover the relationship between the parameters of the supplied methane
and methane-influx of the area and the distribution of methane concentration;
it also enables an explosion risk analysis.
3. determine a zone that is characterised
by a low oxygen concentration, and consequently, to determine an area
where the process of coal combustion is restricted.
In conclusion it should be stated that the experimental research presented
in this work creates a good basis for further studies. The results of
model research have revealed that the method is useful and may be employed
to deepen our knowledge on methane loading into sealed spaces.
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