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)"
STUDY
ON REMOTE CONTROL TECHNOLOGY OF AIRFLOW
DURING A MINE FIRE
In order to realize remote control of airflow during a mine fire and minimize fire losses, two kinds of the airflow remote control systems have been developed. One uses compressed air as power source, and transmits control signals by a monitor system for mine environment. Another uses electric power and transmits control signals through a telephone network underground. The mine door controllers of the remote airflow controlling systems are developed with a single-chip microcomputer. Then the controller can not only do logical analysis and judgement, but also has a strong anti-disturb ability and sufficient reliability. The two kinds of airflow remote control system have been successfully applied in some coal mines in China. Their effects of running are very good
REMOTE CONTROL SYSTEM OF DOORS USING COMPRESSED AIR
The remote control system using compressed air consists of driving unit for doors, UPS (Uninterruptible Power Supply), electromagnet valve, and a monitoring system for mine environment.The compressed air used as energy power to drive the door is supplied by its pipeline system. Air cylinders perform the function of controlling the door state of opening or closing. Further, the operation procedure of air cylinders is controlled by electromagnet valve that is explosion-proof. And the electromagnet valve has three bits and five ports. In details, the electromagnet valve has two power lines inputs to control two outputs of compressed air pipelines. The two compressed air pipelines are connected to the front and the back cavity of gas cylinder respectively. When the back cavity of gas cylinder is attached to compressed air, the pushing bar extends. When the front one is connected, however, the pushing bar retracts. Moreover, if the pushing bar extends, the steel wire connected to the door turns loose, which makes the door closed by its own weight. If the pushing bar retracts, the steel wire pulls the door open. The power supplied to the door controller is provided by UPS that is explosion-proof and intrinsically safe. The door controller is developed with an 80C552-typed single- chip microcomputer. The controller decides the on-or- off state of relay by receiving four output signals of switching value from the monitoring substations. Of the four output signals, two used for handed control are generated by the control terminal on the ground. The other two applied for programmed control are generated by monitoring system according to its information acquired automatically. If the relay is at the state of ON, 12 DC power can be available to initiate the corresponding electromagnet valve and gas cylinder to run the operation of closing or opening the door. Inside the controller, there is a luminescent diode indicating the state of operation. The door controller, to some extent, has intelligence. It can not only be remotely controlled by hand, but also can be done by program that is performed through automatically detecting the warning signal from monitoring system. Because, in the software, the priority of control by hand is greater than that of control by program, it adapts well to the needs of mine rescue work. Besides, the liability of the control is enhanced by means of wave filtering for the input signals and putting out the same output signals for several times. Figure 3 is the remote control automatic door installed in a mine.
REMOTE CONTROL SYSTEM OF DOORS BY TELEPHONE LINE
To meet the
needs of preventing disaster and rescuing personnel under different circumstances
of different mines or mining areas, an another kind of remote control
system of doors underground, which transmits signals through telephone
lines, is also developed. Using telephone lines, it doesn't need to lay
any special cables, which is a great reduction to financial ability and
material consumption. The whole system is composed of main control system,
transmitting system, door controller, and driving unit, seen in Figure
4.
The main control system refers to a computer on the ground. The control
program is worked out by the authors. The main control program, with a
full consideration of the knowledge of operators on the field, has a welcoming
user interface, a feature of visual displaying and easy learning. For
the transmitting system, we apply the telephone lines network in the mine.
The controller receiving control commands from control office on the ground
is developed with a single-chip microcomputer. That makes controller to
analyze and select the signals received, which ensures that it can send
out accurate control signals to the driving unit of the door. In an effort
to avoid disturbance from perturbation of power, the power is commutated
in two terminals and filtered in low pass. Further more, program design
for controller has applied methods of reliable design. Control program
in the computer on the ground is encrypted that ensures its great ability
of anti-disturbance and full reliability.
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