The Research And Development Of The Coal Mine Drainage Automatic Control System

At present, the safety of the coal mine is standing out increasingly in our country. The coal mine drainage system is one of the main running systems of the produce of the coal mine, and it has an important position in the safety problem of the coal mine. If the mine water isn't push out in time, it will threaten the produce of the coal mine and the safety of the workers. The drainage system is one of the most power expenditure systems in the produce of the coal mine. If the drainage system is controlled effectively, and it becomes a high-performance, low-power dissipation, oecumenical, reliable system, it will economize the cost of the produce of the coal mine effectively. In addition, if the mine water can be push out in reason and effectively, it may solve the problem well that most coal mine lack water.The control on the basis of the programmable logic controller that revolves about the microprocessor is replacing the control basing on the relay, and it is being applied universally in the field of autocontrol of every walk of life. But in the coal industry, it applies very little, because of the rugged environment in the mine. At the present time, the most coal mine drainage system still use the control basing on the relay in our country, and the monitoring of the water level, the turning on and off of the pump, the selecting of the pump are all manipulated by the manpower. In these systems, the equipments are laggard, and the manipulation is complicated, and the running is unreliable, and the worker's intensity of labor is very heavy. These faults confine grievously the heightening of the control level and the economic benefit of the mine drainage system.Combining the current excellent industrial control technology, this paper research and develop the coal mine drainage automatic control system fitting the practical situation of our country. Its central control unit is Mitsubishi FX2N series PLC, and it expands the necessary digital quantity input units, the analog quantity input units, and the communication units. It designs three control modes: automation, half-automation, manipulation. These three modes can be switched freely. In the automatic mode, it measures the water level of the sump in real time. According to the movement and the moving speed of the water level of the sump, and the principle of avoiding the peak and trending to the vale, it determines the time of turning on the pump and the number of the pump that will be turn on. On the basis of the safety, reduce its power expenditure for making the coal mine produce economical and high-effective. Using the principle of even wear, and for avoiding the pump rusting because it isn't used for a long time, design the mode of working in turn of the pump and the pipeline. Always turn on the pump and the pipeline, the running time of that are the least, every time.There are enough fault-monitoring and protecting functions to be designed. The high-performance intelligent electrical monitoring module YD2010 is used for monitoring the electrical parameter of the electromotor in real time. YD2010 communicates with PLC's RS485 by the MODBUS protocol. Make the simulative MODBUS protocol program, and using that, achieve the electrical data collection among PLC and five YD2010. After converse the original data, the true electrical data is obtained.Adopting the conversing interface FX-232AWC, PLC's programming interface connects with the monitoring and controlling host computer, and the system state data are transmitted to the host computer in real time. PLC also receives the control command from the monitoring and controlling host computer, and controls the whole system according to it.At last, this paper has some methods and suggestions in the aspect of the reliable designing of the PLC control system.