| Coal resource provides powerful energy support to economic construction in our country. Because the processing technique of coal industry is backward, it is highly energy-consuming, even energy-wasting. For example, ventilator control system wastes a lot of electrical energy.As the key component of mine ventilation system, the ventilator is big power and works all over the year. The wind speed and rate undermine are strickly regulated acoording to the safety regulation in coal mine. When the coal mine is designed, the ventilator capacity is decided based on the wind rate needed in actual. To meet the wind rate of the requirements in the safety regulation under coal mine, the ventilator is working in full power most of time. The traditional system of ventilator controls the wind rate and pressure by using paddle, which causes a lot of waste of electrical power.The control of ventilator could cause some pollution besides the waste of power when it is working. The ventilator of most mine coal is taking out the air under the mine. The ventilator pumps the air that is in the mine tunnel out to the atmosphere, including many dust and some combustible gas such as methane and carbon monoxide which has been incriminated in air pollution .In view of the above problems, it is necessary to reconstruct the mine ventilation system. As the key component of mine ventilation system, mine ventilator plays an important role in coal mine safety. It is one of the main equipments in the system. So research and design of its variable frequency speed regulation system with PLC control have good economic benefits. It not only improves the mechanical and automatic level of coal production, but also saves large electrical energy.Taking a laboratory counter-rotating axial fan as control member, this paper researched and designed its frequency control system combining PLC control technology, frequency control technology and configuration monitoring technology. Firstly, the paper chose rational system control scheme based on experimental performance curves and control requirements of mine ventilator. Then control circuit was designed on the scheme. At the same time, hardware such as PLC, Frequency converter, Touch screen was distributed. Based on the research of air and methane control algorithm, the PLC control program of system was designed with GX8.26. After that, according to functional requirements of system, the monitoring system of mine ventilator was designed with Force Control Configuration software and Touch screen technology and PLC of Mitsubishi. The control system of ventilator could be operated by CC-Link by distance (FX2NPLC with touch screen provides information for man-machine communication). Then the parameters of FR-E500 converter were set up. At last, simulation debugging experiments of running system were finished. It contained air-control simulation debugging experiment, methane-control simulation debugging experiment, dust-removal system simulation debugging experiment and simulation debugging experiment of monitoring system.The ventilation system is designed as subordinative construction which is key part of this paper. The converter, the system of shunt pipe and dust-removal system as secondary station are under control of FX2NPLC. The converter gets ventilator worked. QPLC as primary station of the system controls all the secondary stations through CC-Link. To make sure that the ventilation system could work when there is something wrong with secondary station FX2NPLC, the primary station masters the redundancy of converter, system of shunt pipe and dust-removal system by CC-Link besides controlling itself. The operation of entire system is visual. The monitoring center could control the whole system in remote distance.It was proved that the control system can adjust fan speed to meet wind pressure and rate in heading laneway through simulation debugging experiments in laboratory according to actual wind rate in mine laneway. Besides, the designed system can be mastered by on-site control or remote control. It can also monitor the wind pressure, methane density, fan speed and so on. Meanwhile, the control system had good function of fault warning and treating.
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