Research On Gas Intelligent Drainage For Local Fan Based On Fuzzy Control

The local fan is the main equipment in the mine driving process, whose flexibility and efficiency can directly affect the safety of gas discharge. At present, the driving motor of local fan in the most coal mine can not change its frequency intelligently, whose intellectualized degree is lower, and in the most of mine the frequency of the driving motor is invariable. In the mine well, the local fan works in the long-term constant speed as soon as it meets the electrical network, the phenomenon of invariable speed is extremely serious. It can not only waste energy but also be easy to creat the ultra density gas drainage and cause the potential accidents. Therefore, this paper designed an intelligent drainage system of gas for local fan, combining the fuzzy control algorithm. This system controls and changes the velocity of local fan in the best efficiency automatically and continuously, according to the parameters of changeable gas density, in the condition of satisfying air quantity the workers needed in the heading face.To begin with, the paper indicates the existent problems for mining local fan gas drainage in the heading face, including its actuality and development tendency, as well as the research content and significance. In addition, ventilation requirements and airflow regulation and fan energy conservation principle in coalmine are introduced detailedly among the local ventilation theory. The fuzzy controller is gained as the most important part of gas drainage system in the heading face, whose input variables are gas density error and gas density error change and output variable is the control voltage of the transducer. The self-organizing parameters fuzzy controller, self-organizing weight fuzzy controller and compound fuzzy controller are designed to compare with normal gas fuzzy controller separately by system module and theory analysis in view of the characteristics of normal gas fuzzy controller. With the most important, the membership functions of gas sensors locating on the heading face, on the upcast air and on the gaseous mixture during two states of normal ventilation and gas discharging in the heading face are formulated accurately. In the following, the gas density in different positions and the corresponding power frequency are obtained by double fuzzy control model simulation. In the end, the software and hardware of control system are discussed theoretically, with the TMS320F2812 DSP chip as its control core. The hardware part contains main circuit, control circuit and protection circuit, and the software part provides some subroutine flow charts with the introduction of modulization design concept.It enhances the intelligence and safety of the local fan gas drainage system greatly in the heading face in virtue of fuzzy control theory, which provides some method instructions for local fan gas intelligent drainage.