Study On The Method Of Rapid Measurement And Control Of Local Fan In Mine

In our country’s coal mine ventilation system,the main roadway adopts negative pressure ventilation,but the branch roadway cannot form a through air flow,so local fans need to be used for forced ventilation.Due to the continuous extension of the driving face,the roadway resistance and gas concentration have also changed,and the working condition parameters of the local fan need to be adjusted accordingly,but there is no good solution at the current site.Therefore,for the air volume adjustment of the local fan,due to the limitations of technology and conditions,it is necessary to find a rapid on-site air volume measurement method and air volume control system.The main research contents are as follows:1.The working principles of three ventilation modes,namely press-in,with-out and mixed,are described,and the principles of local ventilation systems and air volume testing methods for mining are introduced.Under the condition of satisfying performance and safety,choose a more energy-saving frequency conversion speed regulation method.At the same time,calculate the minimum air volume required by the roadway and provide the initial value for the automatic air volume control system in the subsequent chapters.2 According to the measurement principle of the field equal ring area method,an experimental platform for the small section sensor bracket of the local ventilator was built to verify the influence of the bracket measuring device on the wind speed measurement results.Based on the influence of the equal loop area method on the results,a test method to quickly measure the average wind speed on site is proposed.The results show that the average wind speed point method has little error with the actual measurement results.At the same time,using a combination of simulation and experiment,verify the position of the average wind speed point on the wind tunnel of Φ400mm,and finally verify the distribution position of the average wind speed point on the wind tunnel with a diameter of Φ800mm.3.Through the design methods and ideas of conventional fuzzy controllers,for the air volume measurement and control system of this subject,on the basis of conventional PID control,using fuzzy control methods,a set of fuzzy PID controllers are designed,which can automatically control according to the demand air volume and gas concentration Motor speed.It can be seen from the simulation results that the fuzzy PID control system responds faster,the time required to reach stability is shorter,and the control effect is better than traditional PID.4.In the hardware design of the air volume intelligent control system,STM32F103 single-chip microcomputer is used as the main controller of the system,sensors and input and output modules realize data collection and processing,and the frequency converter is used to control the motor speed.In terms of software,the program block diagram is designed by the main program calling subprograms,and it communicates with the upper computer in real time,uploading various parameters of the local ventilator to the visual monitoring interface,which is convenient for the staff to view and manage.The on-site air volume rapid measurement method and the air volume automatic control system proposed in this subject have a positive impact on the transformation and optimization of other mine ventilation,and also put forward higher requirements for coal mine safety production.Figure[63]table[18]reference[70]...