Research And Design Of The Low Frequency Excitation System For The Gas Desorption

Our country is a energy consuming country and the coal consumption accounted for a large proportion of energy consumption.Most of the coal mines in the country are gas mines and 48 percent of the mines are high gas mines and gas outburst mines.Gas in mines will cause gas outburst,gas explosion and poisoning and this will seriously harm mine production safety.Hundreds of gas disaster accidents happen in mines of our country which are the most of the whole world.The safety and effect of methods of gas desorption now are unsatisfactory.Therefore there are important research significance and practical value to develop a gas desorption system which is safe and effective enough.The thesis focuses on developing a low frequency excitation gas desorption system by research on the effect of low frequency excitation to gas desorption rate based on gas desorption principle.Firstly,by comparing the advantages and disadvantages of promoting gas desorption process of coal,this thesis sets up a fuzzy model of coal gas desorption which is effected by low frequency excitation.The fuzzy model in Matlab is simulated and error of the model is reduced by training the model with data.The promotion of low frequency excitation of coal gas desorption is demonstrate by model simulation from the theoretical level.Furthermore,the overall program for low frequency excitation gas desorption system is designed and every subsystem of this system is designed in the area of both hardware and software.RS485 is selected as communication interface of every subsystem microcontroller or FPGA chip and field-bus is used between the various subsystems.The key component of the system,frequency vibration transducer,is designed and developed.Innovatively super magnetostrictive material is applied to the frequency vibration transducer and by using this kind of new material the frequency vibration transducer has the advantage of obvious vibration effect and large frequency range.Finally,the verification experiment of the effect of low frequency excitation gas desorption is performed.This thesis concludes that frequency excitation can accelerate coal gas desorption rate and increase the amount of coal gas desorption and proves feasibility and high practical value of the low frequency excitation gas desorption system.