Experimental Study On Catastrophic Regulating Airflow For The Comprehensive Control Of The Coal Spontaneous Combustion And Gas In Coal Mine

The mine ventilation system is one of the most basic and important system for the production system in coal mine,and the mine ventilation is one of the main technology which can safeguard the safety in production.Safety,efficient,adjustable and controllable are very significant for the airflow in stope,which can reduce the energy consumption of ventilation system greatly and aslo can give full play to prevent and decrease the disaster and promote the safety in production.It has fundamental significance.This thesis carries out the experimental study on catastrophic regulating airflow for the comprehensive control of the coal spontaneous combustion and gas in coal mine,which adopts the comprehensive research methods included the theoretical analysis,experimental research,numerical simulation,3-D model test and engineering practice,and achieves some achievements.The confirmation method of the sensitive branch in ventilation network is proposed based on the influenced degree“M_i”of branch.The optimal selection method of the best adjustive branch is proposed based on the sensitivity“d_ij”and the influence degree“Z_j”of branch.The software is developed for monitoring the parameters of airflow and regulating the air quantity.The relationship of the regulative windage and the air quantity is calculated by the program of ventilation network.In summary,the theory,method and technological process for regulating airflow based on the sensitive branch are established.Through the analysis and research on the principle of frequency conversion and regulating airflow,the linear relation formula“f-q”for the frequency conversion of main fan and the air quantity of branch is proposed,and the formula“f-c”for the frequency conversion and gas dilution is also founded.Accordingly,the theory,method and technological process for the frequency conversion and regulating airflow based on the principle of gas control and the principle of prevention of spontaneous combustion are built.The“ZDJT”stope airflow automatic monitoring and control system and its method is established,which consists of the ground automatic monitoring and control center,the industrial ethernet communication system,the frequency conversion monitoring and regulating system of ground fan,and the monitoring and regulating system of underground air network.And it achieves automatic monitoring and controlling for the branch airflow in ventilation network of coal mine.The integrated experimental platform for the stope airflow parameters monitoring and automatic regulating is autonomous designed and built,which is maked up of the three-layer tridimensional pipe network,air pressure transmitters,air velocity transducers,regulator doors,variable-frequency speed regulating fan and PLC acquisition control system.This thesis carries out the experimental research on regulating airflow of the branch in working face,the assemblage of alternative and high-performance regulating branches is obtained fleetly and accurately,which based on the theory,method and technological process for the sensitive branch regulating airflow.Further,it ensures the optimal regulating branch and realizes the accurate regulating airflow for the sensitive branch,by means of adjusting the regulator doors and air regulators.Meanwhile,the cellular automaton model of regulating air is founded,and for the example of simplified local ventilation network,it emulates and verifies the method and process of regulating airflow based on the sensitive branch.This thesis carries out the experiment of frequency conversion and regulating airflow dilution for quantitative release of gas,and proves that the power function relationship between the gas concentration in stope and the working frequency of fan,which decreasing rapidly with the increase of frequency.Moreover,the study on the rules of regulating for the frequency conversion and automatic regulating airflow based on the principle of gas control is launched,and a method of automatic regulating airflow is proposed,which on account of the gas emission monitoring and the capability of diluting gas by the frequency conversion and regulating airflow.It carries out the judgment and regulation by the day,and provides five regulation rules to achieve the dynamic governance and control of the gas emission in working face.And the practicability of the method and the rules of regulating is proved by the experimentation.At the same time,the regulating airflow experiment of coal sample programmed heating and the numerical simulation research on regulating airflow in stope are carried out,these results proved that the frequency conversion and regulating airflow has not going to get faster or auxo-action for the process of coal spontaneous combustion in goaf during the low-temperature oxidation stage.And it has a certain inhibitory effect.This thesis manufactures the 3-D visual model of the goaf seepage in fully mechanized caving stope by the similar proportion of 100:1,and simulates and dynamic observes the change of the seepage path for the porous medium seepage field in goaf based on the frequency conversion and regulating airflow.Meanwhile,the practicability of the theories and methods of the frequency conversion and regulating airflow are proved,which based on the principle of prevention of spontaneous combustion.Finally,according to the theories and methods of the regulating airflow in coal mine,the experimental investigations in the Fifth coal mine of Yangquan Coal Industry Group Co.,Ltd and Wenzhuang coal mine of LU'AN Group are completed.