Study On Temperature Distribution And Dynamic Evolution Law Of Spontaneous Combustion Gangue Hill In Yinying Coal Mine

China ranks third in the world in terms of total coal resources.A large amount of coal gangue is produced in the process of coal construction,mining,washing and processing,which are easily spontaneous,releasing toxic or harmful gases,soil,water heavy metal pollution,even will cause the collapse,landslide,blowout and other major catastrophes,which serious harm the ecological environment and endanger people's life and belongings.Therefore,it is urgent to control the spontaneous combustion of gangue piles and establish a stable environment of gangue fields.In the domestic practice of controlling the spontaneous combustion of coal gangue,only the measures such as soil covering,compaction and grouting are adopted to restrain the inflow of oxygen,which cannot be adapted to local conditions.The problem of poor control effect often appears,and the phenomenon of recombustion is endless.The root of this problem is that the internal temperature field distribution of coal gangue is not clear and the spontaneous combustion mechanism of coal gangue is not clear,so the control measures are not in place.Therefore,in order to put forward effective measures to prevent and control the spontaneous combustion of gangue piles,it is of great significance to explore the internal temperature distribution law of gangue piles and simulate the dynamic evolution of spontaneous combustion.Yangquan Yinying coal gangue pile internal spontaneous combustion for many years,the surface of the occurrence of open fire.The harm is significant,and the hidden danger of the occurrence of open fire again is very high,urgent need to control.Based on the camp of the shadow of coal gangue mountain as the research object,on the basis of full investigation and data collection analysis,composition analysis and industry analysis of 15 # coal gangue,clear the mechanism of spontaneous combustion of coal gangue piles is established for the first time the spontaneous combustion of coal gangue piles temperature monitoring system,using the thermocouple real-time monitoring coal gangue mountain shadow of yangquan city camp temperature of different depth,with the aid of statistical methods to analyze the level and vertical temperature distribution,shallow depth is established using least square method fitting model between the temperature,and test of goodness of fit and significant analysis.Then in the light of predecessors' achievements for consultation,making full use of the theory of porous media fluid dynamics,porous media mass transfer,porous media heat transfer and so on.The air in coal gangue and voidage is defined as porous medium,and the spontaneous combustion of coal gangue piles is regarded as the coupling result of the velocity field of air seepage velocity field,oxygen concentration migration field and temperature field.The geometric model and mathematical model are established according to the actual situation.And the simulation model is established by using the finite element method,simulation from 1 ? 5 years,variation of internal temperature of coal gangue,and through the change of wind speed and thickness of overburden soil,the size of the simulation to predict the influence on spontaneous combustion of coal gangue piles.The main conclusions are as follows:1.In the horizontal direction,gangue piles can be divided into three zones,namely,the high-temperature zone,middle temperature zone and low temperature zone..The high temperature area is mainly distributed on the side near the slope.As the depth increases,the temperature of the measuring point first increases and then decreases,and the temperature reaches a peak at 6 m.The maximum temperature of the platform is 667?,located at the intersection of the horizontal line 6 m below the surface and the parallel line 6 m below the slope,indicating that the spontaneous combustion tendency is the highest 6 m from the surface.Unary quadratic model has better fitting effect and significant regression effect,which can be used as empirical regression formula to estimate shallow temperature and deep temperature.2.The simulation error of multi-field coupling simulation is small and the model is reliable,which can accurately simulate the dynamic evolution process of spontaneous combustion inside gangue hill.The air speed cut down in succession from the inclination to the inside,while the oxygen concentration cut down in succession from the slope and top to the interior.The temperature field as a whole rises rapidly at first,then the rate of temperature rise decreases continuously,and finally becomes stable.In addition,the distribution of temperature field in the high temperature area is continuously moving from the slope to the interior.In addition,with the increase of wind speed,the temperature rises first and then decreases,and the highest wind speed is 1 m/s.With the increase of overburden thickness,the temperature first decreases and then increases,and the lowest soil covering thickness is 1.5 m.The treatment of coal gangue is a long-term and arduous task.This study provides a basis for revealing the internal temperature distribution characteristics and dynamic evolution of spontaneous combustion of coal gangue piles.This study can provide a academic basis for the follow-up precaution and control of inflammation of coal gangue piles and the implementation of cooling measures,which is of great importance for preventing and controlling the recurrence of coal gangue piles.Due to the complexity of coal gangue spontaneous combustion,many studies have limitations.In the future,the mechanism of spontaneous combustion of coal gangue should be deeply studied to provide a more scientific basis for the prevention and control of coal mine disasters.