Transient Temperature Field Of Surrounding Rock Of The High Temperature Roadway And Its Heat Control Mechanism By Heat And Mass Transfer

With the rapid development of economy,the demand of mineral resources is increasing day by day,a lot of coal mining has become an inevitable trend.But the quantity of coal reserve in many shallow coal mines has been in short supply,which forces the mining depth to increase year by year.And the resulting high temperature and thermal damage has become an important issue restricting the safety of mine production.There are many heat sources that cause the mine to heat damage,but the most important factor is the heat dissipation of the surrounding rock.So if you want to solve the problem of high temperature and thermal damage.In order to effectively prevent the heat dissipation of the surrounding rock,it is necessary to master its heat dissipation law and process.Therefore,this paper studies the mechanism and law of heat exchange between surrounding rock and wind flow through the combination of theoretical analysis and numerical simulation.The main contents are demonstrated as follows:(1)Based on the theory of heat transfer and mass transfer,the mathematic model of unsteady heat transfer mass transfer coupled to the thermal environment of high temperature roadway is deduced by studying the mechanism of heat transfer and mass transfer in high temperature roadway.(2)The temperature field of roadway ventilation for two years was simulated by ANSYS FLUENT solver to obtain the temperature distribution evolution of high-temperature tunnel airflow,insulation layer and surrounding rock and surface convective heat transfer coefficient variation in high temperature roadway.(3)Orthogonal tests were carried out on the factors influencing the average temperature of the air outlet at the entrance of the tunnel,and the influence of each factor on the average temperature of the outlet air flow was obtained through range analysis.Through the correlation analysis and variance analysis,the influence degree of each factor on the average temperature of the outlet airflow was obtained,and the main influencing factors were screened for single factor analysis.(4)The main factors on the average temperature of the airflow at the exit of the roadway in the orthogonal test were analyzed by univariate analysis.And the empirical formula is applied to qualitatively and quantitatively analyze the influence of each factor on the average temperature of export airflow.