Simulation Study On Sectional Ventilation Cooling Of Long-Distance Single End Roadway In Deep Mine

At present,a large number of mines in China have gradually transferred to the stage of deep mining,and the effect of geothermal on deep well mining is becoming more and more obvious.Especially in the process of long-distance single end roadway operation,the contact distance between air flow and surrounding rock of roadway is long,and the heat exchange capacity between air flow and surrounding rock is large.In the process of roadway return air,it is easier to produce high temperature heat damage,and then affect the air flow temperature in the air inlet duct.Aiming at the heat damage of return air stage of long-distance single end roadway in deep mine,this paper designs the sectional ventilation cooling method of sectional air leakage of air duct to cool the roadway,and numerical simulation and threedimensional ventilation simulation are used to study the cooling effect and law of sectional ventilation.This paper mainly studies the following:(1)In this paper,the cause of heat disaster in deep mine,the heat release of heat source in deep mine roadway and the heat exchange mechanism between single end roadway and air flow are studied,and the mathematical model of sectional ventilation cooling is established by using static pressure recovery method.(2)According to the mathematical model,the equal section uniform air supply duct with uniform sectional air supply is designed,and the model is simulated and verified by using the computational fluid dynamics software Fluent.(3)The orthogonal test was designed to analyze the influence of different factors on the cooling effect of the roadway,and the Fluent software was used to simulate the cooling effect of the roadway after the conventional forced ventilation and sectional ventilation,and the concept of effective cooling area is proposed,and the cooling effect of two cooling methods is compared and analyzed.(4)The change of wind temperature of roadway by adopting the method of sectional ventilation cooling is studied by designing the air leakage duct with different interval and different air leakage volume.(5)Based on the background of the Yankou mine of Daliuxing gold mine,the present situation of mine ventilation system is simulated and analyzed by using the Ventsim three dimensional ventilation simulation software and the optimization scheme of ventilation system is designed.(6)Based on the optimization scheme of ventilation system,the application effect of sectional ventilation cooling method in actual mine is studied through the design of sectional ventilation cooling in the late stage of the 20 th section mining.The results show that: In the process of ventilation of single end roadway in deep mine,the heat transfer of high temperature surrounding rock to airflow is the main cause of heat damage in deep mine;The simulation results of the mathematical model are consistent with the theoretical calculation results,and the mathematical model is reasonable;The influence of various factors on the cooling effect of roadway ventilation is as follows: inlet air temperature > surrounding rock temperature > inlet air volume;In the established 100 m long tunnel model,the tunnel length that meets the temperature requirement of effective cooling area is taken as the contrast standard.The cooling effect of the tunnel adopting the sectional ventilation cooling technology is 17.7%higher than that of the conventional forced ventilation;The tunnel with the interval of20 m has the best cooling effect;At the same return air distance,the larger the air leakage is,the better the cooling effect is;In the simulation of ventilation cooling in the late mining period of the 20 th middle section of Yankou mining area in Daliuhang gold mine,the cooling effect of the roadway with sectional ventilation cooling is 15.4%higher than that of the conventional local ventilation.Based on the study of sectional ventilation cooling of long-distance single end roadway in deep mine,the following conclusions are obtained: compared with the conventional forced ventilation cooling,sectional ventilation cooling has obvious advantages in solving the problem of back heat in the return air stage of long-distance single end roadway;With the method of sectional ventilation cooling,under the premise of ensuring the ventilation cooling air volume of the working face,the method of increasing the air leakage volume of the air duct can not only effectively reduce the air flow temperature in the return air stage of the long-distance roadway,but also avoid the dust and other new problems in the working face caused by the increase of air volume in the conventional forced ventilation cooling.