Study On Analytical Solution For Roadway Wall Temperature And Airflow Temperature Forecast Under Nonhomogeneous Heat And Humidity Boundary Conditions

Heat and mass transfer coefficient are the key parameters in the process of analysis of heat and wet fountains' distribution and the temperature of calculating roadway wall in the underground roadway.The temperature of roadway wall is the key factor with prediction and calculation for the airflow temperature and ventilation rate in mine.The heat and wet transfer of roadway wall temperature and airflow are influenced the body comfort and labor efficiency of staff.Therefore,accurate determination of mass and heat transfer,solving tunnel wall temperature,prediction of airflow temperature have became the emphasis and difficulty for researching and improving the heat and humidity environment in the underground.This thesis adopts the method combined with theoretical analysis,numerical simulation and field measurement to study the airflow temperature and inhomogeneous thermal boundary temperature in the roadway.On the basis of establishing differential equation of unsteady heat conduction in surrounding rock under wall wetting conditions,nonhomogeneous boundary condition of equation is homogeneous treated for the first time,constructing auxiliary function is applied to nonhomogeneous boundary condition,bessel function and theory of variable separation approach are used to solve the differential equation of unsteady heat conduction in surrounding rock after homogeneous and obtain analytical solution to roadway wall temperature under different moisture coverage of roadway,and the results of solution are analyzed by the temperature of field measurement,Agreement between the two values is better.According to the flow characteristics in the roadway,on the basis of some certain assumptions,pipe of turbulence model is used to build cylindrical coordinates equations of one-dimensional mass transfer,it is considered to constant flux of mass transfer on tunnel wall,The distribution of water vapor concentration in the airflow along the section in tunnel is researched for the first time.On this basis of the distribution law of airflow velocity along the section in tunnel and the integrated boundary-layer equations,the convection mass transfer coefficient was work out,at the same time,the turbulent flow in smooth tube was analyzed with the Blasius criteria equation,The results are very similar.According to the theory of circulating mass coefficient and the rule of Louis,convection heat transfer coefficient was work out.It is considered to the effects of humidity on temperature,roadway properties and the main heat sources,the prediction model of wind temperature in the end of typical roadway was built,at the same time,the second league lane,1#belt down hill and third typical bifurcation tunnel and 2#belt down hill in Baliancheng mine was taken as the research background.The end temperature prediction model was used to forecast the airflow temperature in the typical roadway of Baliancheng mine.Through comparing with on-the-spot measurement data of airflow temperature,the simulating results were proven.According to the prediction model of wind temperature in the end of typical roadway and air network distribution theory,the mine ventilation management information system software MVIS launched in 2013 by Liaoning Technical University was used to forecast airflow temperature of underground roadway in the Baliancheng mine.Predicted values compared with the measured values,the result is better.