The Prediction Of Airflow Temperature And Its Application In The Mine Ventilation Design

With the exhaustion of shallow mineral resources, mining technology is developing gradually towards deep mining. And the original rock temperature is rising along with the increase of mine depth. The heat hazard becomes more and more serious and to be one of the major issues restricting the safety in production. So the accurate prediction of airflow temperature in underground mining becomes very important, it can provide the basis for the prediction and control of underground working environment, and strengthen the guiding function in ventilation design.The present situation of domestic and overseas study in the theory of airflow temperature prediction is briefly stated. Based on the theory of heat transfer between wall rock and airflow, a kind of model and method for airflow forecasting is proposed directing at new mining design. The change laws of airflow temperature are finally summarized through analyzing the influences of initial air temperature, ventilation, heat transfer coefficient, compression heat on airflow temperature from two aspects including theory and practical calculation.The change laws of airflow temperature:(1) The airflow temperature becomes higher overall after the processes of heat exchange with wall rock and self compression in underground mine.(2) When the other condition is certain, the airflow temperature rises with the increase of intake shaft depth, as well as with the increase of drift length, it is approximately direct proportional to initial airflow temperature whose changes will not influent the increase of he airflow temperature in ventilation circuit.(3) When the other condition is certain, the airflow temperature rises with the enlargement of thermal conductivity, and reduces with the strengthening of the ventilation.Through the data calculation and analysis, compression heat is found also as an important factor which influences airflow temperature. In this paper, difference is used to calculate airflow temperature joining compression heat; as a result, the accuracy of airflow temperature is improved.Finally, the temperature prediction technology is applied to the ventilation design. And CFX is used to evidence the correctness of airflow temperature change laws.