Experimental Study On Variation Law Of Airflow Temperature And Moisture Field Of Roadway Under The Action Of High Temperature Fracture Water

The heat hazard is becoming more and more serious with the coal mines in the eastern and central parts of China enter deep mining,which not only causes great harm to the physical and mental health of mine workers,but also seriously restricts the normal production of mines.The deep wells have long ventilation lines and large exposed areas of roadway,there is a complex heat and moisture exchange between the surrounding rock and the wind flow.The field observation and research of the coal mines show that the high temperature of rock is the main factor causing the heat hazard of the deep mine.The deep groundwater cycling rises is an important factor affecting the temperature and moisture field of the airflow.The paper uses the combination of field measurement,theoretical analysis and physical simulation to study the variation of the temperature and moisture field of the roadway under the action of high temperature fissure water.The specific research work includes the following aspects:(1)A mathematical model for heat and moisture exchange of roadway under the action of fissure water seepage is established.The airflow thermal parameters of coal mines' were measured,and the characteristics of temperature and humidity changes along the summer and winter coal mines were analyzed.The geothermal data of coal mines in typical high temperature and heat damage areas in China are summarized.The causes of the formation of high temperature anomaly areas are discussed.The influence factors of temperature under the vertical migration of fluids along the strata are analyzed.The heat and humidity source of coal mine roadway which's high temperature anomaly is caused by deep underwater cycling rises.A mathematical model of the hot wet roadway was established and the calculation method of the heat transfer amount of the wet roadway was derived.(2)The similar simulation experiment system of the hot and humidity environment in high geothermal roadway is transformed and upgraded.Based on the similar simulation experiment system of the hot and humidity environment in high geothermal roadway developed by the research group,the fracture water seepage casing and the large flow water temperature constant temperature control device were developed,which can be used to study the variation of airflow temperature and moisture field under the action of fracture water.The variation law of airflow temperature and moisture field of roadway under different flow and different temperature conditions of fracture water was studied.Research shows:(1)Under the condition that the inlet airflow is relatively dry(relative humidity 20%),in the steady flow section,the influence of fracture water flooding into the roadway on airflow temperature is not obvious.The sensible heat exchange of the wind current is basically unchanged,and the heat exchange between the airflow and the high temperature fracture water is mainly based on latent heat exchange;(2)The increase of water vapor enthalpy value and the increase of wet air enthalpy value in the steady flow section of the roadway under the action of fissure water have a strong positive correlation with the fracture water inlet temperature and the fracture water inlet flow.Moreover,the increase with the temperature of the fracture water inlet is exponentially increasing,and with the flow rate of the fracture water inlet is obviously linear.The research results have reference value for coal mines heat hazard prevention and prediction of downhole airflow temperature and moisture field.