Numerical Simulation Of Jet Ventilation And Thermal Disaster Prevention Study On High Temperature Heading Face

With the exhaustion of shallow surface resources, most underground metal mines in china have transferred to deep mining. Because of increased exploitation depth and other heat source's exothermic function, high temperature heat-harm has become outstanding problem which restrict safety production. There is only one outlet in heading face and it cannot form cycle air-flows naturally so the heat-harm problem becomes more seriously. Ventilation is an economical and effective method and scientific and rational system save cost. Based on the main roadway of Yunxi Company Ltd, with method of numerical simulation the influence factor of forced ventilation field distribution analyzed. Mainly contents as following:(1) The study on theory analysis and mathematical model of heading face flow. From the basic principle of mass conservation, momentum conservation and energy conservation under turbulent state carried on theoretical analysis of air flowing rules and established mathematical model.(2) Numerical simulation and evaluation of thermal environment in heading face. The temperature distribution was measured firstly, and then carried on numerical simulation with Airpark. Compared the result with field test data and analyzed the difference, finally evaluate the thermal environment from subjective consciousness and objective condition two aspects.(3) Analyze the influence factors of heading face jet ventilation. According to the numerical of field situation and the evaluate result, the influence of inlet parameter and tunnel parameter were carried on. Under different parameter condition, flow motion laws, temperature distribution and PMV-PPD index were compared.(4) The research of thermal disaster prevention technology. On the basis of simulation result knew that high-temperature situation can not change by ventilation method. So it must seek other methods to control thermal disaster. The successful technology provided reference for the new mining company and suitable technologies proposed.The result showed that: pressed ventilation in heading face obey restrained wall attached jet ventilation rule. The inlet parameter and tunnel parameter had impact on jet movement. Under different inlet parameter condition, jet had different initial energy which made bending level change, forming different temperature distribution, leading to different human thermal comfort, in which the most obviously parameter was inlet temperature. Under different tunnel parameter condition, jet had different attach force which made the roof effect on jet change, forming different coanda effect, leading to different human thermal comfort, in which the inlet position had the least influence.