掘进巷道热环境与通风效率数值模拟研究

井下工作面必须应用通风系统。采用数值模拟技术分析了两种通风方式下,不同风口布置的掘进巷道内空气龄、空气流速和热舒适性指标PMV值的分布情况。根据模拟结果对掘进巷道通风模式的选择提出了建议。结果表明,长距离送风和短距离抽风方式是最有效率的通风模式。压入式通风方式的风口应布置在距掘进头10 m附近,抽出式通风方式抽风口应布置在距掘进头2m范围内。在相同的送风条件下,可增大短距离抽风方式下的送风温度,以提高掘进巷道内热舒适性和降低能耗。

Numerical simulation of roadway driving thermal environment and evaluation of ventilation modes

The present paper intends to introduce a numerical simulation model developed by the given author of the roadway drilling thermal environment and evaluation of ventilation modes.As is known,the ventilation system plays a key role in underground mining production,which ensures the miners’ safety and thermal comfort.For the time being,there exist two kinds of ventilation methods that have been numerically described by using the computational fluid dynamics(CFD).Taking the airflow distribution of drilling airway as subject,we think it is necessary to set up a physical and mathematical model for the 3-D airflow and the heat transfer,with the governing equation found by SIMPLE algorithm.In addition,it is also necessary to simulate the life of the air,the air velocity and predicted mean vote(PMV) distribution and analyze the efficiency of different layouts of the air opening.The results of our numerical simulation show that the ventilation systems would be efficient if the air were blown at a relatively long distance from the working face(about 10 m) or the exhaust taking place close to the closed side of the gallery(about 2 m).The air velocity of exhaust ventilation is lower than that of the forced ventilation. The vortex of the working face is weak for the exhaust ventilation and the pollutant can not be gathered,if the exhaust ventilation were easy to diffuse the dust while the air opening should be farther away from the working face.If so,the two ventilations would be able to transport the pollutants in the roadway successfully.And in the same air-blowing conditions,the range of PMV value would be 0.4-0.8 in the drilling airway nearby,which can be said to belong to the value of comfortable sensation for the forced ventilation.If the range of PMV value reaches-1.1——0.5 at the same drilling airway nearby,it can be said to satisfy the human thermal comfort requirement for the exhaust ventilation.Moreover,the PMV distribution should agree with the air ventilation velocity and airflow temperature exchange regularity.Therefore,the temperature of the air supply should be increased and the heat comfort can be improves with no increase of the energy cost for the exhaust ventilation.Thus,our calculated results will be able to offer a theoretic basis for improving the ventilation efficiency and the thermal comfort and a guide for selecting a suitable ventilation method of drilling airway.