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通风阻力的计算与测定是保障煤矿安全生产必须进行的日常工作。通常认为巷道内造成风流能量损失的途径主要是沿程摩擦损失、局部阻力损失、热阻力。传热导致流体物性参数会发生大变化,产生热阻力。巷道内不断有水蒸气和瓦斯等气体掺混进入主流空气中,形成复杂的对流传质现象,同样也会影响物性参数,从而产生附加通风阻力。这是一种被人们忽视的能量损失。本文对这种能量损失形式进行了探讨,提出了传质附加阻力概念,并运用CFD模拟技术研究了不同传热、不同散湿强度下通风阻力的变化规律。结果表明:当巷道风流速度低于0.5m/s时,传质使巷道阻力增加15%以上;当风速增大到2m/s以后,传质对巷道阻力的影响减弱,使巷道阻力约增大5%左右;当传质与传热同时存在时,传质会削弱热阻力,其综合效果不是简单的代数相加,传热与传质对阻力的影响是同一数量级。文中给出了传质附加阻力拟合计算式,可用于实际巷道通风设计和日常矿井通风能力核定。
Ventilation resistance calculation and determination is to protect coal mine safety production must be carried out daily work. It is generally considered that the main causes of wind energy loss in the roadway are friction loss, local resistance loss and thermal resistance along the road. Heat transfer fluid properties will lead to major changes in parameters, resulting in thermal resistance. There are continuous gas and other gases in the roadway into the mainstream air mixing, the formation of a complex convection mass transfer phenomenon, the same will affect the physical parameters, resulting in additional ventilation resistance. This is a neglected energy loss. In this paper, the form of energy loss is discussed, and the concept of mass transfer additional resistance is put forward. The variation of ventilation resistance under different heat transfer and different wet strength is studied by CFD simulation. The results show that the mass transfer increases the resistance of the roadway by more than 15% when the air velocity of the roadway is lower than 0.5m / s. When the wind speed increases to 2m / s, the influence of mass transfer on the roadway resistance is weakened and the resistance of the roadway is increased About 5%. When mass transfer and heat transfer coexist, mass transfer will weaken the thermal resistance. The combined effect is not a simple algebraic summation. The effect of heat transfer and mass transfer on the resistance is the same order of magnitude. In this paper, the formula for calculating the additional mass transfer resistance is given, which can be used in the design of actual tunnel ventilation and the routine mine ventilation capacity verification.