井下避难硐室防排烟结构体系的实验与数值模拟

Experiment and Numerical Simulation Study on a Structure System of Smoke Control for Refuge Chamber in Mines

为提高井下避难硐室的防烟能力,提出了一种避难硐室防烟体系。该防烟体系由避难硐室前的正压送风前室和一段具有排烟能力的巷道构成,通过前室送风风流的阻挡和巷道内的排烟共同作用,以阻挡烟气进入硐室。采用小尺寸模型实验和数值模拟方法验证了该体系的可行性,并通过改变正压前室顶部送风口的风速,探讨了其对正压前室防烟和排烟巷道中排烟效果的影响。研究结果表明：前室送风形成的反吹气流,可以有效地阻止烟气侵入避难硐室,降低巷道内烟气的温度。在排烟风速4 m/s的条件下,若送风口的风速大于排烟口风速,烟气的最高温度比送风口风速较小时降低了10~30℃。送风口处正压值增加后,排烟口处的负压值也增加,说明增加正压送风的防烟方式能够促进排烟。

A structure system of the smoke control for the refuge chamber was proposed to improve the smoke control ability of a refuge chamber in mines. The system of the smoke prevention consisted of the front chamber of the pressurized air supply system in front of the refuge chamber and a section of the roadway with the capacity of the smoke extraction. Due to the air barrier of the front chamber and the effect of smoke extraction of the roadway,the flue gas was blocked into the chamber. An approach to a small-scale model experiment and numerical simulation was adopted to verify the feasibility of the system. Besides,its impact on the smoke prevention of the positive pressure front chamber and the smoke extraction of the roadway was discussed by changing the wind speed of the outlet at top of the positive pressure front chamber. The results show that blowback air flow in the formation of the supply of the front chamber can effectively prevent smoke from invading the refuge chamber and reducing the temperature of the flue gas in the roadway. Under the condition of the smoke extraction wind speed 4 m / s and that the wind speed of the delivery outlet was greater than that of the exhaust outlet,the maximum temperature of flue gas was 10 ℃ to 30 ℃ smaller than that of the delivery outlet. When the positive values increased at the delivery outlet,negative ones at the outlet of the smoke extraction also increased. It indicated that supplying air can promote the smoke extraction by way of expanding the positive pressure.