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热害矿井中,热因素的存在会引起井巷各断面气体参数的差异,产生风流流动的热阻力,阻力的变化将导致通风网络风量的变化,影响矿井通风安全。由于热阻力难以用1个参数表征,在通风网络解算中,一般只考虑巷道风阻力,忽略热阻力的存在,即忽略热因素的影响。将有稳定热因素影响的井巷视为壁面粗糙、无热因素和有热因素、无黏性的两个巷道的叠合,分别分析井巷的摩擦阻力和热阻力,对比摩擦阻力与热阻力计算公式,提出类似于风阻的稳定热因素影响下风流流动的热阻概念,并推导其计算公式。结果表明,热阻与初始停滞焓、热源绝对放热量、两断面空气密度以及井巷断面面积等物理参数有关,与风量无关,与风阻量纲一致。最后以常用的通风网络解算方法为基础,对风量修正公式进行修正,提出嵌入热阻后新的风网解算方法。对比热阻融入经验公式前后的结果,证明热因素的存在对网络风量调节有较大影响。
In the heat-affected mines, the existence of thermal factors will cause the difference of gas parameters in each section of the borehole and produce the thermal resistance of the wind flow. The change of the resistance will lead to the change of the air volume of the ventilation network and affect the mine ventilation safety. As the thermal resistance is difficult to characterize a parameter in the ventilation network solution, generally only consider the laneway wind resistance, ignoring the existence of thermal resistance, that is, ignoring the impact of thermal factors. The well with the influence of stable thermal factors is considered as wall roughness. There is no thermal factor and no superposition of the two tunnels with no heat. The friction and thermal resistances of the roadway are respectively analyzed. The frictional resistance and thermal resistance The formula of heat resistance is proposed, which is similar to the influence of stable thermal factor of wind resistance on the flow of wind flow, and the calculation formula is deduced. The results show that the thermal resistance is related to the initial stagnation enthalpy, the absolute heat release from the heat source, the air density at the two cross sections and the section area of the shaft. The thermal resistance is independent of the air volume and is consistent with the dimension of the air resistance. Finally, based on the commonly used ventilation network solution method, the air volume correction formula is modified, and a new wind network solution method after embedded thermal resistance is proposed. Comparison of thermal resistance before and after the empirical formula into the results show that the presence of thermal factors on the network air volume regulation has a greater impact.