煤矿井下风流温度周期性变化研究

Research on periodically change of airflow temperature in coal mine

煤矿井下风流温度受地面大气的周期性变化而变化,但其变化的规律目前没有定量计算方法。通过对圆形巷道导热微分方程及其边界条件的无因次化,将围岩温度场表达成两个温度场的迭加结果,这两个温度场分别受年平均风温和风温波动的影响。重点分析了风温波动微分方程及其定解条件,推导出当地面大气温度周期性波动时,井巷不同地点对应的温度波动的振幅及相位角的表达式,并通过计算分析,得出温度波动的振幅随巷道长度呈负指数曲线下降,相位角随巷道长度线形滞后的结论。

The airflow temperature in coal mine changes with periodical change of surface atmosphere, but its changing law can＇t be worked out by quantitative calculating method currently. In the paper, by differential equation of heat conduction of the round roadway and dimensionless analysis of its boundary conditions, the temperature field of the surrounding rock is expressed as a superposition of two temperature fields and the two temperature fields are respectively affected by annual average wind temperature and air temperature fluctuation. The paper mainly analyses the differential equation of wind temperature fluctuation and its definite condition and deduces the expressions of temperature fluctuation amplitude and phase angle at different points of roadway, while surface air temperature periodically fluctuates; by calculating and analyzing, the paper draws a conclusion that with roadway length increasing, the amplitude of temperature fluctuation declines in negative exponent curve and phase angle linearly lags.