局部通风掘进巷道风筒综合换热系数确定方法研究

Study on the method for determining the overall heat transfer coefficient of auxiliary ventilation duct in head face

在矿井风流与围岩热湿交换理论的基础上,对局部通风掘进巷道内风流与风筒内风流的热量交换过程进行了研究,提出了通过现场测定巷道内的风流温度、湿度、大气压力、风量和风筒内风流温度等参数来计算风筒综合换热系数的方法。并在平顶山煤矿现场进行了实测,通过对实测计算结果的回归分析,得出了确定风筒综合换热系数的计算公式。研究表明,通过计算巷道内平均风速可以获得风筒综合换热系数。

The overall heat transfer coefficient of auxiliary ventilation duct is one of the most important parameters for thermal environmental prediction in an auxiliary ventilation head face. The precision of the value has direct impact on the accuracy and reliability of thermal environmental prediction. Based on the heat exchange theory of mine airflow and roadway surrounding rock, the heat transfer process of airflow between the ventilation duct and head face has been analyzed. The method for determining the overall heat transfer coefficient of auxiliary ventilation duct was put forward through the in-situ measurement of air flow temperature, humidity, atmospheric pressure and airflow rate in head face as well as the airflow temperature in duct. lnsitu measurement was carried out at the coal mines of Pingdingshan colliery and a formula is proposed to calculate the overall heat transfer coefficient of auxiliary ventilation duct. The results of research show that the overall heat transfer coefficient of duct can be calculated according to the average speed in head face. In addition, the relationship between overall heat transfer coefficient and airflow speed can be approximately expressed by a linear equation. The overall heat transfer coefficient increases as the average airflow speed in head face increases.