Referring to the fundamental principle of thermodynamics, the upcast shaft was taken as a special tunnel in mine ventilation system,and the air in the air flow could not be taken as the ideal gas.

• 以热力学基本原理为依据,将回风井看作是矿井通风系统中的一条特殊巷道,指出其风流中的空气不能看作理想气体,推导出了测算矿井外部漏风率的正确方法。