独头巷道空气年龄及通风有效性评价研究

根据独头巷道作业空间的特点，给出了独头巷道局部空气年龄、平均空气年龄的定义及其计算模型，用示踪气体测定平均空气年龄的方法和原理，并用CFD (computational fluid dynamics)对独头巷道附壁受限射流通风流场及平均空气年龄进行了数值计算，得出了独头巷道空间通风流场和平均空气年龄分布，建立了计算换气效率和排污效率的数学模型。研究表明影响通风有效性的主要因素是空气年龄和污染物浓度，而影响空气年龄主要是通风气流组织和通风量。为评价独头巷道通风有效性提供了一种新的理论依据。

Study on Air Age and Evaluation of Ventilation Validity of Heading Face

Heading face is a special underground workspace, generally forced ventilation is chose to supply fresh air, and the air movements in it belong to restricted wall-attached jet. According to the characteristics of workspace in heading face, this paper gives the definition of partial air age and average air age, and their models for calculating. Tracer gas method was used to menstruate the average air age, and numerical simulation has been used to calculate the ventilation airfield of restricted wall-attached jet and average air age of heading face, and elicit ventilation flow field and distributing of average air age of heading face. Based on them, relations between the air age and ventilation flow field, ventilation validity are analyzed, and the mathematical model of air exchange efficiency and ventilation efficiency of heading face were set up. The study revealed that the major influences to air age are air-flow organization and blast volume, and to air quality are air age and pollutant concentration. The conclusion of this research provides a kind of new theory basis for appraising the ventilation validity of heading face.