Tracer gas measurement and simulation of turbulent diffusion in mine ventilation airways

• 来源期刊: 中国煤炭（英文版）
• 关键词: underground,mine ventilation,turbulent,diffusion coefficient,numerical model
• 年，卷（期）: 2008,（4）
• 页码范围: 523-529
• 页数: 7页
• 语种: 英文

摘要

The effective diffusion coefficients in mine ventilation-flows had been obtained as 4 to 200 m2/s by matching the measured concentration-time curves with the advec-tion-diffusion equation. The turbulent diffusion coefficients in the simple airways have good agreement with the equation proposed by Taylor. However, for complex airways in operat-ing mines, the evaluated effective diffusion coefficients in the mines show higher values than that calculated by the Taylor's equation. A numerical simulation model using with movements of discrete particles dosed into ventilation flows has been developed to simu-late diffusion phenomena of gas or dust in mine airways. Numerical simulations had been conducted on distribution of tracers in single airways with ordinary profiles of mean velocity, velocity fluctuations and Reynolds stress. As one of results, long band of diffused particles is obtained at the single airway of 600 m in length, and large effective diffusion coefficient is evaluated as 20 m2/s.