Natural Ventilation Properties and Thermal Environments of a Closed Underground Mine

Abstract

In this study, we measured properties of natural ventilation in a closed Arakawa mine and considered those properties theoretically. The natural ventilation pressure was estimated from the ratio of leakage airflow to the airflow when the ventilation door is fully opened, and the differential pressure between the front and the back of the door. We used a simple calculation method based on the average density of humid air in a simple ventilation circuit model．The measured natural ventilation pressure agreed very well with the results of simple calculation method. Therefore, if the modeling of the ventilation network is performed appropriately, simple calculation method is effective. In addition, seasonal changes in the quantity of ventilation agreed well with the results using the measured nature ventilation pressure, ratio of airflow, and average ventilation resistance value. The direction of airflow, natural ventilation pressure, and quantity of ventilation showed a change approximately every six months.

Keywords

• mine ventilation
• nature ventilation pressure
• ventilation surveys
• air leakage
• underground mine