| Popis: |
The Natural Heat Exchange Area (NHEA) is a large-scale fractured rock mass at Creighton Mine, created by previous sublevel cave mining, that is used to seasonally store thermal energy with the purpose of moderating the temperature of ventilating air for the underground mine. The use of the NHEA has avoided the mechanical cooling and heating otherwise required due to the seasonal variations in ambient temperatures. The NHEA has 96 doors through which air enters the mine airways through the mass of broken rock; these doors are manually operated to improve the tempering capacity. The empirical strategy for operating the doors has proven successful so far, but additional cooling is needed as mining progresses deeper. This paper describes two models, a three-dimensional computational fluid dynamics (CFD) model and an analytical network model. The models are calibrated to agree with the history of measured temperature, airflow and pressure at the NHEA. The calibrated models will be used together to support the assessment of both operation and systems design variations. |
