Optimization of the quantity of heated/refrigerated air required for ventilating underground mines with ventilation-on-request systems.

摘要

Development of deeper and more complex orebodies has increased the demand for efficient use of the air ventilating underground mining operations. Deeper and heavily mechanized operations present increasing difficulty for maintaining the air temperatures encountered by personnel, which must be removed to ensure their safety and health. The efficient use of air is made possible by the implementation of Ventilation-on-Request (VOR) systems. However, reductions in the quantity of air supplied by VOR may reduce the quantity below that which is necessary for effective heat exchange.;The objective of this thesis is to develop a heat simulation program that will determine the heat balance encountered in mining operations with VOR, and determine the appropriate size and number of conditioning plants required to maintain the air temperature at safe and healthy levels. A program written in Visual Basic was used to simulate the heat uptake by mine air and to solve for the conditioning requirements.;The most important advantage for simulating the heat uptake by the mine air is to know if cooling is, or will be required, in the future. As ventilation is a major cost component of an underground operation, and cooling (if needed) is a very large portion of the ventilation costs, accurately simulating these requirements is of primary concern.;Results of the heat simulation indicated that thermal rock conductivity, age of the airway, and geothermal gradient were important controlling parameters in the heat uptake by the air ventilating the mine. The accuracy of the simulation to surveyed values was heavily dependent upon these parameters; with airway temperature values predicted by the simulation showing nearly a one-to-one relationship. This simulation provides an accurate prediction of the heat balance in a mine and the cooling requirements needed to maintain the air temperature at safe and healthy levels.