Energy-efficient thermal management in deep underground mines
It is well known that underground miners are exposed to one of the most dangerous working environments on earth. As miners delve deeper into the earth, the rock pressure and temperature rise, which in turn have an adverse effect on the environment and thus lead to higher operating costs. Furthermore, in coal mines where methane gas and dust is also produced in coal beds, the combination of methane accumulation, oxygen and spark/heat can trigger explosions which may cause fatal accidents. Generally, mining environments are dynamic and changing very rapidly during extraction process. Essentially, changes in mine environment affect the performance of ventilation system. Careful estimation and design of air flow rate, spray system, cooling load and additional ventilation auxiliary equipment are of importance to ensure safety, comfortability and productivity whilst maintaining low operating cost.
In this research, three-dimensional structures of a mine development zone together with its auxiliary ventilation system are simulated using a computational fluid dynamic approach. Several designs and ventilations as well as heating and/or cooling scenarios are evaluated with respect to methane dispersion, dust distribution, diesel emission control and thermal management in mines. Effects of design and operating parameters, e.g., fan power, placement of air duct, length of mine advancement, diesel emission and heat generated from mining machine as well as heating/cooling loads, are examined to ensure good and safe design. The advantages and limitations of each design are discussed and compared not only in terms of quality and quantity, but also in terms of the overall pressure drop and energy requirements which represent the associated cost of ventilation and air conditioning system.
