摘要
With depletion of shallow deposits,the number of underground mines expected to reach more than 3 km depth during their lifetime is growing.Although surface cooling plants are mostly effective in mine airconditioning,usually secondary cooling units are needed below 2 kmdepth.This need emerges due to the elevated thermal impacts caused by auto-compression of mine air as well as heat emissions from strata and mine machinery.As a result,in cold climates,like Canada,ultra-deep mines need their secondary underground cooling plants running year-round while the intake air must be heated to protect the sensitive machinery and liners from freezing during the winter season.To cool mine air,horizontal bulk-airconditioners with direct spray cooling systems are commonly used due to their high performance.Conventionally,sprayed water in bulk-air-coolers are mechanically circulated and refrigerated in coupled refrigeration plants.This set up can be transformed to a natural cooling/heating process by resurfacing the warm underground bulk-air-cooler spray water for mine air heating on the surface and re-sinking the chilled water for cooling in the underground bulk air coolers.This could significantly cut-down the fossil-fuel consumption in burners for mine air pre-conditioning and refrigeration cost when applicable.This paper presents an anonymous real-life example to study the feasibility of the proposed idea for an ultra-deep Canadian mine.
