The meteoric origin of the geothermal water in Xi’an is evidenced by its H and O isotope composition. Based on the temperature dependence of isotopic composition, the temperature of meteoric water that replenishes th...The meteoric origin of the geothermal water in Xi’an is evidenced by its H and O isotope composition. Based on the temperature dependence of isotopic composition, the temperature of meteoric water that replenishes the geothermal aquifers in Xi’an and its neighboring regions is calculated to be -13.28℃. The age of the geothermal water based on 14C dating method is 10-30 kaBP, belonging to a secondary glacial period in Late Quaternary. The source of replenishment is considered to have mainly derived from glacial snow melt water from elevations higher than 2,000m (ASL) in Qinling Mountains.展开更多
Cooling of coal mines in the Bowen Basin, characterized by steep geothermal gradient, is presently achieved mostly through rental surface bulk air cooling in summer months. This paper argues that future mines will be ...Cooling of coal mines in the Bowen Basin, characterized by steep geothermal gradient, is presently achieved mostly through rental surface bulk air cooling in summer months. This paper argues that future mines will be required to focus their cooling resources more intensively to manage a challenging thermal environment where virgin coal temperatures over 50 °C at a depth of 500 m are expected. Currently, mine cooling systems are employed to maintain the wet bulb temperatures(WBT) to below 27 °C at which point the risks of heat stroke or other heat related issues are manageable. The capacities of these systems are in the range of 6–10 MW refrigeration power. The relationship between high working temperature environment and injury frequency rates is well established. Therefore, provision of appropriate cooling strategies and understanding their optimum performance and suitability are important to Australian coal mines of the future. This paper evaluates the underground temperature profiles of deep, gassy coal mines with propensity for spontaneous combustion and proposes the long term cooling pathways to effectively manage the thermal hazards. Thermodynamic modeling is performed on a longwall face and includes air leakage effects from goaf streams at various locations along the longwall face. The strategy summarizes the application of underground bulk air cooling, chilled water sprays on the shearer and the resulting temperature profiles. Considering the new mining projects planned for the Bowen Basin region, a review of implementable cooling strategies such as mid-gate mobile bulk air coolers(BACs), spot coolers, underground bulk air cooling and the use of chilled water to enhance the positional efficiency of cooling plants,are discussed in this paper. Finally, the comparison of ‘rental' versus ‘ownership' of cooling plants is analysed as part of long-term cooling strategies.展开更多
文摘The meteoric origin of the geothermal water in Xi’an is evidenced by its H and O isotope composition. Based on the temperature dependence of isotopic composition, the temperature of meteoric water that replenishes the geothermal aquifers in Xi’an and its neighboring regions is calculated to be -13.28℃. The age of the geothermal water based on 14C dating method is 10-30 kaBP, belonging to a secondary glacial period in Late Quaternary. The source of replenishment is considered to have mainly derived from glacial snow melt water from elevations higher than 2,000m (ASL) in Qinling Mountains.
基金support received from Anglo American Metallurgical CoalAnglo American Operations (Pty) Ltd in preparing this paper
文摘Cooling of coal mines in the Bowen Basin, characterized by steep geothermal gradient, is presently achieved mostly through rental surface bulk air cooling in summer months. This paper argues that future mines will be required to focus their cooling resources more intensively to manage a challenging thermal environment where virgin coal temperatures over 50 °C at a depth of 500 m are expected. Currently, mine cooling systems are employed to maintain the wet bulb temperatures(WBT) to below 27 °C at which point the risks of heat stroke or other heat related issues are manageable. The capacities of these systems are in the range of 6–10 MW refrigeration power. The relationship between high working temperature environment and injury frequency rates is well established. Therefore, provision of appropriate cooling strategies and understanding their optimum performance and suitability are important to Australian coal mines of the future. This paper evaluates the underground temperature profiles of deep, gassy coal mines with propensity for spontaneous combustion and proposes the long term cooling pathways to effectively manage the thermal hazards. Thermodynamic modeling is performed on a longwall face and includes air leakage effects from goaf streams at various locations along the longwall face. The strategy summarizes the application of underground bulk air cooling, chilled water sprays on the shearer and the resulting temperature profiles. Considering the new mining projects planned for the Bowen Basin region, a review of implementable cooling strategies such as mid-gate mobile bulk air coolers(BACs), spot coolers, underground bulk air cooling and the use of chilled water to enhance the positional efficiency of cooling plants,are discussed in this paper. Finally, the comparison of ‘rental' versus ‘ownership' of cooling plants is analysed as part of long-term cooling strategies.
