화학공학소재연구정보센터
International Journal of Coal Geology, Vol.164, 115-122, 2016
Modelling flow and heat transfer in flooded mines for geothermal energy use: A review
In the last decades numerous coal mines have been closed. One way to overtake the costs associated to the mine closure is the geothermal use of the water stored in the closed and flooded mine workings. The temperature of the water flooding from the mine voids, in some cases reaching depths of several hundreds of meters, is suitable for space heating and cooling by means of the use of ground source (geothermal) heat pumps (low-enthalpy geothermal systems). Flooded mine voids constitute new-created pseudokarstic aquifers or reservoirs, which can store significant volumes of groundwater. However, the recharge and the heat capacity of these systems are finite, and this is the main concern when using mine water as a heat source or sink. These reservoirs can be regulated by means of flow extraction and injection depending on the use demands; notwithstanding, these flows have to be limited to a sustainable value, in order to avoid the exhaustion of the capacity of the aquifer to provide or store heat. Several numerical and analytical models have been created with this aim, with the shortage of hydrogeological and thermal data as main drawback. A literature review of the existent flow and heat transfer models applied to geothermal use of mine water has been undertaken, both analytical and numerical models are considered. The main parameters that have influence in the flow and heat exchange processes, have been analysed. The present paper can be used as basic guidelines to aid when selecting a modelling method for a specific scenario. (C) 2016 Elsevier B.V. All rights reserved.