ПОРІВНЯЛЬНИЙ АНАЛІЗ ГЕОТЕРМАЛЬНОГО ПОТЕНЦІАЛУ ЗАКРИТИХ ШАХТ ДОНЕЦЬКОГО ТА РУРСЬКОГО ВУГІЛЬНИХ БАСЕЙНІВ

Abstract

Purpose. This study aims to perform a comparative analysis of the geothermal potential for closed mines in the Donbas and Ruhr regions in terms of the operation efficiency of geothermal systems of various types. Methods. The proposed approach includes ranking closed mines in the Ruhr (Germany) and Donetsk (Ukraine) coalmining areas according to the major parameters of geothermal system efficiency that includes the maximum and net thermal capacity, heat pump coefficient of performance COP, energy efficiency of heat recovery. The last parameter, introduced by the authors earlier, is defined as the ratio of the produced thermal energy to the thermal equivalent of the electricity required for running the heat pumps and the heat transfer fluid circulation. Results. The average expected thermal capacity of open loop geothermal systems at mine drainages in Germany was found higher than the similar indicator for the selected mine drainages in Ukraine, with slightly lower indicators of mine water heat recovery compared to the drainages in the Donbas. The average expected thermal capacity of closed loop geothermal systems based on coaxial probes at the current water level in the mines of two areas is estimated to be within the range of 30-34 kW, and the average indicators of geothermal heat recovery in the mines of two areas differ by no more than 5%, while the mines in the Donbas demonstrate a higher dispersion of calculated indicators. Similarity of operating conditions and energy efficiency indicators of geothermal systems evaluated for two areas indicates the feasibility and the potential of operating such systems in Ukraine. Scientific novelty. The approach to ranking of closed mines according to their geothermal potential based on parameters of mine water heat recovery efficiency has been substantiated and implemented. The developed approach enables identifying the promising sites to install geothermal systems of various types at inactive mines. Practical significance. The proposed approach allows to preliminarily evaluate the ranges of indicators for the effective operation of geothermal systems of various types with identification of the most promising areas for further detailed technical and economic justifications.