Experimental determination thermal conductivity of dolomitic limestone

The origin of geothermal energy is in the hot core of the Earth. Due its inexhaustible potential, it is also included among renewable sources. Renewable sources are, from the point of view of national economies, domestic resources that have the potential to replace and in the future, in certain applications, completely dispose of fossil fuels. These sources already offer the opportunity to significantly diversify energy sources in each country. Their development is also seen as an important tool to protect the national economy from future shocks from the rise in imported fuel prices and the cost of environmental damage [1]. Heat from the Earth's rock is obtained from deep boreholes of 100 m to 300 m. Systems for acquiring natural thermal energy from the ground are referred to as ground (wells) - water, i.e. that the rocks are the source of thermal energy that is pumped from the rocks through a circulating antifreeze mixture into a hermetically sealed collector. The heat pump produces a heat output of up to 65°C through the compressor, which is sufficient for the hot water heating system or for hot water heating [2]. Limestone and dolomite make up four fifths of all sediments on the Earth's surface. The transition between dolomite and limestone is not sharp, and thus is form a dolomitic limestone - a rock made of dolomite and a predominant limestone. Dolomite is a rock of sedimentary origin. It consists predominantly of a mineral of the same name. It is formed by settling of CaMg(CO3) in hypersalinic aqueous medium, but more often it results from dolomitization of settled limestones [3]. In Slovakia and especially in the Žilina region there is a large number of sites on dolomitic limestone, so it is necessary to know the properties of these rocks in what composition they occur in nature. The course of the temperature field in the rock mass can be determined by direct field measurements and analytical calculations. Mostly on-site measurement results provide input data for analytical calculation. On the other hand, the analytical calculation applies to the ideal body, and the information thus obtained provides a sort of temperature field course. By comparison, we can determine whether the temperature field in a rock mass based on the calculations is real or is loaded by errors (in measurements, in ignorance of structural - texture parameters, moisture and other aspects of material and mass) [4].

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2. Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).