| Title | Low-Enthalpy Geothermal Waters in Coal-Mines, Upper Silesia Coal Basin, Poland |
|---|---|
| Authors | Zbigniew Malolepszy |
| Year | 2000 |
| Conference | World Geothermal Congress |
| Keywords | geothermal energy |
| Abstract | The paper presents the potential of utilization of low-enthalpy waters 920-45oC) from 54 coal mines of the Upper Silesia (Southern Poland). The estimate of geothermal energy in water filling post mining excavations of abandoned and existing coal mines of Upper Silesia Coal Basin has been carried on according to geothermal gradient 23-40oC/km and terrestrial heat flow 54-74 mW/m2 in the region. The numerical modeling of the heat transfer by conduction and convection has been used to simulate the heat flow from surrounding rocks into the water in geothermal reservoirs created in coal mines up to 1000 m deep with capacity of several millions m3 each. It show that heat flux induced by the water rock temperature difference in mine openings is of much higher range of W/m2 than the terrestrial heat flow. In practice geothermal energy is provide within a range of up to 20MW per one coal mine. The sensitivity analysis show that the geometry and depth of the mine as well as the thermal properties and permeability of surrounding rocks have a principal influence on the thermal power possible to obtain from the mine. The modeling present's high geothermal potential of lock outed as well as existing imines, where for many years dewatering of mines provides up to 50m3/min water at temperature of about 20oC. The heat pumps combined with gas burners using methane extracted from deep coal seams in the region are proposed for utilization of geothermal heat in the district heating systems. Reduction of CO2 will benefit due to utilization of geothermal energy in this most polluted are of Poland. |