Estimation of the power of a geothermal energy recovery system that uses a heat exchanger

Abstract

Access to new sources of renewable energy free of CO2 emissions is one of the priority needs of the global economy. At great depths underground there are geothermal sources with temperatures of up to several hundred degrees. Recovery of energy from such sources may take place using a heat exchanger placed in rocks at great depths. Before starting the exploitation of such resources, it is necessary to estimate the performance and power of the source with the assumed system parameters. In the conducted research, simulations of the energy acquisition system in the Matlab-simulink environment were carried out. The model of heat flows with distributed variables was used for the simulation, describing changes in the temperature distribution in time and space. The steady-state power of the system, which is possible to download over a long period of time, was also estimated. The most important conclusion from the conducted is that after some time, depending on the power consumed, the system may experience a significant decrease in power. The decrease in power is caused by the cooling of the rocks around the heat exchanger and the thermal resistivity of the medium, which are the rocks.