NUMERICAL MODELING OF THERMAL ENERGY TRANSFER BETWEEN ROCKS AND GROUNDWATER

Geothermal energy, derived from the Earth's internal heat, stands out as a powerful and consistent renewable resource. Unlike intermittent sources such as solar and wind, it provides a stable, 24/7 baseload power supply suitable for everything from large-scale electricity generation to direct-use heating and climate control. This study investigates the low-enthalpy geothermal potential near the Petroleum-Gas University of Ploiesti, Romania, where the ground maintains a constant temperature of 13-14°C at a 100-meter depth. We developed a numerical model to simulate the heat transfer between rock formations and groundwater to assess the viability of a thermal recovery project.The simulation results point to a stable heat transfer rate of 2-10 kW/m² from the surrounding rock to the groundwater. Our model shows that a four-well system could sustainably produce water at 13.5°C with a flow rate of 30 l/h over a 10-year period, causing a negligible temperature drop of less than 0.5°C in the reservoir. Ultimately, the model confirms that harnessing low-enthalpy geothermal energy in Ploiesti is a viable option. The constant and accessible underground temperature presents a significant opportunity for direct-use applications, such as a district heating system for the university campus. This research demonstrates that even modest thermal gradients can be effectively utilized to develop local and sustainable energy solutions.