Convective Heat Transfer Analysis of Supercritical CO 2 in Artificial Rock Fractures

Geothermal energy has emerged as a promising renewable and sustainable resource. This research article explores the utilization of supercritical CO2 and convective heat transfer in porous rock to enhance geothermal extraction. Artificial cement rock with a smooth and manmade slotted surface fracture was used as a working sample for heat transfer source in the test. Heat transfer characteristics under various flow rates, fluid inlet temperature and pressure, rock initial temperature are analyzed. The results indicate that the geometry characteristics of fracture surface impact the overall heat transfer intensity to a certain extent, whereas lithology has little influence on the heat transfer intensity. In addition, it is found that increasing injection pressure affects the operating temperature and density of the injected fluid, which helps to improve the production effect, to obtain more heat. However, limited by the heat transfer area, low injection flow is required. The maximum error of the heat transfer coefficient model is 7.05% compared with the empirical value and less than 10% compared with the experimental results. By examining the interaction between fluid and porous fractures, we aim to provide insights into the potential of these techniques for maximizing energy efficiency and tapping into deep geothermal resources.