Studies of the geothermal heat transfer process using a geothermal thermosyphon with natural circulation

Active development of technologies that allow using “environmentally neutral” renewable energy sources is necessary to in order to achieve the goals of sustainable development of modern society and increase the share of energy resources in the energy balance of the Russian Federation with the minimal man-induced impact on the environment. One of these energy resources is geothermal energy of the Earth, i.e. the energy of natural thermal reservoirs formed mainly as a result of the lithospheric plates activity in the Earth's crust. Currently, geothermal energy is being actively developed in industry, energy, and agriculture of most countries. The choice of extraction method directly depends on the depth of the thermal collector. There are technologies for extracting heat from a depth of more than 3 km, such methods involve high investment risks and capital costs. Currently, heat transfer technologies using near-surface systems are widely used. One of the promising technologies is heat transfer using a geothermal thermosyphon with natural circulation of the working fluid. Operation of a geothermal thermosyphon is analyzed, which is based on the phenomenon of free movement of the working fluid, with a decomposition of its operation stages. While searching for options to increase the efficiency of such systems, an experimental installation was designed to study the patterns of the heat transfer process depending on the geometric parameters of the thermosyphon and its design features. The heat transfer process is investigated depending on the height of the experimental model and the introduction of a structural separator for the ascending and descending flows. It is determined that with an increase in the temperature of the soil mass, the amount of the transferred heat increases due to the presence of a medium separator by an average of 25%.