Numerical modeling of thermal regimes of geothermal heat exchangers

Intensification the heat supply to geothermal heat exchangers is studied, taking into account the relationship between the characteristics of the backfill and the operating modes of the systems under consideration. The prototype of the geothermal energy system under consideration is a real object with known geometric and physical parameters. The solution to the problem is obtained by the finite difference method. An implicit difference scheme and a sweep algorithm are used. The adequacy of the results of numerical modeling follows from checking the methods used to solve the problem for convergence and stability, and is also confirmed by a numerical comparison with known data on the operation of energy systems with geothermal heat exchangers. When analyzing the thermal regimes of the system under consideration, the main attention is paid to the study of the intensification of heat supply to geothermal heat exchangers, taking into account the relationship between the characteristics of the backfill and the operating modes of the systems under consideration. It has been established that an increase in the humidity of the sand backfill leads to an increase in heat inflows by 3.7-7.8 %. The significant influence of the unsteadiness of transfer processes on the intensification of heat transfer in the system under consideration is shown. It is revealed that when choosing an option for regulating the thermal conditions of geothermal heat exchangers, it is necessary to primarily change the volumetric humidity of the sand backfill.