Numerical simulation of hydrothermal flow in the North China Plain: A case study of Henan Province.

• A two-dimensional coupled flow-heat-solid numerical model was established to simulate the dynamic response of stress and temperature field in the North China Plain (Henan). • The stress field alters the flow path and velocity distribution of the fluid, thereby affecting the heat conduction process; the influence of the stress field on heat conduction leads to distortion and uneven distribution of the temperature field. • Taihang Mountains and Yanshan Mountains in the western and northern parts are the main recharge areas for underground geothermal water in the North China Basin, while the recharge proportion in the southwestern mountainous area of western Shandong is relatively small. The distribution and flow of geothermal energy in the North China region are influenced by geological structures and rock thermal properties. However, the interactions between geothermal energy, groundwater movement, and hydrogeochemical processes are not well understood. In this study, a numerical model was developed to simulate these interactions under different geological conditions. The results showed that the stress field of geological structures affects the flow path and velocity distribution of geothermal fluid, leading to distortion and uneven temperature distribution. The distribution of high-mineralized zones of geothermal water indicated the main recharge area in the northern part of the North China Basin (Henan). Hydrochemistry analysis revealed a dynamic balance between centrifugal and centripetal flows in sandstone geothermal water. The study provides important insights for the exploration and development of underground geothermal water, as well as the assessment and optimization of geothermal resources in large basins. [ABSTRACT FROM AUTHOR]