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Abstract An efficient numerical model, which can simulate the coupled fluid flow and heat transfer processes in geothermal fields, is essentially required to evaluate the fate of geothermal wells and the temperature and pressure evolutions of geothermal reservoirs in response to the long-term well operations. Due to the scale disparity between wells and geothermal reservoirs (∼dm vs. ∼km), very fine mesh is required to accurately represent the highly-dynamic zones near geothermal wells, and thus the conventional geothermal reservoir model including geothermal wells is usually time consuming. To improve the computational efficiency without losing accuracy, a simplified one-dimensional geothermal well model considering heat convection and conduction along well axis and heat transfer between geothermal fluid and rocks in the radial direction is proposed and incorporated into the geothermal reservoir model. Both a bench-mark example and a case study of Beijing city geothermal field are presented to demonstrate the reasonability and efficiency of the proposed reservoir modeling method. The computational time are significantly reduced because of avoiding mesh refinement near geothermal wells. The multiple wells effects, interactions between different reservoirs, and the role of faults in reservoir performance are also discussed based on the case study of Beijing city geothermal field. Graphical abstract Image 1 Highlights • Simplified model for geothermal well based on equivalent heat transfer coefficient. • An integrated reservoir-well model for geothermal field including multiple wells. • Robust prediction of the fate of geothermal wells in Beijing urban geothermal field. [ABSTRACT FROM AUTHOR]

• A 3D thermal-fluid-structure coupling analysis model for the longitudinal connected slab track is presented. • The complex heat transfer processes between the longitudinal connected slab track and the environment are considered. • The temperature fields of the longitudinal connected slab track located in Beijing on typical dates are investigated. • The thermal effects of the track and the influence of the construction temperatures are discussed. The temperature field and thermal effects are important factors affecting the serviceability of the longitudinal connected slab track and the safety of high-speed trains, which are necessary to deeply understand. To analyze the temperature field and thermal deformation of the longitudinal connected slab track, based on the heat transfer processes between the track and the environment, a three-dimensional thermal-fluid–structure coupling analysis model is established. The meteorological factors are comprehensively considered in the model, and the temperature field and the thermal effects of the longitudinal connected slab track can be thoroughly investigated. Good agreement is observed between the calculated temperatures of the model and the measured temperatures at the testing platform. On this basis, the temperature and deformation of the longitudinal connected slab track in typical dates in Beijing are analyzed. The results indicate that the maximum temperatures of the track and the time of their occurrence vary in different seasons. The positive temperature gradient is greater than the negative temperature gradient. The temperature distribution of the slab track shows significant non-uniformity in the transverse direction along the track. In summer, the slab track has a U-shaped temperature distribution in daylight, while in winter, the slab track has an S-shaped temperature distribution. The uneven distribution of the track temperature causes uneven deformation of the precast slab. The arching deformation of the precast slab is greatest in summer. Focused observation of the precast slab during the hot season is required to prevent excessive deformation and instability of the slab. The construction temperature of the slab track has pronounced effects on track deformations. The construction temperature should be strictly controlled to prevent the track cracking or instability. [ABSTRACT FROM AUTHOR]

• A 3D thermal-fluid-structure coupling analysis model for the longitudinal connected slab track is presented. • The complex heat transfer processes between the longitudinal connected slab track and the environment are considered. • The temperature fields of the longitudinal connected slab track located in Beijing on typical dates are investigated. • The thermal effects of the track and the influence of the construction temperatures are discussed. The temperature field and thermal effects are important factors affecting the serviceability of the longitudinal connected slab track and the safety of high-speed trains, which are necessary to deeply understand. To analyze the temperature field and thermal deformation of the longitudinal connected slab track, based on the heat transfer processes between the track and the environment, a three-dimensional thermal-fluid–structure coupling analysis model is established. The meteorological factors are comprehensively considered in the model, and the temperature field and the thermal effects of the longitudinal connected slab track can be thoroughly investigated. Good agreement is observed between the calculated temperatures of the model and the measured temperatures at the testing platform. On this basis, the temperature and deformation of the longitudinal connected slab track in typical dates in Beijing are analyzed. The results indicate that the maximum temperatures of the track and the time of their occurrence vary in different seasons. The positive temperature gradient is greater than the negative temperature gradient. The temperature distribution of the slab track shows significant non-uniformity in the transverse direction along the track. In summer, the slab track has a U-shaped temperature distribution in daylight, while in winter, the slab track has an S-shaped temperature distribution. The uneven distribution of the track temperature causes uneven deformation of the precast slab. The arching deformation of the precast slab is greatest in summer. Focused observation of the precast slab during the hot season is required to prevent excessive deformation and instability of the slab. The construction temperature of the slab track has pronounced effects on track deformations. The construction temperature should be strictly controlled to prevent the track cracking or instability. [ABSTRACT FROM AUTHOR]