Cooling and heat recovery performance evaluation of an advanced geothermal exploitation cooling system for deep mines based on physical experiment

To address the challenge of heat hazards in deep high-temperature mines, this study proposes an advanced geothermal exploitation cooling system (AGECS) based on the concept of synergetic mining of mine geothermal energy. Unlike conventional passive cooling measures applied after mining begins, the proposed system is deployed during the mining preparation stage, allowing the surrounding rock temperature to be reduced in advance. This approach improves the thermal environment from the outset and enables integrated heat hazard control and geothermal energy recovery throughout the mining process. A physical experimental platform with a geometric similarity ratio of 1:100 was constructed to investigate the effects of three key injection parameters (injection temperature, injection duration, and injection flow rate) on the cooling behaviour of the surrounding rock. Results showed that reducing the injection temperature from 25 °C to 10 °C shifted the innermost isotherm value from 31.10 °C to 24.13 °C. Extending the injection duration from 1 h to 2.5 h reduced the innermost isotherm value from 33.43 °C to 24.13 °C and expanded the cooling area. Under a fixed total injected volume, higher injection flow rates improved early-stage cooling but led to faster thermal rebound. Partial least squares regression analysis confirmed that injection temperature consistently dominated the cooling area ratio, while the influence of duration and flow rate varied over time. These findings reveal the effects of injection parameters on cooling performance and provide a theoretical basis for the parameter configuration of the AGECS system in deep mine thermal management.