Prediction of Temperature Field and Control Method for Heat Damage in Deep Shaft

During the excavation of the shaft, the inlet air temperature undergoes seasonal variations and is influenced by geothermal effects and air compression heat. Merely augmenting the inlet air volume fails to mitigate the extreme temperatures encountered at the deep working face. Consequently, the implementation of refrigeration and cooling technologies becomes imperative to manage the heat-induced issues. To address the high-temperature challenge during shaft excavation at the Sanshandao Gold Mine, a ventilation system model was developed utilizing Fluent simulation software. This model facilitated the prediction of the temperature field dynamics at the working face, taking into account project progression and seasonal shifts. Through a comprehensive analysis of factors encompassing cooling capacity deterioration, energy consumption for cooling, and the installation and maintenance requirements of refrigeration units across various systems, a surface-based centralized refrigeration system was devised. Furthermore, a simulation analysis was conducted to evaluate the refrigeration technology, offering valuable technical insights for the calculation of cooling capacity, as well as the selection and application of appropriate refrigeration systems. The results indicated that subsequent to excavating the shaft to a depth of 1600 m, the working face temperature fluctuated with seasonal variations but consistently remained above 28°C. At a depth of 1800 m, the temperature peaked, reaching a maximum of 40.19°C. Following the implementation of the surface centralized refrigeration system, with an inlet air volume of 22.6 m³/s and an inlet air temperature maintained below 10°C, the working face temperature was effectively reduced to below 27°C. This study presents a comprehensive suite of refrigeration and cooling methodologies, encompassing temperature field prediction, refrigeration parameter calculation, simulation analysis of cooling performance, refrigeration system design, and their application in deep shaft excavation. These methods provide a technical foundation for mitigating heat-induced damage in deep shafts.