Abstract:
This paper addressed the high-temperature thermal hazards encountered in mining operations of ultra-deep mines, proposing a spray cooling technology based on the intake airflow of deep ventilation systems. A case study was conducted using an ultra-deep mine in Yunnan Province as an example for simulation experiments. By using a control variate method, tests were conducted to measure the spray droplet size distribution and liquid flow rate at nozzle orifice diameters of 0.15–0.8 mm and spray pressures of 2–10 MPa. The results indicate that using a 0.15 mm nozzle orifice diameter at a spray pressure of 6 MPa produces droplets with a spray droplet size below 10 μm, closely matching the size of respirable dust particles. Theoretically, the water mist effect is the most ideal for the sedimentation of respirable dust. Numerical simulations further validate the feasibility of the spray cooling system, demonstrating that installing such a system in mine roadways can significantly improve temperature distribution, with maximum cooling reaching approximately 10 K. This research provides data support for thermal hazard mitigation in ultra-deep mines in Yunnan Province, addressing issues such as excessive cooling loss and humidity accumulation associated with traditional cooling methods.