Deep Mine Geothermal Resource Collaborative Exploitation Technology Research

Abstract

Deep mines must remove heat to keep working faces habitable, while the same rock mass and mine water form a large low-grade geothermal resource. This study examines how heat hazard control and geothermal recovery can be operated collaboratively, using a parameterized energy-balance model of a deep mine district at 1,200 m depth. Three scenarios were compared: an independent baseline with a capacity-limited chiller and a gas boiler (S0), a mine water source heat pump that supplies heat only (S1), and a collaborative cascade in which mine water first feeds the heat pump evaporator and is then used as the cold source of airway coolers (S2). Seventeen runs covering mine water inflow of 100–300 m³/h with S1 at 0.60 and S2 at three effectiveness levels were evaluated with relations for air temperature, water-side heat extraction, heat pump performance, primary energy and operating cost. For the typical scenario of 250 m³/h, the model estimates working-face air temperatures of 31.2, 31.2 and 28.0 °C, recovered heat supplies of 0, 6.34 and 8.19 MW, and primary energy reductions of 0, 29.1% and 39.8% for S0, S1 and S2, respectively. The cascade requires an inflow of about 192 m³/h to reach the 28 °C design target. The results indicate that sharing one water loop between cooling and heat recovery improves both thermal safety and energy performance, provided that inflow and exchanger effectiveness are adequate. The conclusions apply to the stated parameter ranges and require field calibration before engineering use.