Numerical simulation and experimental study of ARS for the resourceful utilization of low-grade heat hazards from high-geothermal tunnels

To address the critical challenges posed by high geothermal heat hazards in tunnel construction that threaten worker safety and constrain operational efficiency, this study pioneers the utilization of high-temperature water inrush within the tunnel as a heat source to drive an absorption refrigeration system (ARS), thereby enabling proactive thermal regulation of the construction environment. A steady-state ARS model was established using Simulink to comprehensively analyze the impacts of parameters including heat source water, cooling water, and chilled water on the system's coefficient of performance (COP). The investigation revealed that elevated heat source water temperatures significantly enhance refrigeration performance, while increased cooling water temperatures cause synchronous reductions in both cooling capacity and COP. Chilled water flow rate variations demonstrate negligible effects on COP. Furthermore, an ARS laboratory test platform was constructed and validated through indoor experiments, incorporating environmental parameters from an ongoing high geothermal tunnel project and numerical simulation results. The findings demonstrate excellent agreement between computational predictions and experimental data, confirming the robust adaptability of the designed ARS under the specific tunnel conditions. In summary, this research establishes a theoretical foundation for resourceful utilization of high geothermal heat hazards, contributing to green construction practices and sustainable development in tunneling engineering.