Abstract:

 To mitigate or prevent high temperature heat damage during tunnel construction in areas with elevated ground temperatures, an auxiliary tunnel cooling measure that utilizes high temperature gushed water to drive an absorption refrigeration system and ultimately producing frozen water is proposed. Thermodynamic models for each component of the refrigeration system are formulated based on the principles of energy conservation and mass conservation. The Engineering Equation Solver numerical simulation platform is employed to calculate and analyze the performance of both singleeffect and twostage lithium bromide absorption refrigeration systems. Results are as follows: (1) The absorption refrigeration system can be driven by water with a temperature exceeding 60 ℃ when the evaporation temperature is maintained at 5 ℃. (2) Adjusting the evaporation temperature and reducing the condensation temperature enables the system to be powered by a heat source with a lower temperature, facilitating the use of gushed water at a lower temperature. (3) At an evaporation temperature of 15 ℃, the absorption refrigeration system remains operable with water temperatures exceeding 50 ℃, and a theoretical analysis supporting the feasibility of using high temperature gushed water to drive the lithium bromide absorption refrigeration system is proposed. (4) For gushed water temperatures in the range of 50 ℃~63 ℃ within the tunnel, a twostage lithium bromide absorption refrigeration system is suitable, whereas temperatures exceeding 63 ℃ warrant the use of a singleeffect lithium bromide absorption refrigeration system.

Key words: absorption refrigeration system, high temperature heat damage, high temperature water gushing in tunnel, numerical simulation, steady state, performance analysis