The Influence of Mass Transfer on the Effective Thermal Conductivity of Surrounding Rock in Deep Buried Air Intake Tunnels

Optimizing the heat and mass transfer calculation between tunnel surrounding rock and air is the key to alleviate the huge heat and humidity treatment demand of underground engineering and improve the overall energy efficiency of underground engineering. This paper presents a more comprehensive numerical model to calculate the heat and mass transfer within the surrounding rock and the heat and mass exchange between surrounding rock and air, and the validation of this model is verified. The influence of mass transfer on the effective thermal conductivity (ETC) of surrounding rock in the air intake tunnel of Hainan pumped storage hydropower station is also quantitatively analyzed. Based on the calculation results, the initial water content of surrounding rock has a relatively significant impact on the effective thermal conductivity, whereas the dynamic changes in the water content of the surrounding rock in the process of heat and humidity exchange between surrounding rock and air exert slight effect and can be neglected.