Impact of the water evaporation on the heat and moisture transfer in a high-temperature underground roadway

TLDR

High‑temperature surrounding rock induces thermal stresses that threaten deep underground construction, making understanding heat and moisture transfer essential for predicting and improving the roadway thermal environment. This study aims to develop a fully coupled model that simulates non‑isothermal airflow, heat transfer in surrounding rock, and moisture transfer driven by water evaporation. The model couples airflow dynamics, rock heat conduction, and evaporation‑driven moisture transport to capture latent heat effects within the roadway. Validated against field data, the model shows that neglecting latent heat leads to significant temperature prediction errors, while dehumidifying airflow or increasing ventilation speed effectively releases latent heat and lowers temperatures—effects amplified in hotter roadways—providing a robust basis for underground heat hazard control.

Abstract

As the underground engineering proceeds to a greater depth, the thermal stresses resulted from high-temperature surrounding rock become a major challenge for the deep construction and safe operation. Understanding of the characteristics of heat and moisture transfer in a roadway is critically required to assist in predicting and improving the thermal environment in the underground. The present work developed a fully coupled model capable of simulating the non-isothermal flow inside the roadway and heat transfer in surrounding rock together with moisture transfer driven by water evaporation. And the proposed model has been validated with the field test data and reasonable agreement was achieved. Comparing the models with or without water evaporation, it is discovered that ignoring latent heat will cause a serious deviation in air temperature prediction. Examining the critical factors on the effect of heat and mass transfer in the roadway is found that dehumidifying the initial airflow or increasing ventilation speed can effectively promote the latent heat release and reduce the temperature of airflow and surrounding rock. And this effect is greater significant for the higher temperature roadway. The present study can provide a robust theoretical basis and foundation for heat hazard control in underground engineering.