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

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.