Numerical study on interactions between climate conditions and diesel exhaust and optimization of auxiliary ventilation in underground mines

With the advances in deep mining, workers may be subjected to harsh thermal environments and diesel exhaust in the development headings of deep underground mines. Thus, to maintain the thermal environment and air quality in such mines, it is necessary to carefully design auxiliary ventilation systems based on the distribution of the airflow velocity, airflow temperature and humidity, and diesel exhaust. In this study, a three-dimensional model of a development heading was constructed based on an actual underground mine; subsequently, appro-priate turbulence and species transport models were applied to perform numerical simulations using computa-tional fluid dynamics. The simulation results revealed the following: (1) the importance of accurately setting temperature and/or heat flux boundary conditions for the design of ventilation systems and (2) the underesti-mation of the air supply volume based on the enthalpy difference method. Therefore, this study combined the sigma heat difference method and the power of diesel equipment with a multiplier to achieve an optimal ventilation strategy that can realize the dual functions of improving both the thermal environment and air quality. Notably, this study addresses the deficiency of conventional numerical simulations for diesel exhaust distributions and lays the foundation for accurate ventilation designs of hot development headings.