In order to gain a knowledge of the heat emitted from a variety of sources at the blind heading of an underground gold mine, the present study conducts an in situ measurement study in a blind heading within the load haul dumps (LHDs) that are operating. The measurements can provide a reliable data basis for the setting of numerical simulations. The results demonstrate that the distances between the forcing outlet and the mining face (denoted as Z_m), as well as the heat generation from LHDs (denoted as Q_L), has brought significant impacts on the airflow velocity, relative humidity, and temperature distributions in the blind heading. Setting Z_m to 5 m could achieve a relative optimal cooling performance, also indicating that when the LHD is fully operating in the mining face, employing the pure forcing system has a limited effect on the temperature decrease of the blind heading. According to the numerical simulations, a better cooling performance can be achieved based on the near-forcing-far-exhausting (NFFE) ventilation system.

The thermal environment of the development headings in deep underground mines tends to be harsh. The design of a reliable auxiliary ventilation system is an important strategy to maintain the thermal environment and air quality in the workplace. Hence, it is of great significance to comprehensively evaluate the effects of different air supply conditions and explore the optimal solution for the auxiliary ventilation system. In this study, cooling efficiency (CE) and ventilation efficiency (VE), which are the two most widely used indices for evaluating the ventilation in public places, were introduced into the field of underground mine ventilation. Numerical simulations of multiple air supply conditions were carried out to obtain the CE and VE, respectively. A data envelopment analysis model was used innovatively to evaluate and rank the efficiency of the different conditions. In the evaluation model, the air supply temperature and air supply velocity were the inputs, whereas CE and VE were the outputs. The preliminary results showed that cases with either the highest VE or highest CE alone may not actually indicate efficient air supply conditions. The optimum efficiency was determined to be at an air supply temperature difference of 6 °C. Thereafter, the air supply rate could be determined using the psychrometric chart based on the cooling and moisture loads. These results can provide theoretical guidance for optimizing air supply conditions and energy-saving control of mining ventilation and cooling systems.