Experimental study on the optimization of thermal environment and airflow organization in a ventilated underground refuge chamber using deflectors

Acceptable temperature is crucial for underground refuge chamber (URC) to ensure the safety and comfort of occupants. A novel temperature control scheme combining mechanical ventilation with deflectors was proposed for URCs. In this study, the effects of ventilation rate (VR), deflector height and deflector angle on ambient temperature control performance and airflow organization of URC were investigated through orthogonal experiments. Results show that: (Ⅰ) The ambient temperature gradient of URC decreases with the increase of VR and deflector height. (Ⅱ) With VR of 350 m3/h, deflector height of 1.40 m, and deflector angle of 0°, compared to the situation without deflectors, the temperature unevenness coefficient can be effectively reduced, the head-to-foot temperature difference can meet the design standard requirements, the waste heat emissions efficiency is increased by 46.1 %, and an average decrease in ambient temperature of 2 °C (Ⅲ) The influence of various factors on the ambient temperature control performance in the URC is as follows: deflector height > VR > deflector angle.