Evaluation on effects of air inflow on indoor environment in an air-supported membrane coal-shed building

Air-supported membrane structures are commonly used in coal storage facilities due to their large span, high clearance, and airtight properties. However, high external temperatures and methane emissions from coal piles present significant challenges to the indoor environment, impacting worker health and productivity. This study investigates the effects of ventilation enhancements on temperature regulation and methane dispersion within an air-supported membrane coal-shed building through numerical simulation. The simulation employs the k-epsilon turbulent flow model, coupled with heat transfer and species transport models, to assess the impact of fan operation on air velocity, temperature, and methane concentration. Experimental data, including indoor air velocity, temperature, and methane concentration under different fan configurations, were collected and compared with simulation results to validate the model. Key findings indicate that while increasing the number of fans (from 3 to 8) has minimal effect on overall air velocity, localized airflow improvements near exhaust vents are observed. A significant reduction in the average indoor temperature (approximately 2.5 degrees C) and notable improvements in methane dilution were achieved, with the average methane concentration decreasing from 5.51 % LEL with 3 fans to 0.87 % LEL with 8 fans. These results validate the simulation model and highlight the potential for optimizing ventilation strategies to enhance safety and comfort in large-span coal storage facilities.