Study on PM diffusion and distribution of trackless rubber-tyred vehicle under different driving conditions in underground coal mining environment

Abstract

Abstract Particulate matter (PM) is one of the most harmful exhaust pollutants to human health. In this study, the PM diffusion and distribution emitted by trackless rubber-tyred vehicle under different driving conditions in coal mine was analyzed with numerical simulations and field measurements. The results show that when the vehicle velocity was constant, the proportion of PM with a concentration below 6 mg/m3 was the highest owing to the influences of diffusion and airflow dilution. However, when the diffusion distance is less than 3 m, the PM concentration far exceeds the occupational exposure limit (C = 10 mg/m3) specified in the coal mine safety regulations.With increasing vehicle velocity, the PM concentration gradient at a diffusion distance of 0–6 m showed the most significant slope. Besides, the concentration fluctuation of PM was the largest and relatively high when the diffusion distance was 5–15m. Therefore, the area 15 m from the exhaust gas pipe opening of the trackless rubber-tyred vehicle should be controlled.