A numerical study on the diffusion of CO emitted during trackless rubber-tyred diesel vehicle meetings in underground coal mines

An investigation into the diffusion and concentration of CO emitted by underground rubber‑tyred diesel vehicles meeting and passing each other in coal mines was conducted for safety risk assessment. The diffusion and distribution of CO in the following four stages of a vehicle meeting event were examined: two vehicles driving toward each other, one vehicle entering a chamber to avoid the other, one vehicle passing through a chamber, and two vehicles driving away from each other. A computational fluid dynamics (CFD) model was established to simulate the CO diffusion and analyze the distribution characteristics of CO emissions from rubber‑tyred diesel vehicles. The results provide insights into the distribution of CO‑rich and high‑risk zones around the vehicles and offer a basis for managing the risk of exhaust gases emitted by underground rubber‑tyred diesel vehicles. • The CO diffusion behavior of two vehicles in transportation scenarios was studied. • The impact of CO distribution on the health of underground workers was analyzed. • CO accumulated inside the chamber and in the corners of the roadway ground. • There were cases where CO concentration >24 mg/m³ at the height of respiratory zone. • Personnel in the coal mine underground should have safety protection.