Experimental study and numerical simulation of the combustion characteristics of dust clouds in vertical pipelines underneath unilateral obstacles

To reveal the impact of unilateral obstacles on the combustion characteristics of dust clouds inside vertical pipelines. This paper uses high-speed photography to conduct research on the combustion of vertical dust clouds using a self-designed experimental platform. A numerical model is established using Fluent to numerically simulate the combustion process. The results show that obstacles can increase flame spread velocity inside the pipeline, leading to an increase in peak temperature. As the blockage ratio of the obstacles increases, the flame profile becomes increasingly distorted. The maximum flame spread velocity and temperature initially increase and then decrease, with the maximum flame spread velocity reaching further away from the pipeline outlet. At the same time, high blockage ratios can lead to the accumulation of dust concentration underneath obstacles, resulting in a continuous turbulent reaction. As the number of obstacles increases, the maximum flame spread velocity and temperature gradually increase, and the maximum flame propagation ratio is closer to the pipeline outlet. The experiment and the flame propagation procedure (as calculated by numerical simulation) are consistent. The discrepancy between the simulated results and the experimental results is < 15 %.