Numerical modeling of water spray suppression of conveyor belt fires in a large-scale tunnel

• A CFD model was developed to simulate water spray suppression of conveyor belt fire.
• The model coupled flame spread with water spray suppression.
• The model was validated against large-scale experimental results.
• The sprinkler location has a major effect on the suppression of the belt fire.
• The water flow rate beyond a critical value has a minor effect on the suppression.

Conveyor belt fires in an underground mine pose a serious life threat to miners. Water sprinkler systems are usually used to extinguish underground conveyor belt fires, but because of the complex interaction between conveyor belt fires and mine ventilation airflow, more effective engineering designs are needed for the installation of water sprinkler systems. A computational fluid dynamics (CFD) model was developed to simulate the interaction between the ventilation airflow, the belt flame spread, and the water spray system in a mine entry. The CFD model was calibrated using test results from a large-scale conveyor belt fire suppression experiment. Simulations were conducted using the calibrated CFD model to investigate the effects of sprinkler location, water flow rate, and sprinkler activation temperature on the suppression of conveyor belt fires. The sprinkler location and the activation temperature were found to have a major effect on the suppression of the belt fire, while the water flow rate had a minor effect.