Simulation research on the temperature distribution and smoke control in tunnel fires under a water curtain system

Abstract

This study determined the optimum number of water spray particles and the angle of the inner angle of the nozzle, simulated and studied the suppression effect of the water curtain system on roadway belt fires and toxic and harmful gases, and analysed the barrier effect of heat and smoke under the water curtain system using the flow field. The results show that the number of water curtain rows has a suppressive effect on the temperature and that increasing the number of rows has a better barrier effect on the hot smoke downstream of the roadway. From the velocity and temperature fields, it is clear that there is significant upward movement between the water mists of the water curtain system, which is caused by the water mists colliding with each other on the roadway floor. These jets are entrained into the water mists and merge to form an area of upward movement that acts as a 'barrier’ to prevent the fumes from spreading downstream of the water curtain. When the water curtain system is activated, it increases the concentration of component gases in the downstream space of the roadway and rapidly restores visibility to meet the requirements for safe evacuation.