Factors affecting water flux distribution of fire sprinklers and effect of water flux uniformity on fire suppression characteristics

Abstract

The water flux distribution of the sprinkler spray is not uniform due to the spray formation mechanism impinging on the deflector. In this study, the effect of factors such as installation height, flow rate, and deflector design on the uniformity of the water flux was investigated by experiment. Then, the water flux distribution has been reproduced with simulation and compared with measured data. When the installation height was increased, there was no significant change in the water flux pattern, only radial direction mixing. The water flux distribution predicted by changing the installation height through simulation showed excellent reproducibility with an R2 value over 0.77. Increasing the flow rate maintained the water flux and its pattern near the sprinkler head, however increased the water flux away from the sprinkler head. The modified sprinkler deflector has a deep slot design that increases the water flux near the sprinkler head, which improves the water flux uniformity. Also, the large tines of the modified sprinkler deflector restored the flow after the frame arm, eliminating the effect of the frame arm.