An Experimental Study on the Extinguishing Performance of Sprinkler Heads according to Discharge Coefficient

The sprinkler system is a basic fire extinguishing system widely used, but there is a lack of quantitative assessment of its performance. In this study, to evaluate the fire extinguishing performance of the sprinkler head according to the discharge coefficients, experiments were conducted. Experimental sprinkler heads were selected with heads having K50, K80 and K115 water discharge coefficients, and the fire source was assumed to be an indoor fire in Class A Model 1. As experimental results, the time required for the fire chamber to cool down to $200^{\circ}C$ was 26 seconds for the K115 head, 414 seconds for the K80 head, and 481 seconds for the K50 head, so the cooling time of the K115 head was decreased by 94.5% compared to K50 head. In the case of restoring the oxygen concentration to 15%, the K115 head did not decrease below the oxygen concentration of 15%, and the K80 head took 145 seconds and the K50 head took 484 seconds. The lowest oxygen concentration in the fire chamber was 16.1% for the K115 head, 14.33% for the K80 head, and 11.28% for the K50 head, indicating that the K115 head was superior to the K80 and K50 heads by 13.1% and 43.7%, respectively. As the experimental results show, there is big difference in the extinguishing performance depending on the discharge coefficients of the sprinkler head. Therefore, in designing the sprinkler system, the discharge coefficients of the sprinkler head should be selected considering the heat release rate at the installation site and the fire extinguishing characteristics of sprinkler head.

스프링클러 헤드의 방수상수에 따른 소화성능에 관한 실험적 연구