Investigation of Sprinkler Sprays on Fire Induced Doorway Flows

Abstract

Performance based methodologies are becoming increasingly common in fire safety due to the inability of prescriptive codes to account for every architectural feature. Fire Sprinkler suppression systems have long been used to provide property protection and enhance life safety. However, very few methodologies exist to account for the impact of sprinkler sprays on fire scenarios. Current methods are extremely complicated and difficult to use as an engineering tool for performance based design. Twenty-four full scale fire tests were conducted at Tyco Fire Suppression & Building Products Global Technology Center to determine a simple method for accounting for the impact of a single residential sprinkler on fire induced doorway flows. It was found that a spraying sprinkler reduced the mass flows at the doorway while maintaining two stratified layers away from the sprinkler spray. The mass flow reduction was consistent and could be predicted through the use of a simple buoyancy based equation. The current study suggests that the buoyancy equation can be altered through the use of a constant cooling coefficient (equal to 0.84 for a Tyco LFII (TY2234) sprinkler) based on the test results reported in this paper. This study is a proof of concept and the results suggest the methodology can be applicable to similar situations.

Description and application of an analytical model to quantify downward smoke displacement caused by a water spray

“…In the literature, many studies are found on the topic of interaction of water droplets with fire smoke layer [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The cooling effect and drag force produced by water droplets are considered generally to yield smoke logging [1][2][3][4][5][6][7][8].…”

A Numerical Study of the Effect of Sprinkler Spray on the Flow Characteristics Induced by Fire

“…최근에는 스프링클러 작동시 출 입구를 통해 배출되는 연소가스의 질량유량에 미치는 영 향에 대한 연구에 관심이 증대되고 있다. Crocker (3) 는 구 획공간 화재실험에서 출입구의 상세 온도 및 유속 측정을 통해 유출되는 연소가스의 질량유량이 감소한다는 사실을 보고하였으며 이는 스프링클러 분무에 의한 연층냉각에 기인하는 것으로 분석하였다. 추가적인 연구 (4) 에서 FDS 모델을 이용하여 출입구 유동에 대한 수치해석결과와 실 험결과를 비교하였다.…”

Comparison of Numerical and Experimental Results of Fire Induced Doorway Flows

“…The present study models a fire in a three dimensional room with an open doorway according to Crocker's experiments [8]. …”

“…Crocker [8] analyzed the mass flow rate with and without a Tyco LFII residential sprinkler in a fire scenario. He introduced Bernoulli's principle to calculate the doorway mass flow rate with consideration of the hydrostatic pressure and density differences.…”

“…The present study establishes a FDS model and compares the results with the experimental data according to the real fire tests conducted by Crocker [8]. Simulations with three different fire sizes under unsprinklered conditions and fire tests with a Tyco LFII residential sprinkler are conducted, respectively.…”