Examination of Performance of WaterMist Fire Suppression Systems underVentilation Conditions

Abstract

This paper describes water mist fire suppression effectiveness under various ventilation conditions. The full-scale fire test series were conducted in an empty enclosure and in a simulated machinery space. Fire scenarios in the tests included small and large pool fires, spray fires and wood crib fires that were placed at different locations within the compartment. The ventilation conditions varied from non-ventilation, natural ventilation to forced ventilation. A single-fluid/high pressure and a twin-fluid/low pressure water mist system were used, respectively, in the tests. The test results showed that water mist suppression effectiveness was dependent on ventilation rates, fire size, type and location in the compartment as well as the characteristics of the water mist system used. During tests, both single-and twinfluid water mist systems effectively extinguished fires under natural ventilation. Under forced ventilation, however, water mist fire suppression effectiveness was substantially reduced due to the strong mass exchange between the room and its surroundings.

Application of Water Mist Fire Suppression Systems in Small Retail Shops

“…If the entire compartment is covered by the WMFSS, these two effects will act together. System performance depends on spray characteristics such as water mist droplet size and external factors including fuel of the fire to be controlled, compartment geometry and aerodynamics induced by the ventilation configurations [17]. Ventilation plays a very important role and this should be considered carefully for small retail shops.…”

“…Smoke temperature, smoke production rate, time to flashover, and interaction of water mist and smoke are affected by ventilation. As investigated by Liu and coworkers [17] with full-scale burning tests, water mist suppression effectiveness under forced ventilation was substantially reduced due to the strong mass exchange between the room and its surroundings. Therefore, a total flooding system is not suitable in small retail shops with adequate ventilation as fresh air supply into the shop would keep oxygen concentration high.…”

“…Some experimental and simulated results have been reported for compartmental fires with limited openings, and the scheme can be referred to for the present application e.g. [17,18,29].…”

“…Key aspects such as spray characteristics, suppression mechanisms, application areas and fire test protocols have been studied actively e.g. [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The WMFSS can be used in many areas though the system is most widely used in marine engineering.…”

Numerical Analysis of the Effects of Droplets Characteristics of Water Spray on Fire Suppression

“…또한, 화재진압 시간은 화재의 크기, 격실의 크기, 환기 조건 등 에 따라 달라질 수 있다. 이전의 연구들 (3)(4)(5)(6)(7) 은 노즐 특성 및 격실 조건 변화가 화재진압 특성에 미치는 영향을 실험 및 수치적인 방법으로 연구해 왔다.…”