細水霧系統在通風排煙下對滅火性能之評估研究

Abstract

針對細水霧滅火系統在通風排煙環境下對於在火災控制上的整合及應用，選定辦公室火災來做為火災場景，以油盆火和木堆火當作標準火源。經由不同的噴頭條件、排煙條件及火源位置與排煙口之相對位置，來觀察煙流動變化並且量測標準火源被撲滅的時間，以及火場內部之溫度變化以深入探討細水霧與排煙系統設置之相對位置與其滅火能力之相關性。 由目前的結果顯示，細水霧在排煙的情況下，亦能有效的撲滅油盆火災。但滅火時間會受到排煙風量大小的影響，當排煙風量愈大，其滅火時間就愈長，並能有效降低火場的煙濃度、CO2、CO和溫度，降低了火場內部的危害，可以延長火場內人員避難逃生的時間。在木堆火源的實驗中，細水霧對於火場的抑制能力和火場內部的降溫效果，以及對氣體濃度的影響，都比傳統撒水頭還要好，對於人員的避難逃生也較為有利。

Aiming on the fire control/suppression by applying and integrating the water mist system with the ventilation and desmoke systems, the office fire was selected as the scenario, which specified the pool and crib (wooden) fire as the fire source, including its fire load. The smoke flows, extinction times of standard fire sources, and field temperatures were observed and measured by varying the working pressure, desmoke condition and relative orientation between fire source and smoke exhaust to investigate the relationship between the water mist and desmoke systems. From the experimental results, it found that water mist system even under the desmoking condition still can effectively put out the pool fire. However, the fire extinction time is greatly affected by the desmoke capacity. The extinction time becomes longer as the desmoke capacity is higher that also can reduce the smoke density, CO2 and CO concentrations, and temperature. In other words, it can mitigate the fire hazard and extend the occupant egress time. In the crib fire tests, water mist system was found to be able to control the fire and reduce the field temperature. It was found as well that the toxic gas concentration is reduced comparing to that of regular sprinkler system so that the occupancy evacuation becomes safer.