固定式压缩空气泡沫系统单喷头喷洒特性及灭火效能

Spraying characteristics of single nozzle and fire extinguishing test of fixed compressed air foam system

对5种典型结构喷头进行了单喷头喷洒压缩空气泡沫和纯水试验,对喷洒介质在底面上的密度分布以及喷洒的泡沫25%析液时间进行比较分析。研究发现,喷头结构类型和流动参数都会影响泡沫析液特性,喷头内部旋芯会使泡沫稳定性降低;下垂式水喷头的底面分布均匀性较好,而扰流喷头和两种七孔喷头的底面分布均匀性相对较差,且下垂式水喷头和扰流喷头在更高的压力和流量条件下的底面分布均匀性降低;同时,压缩空气泡沫系统的喷头选型可以在一定程度上参考相应喷头的喷水特性。选用最优性能参数喷头,建立火灾模型,开展固定式压缩空气泡沫系统全尺寸变压器热油火灾试验,验证喷头与固定式系统的适配性。

A single nozzle spray of compressed air foam and pure water experiments have been conducted with of five typical types of nozzles.The density distribution of the spray medium at the bottom surface and the 25%liquid separation time of the sprayed foam are compared and analyzed.It is found that the structural type and flow parameters of the nozzles will affect the foaming characteristics of the foam.The internal core of the nozzles will reduce the foam stability;the uniformity of the bottom surface of the suspended nozzles is relatively good,while the turbulent nozzle and two types of seven-hole nozzles are relatively uniform,besides,the uniformity of the bottom surface distribution of the suspended nozzle and the gas nozzle under higher pressure and flow conditions is reduced;Meanwhile,nozzles selection of the compressed air foam system can refer to the corresponding nozzle’s water spray characteristics.Based on the research,optimal performance nozzle was selected,the fire model was established,and full-scale transformer hot oil fire test of the fixed compressed air foam system was carried out to verify the adaptability of the nozzle and the system.