Abstract:

To address the wide applicability of the route of preparing fluorine-free foam extinguishing agent with low-carbon alcohol modulated hydrocarbon and silicone surfactants, as well as the limitation of evaluating the fire extinguishing effect in small-scale fire extinguishing experiments, a new silicone surfactant SILOK and two types of hydrocarbon surfactants CHX-3 and SDS were selected as the key basic components to carry out the design of the compounding scheme of the fluorine-free foam extinguishing agent, the foam basic performance test, real fire extinguishing experiment and molecular dynamics simulation. The test showed that the fluorine-free foam extinguishing agents of CHX-3/SILOK/isobutanol and SDS/SILOK/isobutanol with five compounding systems had good foam base performance, and the surface tension of the design scheme was in the range of 20.3—22.7 mN/m, the stabilizing coefficient of foam was in the range of 0.9617—0.9762, and the 25% drainage time was in the range of 203—238 s. But relatively speaking, the Case5 formulation which the mass fraction of CHX-3/SILOK/isobutanol is 0.48%/0.1%/0.03%, respectively, had better foam base properties, low surface tension, good foaming and stabilizing properties. True fire extinguishing experiment has proved that in the Case5 scheme of the CHX-3/SILOK/isobutanol system, 90% flame control time is only 42 s, the fire extinguishing time is the shortest, only 49 s, and the average fire cooling rate is the largest, reaching 7.59℃/s. Through molecular dynamics simulation, it was found that the hydrogen bond types, bond lengths and bond angles of the two types of complex systems were different due to the difference of hydrocarbon surfactants. The essential law of the effects of CHX-3 and SDS on foam stability and surface tension was clarified. The research results can provide data support and theoretical support for the development, application and popularization of fluorine-free foam extinguishing agent.

Key words: fluorine-free foam extinguishing agent, foam properties, true fire experiment, cooling rate, molecular dynamics, inter-molecular hydrogen bonds

摘要：

针对低碳醇调控碳氢和有机硅表面活性剂制备无氟泡沫灭火剂路线的广泛适用性以及小尺度灭火实验评价灭火效果的局限性，选取一种新型有机硅表面活性剂SILOK与两类碳氢表面活性剂CHX-3和SDS为关键组分，开展无氟泡沫灭火剂的复配方案设计、泡沫性能测试、真火灭火实验和分子动力学模拟。测试结果表明：CHX-3/SILOK/异丁醇和SDS/SILOK/异丁醇两类复配体系5种复配方案的无氟泡沫灭火剂均具有良好的泡沫基础性能，设计方案的表面张力为20.3~22.7 mN/m，稳泡系数为0.9617~0.9762，25%析液时间为203~238 s。相对来说，CHX-3/SILOK/异丁醇的质量分数为0.48%/0.1%/0.03%的Case5配方具有更加优良的泡沫基础性能，表面张力低，发泡性和稳泡性能良好。真火灭火实验证明：CHX-3/SILOK/异丁醇体系的Case5方案，90%控火时间仅为42 s；灭火时间最短，仅为49 s；平均灭火降温速率最大，达到了7.59℃/s。通过分子动力学模拟研究了复配体系的氢键和扩散系数，阐明了CHX-3和SDS对泡沫稳定性和表面张力的影响规律。研究成果能够为无氟泡沫灭火剂的开发、应用和推广提供数据支持和理论支撑。

关键词: 无氟泡沫灭火剂, 泡沫性能, 真火实验, 降温速率, 分子动力学, 分子间氢键