Study on the flow characteristics of fire extinguishing agent FK-5-1-12 in the pipeline release process

Studying the flow characteristics of FK-5-1-12 in the pipeline during the release process is important for appropriate hydraulic calculations and fire extinguishing efficiency evaluation. This work proposes a well-documented dataset of flow results to investigate the flow state and characteristics. Through comparing the evaporation properties of FK-5-1-12 and those of other typical extinguishers, the flow state of FK-5-1-12 was assumed to be a single-phase flow, and hydraulic calculations were carried out using single-phase fluid formulas. The calculated values were compared with experimental data. The release tests of water (pure single-phase flow), Halon1301 (two-phase flow), and FK-5-1-12 were carried out under the same piping system, and the flow characteristics of the three media were compared to further verify the piping flow state. The experimental results show that the release process of FK-5-1-12 in the cylinder has a single-phase flow similar to water, but differs in density and expansion performance. However, FK-5-1-12 only conformed to single-phase flow in the more upstream sections of the pipeline, but presented obvious two-phase flow state in the main pipe and the more downstream sections. When the vaporization is the most serious, the density of the mixture is only 1/26 of that of liquid FK-5-1-12.