Abstract: In order to understand the effects of six alkali metal salts including NaCl, KCl, Na2CO3, K2CO3, NaHCO3 and KHCO3, and three foaming agents including SDBS, CAB35 and APG0810 on the suppression performance of high pressure water mist for ethanol tank fire, a comparative experiment of pure high pressure water mist and high pressure water mist with different additives on the suppression performance of ethanol pool fire was carried out in a confined space of 6 m×6 m×4 m. Results revealed that compared with pure high pressure water mist ,adding alkali metal salts and foaming agents additives could effectively shorten the fire suppression duration of high pressure water mist, especially in the stage when the flame was torn and suppressed and the flame moved around. When other conditions remain unchanged, with the increase of additive concentration, the fire suppression duration first decreased and then increased. When the pool fire was extinguished by the high pressure water mist containing 3%KHCO3 and 3%SDBS, compared with pure high pressure water mist, the suppression duration was shortened by 57.4% and 64.6% respectively. The average cooling rate increased firstly and then decreased with the increase of concentration. The highest cooling rate was the fine water mist containing 3%SDBS, which increased by 217.54% compared with the pure fine water mist. The high pressure water mist containing different alkali metal salts and foaming agents had different suppression performance on ethanol tank fire, but they were significantly improved compared with pure high pressure water mist.

Key words: high pressure water mist, ethanol pool fire, alkali metal salt, foaming agent, average cooling rate, suppression performance