Experimental study on the combined effects of obstacles and local water mist on gas explosion for maritime safety

A variety of experimental configurations including different water mist obstacles, are used to investigate the combined effects of obstacles and water mist upon the gas explosion. The results demonstrate the 8 ㎛ water mist can significantly inhibit the deflagration, while both 45 ㎛ and 80 ㎛ water mists exhibit the opposite effect under all the locally distributed positions of water spray nozzle without obstacles inside the vessel. When considering the obstacles, the 45 ㎛ water mist starts to mitigate the deflagration and its mitigation effect is more significant than that induced by the 8 ㎛ water mist. What's more, the 80 ㎛ water mist can slow down the flame propagation speed while it would still lead to the gas explosion. Additionally, there remains unchanged about the effect of locally spraying 8 ㎛ water mist upon deflagration at the initial stage of flame development as varying the position of obstacles, while the effects of mitigating deflagration by 45 ㎛ and 80 ㎛ water mist are decreased. The results will make contributions to design the arrangement of equipment and water mist configuration on the offshore platform or NG-fueled ship's engine room so as to mitigate the gas explosion accident.