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 μm water mist can significantly inhibit the deflagration, while both 45 μm and 80 μm 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 μm water mist starts to mitigate the deflagration and its mitigation effect is more significant than that induced by the 8 μm water mist. What's more, the 80 μm 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 μm 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 μm and 80 μm 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.