Safety design analysis of a vent mast on an LNG powered ship during a low-temperature combustible gas leakage accident
Safety design analysis of a vent mast on an LNG powered ship during a low-temperature combustible gas leakage accident
复制标题
LNG动力船舶低温可燃气体泄漏事故中通风桅杆安全设计分析
DOI：
10.1016/j.joes.2021.06.001
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发表时间：
2021-06
影响因子：
7.1
通讯作者：
Yu Cao;Qiaojiao Jia;Shiming Wang;Yong Jiang;Yong Bai
中科院分区：
文献类型：
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作者：
Yu Cao;Qiaojiao Jia;Shiming Wang;Yong Jiang;Yong Bai
液化天然气(LNG)是一种清洁能源，世界各地设计和建造了许多LNG动力船舶。然而，液化天然气带来了泄漏和爆炸事故的潜在风险，因此，有必要在设计初期对典型设施的布局进行安全评估。本文以一艘Aframax油轮为研究对象，采用计算流体力学(CFD)方法建立了LNG燃料区甲板模型。给出了不同高度的通风口桅杆在泄漏扩散事故条件下浓度场和温度场上的潜在危险区域分布。结果表明：泄漏初期气体浓度迅速上升，一段时间后趋于稳定；轻气的泄漏扩散趋势与重气基本一致，当泄漏点位于6m时，储罐与上部建筑之间甲板上的重气和轻气最低温度分别为-7.9℃和4.7℃；泄漏点越高，船舶设计越安全。出于安全考虑，本文设计的通风桅杆高度不应低于LNG储罐高度，即10m。
Liquefied natural gas (LNG) is a kind of clean energy, and many LNG-powered vessels have been designed and built around the world. However, LNG introduces the potential risk of leakage and explosion accidents; thus, it is necessary to conduct safety assessments on the layout of typical facilities during the initial design stage. In this paper, an on-deck LNG fuel area model is established by employing the computational fluid dynamics (CFD) method according to an LNG-powered Aframax oil tanker. The distribution of potential dangerous areas on the concentration field and temperature field is presented under leakage and diffusion accident conditions with vent masts of different heights. The results show the following: the gas concentration rises rapidly at the initial stage of leakage and tends to stabilize after a certain period; the leakage and diffusion trend of light gas is basically the same as that of heavy gas, and the lowest heavy gas and light gas temperature on the deck between the storage tank and the upper building is -7.9°C and 4.7°C, respectively, when the venting mast leakage point is at the height of 6 m; and the higher the mast leakage point is, the more safe the ship design. For safety considerations, the height of the venting mast designed in this paper should not be lower than the height of the LNG storage tank, which is 10 m.