摘要
船舶通常使用柴油作為燃料，而本文研究的柴油-LNG雙燃料散貨船以柴油作為發(fā)動燃料，然后在船舶的運行過程中使用天然氣作為燃料。對船用柴油機進行柴油-LNG雙燃料混合動力的研究開發(fā)，意在推動低碳經(jīng)濟、發(fā)展綠色航運、打造低碳船舶。天然氣燃燒后只產(chǎn)生二氧化碳和水，不產(chǎn)生對大氣危害較大的物質(zhì)，是一種高效清潔的能源，符合節(jié)能環(huán)保的要求。然而，改裝后的船舶，因為加設(shè)了LNG儲氣罐，增加了LNG泄露后發(fā)生火災(zāi)事故的風險，因此需要對LNG儲氣罐進行火災(zāi)事故的風險分析。
本文在風險評估理論的基礎(chǔ)上，對柴油-LNG內(nèi)河散貨船的天然氣泄漏事故進行了風險識別；根據(jù)石油化工行業(yè)的風險評估標準，研究了燃氣泄漏后發(fā)生火災(zāi)的概率，預(yù)測了火災(zāi)事故的損害半徑，實現(xiàn)了對事故影響范圍和人員、環(huán)境傷害后果的預(yù)測并提出了降低風險的措施；利用DYTRAN軟件，對天然氣泄漏爆炸后對船體結(jié)構(gòu)的損傷后果進行了模擬分析。
本文主要研究工作如下：
（1）闡述了風險評估的內(nèi)容，重點介紹危險識別的方法，并對雙燃料船舶的燃氣泄露事故進行了風險識別；運用故障樹法探討了LNG儲罐發(fā)生天然氣泄漏事故的后果；利用事件樹法分析了機艙發(fā)生天然氣泄漏的事故后果。
（2）基于DNV概率統(tǒng)計法研究了甲板上部管路發(fā)生泄露的概率，利用石油化工行業(yè)的風險評估標準對LNG儲罐附管和甲板上部管路在不同泄漏工況下發(fā)生火災(zāi)的概率分別進行了計算。
（3）在不同泄漏工況下，量化模擬了LNG儲罐附管和甲板上部管路泄漏氣體濃度擴散范圍、火災(zāi)影響范圍、火災(zāi)熱輻射、爆炸后果，并且提出了降低風險的措施。
（4）對可能發(fā)生天然氣泄漏的機艙部分進行定量風險分析，介紹了機艙發(fā)生火災(zāi)的原因和特點，并將機艙的管路分為管道泄漏模型和小孔泄漏模型兩種類型進行分析，提出保證機艙安全的措施。
（5）利用Neptune軟件預(yù)測了機艙天然氣泄露的概率和極端狀況下機艙管路天然氣泄漏引發(fā)火災(zāi)的后果，根據(jù)石油化工行業(yè)的風險評估標準得出發(fā)生火災(zāi)的概率。
（6）在MSC.Dytran的基本理論基礎(chǔ)上，研究了天然氣發(fā)生蒸氣云爆炸對船體結(jié)構(gòu)的影響后果，數(shù)值模擬了船尾上層建筑和甲板結(jié)構(gòu)在空中爆炸沖擊波作用下的動態(tài)響應(yīng)，分析了雙燃料船在沖擊波載荷作用下的響應(yīng)特征和能量吸收特性。

關(guān)鍵詞：柴油—LNG雙燃料船；天然氣泄漏；火災(zāi)爆炸；風險評估











Abstract
Ship diesel fuel used as usual, and diesel-LNG dual fuel bulk carriers this paper studied use diesel fuel as a start, and then use natural gas as fuel in the operation of the ship. Hybrid's research and development of diesel-LNG dual fuel is to promote a low carbon economy, develop green shipping and make the low carbon ships. Natural gas is a kind of high efficient clean energy meeting the energy conservation and environmental protection requirements, which wouldn’t produce the materials that harm to the atmosphere but carbon dioxide and water after burning. However, the modification of the ship, for adding the LNG storage tank, is increased discoverable LNG fire accident risk. So we need to analysis LNG storage tank fire accident risk.
In this paper, risk identification of diesel-LNG inland bulk carrier, when gas leakage accident happened, is analyzed based on the theory of risk assessment. According to the risk assessment risk of petrochemical industry standard, the fire probabilities after LNG gas leaking are calculated, the fire accident damage radius are forecasted. Influence scope of accident, damage of personnel and environment are forecasted. The measures to reduce the risks are put forward. By using DYTRAN software, the damage to the hull structure after the explosion of natural gas leaking are simulated and analyzed.
This paper main research works and the conclusions are as follows:
(1) The content of the risk assessment is expounded, the key risk identification method is introduced and the risk of dual fuel ship gas leak accident is identified. By using the fault tree method, the consequences when LNG storage tank of gas accident are probed; By using event tree analysis method, the consequences of the natural gas leakage are analyzed.
(2) Fire probabilities of pipeline leakage of LNG storage tanks and upper deck in different conditions are respectively calculated based on DNV probability statistics. By using mathematical model, LNG storage tanks and the upper deck subject to pipeline leak in different conditions, the probabilities of fire are calculated.
(3) In different leak conditions, with pipe and the diffusion area of the gas pipeline leaking of LNG tanks and upper the deck, fires affecting range, fire thermal radiation, explosion consequences are simulated quantitatively and the measures to reduce the risks are put forward.
(4) Gas leak which may happen in cabin part of quantitative risk is analysis, the reasons and characteristics of fire are introduced. And the pipeline leak model and two holes leak model are analyzed, the measures to ensure the safety are proposed.
(5) Probabilities of fuel gas leaking and fires consequences of cabin in extreme conditions of natural gas pipeline leaking by Neptune software are forecasted. According to the mathematical mode, fire probabilities are calculated.
(6) According to the basic theory of MSC. DYTRAN theory, the consequences to hull structure are researched, dynamic responses of stern superstructure and ..