摘要随着煤和石油的开采,世界能源形式愈发紧张,同时,煤和石油的大量燃烧, 产生了巨大的环境污染,天然气作为一种清洁能源在全球范围内受到了广泛的关注, 但是,天然气作为一种气体能源,限制其在全球范围内广泛使用的缺点就是能源分 布不均匀,且运输工艺复杂。其需要降温液化成液化天然气(Liquefied Natural Gas, 简称 LNG)通过远洋 LNG 运输船进行 LNG 的运输。
大型 LNG 动力船每天需要消耗大量的 LNG,作为液体的 LNG 无法直接供给船 舶动力系统燃烧,LNG 需要经过船上的再汽化装置进行汽化才能供给船舶主机、辅 机和锅炉燃烧。LNG 储罐中的-163℃液化天然气经过汽化装置汽化到到常温气体的 过程会释放出大约 830~860kJ/kg 的冷能。这部分冷能通常直接被海水带走,造成 了极大的能源浪费。84525
如果充分利用这部分冷能,将带来巨大的经济效益。本文以此作为出发点,对
LNG 汽化冷能用于船舶冷库系统进行设计分析,主要工作如下:
(1)对传统低温冷库制冷工艺进行分析,指出其涉及设备较多,安装检修工艺 繁琐,运行时还需要消耗较多的电能的缺点,提出 LNG 汽化冷能利用工艺。
(2)针对用于金枪鱼冷冻的船舶冷库制冷流程进行设计与分析,完成流程设计 与冷媒选择。
(3)对冷库进行设计分析,进行负荷计算,得出库容量大小,并对系统关键设 备进行选型计算。
(4)对本文提出的 LNG 汽化冷能用于船舶冷库系统进行经济效益以及环境效 益分析,总结该方案对社会产生的深远影响。
毕业论文关键词:LNG 动力船 超低温冷库 冷库设计
Abstract With the mining of coal and oil, the world's energy form is increasingly nervous, at the same time, the burning of coal and oil causes severely environmental pollution, natural gas as a clean energy has received the widespread attention in the global scope, however, natural gas as a kind of gas energy, limiting its widely used worldwide weakness is uneven distribution of energy, and complicated transport process。 The need to cool the Liquefied into Liquefied Natural Gas (Liquefied Natural Gas, or LNG) transport through the ocean of LNG carrier for LNG。
Large LNG ship every day need to consume large amounts of LNG, as a liquid supply of LNG does not directly offer burning ship power system, it need to pass the ship's LNG vaporizing device of vaporization and can supply ship again host, vice machine and boiler
combustion。 - 163 ℃ in LNG storage tank of liquefied natural gas (LNG) through
vaporizing device to room temperature gas vaporization 。This process releases about 830 ~ 860 kJ/kg to the cold。 This part of the cold can often taken away by the sea, which directly caused great waste of energy。
If we can use this part of the cold to the full,it will bring substantial economic benefits。 This article mainly discusses the application of LNG cold energy of ultra-low temperature tuna cold storage for the design of the system。 The groundwork that this thesis is done is as follows:
(1)Most of the Marine low temperature cold storage are still using traditional multistage compression refrigeration to maintain the cold storage at low temperature environment, many large equipment are applied ,installation maintenance process trival, runtime also need to consume more electricity。
(2)Discussing the application of LNG cold energy of ultra-low temperature tuna cold storage for the design of the system。