LNG加气站几个关键安全技术的研究

发布时间：2018-02-21 17:23

本文关键词： LNG加气站安全技术低温管道补偿量绝热层蒸发气体(BOG)　出处：《山东建筑大学》2013年硕士论文　论文类型：学位论文

【摘要】：液化天然气(LNG)作为汽车燃料,与汽油、柴油以及压缩天然气相比,具有环保性、经济性和安全性等优点,LNG汽车成为了天然气汽车行业新的发展趋势。随着我国能源结构的调整和环保要求的提高,LNG汽车的发展步伐越来越快,为满足LNG汽车的加气需求,LNG加气站的数量日益增多。安全问题是LNG加气站中最重要的课题,本课题针对LNG加气站的安全问题,对加气站的几个关键安全技术进行了分析研究和探讨,主要包括以下研究内容： (1)应用LKP方程计算LNG的热力学性质和迁移性质,对国内几种LNG典型气源的物性进行计算,结果与实验提供数据基本相符；以江苏如东LNG接收站气源为例,计算LNG的饱和物性和压力的关系,计算结果表明饱和温度随着压力的增大而升高,汽化潜热随着压力的增大而降低；液相密度和气相密度分别随着压力的增大而减小和增大 (2)对于LNG低温管道的补偿量,通过计算比较不同计算状态温度下的补偿量,提出以预冷介质的温度作为计算状态温度,更能满足低温管道的冷收缩要求。在热平衡原理的基础上对LNG普通绝热管道的一维稳态传热过程进行了分析,采用控制管道单位长度冷损失的方法来计算LNG绝热层的厚度,得出LNG加气站内液体输送管道的绝热层厚度的推荐值。 (3)根据LNG加气站的工艺流程和设备特点,分析得出产生BOG的主要原因包括储罐和管道的漏热、卸车过程中槽车和储罐的压力差、LNG潜液泵运行产生的热量、加气过程中的容积置换以及大气压力的变化等。针对BOG产生的各种原因,得出了加气站内BOG量的静态计算模型,通过对某加气站不同工作状态下产生BOG量进行计算,探讨了LNG加气站内BOG的抑制措施和处理工艺。
[Abstract]:Liquefied natural gas (LNG) as a vehicle fuel, compared with gasoline, diesel and compressed natural gas, it is environmentally friendly. The advantages of economy and safety have become the new development trend of the natural gas automobile industry. With the adjustment of energy structure and the improvement of environmental protection requirements in China, the pace of development of LNG vehicles is getting faster and faster. In order to meet the needs of LNG vehicles, the number of LNG filling stations is increasing day by day. The safety problem is the most important issue in LNG filling stations. This topic is aimed at the safety problems of LNG filling stations. Several key safety technologies of gas filling station are analyzed and discussed, including the following research contents:. 1) the thermodynamic and migration properties of LNG are calculated by using LKP equation, and the physical properties of several typical LNG gas sources in China are calculated. The results are in good agreement with the experimental data, taking the gas source of the LNG receiving station in Rudong, Jiangsu Province as an example. The relationship between saturation properties and pressure of LNG is calculated. The results show that the saturation temperature increases with the increase of pressure, the latent heat of vaporization decreases with the increase of pressure, and the density of liquid phase and gas phase decrease and increase with the increase of pressure, respectively. 2) for the compensation amount of LNG cryogenic pipeline, by calculating and comparing the compensation amount under different calculated state temperature, the temperature of precooled medium is proposed as the calculated state temperature. On the basis of the principle of heat balance, the one-dimensional steady-state heat transfer process of LNG adiabatic pipe is analyzed, and the thickness of LNG adiabatic layer is calculated by controlling the cold loss per unit length of the pipe. The recommended thickness of the adiabatic layer of the liquid conveying pipeline in the LNG gas station is obtained. 3) according to the process flow and equipment characteristics of LNG filling station, the main reasons for producing BOG include heat leakage in storage tank and pipeline, the pressure difference between tank and tank during unloading, and the heat produced by the operation of submersible liquid pump. According to the various reasons of BOG, the static calculation model of BOG quantity in the filling station is obtained. Through the calculation of the BOG quantity produced in different working state of a gas filling station, the volume displacement and the change of atmospheric pressure in the process of aeration are obtained. The inhibition measures and treatment process of BOG in LNG filling station are discussed.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：U473.8;X937

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