用于撬装式LNG的引射器研究与实验

发布时间：2018-03-28 05:20

本文选题：引射器　切入点：LNG　出处：《西安石油大学》2016年硕士论文

【摘要】：在一些小产量气田、废气井、偏远气田,铺设管道来收集这些天然气明显不经济,而液化天然气(Liquefied Natural Gas,简称LNG)的体积约为同量气态天然气体积的1/625,撬装式液化天然气设备在这种背景下应运而生。目前运行的小型橇装LNG装置采用的工艺主要有级联式液化工艺、混合冷剂循环制冷(MRC)工艺、N2膨胀制冷工艺和高压引射制冷工艺4种液化工艺。高压引射制冷工艺具有流程简单、操作弹性大、原料气适应性强等优点,故广泛用于收集上述地方气体。在本文的引射工艺中,原料天然气经过两级换热器、一级制冷机、然后经过两级引射器被液化。引射器作为关键的制冷零部件,其性能的好坏直接影响整个工艺系统的效率的高低,本文将其进行重点研究。首先,本文以索科洛夫的一维设计理论为基础,选择空气作为工作介质进行设计计算,得出了引射器的结构尺寸。然后,以fluent软件作为平台,对引射器的内部流场进行了数值模拟,得到了引射器内部的温度分布情况。同时,改变引射器的结构参数(混合室直径,工作喷嘴出口到混合室入口的距离,工作喷嘴出口直径,混合室等截面段的长度),继续对其温度场进行数值模拟,得到了各参数对喷射器性能的影响规律,优化了引射器的结构。将仿真优化的引射器进行加工、制造,用于实验,并与俄罗斯深冷机械制造股份公司制造的引射器进行实验对比。对比结果发现:(1)在实验时间内,俄罗斯深冷机械制造股份公司引射器的温度变化大,但是没有本文设计的引射器的温度梯度下降得快。(2)随着时间的推进,本文设计的引射器的温度梯度有下降越来越大、温差变化也会越来越大,引射器效果也更好的趋势。
[Abstract]:In some small production gas fields, waste gas wells, remote gas fields, the laying of pipelines to collect this natural gas is obviously not economical. The volume of liquefied natural gas (Natural) is about 1 / 625 of that of the same amount of gaseous natural gas, and the pry-mounted liquefied natural gas (LNG) equipment emerges as the times require under this background. The main process used in the small skid-mounted LNG plant at present is cascade liquefaction process. Mixed refrigerant cycle Refrigeration (MRC) process N _ 2 expansion Refrigeration and High pressure ejection Refrigeration are four liquefaction processes. High-pressure ejection refrigeration has the advantages of simple flow, high operating elasticity, and strong adaptability to raw gas, etc. So it is widely used to collect the local gas mentioned above. In the ejection process of this paper, the raw gas passes through the two-stage heat exchanger, the first stage refrigerator, and then the two-stage ejector is liquefied. The ejector is used as the key refrigeration component. The performance of the system directly affects the efficiency of the whole process system. Firstly, based on Sokolov's one-dimensional design theory, air is chosen as the working medium to design and calculate. The structure size of ejector is obtained. Then, the internal flow field of ejector is numerically simulated with fluent software, and the temperature distribution inside ejector is obtained. At the same time, the structure parameter of ejector (mixing chamber diameter) is changed. The distance from the working nozzle outlet to the inlet of the mixing chamber, the diameter of the working nozzle outlet, and the length of the equal section of the mixing chamber continue to be numerically simulated, and the influence of various parameters on the performance of the injector is obtained. The structure of ejector is optimized. The emulation optimized ejector is processed, manufactured, and used for experiment, and compared with the ejector manufactured by Russian cryogenic machinery manufacturing company. The comparison results show that the ejector is in the experimental time. The temperature of ejector in Russian cryogenic machinery manufacturing company varies greatly, but the temperature gradient of ejector designed in this paper is decreased more and more with the advance of time, but the temperature gradient of ejector designed in this paper is decreasing more and more. The temperature difference will be larger and larger, and the ejector effect will be better.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE96

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