超音速低温天然气脱水及重烃实验装置的研发

发布时间：2018-02-26 17:08

  本文关键词： 超音速 低温 脱水 Laval喷管 分离效率 压损比　出处：《青岛科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来我国的空气污染严重影响着国民的日常生活,因此天然气作为一种清洁能源需求量在不断增加。超音速低温分离是将气体动力学与热力学应用到实际工程中的一种先进工艺技术。气体在通过收缩—扩张管(Laval喷管)后,会形成低温低压的超音速流场。研究表明:当气体温度低于水及重烃组分的露点温度后会凝结成为液态水滴,在旋流发生装置后产生离心加速度将液滴分离出来。该装置在工作中未使用,因此节能环保的同时还降低了一定的运行成本。本文选用氮气为实验介质,以符合天然气实际操作工况的13.2MPa,处理量2000Nm3/h为设计依据。首先开展了超音速低温天然气脱水及重烃实验装置的核心部件的结构设计,在此基础上,采用大型商业流体力学计算软件FLUENT对实验装置的本体结构(入口旋流器及Laval喷管及后续的脱水装置)进行了流体特性模拟。最后依据本文的结构设计,完成了实验装置的搭建,并进行了相应的实验工作,实验内容主要包括不同操作参数以及不同喷管装置尺寸结构对超音速低温分离装置工作效率影响。一方面验证数值模拟的可行性和正确性,另一方面也为该项技术的进一步工业化推广应用提供实验数据。本文的研究结果如下:(1)实验结果与数值模拟结果比较,两者误差较小,数值模拟结果可以用于对装置内流场的预测。(2)本实验装置在设计工况下,入口压力13.2MPa,出口压力9.25MPa(压损比30%)入口温度28℃时,装置进出口温度差6.3℃,露点降7℃。当进出口压损比为54%时,该装置实验中得到的最大露点降为15℃。(3)实验结果表明:在高压环境下,随着压损比的升高,进出口露点降温度不断升高。(4)模拟结果显示,在高压环境下,进口压力一定时,出口压力升高,装置内的激波位置向喉口处移动,不利于水蒸气的凝结分离。同时进出口的温差升高,超音速喷管内最大马赫数降低。在Laval喷管入口直径和喉口直径一定的情况下,喷管出口直径对装置内的流场影响较大。当喷管出口直径增大时,激波位置向喉口移动,但气体在Laval喷管内可以达到更低的温度。而扩压段入口的径向尺寸叫喷管出口直径对装置内流场影响较小。
[Abstract]:In recent years, air pollution in our country has seriously affected the daily life of the people. As a result, the demand for natural gas as a clean energy is increasing. Supersonic cryogenic separation is an advanced technology that applies gas dynamics and thermodynamics to practical projects. A supersonic flow field at low temperature and low pressure is formed. Studies show that when the gas temperature is below the dew point temperature of water and heavy hydrocarbon components, it condenses into a liquid water droplet. The liquid droplets are separated by centrifugal acceleration after the swirl generator. The device is not used in work, so the operation cost is reduced while saving energy and environmental protection. In this paper, nitrogen is chosen as the experimental medium. According to the design basis of 13.2 MPA and 2000Nm ~ 3 / h, the structural design of the core components of the supersonic low-temperature natural gas dehydration and heavy hydrocarbon experimental device is carried out. The fluid characteristics of the main structure of the experimental device (inlet cyclone, Laval nozzle and subsequent dehydration device) are simulated by the large-scale commercial fluid dynamics calculation software FLUENT. Finally, according to the structure design of this paper, the experimental device is constructed. The experimental work includes the effect of different operating parameters and nozzle size structure on the working efficiency of supersonic cryogenic separation device. On the one hand, the feasibility and correctness of numerical simulation are verified. On the other hand, it also provides experimental data for the further industrial application of this technology. The results of this paper are as follows: 1) the experimental results are smaller than those of the numerical simulation results. The numerical simulation results can be used to predict the flow field in the device. (2) under the design condition, the inlet pressure is 13.2MPa, the outlet pressure is 9.25MPa (pressure loss ratio is 30) and the inlet temperature is 28 鈩，

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