前置式超声速旋流分离器设计与凝结特性分析

针对天然气在长距离管道输送过程中,所含水蒸汽杂质会凝结成液态水的问题,通过运用动力学原理与液滴成核生长理论,开发设计了一种全新的前置式超声速旋流脱水装置。利用CFD中的用户自定义接口建立了含湿天然气的凝结流动模型,数值分析了装置内部的马赫数、过冷度、液滴成核率、液滴半径和湿度等关键凝结参数的变化规律。结果表明:所建立的三维含湿天然气的凝结流动模型可以真实描述超声速旋流分离器中的流动变化规律,为以后装置的工业应用和下一步提高分离效率提供了理论参考。     

超声速气体流动的凝结现象研究综述

超声速气体流动的凝结是一个非常普遍的现象。气体转变为液体的凝结过程,伴随着凝结潜热的释放,急剧改变了流场的热力学性质,流场的改变直接影响了设备的运行状态如汽轮机运行效率降低、风洞偏离设计参数等。本文对超声速气体流动的凝结现象进行了简单的分析,对研究的历史和现状进行了总结．介绍了凝结成核理论、液滴增长模型和相关实验,并对下一步的研究进行了展望。     

旋流分离对天然气水合物除砂提纯的影响

针对固态流化开采方法开采海底天然气水合物含砂量大导致开采效率低的问题,提出原位分离工艺,设计了旋流分离装置,基于该装置利用CFD数值模拟方法研究了固相(砂和水合物颗粒)直径、入口浆体流量及浆体中砂浓度对装置分离性能的影响。结果表明,在研究范围内,砂和水合物分离效率大部分高于60%,最高达98.72%,压降大部分低于0.5 MPa,最低至0.03 MPa。砂粒分离效率随固相粒径增大先增大后趋于平稳,随浆体入口流量增大先增大后减小,随砂浓度增大而降低;水合物分离效率随固相粒径增大先增大后趋于平稳,随浆体入口流量增大先增大后减小,随砂浓度增大而降低。溢流口和底流口压降几乎不随固相粒径变化,随砂浓度和浆体入口流量增大而增大。固相粒径、入口流量、砂浓度对分离性能有较大影响,在砂粒径大于20 ?m、水合物粒径大于40 ?m、浆体入口流量约5 m3/h、入口砂浓度不超过25vol%的条件下分离性能良好。     

天然气跨音速膨胀凝结研究进展

天然气在跨音速膨胀凝结的过程中,水分和重烃的凝结是极其重要且起关键作用的环节,主要包括蒸气的凝结成核和液滴的生长过程。为了探求准确的蒸气成核和生长模型,文中阐述了蒸气成核及液滴生长理论的研究进展,总结了相关实验研究和数值模拟,分析了影响蒸气凝结的因素,并对凝结理论中亟待解决的问题进行了展望。研究结果表明:CNT模型和非等温修正的ICCT模型能较准确地预测单组分凝结过程;修正的双组分成核理论具有较好的准确性。亟待解决的问题有:液滴表面张力模型还不完善,无法准确计算微观表面张力;双组分成核理论的精确度不高;亟待探究多组分成核理论模型,以期为天然气凝结和提高超音速喷管的分离性能打下坚实的理论基础。     

天然气超声速脱二氧化碳技术研究

进行了Laval喷管的结构设计。基于真实气体状态方程和湍流方程,结合凝结成核与液滴生长理论,建立了描述喷管内超声速气体凝结流动的数学模型,进行了CO_2-CH_4气体凝结流动规律研究。研究结果表明:在特定的入口温度与压力条件下可以实现CO_2气体的凝结与脱除,当气体发生凝结后,喷管内形成气、液两相流动,产生的亚微米级微小液滴可随气流运动至喷管出口;CO_2气体成核过程在时间和空间上表现出急剧性,凝结核心形成后,液滴生长过程可维持较长时间和距离,直至液滴到达喷管出口;由于凝结的发生和液滴生长过程释放了大量潜热,喷管内表现出明显的凝结冲波现象,压力下降减缓,温度出现回升。     

旋流分离技术的现状与应用前景

在化工领域旋流分离技术越来越受到重视,其应用程度也随着技术的不断完善而更加普遍,在此通过简述液旋流分离器的基本结构和工作原理及特点的基础上,介绍了旋流分离技术用于化工方面的现状并展望了旋流分离技术在液液分离过程中的应用前景。     

动态旋流分离技术研究进展

在对国内外技术文献广泛分析的基础上,结合研究实际,从动态旋流器的结构形式、结构参数等方面较为深入地论述了动态旋流分离技术的研究进展。并对动态旋流分离技术的发展趋势作了简要分析。     

旋流分离技术研究进展

介绍了旋流分离技术的研究进展,包括水力旋流器的结构形式与结构参数、新结构类型、主要水力学参数、混合液性质及流量稳定性、材料与制造技术、磨损与腐蚀及旋流分离应用技术的研究进展等,还对旋流分离技术的发展趋势作了简要分析。研究表明,随着人们对旋流分离技术的不断开发,其在石油、化工等行业得到了越来越广泛的应用。     

旋流分离技术的现状与应用前景

在简述了液液旋流分离器的基本结构和工作原理及特点的基础上 ,介绍了旋流分离技术用于油污水处理、原油或其他油品脱水、液化气脱胺等方面的研究与发展现状 ,并展望了旋流分离技术在液液分离过程中的应用前景     

基于入口分散相重排序的旋流强化分离研究进展

随着工业化进程的飞速前进,适用于分离多相不互溶介质的旋流分离器已广泛应用于石化、环保等重点行业。为了提高旋流分离器在全粒径范围内分散相的分离效率,涌现出了多种旋流分离过程强化技术。其中,对入口分散相进行重排序的旋流强化技术因具有加工成本及运行费用低、易于实施、强化效果明显等优势,展现出了重要的应用价值及推广前景。本文聚焦于入口分散相重排序的旋流强化技术,对基于惯性力场和离心力场进行分散相重排序的旋流强化原理、排序器结构类型及应用于液-液、固-液、气-固两相的分散相重排序强化技术及研究成果进行了系统的分析和总结。在此基础上,从组织构建分散相重排序后的多股液流,选择促进多股液流间协同高效分离的旋流场入射方案,强化分散相移动过程中的聚并长大和/或惯性碰撞等角度出发,总结了分散相重排序的技术路线并进行研究展望,从而指导旋流器的旋流分离过程强化及优化设计,助力于旋流分离效率的深度提升。     

采用增大凝结液滴方法的锥芯超音速旋流分离装置性能研究

To improve the separation performance of a supersonic gas separation device for the treatment of gas mixture with a single heavy component, a novel structure with shorter settlement distance was constructed and a method of droplet enlargement was applied. A series of experiments were carried out in the improved separation device under various conditions, using air-ethanol vapor as the medium and micro water droplets as nucleation centers. The effects of the inlet pressure, temperature and relative humidity, the swirling intensity, and mass flow rate of water on the separation performance were investigated. The separation was improved by increasing the inlet pressure and relative humidity. With the decrease of swirling intensity and mass flow rate of water, the separation efficiency increased first and then decreased. The inlet temperature had a slight effect on the separation. The results showed that the separation performance was effectively improved using the proposed structure and method, and the best separation in this study was obtained with the ethanol removal rate about 55% and dew point depression 27 K. The addition of water had little pollution to the air-ethanol vapor system since the water carry-over rate was within the range of %-0 in most cases.     

Nucleation curves of model natural gas hydrates on a quasi‐free water droplet

Heterogeneous nucleation probability distributions of gas hydrates on a water droplet that was supported by inert and immiscible perfluorocarbon oil, perfluorodecalin is studied. The guest gas used was a mixture of 90 mol % methane and 10 mol % propane. The probability distribution was measured using a high pressure automated lag time apparatus under the guest gas pressure range of 6.7–12.5 MPa and the cooling rate range of 0.002–0.02 K/s. Nucleation curves were derived for unit area of water surface. The nucleation rate per unit area of water surface that was contained in a glass sample cell, which differed significantly from that on a quasi‐free water droplet, is also derived. It is concluded that the nucleation curves in the presence of a solid wall should be normalized to the unit length of the three‐phase line at which water, guest gas, and the solid wall meet. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2611–2617, 2015     

超音速分离技术在天然气工业上应用浅析

随着超音速分离技术的研究和发展,超音速分离设备逐步应用到天然气的脱水脱烃和天然气凝液回收等工艺中。本文介绍了超音速分离技术的发展过程,分析了超音速分离技术的原理以及在天然气工业中的应用,结果表明此技术对提高天然气气液分离效果显著,有助于增加天然气凝液的收率,在天然气工业上有较广阔的应用前景。     

天然气超声波旋流脱水装置的工作性能

A new type of dehydration unit for natural gas was briefly described and its basic structure and working principles were presented. An indoor test rig for testing the unit performance was set up and the experimental results were given. The results showed that the unit could attain a maximum dew point depression of about 20~C without any need of external mechanical power and chemicals. The pressure loss ratio, shock wave and the flow rate had great influence on the dehydration characteristics. From the systematic analysis of the factors that affect the dehydration efficiency of the unit, the suggestions for improving the unit are put forward.     

天然气中单组分冷凝特性的研究

我国具有丰富的天然气资源,但大多数从气藏中开发出的天然气都含有一定量的轻烃。为了回收这部分轻烃,为轻烃回收工艺确定最经济的操作条件,掌握天然气中烃类单组分的冷凝特性就显得尤为重要。本文正是基于这种考虑,选取国内3种典型的天然气组成,以BWRS真实气体状态方程为平衡计算的数学模型,利用VB语言编制LPGProcess软件,考察天然气中单组分的冷凝特性。     

Review on key issues of an axial gas–liquid separator for ultralow gas content

The separation of gas and liquid is a topic of general interest in science and engineering, for which tremendous efforts are endeavored to develop separators with high efficiency and reliability. However, when it comes to ultralow gas content, some of the separators fail. A special separator finds the potential herein, which consists of a swirl vane, a swirl chamber and a recovery vane. When the gas–liquid mixture goes through the swirl vane, bubbles will be concentrated into the swirl chamber center and evolved into a gas core. However, two key issues need to be addressed for the axial separator before industrial applications. One issue is that all the bubbles must be captured without exception, that is, the separation efficiency is close to 100%. The other issue is the stability of the gas core, the shape of which is sometimes rectilinear and sometimes spiral. A successful separation relies on the rectilinear shaped gas core. Focused on the two issues above, tremendous experimental, numerical and theoretical investigations have been carried out. In this article, the key challenges and solutions for the two issues are summarized.     

超声波作用于天然气水合物形成分解研究进展

简述了超声空化的基本理论;介绍了国内外超声波影响天然气水合物形成分解的研究进展、超声波对水成核结冰影响的研究情况;最后进行了简要总结并提出几点建议,指出开展相应研究的必要性。