高压气瓶快速放气的动态特性研究

高压气瓶的快速放气过程广泛存在于能源、化工、航天等领域。放气过程的动态特性是相关系统设计的重要基础。针对高压气瓶的快速放气过程进行了分析,基于实际物理过程并进行部分简化后,建立了理论模型,推导了高压气瓶和低压容器腔内压力随时间变化函数。同时,开展了高压气瓶快速放气的验证试验,对放气过程中的动态参数（包括温度、压力等）进行了测量。理论模型的计算结果与试验结果较为吻合,验证了模型的准确性。最后,基于理论模型,对低压容腔的压力变化、系统放气速率等参数进行了分析。     

刚性过滤器脉冲反吹过程中滤管内动态压力特性

催化汽油吸附脱硫（S-Zorb）装置中反应器过滤器的脉冲反吹性能直接影响吸附剂的分离与循环。利用建立的滤管过滤性能实验装置,采用高频动态压力传感器,测定脉冲反吹过程中沿滤管长度方向不同位置处滤管内动态压力随时间的变化特性,分析了滤管长度、反吹压力和脉冲宽度对滤管内动态压力特性的影响规律。结果表明：自开口端至盲端,滤管内动态压力的压力峰值先逐渐变大后基本不变;相同反吹条件下,随着滤管长度的增加,滤管内沿长度方向各位置处的压力峰值均降低。实验范围内,1750～2000 mm滤管开口端附近的动态压力在达到压力峰值后降低为负压,并在反吹气流和脉冲压力波的共同作用下持续振荡。适当提高反吹压力以及增加脉冲宽度可以改善长滤管的反吹效果。     

新型高压脉冲等离子体反应器降解苯胺

针电极置于液中,接地电极置于液面之上,同时喷头在接地极板之上向下雾状喷液,形成了一种水包气放电（水中放电）和气包水放电（气体中放电）同时进行的新型反应器。实验表明,在脉冲峰值电压29kV、脉冲频率180Hz、接地电极与液面距离10mm时,高压脉冲电源与反应器的匹配性能良好。同时,考察了多种因素对高压脉冲等离子体反应器降解苯胺效果的影响。结果表明,苯胺降解率随脉冲峰值电压的增大、脉冲频率的增大、接地电极与液面距离的减小和溶液电导率的减小而增大;通入氧气时苯胺随降解率比通入空气和氮气时高;使用铜电极时苯胺降解率比使用不锈钢电极时高;苯胺降解率随乙醇加入量的增大而减小,且·OH在苯胺降解过程中的作用比例约为40％。     

低频脉冲流化床压力波动的模拟计算

当脉冲频率较低时,将脉冲流化床的通气阶段视为平稳流化,将停气阶段视为床层塌落过程,提出了一个用于计算脉冲流化床压力波动的数学模型．利用压力传感器测量了不同操作条件下的脉冲流化床壁面上几个点的压力变化ｐ（ｔ）,当脉冲频率较低时（对于本文所用物料,频率ｆ１０Ｈｚ）,模型计算结果和实验结果相当吻合     

换热器内置弹簧脉冲流动防垢除垢实验研究

以二甲基甲酰胺生产中易于结垢的换热器冷却过程为研究对象,采用换热管内置弹簧并利用泵的开、停措施使流体产生脉冲流动的方法对换热器在线防垢除垢进行研究。采用测定换热管外冷却水的吸热量随时间的变化关系以及试验结束后管内污垢称重法研究内置弹簧脉冲流动法对换热器在线防垢除垢效果。研究了泵的开、停时间,内置弹簧长度等因素对防垢除垢的影响。结果表明:在试验装置上,内置弹簧长度175～198cm、泵运行时间5～10s、泵停止时间5s时,具有显著的防垢除垢效果,在试验装置运行4h除垢率高达92.9%。同时在此条件下装置运行4～12h内,污垢增长量较少,说明此法除垢效果稳定。实验研究结果对实际工业换热器的改造具有一定的参考意义和指导价值。     

刚性过滤器脉冲反吹过程中滤管内动态压力特性

催化汽油吸附脱硫(S-Zorb)装置中反应器过滤器的脉冲反吹性能直接影响吸附剂的分离与循环。利用建立的滤管过滤性能实验装置,采用高频动态压力传感器,测定脉冲反吹过程中沿滤管长度方向不同位置处滤管内动态压力随时间的变化特性,分析了滤管长度、反吹压力和脉冲宽度对滤管内动态压力特性的影响规律。结果表明:自开口端至盲端,滤管内动态压力的压力峰值先逐渐变大后基本不变;相同反吹条件下,随着滤管长度的增加,滤管内沿长度方向各位置处的压力峰值均降低。实验范围内,1750~2000 mm滤管开口端附近的动态压力在达到压力峰值后降低为负压,并在反吹气流和脉冲压力波的共同作用下持续振荡。适当提高反吹压力以及增加脉冲宽度可以改善长滤管的反吹效果。     

行列式刚性陶瓷过滤器脉冲反吹系统中的压力特性

利用高频动态压力传感器测定脉冲反吹系统中各位置的压力特性,研究了反吹压力和喷嘴孔径对压力特性的影响,提出了解决反吹不均匀的设计方案,采用过滤循环实验进行验证. 结果表明,采用相同孔径的喷嘴时,喷吹管内、喷嘴出口及过滤管内的压力特性存在较大差异,各喷嘴的反吹不均匀性随反吹压力升高而增大,反吹强度随喷嘴孔径增大而减小,喷吹管内的静压沿喷吹方向逐渐增大. 沿喷吹方向将喷嘴孔径递减能改善反吹不均匀的状况,喷嘴截面积与喷吹管截面积之比s/S对脉冲反吹均匀性的影响较大,s/S=48%~55%较佳.     

气-液并流通过堆叠筛板填料的脉冲流特性

通过高速摄像机和压力传感器测量,对脉冲流的产生机理、筛板数的影响、液相脉冲传播速度及频率进行了系统的研究。实验发现：脉冲流是重力和气流曳力作用下,孔口液相波动在向下传播过程中被叠加放大的动力学过程,且与气、液流量及筛板数密切相关;一定气量下,脉冲流的产生需要有一个最小（临界）液相流量,且增加液量可促进局部脉冲的产生,并使液相脉冲传播速度与频率均增大;临界液量之上,增大气量,气相的扰动作用增强,局部脉冲越容易产生,从而导致脉冲传播速度与频率均增大;进一步增大气量,液相脉冲会被逐渐分散,导致脉冲传播速度与脉冲频率均减小。增加筛板数,有利于增强脉冲流强度,从而导致脉冲流范围变宽,当筛板数少于三块时不会出现脉冲流。最后,基于实验结果分析,提出了脉冲传播速度及频率的预测关联式。     

油井井口激动压力脉冲解堵增油技术

为了研究油井井口激动压力脉冲解堵增油技术,对油气田开发后期注水产生的地层损坏做系统分析.预设实验重点针对压力脉冲解堵影响因素进行分析.对管径对脉冲效果的影响、井口压力对井筒内脉冲波动的影响、井口压力对地层脉冲压力的影响和泄压时间对脉冲压力的影响进行分类总结.得出:运用连续油管作业配合800型泵车可以在一定井深达到较好的...     

滴流床反应器内脉冲流流体力学特性参数的模型预测

通过对气流两相在填料床反应器并流向下流动情况的分析,提出了计算如气、液两流体在富液和富气脉冲柱内的速度、持流量及脉冲柱长度等流体力学参数的数学模型方程,为使模型方程封闭,根据实验数据提出三个经验关联式关联表观脉冲速度、脉冲频率和平均持流量三个宏观平均参数,模型计算结果与分析结论吻合良好。     

The dynamics of extraction processes: Part II. Comparison of dynamic testing methods and their application to an extraction process

A comparison of the theoretical and experimental difficulties and advantages of sinusoidal, pulse, and step testing procedures, as applied to a continuous stagewise extraction process, is made. An experimental extraction apparatus suitable for a variety of dynamic studies is described. For this apparatus step testing has been found to give results as reliable as those from pulse methods. The paper develops the theoretical background and describes experimental implementation of double pulse testing. The extraction column when used with the system water-acetic acid-methyl isobutyl ketone was found to behave linearly over the range of variables studied. The stages of the column were found to be “well-mixed”, and it was concluded that the column could be best represented by a lumped parameter model.     

Performance of an Industrial Pulsed Disc-and-Doughnut Extraction Column

Axial-dispersion and plug-flow models have been used to describe the solvent extraction performance of a 18 m high and 4 m diameter industrial pulsed disc-and-doughnut column. Uranium extraction phase-equilibrium data were fitted with the Langmuir model. Using the industrial column dimensions, operational parameters, physical properties, and the Langmuir parameters, the axial-dispersion model was shown to predict the organic-phase outlet concentration and the aqueous-phase outlet concentration, respectively, while the plug-flow model exhibited a poorer predictive ability.,     

Influence d'une agitation rotative sur le mélange en retour dans une colonne pulsée à plateaux perforés

The efficiency of a pulsed perforated plate extraction column can be improved, particularly at low values of A.f, by superimposing a rotary agitation. The hold up and the Peclet number have been measured in such a column in order to calculate the coefficient of backmixing of the continuous phase. A comparison of the results with those for a conventional pulsed column has indicated that the improved performance is due to an increase in hold up and not, as might have been supposed, to reduced backmixing.     

Comparison of normal phase operation and phase reversal studies in a pulsed sieve plate extraction column

The hydrodynamic characteristics of a pulsed sieve plate extraction column (PSPEC) was studied experimentally using two different liquid phase systems, namely water/kerosene and 30%TBP (tributyl phosphate) in NPH (normal paraffin hydrocarbon)/0.3 M HNO₃. The aqueous phase as the dispersed phase and the organic phase as the continuous phase (phase reversal) and vice versa (normal phase operation) studies in a pulsed sieve plate extraction column 0.076 m in diameter and 1 m height are presented in this paper. The hydrodynamic properties like drop size and holdup are characterized as a function of various operating parameters namely pulse velocity, dispersed phase and continuous phase velocity and duty cycle of pulsing. Flooding in the column was also investigated for the changes involving flow ratio of continuous phase to that of the dispersed phase for both insufficient and excessive pulsing. It has been observed that phase reversal mode of operation is not efficient as compared to normal phase operation for the PSPEC.     

Experimental Investigation and CFD Modeling of Hydrodynamic Parameters in a Pulsed Packed Column

In this work, a combination of computational fluid dynamics (CFD) and droplet population-balance model (DPBM) in the framework of Fluent was applied to simulate the drop-size distributions and flow fields in a pilot-plant liquid–liquid extraction pulsed packed column. The three-dimensional unsteady-state liquid–liquid flow was modeled using the Eulerian two-fluid equations in conjunction with the realizable k – ε turbulence model. The classes method (CM) was chosen for solving population-balance equations. Two models for breakage and coalescence, the models of Luo and Garthe, were used in the CFD code. The model was validated by comparing the simulated drop-size distributions and holdup with experimental measurements. After the validation of the model, the effects of the operating conditions (feed rates and pulsation) on the dispersed phase holdup and drop-size distributions were studied. The results of linked CFD-DPBM model and experiments revealed that the dispersed phase holdup was increased when the organic and aqueous flow rates increased and when the intensity of pulse was increased, the holdup increased. Increasing the dispersed and continuous feed rates caused the Sauter mean diameter of the drops decreased and when the intensity of pulse was increased, because of high droplets break up rate, the Sauter mean diameter decreased. Results of linked CFD-DPBM model show that the CFD-DPBM tool is able to predict hydrodynamic parameters in a pulsed packed column.     

折流板脉冲萃取柱的结构参数对孔收缩因子的影响

利用吹气法研究了折流板脉冲萃取柱的结构参数（板间距、柱径和板开孔率）对预测摩擦压降模型中孔收缩因子Co的影响。研究结果表明：当实验体系为硝酸溶液时,Co值随柱径、板间距和板开孔率的增加而减小;当实验体系为30％三烷基氧膦-煤油溶液且柱径不大于0．05m时,Co值与脉冲雷诺数ReAf和板开孔率有关,与板间距无关,而当柱径为0．1m时,Co值与板间距和板开孔率有关,而与操作参数ReAf无关。     

Determination of holdup by air purge in φ50 mm discs and doughnuts pulsed extraction column

在柱径为50 mm的折流板脉冲萃取柱中,首先利用吹气法研究了硝酸水溶液和30％TRPO-煤油水溶液体系的单相流时均摩擦压降Δp_f特性.实验结果表明当A′ω≠0,且u_c＝0时,Δp_f可以忽略;而当Aω＝0时,Δp_f与u_c满足Noh模型的线性关系.在Noh模型的基础上,给出了计算Aω≠0时单相流时均摩擦压降的模型,实验结果与模型预测相一致.在单相流摩擦压降的基础上,又研究了连续相分别为硝酸溶液和30％TRPO-煤油溶液体系的两相流时均摩擦压降Δp_f特征.实验结果表明：两相流时均摩擦压降Δp_f可用于计算分散相存留分数,其近似由连续相所对应的Noh单相流模型求得,并可用于折流板脉冲萃取柱分散相存留分数的确定.     

Measurement and CFD simulation of single-phase flow in solvent extraction pulsed column

A CFD (computational fluid dynamics) model of a solvent extraction pulsed column has been developed and run with a single water phase. The results are compared with experimental measurements taken on a pilot scale column using PIV (particle image velocimetry).The pulsed column investigated had disk-doughnut internals and was operated under pulsing intensities ranging from 10 to 32.5 mm/s. PIV measurements of velocity were used to validate the CFD model and to characterise the pulsing flow of a single phase through the column. The CFD modelling was performed for the same geometry and operating conditions using a 2D computational grid and a low Reynolds Number k-ε turbulence model. An improved velocity prediction was achieved by adding a gap between the doughnut internal and the pulsed column wall. The combined measurements and predictions give insight into the effect of the geometry internals on the flow hydrodynamics in the pulsed column.     

不同隙径比环形脉冲萃取柱的传质性能

以30%TBP(煤油)-HNO_3-H_2O为实验体系,在外柱内径为100mm的环形脉冲萃取柱中以4种不同隙径比进行了传质性能研究.实验测定了环形柱的稳态浓度剖面,以扩散模型为基础拟合求取了传质模型参数,建立了相应的关联式.研究结果表明,4种不同隙径比环形柱的“真实”传质单元高度H_(ox)值可以用相同关联式表述;分散单元高度H_(oxd)值则与隙径比的0.16次方成正比.与外柱内径为50mm的环形柱相比较,其H_(ox)值可采用相同关联式描述;其H_(oxd)值与环形柱外柱内径有关.这反映了外柱径对环形柱轴向混合的影响.     

φ50 mm折流板脉冲萃取柱吹气法测量存留分数

在柱径为50 mm的折流板脉冲萃取柱中,首先利用吹气法研究了硝酸水溶液和30％TRPO-煤油水溶液体系的单相流时均摩擦压降Δp_f特性.实验结果表明当A′ω≠0,且u_c＝0时,Δp_f可以忽略;而当Aω＝0时,Δp_f与u_c满足Noh模型的线性关系.在Noh模型的基础上,给出了计算Aω≠0时单相流时均摩擦压降的模型,实验结果与模型预测相一致.在单相流摩擦压降的基础上,又研究了连续相分别为硝酸溶液和30％TRPO-煤油溶液体系的两相流时均摩擦压降Δp_f特征.实验结果表明：两相流时均摩擦压降Δp_f可用于计算分散相存留分数,其近似由连续相所对应的Noh单相流模型求得,并可用于折流板脉冲萃取柱分散相存留分数的确定.