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1.
纯组分高压流体的粘度模型   总被引:1,自引:1,他引:0  
基于p-V-T和T-μ-p图形有相似性,并结合两参数Peng-Robinson状态方程,建立了一个能够同时预测纯流体气、液相粘度的统一模型。该模型能够同时描述气、液相及超临界流体的粘度随温度、压力和组成的变化情况。模型的纯组分参数已普遍化为对比温度、对比压力和偏心因子的函数。在较宽的温度、压力范围内(T=280 ̄600K,p=0.1 ̄100MPa),对22种烷烃、二氧化碳和氮气的粘度进行了计算,其  相似文献   

2.
对温度T、导热系数λ和压力p三者之间的关系进行了分析,建立了一个能够同时预测纯组分气-液相导热系数的统一模型,它能够描述高压流体和超临界流体的导热系数随温度和压力的变化。在较宽的温度和压力范围内(T=80-1400K,p=0.1-350MPa),对油气藏流体中常见组分的气-流相导热系数进行了计算,22个组分3263个数据点的拟合结果的平均相对误差为12.53%。通过引入常规的态方程混合规则,将模型  相似文献   

3.
对温度T、导热系数λ和压力p三者之间的关系进行了分析,建立了一个能够同时预测纯组分气液相导热系数的统一模型,它能够描述高压流体和超临界流体的导热系数随温度和压力的变化。在较宽的温度和压力范围内(T=80~1400K,p=0.1~350MPa),对油气藏流体中常见组分的气液相导热系数进行了计算,22个组分3263个数据点的拟合结果的平均相对误差为12.53%。通过引入常规的状态方程混合规则,将模型拓展应用于混合物导热系数的计算,13种二元和三元混合物260个数据点的平均相对误差为11.19%;对3个石油馏分22个点导热系数的预测结果的平均相对误差为8.89%  相似文献   

4.
在表面张力长程校正公式的基础上,应用正则系综分子动力学模拟方法较为系统地对Lennard-Jones(LJ)纯流体的液汽平衡及界面性质进行了模拟研究。在温度T*=kBT/ε为0.75~1.20范围内,分别计算了7个温度条件下LJ纯流体的汽液相共存平衡密度、密度分布、表面张力和界面厚度。研究结果表明:文中得到的LJ纯流体汽液相平衡密度与采用Gibbs系综MonteCarlo模拟计算结果基本一致;表面张力的模拟计算值与实验数据符合较好;另外,随着温度的升高,流体的表面张力降低而界面厚度变大。  相似文献   

5.
利用剪切速率趋于零时聚合物熔体粘度与分子参数和流体本征性质的直接相关性,在低剪切速率0.05~0.2s-1、温度180~220℃条件下,测定了分子量Mw=105×104~266×1043种超高分子量聚苯乙烯(ps)的流动活化能,结果表明,聚合物分子量大幅度增加对流动活化能的变化不敏感。  相似文献   

6.
孤山子超镁铁质岩体是冀东地区重要的磁铁矿源之一,同时也拥有较好的铜镍矿床的成矿条件。流体包裹体的研究表明,该铜镍矿床的流体包裹体主要有3种类型:气液两相包裹体(个别为纯液相包裹体)、富CO2三相包裹体和纯气相包裹体。孤山子铜镍矿床的成矿流体属于中低温、中盐度和中低密度的酸性流体,形成深度约为85.~98.km,成矿流体压力约为106~138 M Pa。  相似文献   

7.
分别采用LennardJones(LJ)和Kihara位能模型并结合顺序解析法计算了径向分布函数,然后代入统计热力学所给出的严格理论状态方程来预测真实流体的PVT性质。位能模型参数由纯流体的临界温度性质确定。计算结果表明,该方法可用于预测较宽广的压力、温度范围内的非极性和弱极性纯流体的PVT性质。当分子尺寸小于正己烷时,近临界区除外,由LJ模型预测的饱和液体体积的相对平均误差一般小于5%。对于分子尺寸更大的流体,需用三参数Kihara位能模型来提高预测精度  相似文献   

8.
格子Boltzmann伪势能两相模型由于缺少与真实流体相关的物理参数,因此无法实现对某种特定流体的模拟。本文将比容平移后的Peng-Robinson状态方程(MPR)引入模型中,通过状态方程中的无量纲参数偏心因子和临界压缩因子,建立模拟流体与真实流体的关联,使得模型可以区别各种真实流体,并模拟了氩、氧气、烷烃等8种流体在不同温度下的饱和气液相密度。结果表明,MPR和Peng-Robinson方程(PR)的格子Boltzmann两相模型均能很好的描述8种流体的饱和气相密度;而MPR方程能够很好的再现氩、氮气、氧气等非极性流体的饱和液相密度,对于其它流体,MPR方程较PR方程对液相密度的描述有所改进,但仍与实验数据有一定差异。总体上MPR方程能够更好地模拟不同流体的饱和气液相密度。  相似文献   

9.
在原PR导热系数模型基础上,改进建立了一个PR导热系数普遍化模型,在温度80~1400K和压力0.1~350MPa内对油气藏流体中常见的22个纯组分的气、液相导热系数总共3263个数据点进行了拟合,总平均相对误差为7.34%。对13个二元和三元混合物总共260个数据点预测的总平均相对误差为7.94%;对3个石油馏分总共22个数据点导热系数预测的总平均相对误差为9.68%。对极性纯物质的总共810个数据点预测的总平均相对误差为6.86%;对极性二元混合物的共439个数据点预测的总平均相对误差为6.03%。该模型的计算精度明显优于石油工程中常用的导热系数模型。  相似文献   

10.
分别采用Lennard-Jones(L-J)和Kihara位能模型并结合顺序解析法计算了径向分布函数,然后代入统计热力学所给出的严格理论状态方程来预测真实流体的PVT性质。位能模型参数由纯流体的临界温度性质确定。计算结果表明,该方法可用于预测较度广的压力、温度范围内的非极性和弱极性纯流体的PVT性质。讨还上于正己烷时,近临界区除外,由L-J模型预测的饱和液体体积的相对平均误差一般小于5%。对于分子  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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