麦草蒸汽爆破处理的研究

对汽爆麦草进行了电镜观察及差热、红外光谱和纤维表面特征的Ｘ－射线光电子能谱分析（ＸＰＳ）。汽爆麦草显微形态表明,在汽爆过程中木质素部分被抽提出之后,又重新分布沉聚于纤维的表面。汽爆麦草的差热性质分析了汽爆使麦草的半纤维素和部分木质素降解为低分子物质,并且使纤维疏松,形成多孔性,易于燃烧。汽爆麦草红外光谱分析表明,添加了碱性物质,半纤维素降解得很少。因此,汽相蒸煮的酸碱度是半纤维素溶出的关键性因素。     

较高温度下3-甲-1-丁醇、乙酸丁酯、乙苯的汽液平衡

较高温度下３－甲－１－丁醇、乙酸丁酯、乙苯的汽液平衡王琦严新焕（浙江大学化学系,杭州３１００２７）关键词汽液平衡Ｗｉｌｓｏｎ方程１前言关于汽液平衡行为与温度的关系的研究虽已有文献报导,但在３７３Ｋ以上的等温汽液平衡数据很少,这给理论研究和模型化...     

甲烷的状态方程研究及应用

本文以MH方程为基础,用甲烷在90－400K,0．01－50MPa范围内的PVT数据,对方程的形式和常数进行显著性检验,得到了一个适用于气液两相的27常数方程。新的方不但较重现了PVT和汽液平衡性质,而且很好地预测了焓、熵和等压热容等性质。改进方程的计算结果达到或优于改进的BWR方程。可以作为甲烷的一个较满意的状态方程。     

汽相循环法测定CO_2－C_2H_5OH－H_2O－夹带剂体系相平衡

本文建立了一种新型的单汽相循环法汽液平衡测定装置，仅用一只循环泵实现了汽相循环和汽、液相的采样分析。测定了３１３．２Ｋ、１０ＭＰａ下，ＣＯ_２－Ｃ_２Ｈ_５ＯＨ－Ｈ_２Ｏ－夹带剂（乙二醇或丙三醇）体系的相平衡数据。实验结果表明：对于乙醇浓度高于０．３５ｍｏｌ的乙醇水溶液，其中含有０．１ｍｏｌ的夹带剂的原料，比单用二氧化碳萃取（无夹带剂加入）具有更高的汽相溶解度和分离选择性，但仍然不能打破乙醇－水体系的常压恒沸点。     

苯－三聚甲醛、环己烷－三聚甲醛二元汽－液相平衡

苯－三聚甲醛、环己烷－三聚甲醛二元汽－液相平衡王桂英，王广铨（吉林化工学院，１３２０２２）关键词苯；环己烷；三聚甲醛；汽－液平衡；关联１引言汽－液相平衡（ＶＬＥ）数据是化工基础数据的重要组成部分，国内外均有大量文献报导、并建有相应的ＶＬＥ数据库，对常...     

汽相循环法测定CO2—C2H5OH—H2O—夹带剂体系相平衡

本文建立了一种新型的单汽相循环法汽液平衡测定装置，仅用一只循环泵实现了汽相循环和汽、液相的采样分析。测定了３１３．２Ｋ、１０ＭＰａ下，ＣＯ２－Ｃ２Ｈ５ＯＨ－Ｈ２Ｏ－夹带剂（乙二醇或丙三醇）体系折相平衡数据。实验结果表明：对于乙醇浓度高于０．３５ｍｏｌ的乙醇水溶液，其中含有０．１ｍｏｌ的夹带剂的原料，比单用二氧化碳萃取（无夹带剂加入）具有更高的汽相溶解度和分离选择性，但仍然不能打破乙醇－水体系的常压     

甲缩醛—甲醇—甲醛—水四元系的汽液平衡

甲缩醛－甲醇－甲醛－水四元系的汽液平衡邱祖民骆赞椿胡英（南昌大学化工系,南昌３３００２９）（华东理工大学化工系,上海２００２３７）关键词沸点仪汽液平衡甲缩醛甲醇甲醛甲醛虚拟饱和蒸汽压１前言甲缩醛－甲醇－甲醛－水四元系的汽液平衡数据为甲缩醛氧化制甲醛...     

氯仿－正丙醇及其含盐体系的汽液平衡

实验测定了在１０１．３ｋＰａ压力下氯仿－正丙醇、氯仿－正丙醇－氯化锂及氯仿－正丙醇－氯化钙体系的汽液平衡数据。用Ｈｅｒｉｎｇｔｏｎ方法对无盐体系的实验数据作了热力学校验，并以ＶａｎＬａａｒ方程及Ｗｉｌｓｏｎ方程关联了无盐体系，结果较为满意。用汽液平衡盐效应方程计算了含盐体系在不同液相组成下的盐效应参数。提出了关联盐效应参数与液相组成的经验方程，并以经验方程及汽液平衡盐效应方程计算了平衡汽相组成，实验值与计算值吻合较好。     

氯仿－正丙醇及其含盐体系的汽液平衡

实验测定了在１０１．３ｋＰａ压力下氯仿－正丙醇、氯仿－正丙醇－氯化锂及氯仿－正丙醇－氯化钙体系的汽液平衡数据。用Ｈｅｒｉｎｇｔｏｎ方法对无盐体系的实验数据作了热力学校验，并以ＶａｎＬａａｒ方程及Ｗｉｌｓｏｎ方程关联了无盐体系，结果较为满意。用汽液平衡盐效应方程计算了含盐体系在不同液相组成下的盐效应参数。提出了关联盐效应参数与液相组成的经验方程，并以经验方程及汽液平衡盐效应方程计算了平衡汽相组成，实验值与计算值吻合较好。     

碳酸二甲酯-甲醇-氯苯体系汽液平衡数据推算

利用二元体系的汽液平衡数据,选用Ｗｉｌｓｏｎ方程推算了三元体系碳酸二甲酯－甲醇－氯苯的汽液平衡数据,为建立萃取精馏分离碳酸二甲酯和甲醇的数学模型提供了基础数据。     

六氟化硫PVT关系测定实验教学体会与思考

纯流体PVT关系测定及临界状态观察实验对于学生理解问题的本质,提高理论教学效果具有不可替代的作用。本文介绍了六氟化硫临界状态观察及PVT关系测定仪的制造及使用情况,重点介绍实验数据记录处理等细节上的一些经验体会和我们的建议。     

A multi-fluid nonrandom lattice fluid model: General derivation and application to pure fluids

A multi-fluid nonrandom lattice fluid model with no temperature dependence of close packed volumes of a mer, segment numbers and energy parameters of pure systems is presented. The multi-fluid nonrandom lattice fluid (MF-NLF) model with the local composition concept was capable of describing properties for complex systems. However, the MF-NLF model has strong temperature dependence of energy parameters and segment numbers of pure systems; thus empirical correlations as functions of temperature were represented for reliable and convenient use in engineering practices. The MF-NLF model without temperature dependence of pure parameters could not predict thermodynamic properties accurately. It was found that the present model with three parameters describes quantitatively the vapor pressure and the saturated density for the pure fluid.     

变阱宽方阱链流体状态方程模拟制冷剂的汽液平衡

应用作者先前基于二阶微扰理论和PY2近似积分方程建立的可变阱宽方阱链流体状态方程模拟了纯制冷剂及其混合体系的汽液平衡。通过关联不同温度下制冷剂的饱和蒸气压和液体体积得到了18种纯制冷剂的分子参数,新方程计算的饱和蒸气压和液体体积总的平均偏差分别为1.11％和0.92％。结合简单混合规则,将此方程扩展到混合体系。研究发现,建立的方程可满意预测制冷剂二元混合体系除临界区附近外的汽液平衡,对两个三元体系汽液平衡的预测也取得了满意的效果,当引入一个与温度无关的可调参数时,关联精度大为提高,预示着新的方程可模拟制冷剂的汽液平衡。     

UNIFAC基团贡献法研究及应用进展

UNIFAC 基团贡献法是推箅组分活度系数应用最广泛的模型之一.介绍了UNIFAC基团贡献法的研究进展,分析了UNIFAC模型在气液平衡(气体溶解度、纯组分的蒸汽压、典型气液平衡预测)、液液平衡(液体混合物的表面张力、萃取精馏体系、聚合物溶液粘度的推算、典型液液平衡预测)、固液平衡(同分异构体的平衡体系、固体溶解度的计算)体系的应用领域及其局限性,并针对UNIFAC基团贡献法存在的问题,提出UNIFAC基团贡献法的研究方向和具体的研究内容.     

THE MODIFIED PGR EQUATION OF STATE: PURE-FLUID PREDICTIONS

The Park-Gasem-Robinson (PGR) equation of state (EOS) has been modified to improve its volumetric and equilibrium predictions. Specifically, the attractive term of the PGR equation was modified to enhance the flexibility of the model, and a new expression was developed for the temperature dependence of the attractive term in this segment-segment interaction model.

The predictive capability of the modified PGR EOS for vapor pressure and saturated liquid and vapor densities was evaluated for selected normal paraffins, normal alkenes, cyclo-paraffins, light aromatics, argon, carbon dioxide, and water. The generalized EOS constants and substance-specific characteristic parameters in the modified PGR EOS were obtained from pure component vapor pressures and saturated liquid and vapor molar volumes. The calculated phase properties were compared with those of the Peng-Robinson (PR), the simplified-perturbed-hard-chain theory (SPHCT), and the original PGR equations. Generally, the performance of the proposed EOS (%AAD of 1.3, 2.8, and 3.7 for vapor pressure, saturated liquid, and vapor densities, respectively) was better than the SPHCT and original PGR equations in predicting the pure fluid properties.     

Prediction of partial molal volumes of normal fluid mixtures

Partial molal volumes of normal fluid mixtures in the liquid state were evaluated by means of a modified Redlich-Kwong equation of state. Molal volumes and vapor pressures of pure saturated liquids were used for evaluating the two parameters of the equation. These parameters were treated as temperature dependent. Partial molal volumes of six binary systems were satisfactorily predicted in this investigation. Satisfactory compressibility factors for pure liquids at high pressures were also obtained by the proposed method.     

EQUATION OF STATE FOR POLAR AND NONPOLAR SUBSTANCES FROM CORRELATIONS OF PURE COMPONENT PROPERTIES

A cubic equation of state of the van der Waals type is presented which is suitable for polar and nonpolar fluids and fluid mixtures. The form is based on the three-parameter equation of lwai, Margerum and Lu. Problems in parameter generalization are avoided by calculating the parameters directly from existing pure component vapor pressure and saturated liquid molar volume correlations. The proposed approach yields excellent representation of pure component saturated and single-phase region properties. Excellent results are also obtained for mixtures.     

Experiments and Computational Fluid Dynamics on Vapor and Gas Cavitation for Oil Hydraulics

A compressible Euler-Euler computational fluid dynamics (CFD) model for vapor, gas, and pseudo-cavitation in oil-hydraulic flows is presented. For vapor, the Zwart-Gerber-Belamri (ZGB) model is used and for gas cavitation, the Lifante model. The aim is to determine the empirical parameters within the cavitation models for hydraulic oil by comparing CFD results to experiments in a realistic valve. The cavitating flow is visualized and measured for numerous operating points. By degassing, states of pure vapor cavitation are generated. The major findings are: (1) large eddy simulation turbulence modeling is essential, (2) vapor cavitation in mineral oil can be simulated very well with the ZGB model using the determined parameter, and (3) gas cavitation model provides useful results although not all details can be reflected and its scope is limited.     

水平管内R245fa/R141b沸腾换热特性的实验研究

针对新型混合工质R245fa/R141b,开展水平光滑管(外径10 mm)内工质沸腾换热特性的实验研究,对比纯工质与混合工质的换热性能及4种常用关联式的预测精度。结果表明：纯工质与混合工质的沸腾传热系数均随质量流速和热通量的增加而增大,随饱和压力的增加而减小;随干度的增加,沸腾传热系数均先增大后减小,即存在“过渡干度”,且混合工质的过渡干度大于纯工质;干度小于0.55时,混合工质传热系数小于纯工质;干度大于0.55后,混合工质的传热系数更高;随R245fa质量分数的增加,混合工质的沸腾传热系数增大。在所选关联式中,Gungor-Winterton关联式能准确地预测工质在光滑管内的沸腾换热特性,平均相对误差为16.67%。     

基于第一原理力场预测热力学参数的探讨

讨论用第一原理全原子力场计算热力学参数的可行性.新开发的TEAM力场,在用气、液相基本性质验证后,不加任何参数调整,直接用于计算具有代表性的几个分子液体在不同热力学状态下的密度、蒸发焓、混合焓、亨利常数、饱和蒸气压等热力学参数.初步结果表明：液体密度和蒸发焓的预测结果良好,在较大范围内可获得与实验数据相吻合的结果;而混合焓的准确预测需要纯液体内聚能的高精度模拟数据;亨利常数的计算对液体的密度极为敏感.后两种性质的计算均可用全原子力场但需要高质量的力场参数.为了采用全原子力场计算气液相平衡数据,提出了一种半经验的、基于积分Clausius-Clapeyron方程的循环自洽方法计算液体的饱和蒸气压.