Application of an extended Lee-Kesler corresponding-states technique to prediction of vapor-liquid equilibria in multicomponent mixtures containing polar components

Mixing rules for an extended Lee-Kesler (ELK) corresponding-states method for prediction of thermodynamic properties are presented. The mixing rules, which do not contain adjustable parameters, permit calculation of vapor-liquid equilibria in mixtures containing one or more polar components. While a single heat-of-mixing datum may be included for strongly associating components, generally only pure component properties are used in the calculations. A comparison of calculated bubble-point pressures and equilibrium vaporization ratios to experimental values is made for 26 ternary mixtures (791 points) and 5 quaternary mixtures (175 points). Bubble-point pressures are predicted quite well with ELK (9.1 % AAD for ternaries and 7.9% for quaternaries). Composition predictions are difficult to compare in multicomponent systems, but ELK predictions appear to be acceptable on both a system-by-system and an overall AAD basis.Paper presented at the Tenth Symposium on Thermophysical properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

Automated System for Calculating Thermophysical Properties of Fluids and Thermal Processes of Cryogenic Plants

An automated system for calculating thermophysical properties of gases and liquids over a wide range of parameters has been developed. On the basis of values of the properties, the processes of isothermal compression, adiabatic throttling, polytropic expansion, heat exchange in two- and multi-stream heat exchangers, separation of vapor-liquid mixtures in the liquid vessel, and rectification in an air separation plant can be analyzed. For a specified structure scheme of a cryogenic plant, optimization of a corresponding thermodynamic cycle can be fulfilled.     

分层改造中压裂液优化研究

苏里格气田储层具有多层、薄层的特点，分压改造是有效开发气田的主体技术之一。针对分层压裂使用的压裂液进行了室内优化及测试研究，在优选压裂液添加剂基础上，优选出了分层压裂使用的压裂液配方，并针对分压中出现的高剪切及压裂液滞留等问题，开展了试验研究。该压裂液配方能较好地降低储层喉道毛细管的界面张力，有利于压裂后残液的返排。优化的压裂液配方能降低对储层造成的伤害，其性能指标满足了储层及分压工艺的要求。     

Equations of State for Technical Applications. II. Results for Nonpolar Fluids

New functional forms have been developed for multiparameter equations of state for non- and weakly polar fluids and for polar fluids. The resulting functional forms, which were established with an optimization algorithm which considers data sets for different fluids simultaneously, are suitable as a basis for equations of state for a broad variety of fluids. The functional forms were designed to fulfill typical demands of advanced technical applications with regard to the achieved accuracy. They are numerically very stable and their substance-specific coefficients can easily be fitted to restricted data sets. In this way, a fast extension of the group of fluids for which accurate empirical equations of state are available becomes possible. This article deals with the results found for the non- and weakly polar fluids methane, ethane, propane, isobutane, n-butane, n-pentane, n-hexane, n-heptane, n-octane, argon, oxygen, nitrogen, ethylene, cyclohexane, and sulfur hexafluoride. The substance-specific parameters of the new equations of state are given as well as statistical and graphical comparisons with experimental data. General features of the new class of equations of state such as their extrapolation behavior and their numerical stability have been discussed in a preceding article. Results for typical polar fluids will be discussed in a subsequent article.     

肿瘤治疗用磁流体研究进展

磁流体因其所具有的独特性质(流动性，磁响应性，靶向性)而应用广泛，与现代医药学相结合则更加显示出其优越性。综述了其在肿瘤治疗领域的应用研究进展。     

Advanced Distillation Curve Measurement with a Model Predictive Temperature Controller

In previous work, several significant improvements in the measurement of distillation curves for complex fluids were introduced. The modifications to the classical measurement provide for (1) temperature and volume measurement(s) of low uncertainty, and most important, (2) a composition-explicit data channel in addition to the usual temperature–volume relationship. This latter modification is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. In the new approach, the distillation temperature is measured in two locations. The temperature is measured in the usual location, at the bottom of the take-off in the distillation head, but it is also measured directly in the fluid. We have further modified our developmental instrument to incorporate a model predictive temperature controller. In response to either an equation-of-state calculation or a previous distillation curve, the programmable temperature controller increases the fluid temperature to achieve a constant mass flow rate of vapor through the distillation head. This approach eliminates the aberrations that one typically encounters in the data due to fluctuations in distillation rate, often referred to as hesitation. Thus, we can collect data from two temperature channels: one a true state point measurement (measured directly in the fluid) and the other comparable to previous data (measured in the head).     

Petroleum-Based Hydraulic Fluids and Flammability

Hydraulic fluids for the most part are considered to be much less flammable than middle distillate fuels. Petroleum-based hydraulic fluids have high flash points, while water-based hydraulic fluids (because of their high water content) are definitely nonflammable. The major problem with water-based hydraulic fluids is corrosion. Petroleum-based fluids are much less corrosive and thus equipment lifetime is considerably increased. However, some petroleum-based hydraulic fluids have been observed to be a fire safety hazard in situations where high-pressure leaks can result in aerosol formation. These fire hazards cannot be adequately explained based solely on flash point considerations of the hydraulic fluids alone.     

AM/AA/DMDAAC三元共聚物的合成及性能

采用氧化-还原引发体系合成了丙烯酰胺(AM)/丙烯酸(AA)/二甲基二烯丙基氯化铵(DMDAAC)三元共聚物,并对此三元共聚物的泥浆性能进行了初步评价。结果表明,AM/AA/DMDAAC三元共聚物具有较强的降滤失、抑制页岩水化膨胀能力。     

Environmentally Friendly Precision Machining

Material removal processing has been investigated both theoretically and experimentally to a certain extent. The demands for environmentally friendly processes impose new parameters such as the use of minimal quantity or even the complete omission of cutting fluids. Therefore, the related processes need to be newly studied in order to be optimized for specific cutting conditions. Cutting fluids are used in material removal processes mainly for lubrication, reduction of the temperature in the cutting region, and increase of tool life. However, cutting fluids are associated with skin and breathing problems of the machine operators. Furthermore, after their disposal and if, as in most cases, recycling is not possible, they may become polluting agents in soil and water when inappropriately handled. In this paper the case of hard cutting, a process that can be performed without the use of a cutting fluid, is investigated. A discussion on the technological parameters involved is given and experimental data are presented in order to point out the environmental as well as the economical benefits emerging from the use of such a technology.     

新型甲酸盐/正电聚醇钻井液在南部滩海地区的应用

南部滩海是大港油田的重点勘探区域之一.该地区明化镇组和馆陶组地层粘土矿物以伊蒙无序间层为主,而且间层比很高,在钻井过程中常出现易塌、易漏失、起下钻遇阻及钻井液性能不稳定等复杂情况.为实现安全、快速钻进,充分利用甲酸盐与正电聚醇的协同增效作用,研制并优选出了一种甲酸盐/正电聚醇强抑制性钻井液.在张海5井等5口井的现场应用试验表明,这种钻井液体系表现出抗温性好、抑制性强、润滑性好、储层保护效果好等多种功能;该体系性能稳定,容易维护,很大程度地提高了井壁稳定性,如张海5井三开井段平均井径扩大率仅为5.66%,井径规则,现场进行多次电测和核磁共振测试,均一次成功,建议在该地区进行推广应用.