Saturated Liquid Research Articles

Thermodynamic Properties of cis-1,1,1,4,4,4-Hexafluorobutene [R‑1336mzz(Z)]: Vapor Pressure, (p, ρ, T) Behavior, and Speed of Sound Measurements and Equation of State.

We present experimental measurements of the density, speed of sound, vapor pressure, and dew-point pressure of cis-1,1,1,4,4,4-hexafluorobutene, which is also known as R-1336mzz(Z). Vapor pressures were measured at temperatures from 330 to 440 K; the dew-point pressure was measured at T = 293.15 K. Densities were measured in the liquid and supercritical regions over the temperature range of 230 to 460 K, with pressures up to 36 MPa. Vapor-phase sound speeds were measured at temperatures between 280 and 480 K, with pressures from 0.021 to 2.2 MPa. Densities and dew points were measured in a two-sinker densimeter with a magnetic suspension coupling. Vapor pressures were measured with a static technique in the densimeter. Sound speed data were measured with a spherical acoustic resonator. An equation of state written in terms of the Helmholtz energy was developed based on these data together with additional data from the literature; it represents the present experimental data with relative average absolute deviations (AAD) of 0.0081% for densities, 0.027% for vapor pressure, and 0.017% for vapor-phase speed of sound. Literature data for liquid-phase speed of sound have an AAD of 0.023%, and for saturated liquid density data, the AAD is 0.049%.

Numerical investigation of anode channel clogging of a PEMFC with a realistic droplet size distribution

In this paper, a parametric study of anode channel clogging of a proton exchange membrane fuel cell (PEMFC) is presented using the numerical volume of fluid method. The droplet size distribution in the present research is considered close to reality. Therefore, three droplets with different sizes are initially placed on the anode channel wall. The droplet sizes are obtained based on the distribution of the saturated liquid water along the whole channel under a specific working condition and the amount of condensed water in the channel, using the PEMFC code. Finally, the dynamic behavior of the droplets is investigated and compared to that of a single droplet with the same total volume. Numerical results show that, in the case of three droplets, the droplets coalesce during the removal time and form a larger droplet. Also, the droplets gradually spread over the channel walls and eventually reach the upper corners of the channel and form liquid slugs. Then, the slugs move slowly toward the channel outlet, and after a while, their shapes and positions are fixed and cause the channel clogging. Changing the number of droplets does not significantly change the time of channel clogging. The numerical results show that the time-averaged pressure drop of three droplets is about 85% less than that of a single droplet.

Description of phase equilibrium and volumetric properties for CO2+water and CO2+ethanol using the CPA equation of state

Properties of fluids under high pressure is of interest for processes design. A literature survey was conducted on experimental vapor-liquid equilibrium (VLE) and density for CO2+water and CO2+ethanol. Phase equilibrium and density of pure water, ethanol and CO2 were evaluated considering 1868 data points. VLE and saturated liquid density data were collected: 544 data points for CO2+water and 859 data points for CO2+ethanol. Soave Redlich-Kwong (SRK) equation of state (EoS) with Cubic Plus Association (CPA) was applied for calculation of these properties. Peng-Robinson EoS was evaluated to demonstrate CPA improvement in properties description. The binary interaction parameters were estimated from VLE. For pure compounds, the results indicated suitable description for both phase behavior and density. For CO2+water, density calculations were accurate (Δρ = 0.5%) and VLE was adequately described (ΔxH2O = 0.49% and ΔyCO2 = 4.63%). CO2+ethanol volumetric behavior and VLE were also satisfactorily described in CO2 concentrations up to 30% (Δρ = 2.92%, ΔxEtOH = 1.37% and ΔyCO2 = 5.86%, respectively).

Simultaneous assessment of wettability and water saturation using 2D NMR measurements

Nuclear Magnetic Resonance (NMR) measurements can be used for estimating porosity, fluid saturation, pore-size distribution, and sometimes wettability. However, quantitative interpretation of rock wettability can be challenging in rocks with complex pore structures in the presence of different fluid types. Conventional NMR-based wettability models are applicable only for rocks with unimodal pore-size distributions. In this paper, we develop a new workflow for simultaneous assessment of fluid saturation and wettability in partially-saturated mixed-wet rock samples using 2D NMR measurements. We verify the reliability of this new workflow in three rock types, including unimodal and multi-modal pore-size distributions.The main inputs to the introduced workflow include the transverse relaxivity (T2) and Diffusivity-T2 (D-T2) or longitudinal-T2 (T1-T2) NMR measurements of the partially-saturated mixed-wet rock samples. Other input parameters include the bulk relaxivities of the saturating fluids and the NMR responses of fully water-saturated water-wet and fully oil-saturated oil-wet samples of the same rock type as the partially-saturated mixed-wet rock. In the verification step, we vary the fluid saturation by injecting brine, decane, or diesel into the rock sample using a core-flood setup. Then, we obtain NMR measurements at different fluid saturations to estimate the water/hydrocarbon saturation and wettability. Results demonstrated that the NMR-based wettability index has an average absolute difference of 0.18 when compared to the Amott Index, and the NMR-based water saturation estimates are within 18% average relative error of the gravimetric-estimates for the brine and diesel saturated rock samples.

Three-parameter correlation for the temperature dependent thermal conductivity of saturated liquids

We here report a three-parameter correlation for the temperature T dependent thermal conductivity λ of different kinds of saturated liquids including n-alkanes, refrigerants and others such as argon and nitrogen. The correlation is proven to be more accurate than other known correlations. Compared with the REFPROP data in NIST, the proposed correlation reproduces the corresponding data with the average absolute deviation (AAD) less than 1.20% for all the liquids considered. At the same time, it well holds in a wider temperature range which begins from the triple point temperature and ends at about 0.98 times the critical temperature, at which the thermal conductivity experimentally takes a minimal value for the liquids we study. Engineers and researchers can use the proposed correlation to directly estimate/calculate the thermal conductivity of the liquids considered here with high accuracy. Thermal conductivity related industrial and engineering equipment designs and chemical process designs will benefit from it greatly.

Experimental verification of the self-condensing CO2 transcritical power cycle

CO2 is an excellent natural working fluid for both power cycles and refrigeration cycles. However, it limits the actual application of the CO2 transcritical power cycle that subcritical CO2 is hard to be condensed by conventional cooling water. Aiming to search solutions for this condensing problem, this work carried out an experimental verification of a novel cycle named self-condensing CO2 transcritical power cycle and got some operation laws of the system. The results showed that the self-condensing CO2 transcritical power cycle can operate well with conventional cooling water around 30 °C. In most cases, the operation was steady and could be adjusted easily. The saturated liquid CO2 even as cold as 5 °C was generated for the pump. It is beneficial for the power sub-cycle to keep inlet pressure and outlet temperature of the throttle valve as high as possible. In the throttling process, the maximum pressure drop and temperature drop were about 3.6 MPa and 25 °C, respectively. A transcritical or near-critical throttling occurred in the experimental investigation and the pump usually experienced a transcritical compression under high pump inlet temperature. In summary, the self-condensing CO2 transcritical power cycle had been verified and is fully feasible in a practical application.

Micro- and Macroscale Consequences of Interactions between CO2 and Shale Rocks

In carbon storage activities, and in shale oil and gas extraction (SOGE) with carbon dioxide (CO2) as stimulation fluid, CO2 comes into contact with shale rock and its pore fluid. As a reactive fluid, the injected CO2 displays a large potential to modify the shale’s chemical, physical, and mechanical properties, which need to be well studied and documented. The state of the art on shale–CO2 interactions published in several review articles does not exhaust all aspects of these interactions, such as changes in the mechanical, petrophysical, or petrochemical properties of shales. This review paper presents a characterization of shale rocks and reviews their possible interaction mechanisms with different phases of CO2. The effects of these interactions on petrophysical, chemical and mechanical properties are highlighted. In addition, a novel experimental approach is presented, developed and used by our team to investigate mechanical properties by exposing shale to different saturation fluids under controlled temperatures and pressures, without modifying the test exposure conditions prior to mechanical and acoustic measurements. This paper also underlines the major knowledge gaps that need to be filled in order to improve the safety and efficiency of SOGE and CO2 storage.

Semi-Analytical Model for Heat and Mass Transfer Evaluation of Vapor Bubbling

Multi-stage refrigeration systems cover a wide range of possibilities and are diffusing more and more. The idea that inspired this work derived from the need to have a tool to model the energy behavior of the intercooler inside a multi-stage refrigeration system. In this work, a semi-analytical model of a single bubble, injected into the liquid of an intercooler of a multi-stage system, has been developed. The developed model is a set of equations derived from the Fourier equation for heat conduction in defined conditions and includes the effects of sensible and latent heat. The vapor bubble is supposed to be injected in the saturated liquid contained in a tank at a defined depth, at an intermediate pressure. The model has been implemented in Matlab and the results show the influence of the liquid surface tension, the injection depth and the thermal diffusivity of the vapor. The model developed here is a useful low-cost tool for evaluating heat transfer optimization of a separator/intercooler of a multi-stage refrigeration system.

RETRACTED: Experimental characterization of human cancellous bone via the first ultrasonic reflected wave – Application of Biot’s theory

Abstract In this paper, enhanced characterization of human cancellous bone using reflected ultrasound waves is proposed using the Biot theory modified by the Johnson et al. model for viscous exchange between the structure and the saturating fluid. A simplified expression of the reflection coefficient at the first surface is obtained in the frequency domain. This expression is based on the three physical parameters which are porosity, tortuosity and viscous characteristic length, as well as on the mechanical parameters: Young modulus and poison ratio of the skeleton part. The reflected signal is calculated in the frequency domain by the product of the spectrum of the incident signal with the reflection coefficient. In the time domain, the reflected wave is obtained by taking the inverse Fourier transform of the reflected frequency signal. The inverse problem is solved numerically by minimizing between simulated and experimental reflected signals. Three physical parameters are inverted simultaneously: porosity, tortuosity and viscous characteristic length. Tests are performed using two samples of trabecular bone. Experimental results are compared with theoretical predictions, giving a good correlation.

Three-parameter correlation for the surface tension of saturated liquids

In this paper, we study the multiple-parameter correlations for the surface tension of saturated liquids. The proposed three-parameter correlation requires only the critical temperature as inputs and is tested by using the NIST REFPROP data for 72 saturated liquids including refrigerants, alkanes and some other simple liquids such as argon, carbon dioxide, etc. It is found that this correlation well stands in the whole temperature range from the triple point to the critical point with high accuracy for 71 liquids with average absolute deviations (AADs) less than 5% and for 66 liquids with AADs less than 1%. These results are clearly better than the ones of other available correlations. This correlation can be directly used to estimate the value of the surface tension of the corresponding liquids at any temperature point from the triple point to the critical point. The accuracy of the predictions would clearly have economic benefits since it would allow improvement of process operating conditions, the development of new processes, the reduction of oversizing in the design of new equipment and even reduction of energy requirements.

Surface Free Energy Estimation: A New Methodology for Solid Surfaces

AbstractAn interpretation of solid surfaces is generated based on physical considerations and the laws of thermodynamics. Like the widely used Owens–Wendt (OW) method, the proposed method uses liquids for characterization. Each liquid provides an absolute lower bound on the surface energy with some uncertainty from measurement variations. If multiple liquids are employed, the largest lower bound is taken as the most accurate, with uncertainty due to measurement errors. The more liquids used, the more accurate is the greatest lower bound. This method links generalizations of the Good–Girifalco equation with a general thermodynamic inequality relating the three‐interfacial tensions in a three‐phase equilibrium system. The method always satisfies this inequality with better than a 65% certainty. However, the OW seldom, if ever, conforms to this inequality and even then, the degree of satisfaction is insignificant. A reconciliation of the two methods is proposed based on rescaling the OW surface energies to conform to the inequality. This enables interpretations of dispersion and polar components of the surface energy, which are thermodynamically self‐consistent. The proposed method is also capable of dealing with material exchange between liquid and solid phases, when the surface tension and contact angle of the saturated liquids can be measured.

Liquid metal embrittlement sensitivity of the T91 steel in lead, in bismuth and in lead-bismuth eutectic

The liquid metal embrittlement (LME) sensitivity of the martensitic T91 steel by Pb, Bi and LBE has been studied by small punch tests at different temperatures and strain rates. The LME occurrence in the three liquid metals depends on the strain rate and on the temperature. The T91 steel loaded in Bi, Pb or LBE presents ductile behaviour at 300 °C and at 400 °C except in LBE at 300 °C at very slow strain rate for which fully brittle fracture surface was observed. It appears that the LME sensitivity of the T91 steel by LBE and bismuth is more important at 300 °C than 400 °C. No LME by lead has been observed. The most embrittling liquid metal is LBE, then bismuth while the less one is lead. Some differences in the reactive wetting of the T91 steel by the saturated oxygen liquid metal could explain the difference in LME sensitivity in the three liquid metals.

A mixed stabilized finite element formulation for finite deformation of a poroelastic solid saturated with a compressible fluid

A stabilized finite element formulation is proposed to the study of the finite deformation of a porous solid saturated with a compressible fluid. Unlike previous finite element schemes, the compressibility of the fluid constituent is entirely considered, and particularly, the a porosity-dependent permeability is utilized in the present formulation. As a special case, the formulation for the saturating fluid being an ideal gas is also derived. The displacement of solid skeleton and pore pressure are treated as primary variables to express the resulting coupled nonlinear system of equations. Equal-order $$C^{0}$$ elements are employed to approximate displacement and pressure fields. The stability problem caused by the equal-order interpolation is overcome by using the method of polynomial pressure projections. Two examples are provided to demonstrate the effect of fluid compressibility, as well as the porosity-dependent permeability, on the responses of the material.

Corresponding state principle based correlation for the thermal conductivity of saturated refrigerants liquids from Ttr to 0.90Tc

We here report that the corresponding state principle well stands for the temperature dependent thermal conductivity of the saturated refrigerants liquids by using the reduced quantities proposed here. A corresponding state principle based correlation is proposed and proven to be accurate in the temperature range from the triple point temperature to 0.90 times the critical temperature. Additionally, this correlation also stands for the saturated n-alkanes liquids. For the 23 refrigerants and 11 n-alkanes considered here, the proposed correlation can reproduce the REFPROP data with AAD<2% for 21 liquids, and AAD<5% for all the liquids considered.

Viscosity and self-diffusion coefficient of dipolar liquids

Equilibrium molecular dynamics simulations were used to calculate the viscosity and self-diffusion coefficient of Stockmayer fluids at different dipole moments from the saturated liquid state to the supercritical fluid state. On the basis of the theory of Longuet-Higgins and Pople (J. Chem. Phys. 25 (1956) 884) a physically based correlation equations was proposed for the correlation of density, temperature and dipole moment dependence of viscosity and self-diffusion coefficient simulation data. As an application, with appropriate Stockmayer parameter sets the viscosity of fluoroalkanes were calculated along the saturated liquid curves, and good agreement has been obtained between the experimental and correlation equation data.

Preliminary study on the contribution of osmotic effects for the electrical resistivity of sands

Electrical resistivity of soils can be used to evaluate the level of contamination in soils in geophysical prospection tests. The chemical composition of pore fluid also corresponds to a given water potential, named as osmotic suction. Therefore both electrical resistivity and osmotic suction can be related when soil is saturated. This paper investigates their relationship when the soil is not saturated. The osmotic suction and electrical resistivity were measured for uniform grading size samples of sand prepared with different concentrations of an ionic leachate from a real landfield. Both were measured also for the fluid with the different concentrations. Suction was measured for different degrees of saturation using the ionic fluid for the different concentrations. The soil osmotic suction is similar to the osmotic suction of the pore fluid independently from the degree of saturation, and the differences in electrical resistivity in the saturated samples and pore fluid alone as function of osmotic suction are related by a constant. Although pore fluid composition affects electrical resistivity, when evaluating the electrical resistivity considering the degree of saturation one should pay attention to factors that are related with matric suction instead of osmotic suction.

Simultaneous optimization of saturation equations for two hydrocarbons and four hydrofluoroolefins refrigerants

This research exhibits a different simultaneous optimization for saturation equations of six pure refrigerants from Hydrocarbon (HCs) and Hydrofluoroolefins (HFOs). The study objective is to model two different group of saturation equations in accordance with the same structural forms, one for n-butane (R600) and isobutane (R600a), and other for 2,3,3,3-tetrafluoropropan (R1234yf), trans-1,3,3,3-tetrafuoropropene (R1234ze(E)), cis-1,3,3,3-tetrafuoropropene (R1234ze(Z)), and trans-1-chloro-3,3,3-trifluoropropene (R1233zd(E)) refrigerants. Genetic algorithm with weighted least square regression was assigned to carry out the research objectives. The modeling equations for both groups are valid from triple points up to temperature nearby the critical points. The uncertainties respecting to each equation of R600, R600a, R1234yf, R1234ze(E), R1234ze(Z), and R1233zd(E) refrigerants are estimated to be 0.05%, 0.75%, 0.10%, 0.35%, 0.57%, and 0.22% in saturated liquid density; 0.30%, 2.68%, 0.86%, 1.48%, 4.13%, and 1.23% in saturated vapor density; and 0.73%, 2.15%, 0.08%, 0.47%, 0.97%, and 2.85% in vapor-pressures, respectively. The new ancillary equations can be used to calculate the saturation properties for engineering interests.

Aeroacoustics of Jet Streams Used in Metallurgy

The supersonic jets of gas which is expiring into the melt from nozzle of BOF lance have a powerful acoustic radiation. The sound intensity of the jets is up to 200 dB and it is the most powerful natural source of sound. The jets invasion into heterogeneous unstable and gas saturated liquid melt-solution is the cause of the cavitation phenomena into the liquid. This explains the spontaneity of the gas formation and the speed of the decarburization process throughout the entire volume of the liquid metal volume. Using sound intensity changes, in the 60-th years of the last century, was developed the acoustic monitoring and control system of slag process into the BOF furnace.

The effect of fluid saturation on the elastic-plastic properties of oil reservoir rocks

Abstract Background: The success of planning geological and technical measures aimed at intensifying oil production is of high importance. Methodology: To increase the efficiency of operations aimed at oil recovery enhancement, it is necessary to use mathematical models of the rock mass deformation, taking into account the physical and mechanical properties of the rocks. Results: Currently, the application of these models is difficult due to a lack of data. As a result, the use of simpler models is resorted to, which is not always correct in the practical application of these models. This article describes experimental studies aimed at determining the mechanical properties of rock and establishing the correlation between properties and the fluid saturation of the rocks. The study determined the physical-mechanical properties of the rocks (taking into account the stage of field development) and established the dependencies of the change in the oil reservoir rock properties on the saturation and type of load on a sample. Conclusions: The results show that the saturation of the rock with a liquid phase (hydrocarbon or water) decreases the strength of the reservoir rock, which in turn depends on the type of saturating fluid.

Thermo-hydro-mechanical modeling of artificial ground freezing taking into account the salinity of the saturating fluid

The modeling of Artificial Ground Freezing in geotechnical engineering applications has two main objectives, the first is the prediction of the extent of the frozen zone around the cooling sources (Thermo-Hydraulic models) and the second is the prediction of the ground’s deformations and the site stability (Thermo-Hydro-Mechanical models). Reliable predictions require the consideration of unfavorable hydro-geological conditions such as high seepage velocities, ground heterogeneity and saline groundwater that may negatively influence the performance of AGF. The influence of the saturating fluid salinity on the THM behavior of the ground during freezing is the less documented point among the three and is therefore the subject of this paper. To this end, a fully coupled THM model considering the salinity effect has been derived. The formalism is completely thermodynamically consistent and introduces some simplifying assumptions, especially to describe phase change terms (capillary pressure and latent heat), in order to achieve a mathematical formulation that can be easily handled by computation software. Stress-free freezing laboratory tests carried out on specimens initially fully saturated with sodium chloride solutions at three different concentrations allowed to validate the proposed approach and to highlight some key mechanisms associated with the phase change of saline-saturated porous media.