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1
Durakovic and Skaugen. "Analysis of Thermodynamic Models for Simulation and Optimisation of Organic Rankine Cycles." Energies 12, no. 17 (August 27, 2019): 3307. http://dx.doi.org/10.3390/en12173307.
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Equations of state (EOSs) form the base of every thermodynamic model used in the design of industrial processes, but little work has been done to evaluate these in the context of such models. This work evaluates 13 EOSs for their accuracy, computational time and robustness when used in an in-house optimisation program that finds the maximum power output of an organic Rankine cycle. The EOSs represent popular choices in the industry, such as the simple cubic EOSs, and more complex EOSs such as the ones based on corresponding state principles (CSP). These results were compared with results from using the Groupe Européen de Recherches Gazières (GERG) EOS, whose error is within experimental uncertainty. It appears that the corresponding state EOSs find a solution to the optimisation problem notably faster than GERG without significant loss of accuracy. A corresponding state method which used the Peng–Robinson EOS to calculate the shape factors and a highly accurate EOS for propane as the reference EOS, was shown to have a total deviation of just 0.6% as compared to GERG while also being 10 times as fast. The CSP implementation was also more robust, being able to converge successfully more often.
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Trawiński, Paweł. "Development and implementation of mathematical models of working mediums for gas part of combined cycle gas turbine system in Python programming environment." E3S Web of Conferences 137 (2019): 01047. http://dx.doi.org/10.1051/e3sconf/201913701047.
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The working mediums in the gas turbine systems are: atmospheric air, natural gas and exhaust gases. For the detailed analysis of thermodynamic performance and values at characteristic points of the cycle it is necessary to know the relations defining: specific volume, specific isobaric and isochoric heat capacity, isentropic exponent, specific enthalpy and specific entropy. Mathematical models of thermodynamic parameters for the mentioned mediums were developed based on dependencies for mixtures of ideal and semi-ideal gases. The functions obtained for semi-ideal gas mixtures were extended by pressure correction factors derived from the Redlich-Kwong and Peng-Robinson equations of state. The thermodynamic parameters of the working mediums were dependent on the mass fractions of the components, temperature and pressure. Developed models approximated the behaviour and parameters of real gas mixtures. All calculation algorithms were implemented and optimized using appropriate numerical methods in the Python programming environment. As a result, mathematical models of working mediums for the gas part of the combined cycle gas turbine system were obtained.
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Mehl, Ana, Fabio P. Nascimento, Pedro W. Falcão, Fernando L. P. Pessoa, and Lucio Cardozo-Filho. "Vapor-Liquid Equilibrium of Carbon Dioxide + Ethanol: Experimental Measurements with Acoustic Method and Thermodynamic Modeling." Journal of Thermodynamics 2011 (May 24, 2011): 1–11. http://dx.doi.org/10.1155/2011/251075.
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Phase behavior of systems composed by supercritical carbon dioxide and ethanol is of great interest, especially in the processes involving supercritical extraction in which ethanol is used as a cosolvent. The development of an apparatus, which is able to perform the measurements of vapor-liquid equilibrium (VLE) at high pressure using a combination of the visual and the acoustic methods, was successful and was proven to be suited for determining the isothermal VLE data of this system. The acoustic method, based on the variation of the amplitude of an ultra-sound signal passing through a mixture during a phase transition, was applied to investigate the phase equilibria of the system carbon dioxide + ethanol at temperatures ranging from 298.2 K to 323.2 K and pressures from 3.0 MPa to 9.0 MPa. The VLE data were correlated with Peng-Robinson equation of state combined with two different mixing rules and the SAFT equations of state as well. The compositions calculated with the models are in good agreement with the experimental data for the isotherms evaluated.
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Ouaer, Hocine, Amir Hossein Hosseini, Menad Nait Amar, Mohamed El Amine Ben Seghier, Mohammed Abdelfetah Ghriga, Narjes Nabipour, Pål Østebø Andersen, Amir Mosavi, and Shahaboddin Shamshirband. "Rigorous Connectionist Models to Predict Carbon Dioxide Solubility in Various Ionic Liquids." Applied Sciences 10, no. 1 (December 31, 2019): 304. http://dx.doi.org/10.3390/app10010304.
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Estimating the solubility of carbon dioxide in ionic liquids, using reliable models, is of paramount importance from both environmental and economic points of view. In this regard, the current research aims at evaluating the performance of two data-driven techniques, namely multilayer perceptron (MLP) and gene expression programming (GEP), for predicting the solubility of carbon dioxide (CO2) in ionic liquids (ILs) as the function of pressure, temperature, and four thermodynamical parameters of the ionic liquid. To develop the above techniques, 744 experimental data points derived from the literature including 13 ILs were used (80% of the points for training and 20% for validation). Two backpropagation-based methods, namely Levenberg–Marquardt (LM) and Bayesian Regularization (BR), were applied to optimize the MLP algorithm. Various statistical and graphical assessments were applied to check the credibility of the developed techniques. The results were then compared with those calculated using Peng–Robinson (PR) or Soave–Redlich–Kwong (SRK) equations of state (EoS). The highest coefficient of determination (R2 = 0.9965) and the lowest root mean square error (RMSE = 0.0116) were recorded for the MLP-LMA model on the full dataset (with a negligible difference to the MLP-BR model). The comparison of results from this model with the vastly applied thermodynamic equation of state models revealed slightly better performance, but the EoS approaches also performed well with R2 from 0.984 up to 0.996. Lastly, the newly established correlation based on the GEP model exhibited very satisfactory results with overall values of R2 = 0.9896 and RMSE = 0.0201.
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GUARDONE, ALBERTO, CALIN ZAMFIRESCU, and PIERO COLONNA. "Maximum intensity of rarefaction shock waves for dense gases." Journal of Fluid Mechanics 642 (December 23, 2009): 127–46. http://dx.doi.org/10.1017/s0022112009991716.
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Modern thermodynamic models indicate that fluids consisting of complex molecules may display non-classical gasdynamic phenomena such as rarefaction shock waves (RSWs) in the vapour phase. Since the thermodynamic region in which non-classical phenomena are physically admissible is finite in terms of pressure, density and temperature intervals, the intensity of RSWs is expected to exhibit a maximum for any given fluid. The identification of the operating conditions leading to the RSW with maximum intensity is of paramount importance for the experimental verification of the existence of non-classical phenomena in the vapour phase and for technical applications taking advantage of the peculiarities of the non-classical regime. This study investigates the conditions resulting in an RSW with maximum intensity in terms of pressure jump, wave Mach number and shock strength. The upstream state of the RSW with maximum pressure drop is found to be located along the double-sonic locus formed by the thermodynamic states associated with an RSW having both pre- and post-shock sonic conditions. Correspondingly, the maximum-Mach thermodynamic and maximum-strength loci locate the pre-shock states from which the RSW with the maximum wave Mach number and shock strength can originate. The qualitative results obtained with the simple van der Waals model are confirmed with the more complex Stryjek–Vera–Peng–Robinson, Martin–Hou and Span–Wagner equations of state for selected siloxane and perfluorocarbon fluids. Among siloxanes, which are arguably the best fluids for experiments aimed at the generation and measurement of an RSW, the state-of-the-art Span–Wagner multi-parameter equation of state predicts a maximum wave Mach number close to 1.026 for D6 (dodecamethylcyclohexasiloxane, [O-Si-(CH3)2]6). Such value is well within the capacity of the measurement system of a newly built experimental set-up aimed at the first-ever demonstration of the existence of RSWs in dense vapours.
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Sima, Sergiu, and Catinca Secuianu. "The Effect of Functional Groups on the Phase Behavior of Carbon Dioxide Binaries and Their Role in CCS." Molecules 26, no. 12 (June 18, 2021): 3733. http://dx.doi.org/10.3390/molecules26123733.
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In recent years we have focused our efforts on investigating various binary mixtures containing carbon dioxide to find the best candidate for CO2 capture and, therefore, for applications in the field of CCS and CCUS technologies. Continuing this project, the present study investigates the phase behavior of three binary systems containing carbon dioxide and different oxygenated compounds. Two thermodynamic models are examined for their ability to predict the phase behavior of these systems. The selected models are the well-known Peng–Robinson (PR) equation of state and the General Equation of State (GEOS), which is a generalization for all cubic equations of state with two, three, and four parameters, coupled with classical van der Waals mixing rules (two-parameter conventional mixing rule, 2PCMR). The carbon dioxide + ethyl acetate, carbon dioxide + 1,4-dioxane, and carbon dioxide + 1,2-dimethoxyethane binary systems were analyzed based on GEOS and PR equation of state models. The modeling approach is entirely predictive. Previously, it was proved that this approach was successful for members of the same homologous series. Unique sets of binary interaction parameters for each equation of state, determined for the carbon dioxide + 2-butanol binary model system, based on k12–l12 method, were used to examine the three systems. It was shown that the models predict that CO2 solubility in the three substances increases globally in the order 1,4-dioxane, 1,2-dimethoxyethane, and ethyl acetate. CO2 solubility in 1,2-dimethoxyethane, 1.4-dioxane, and ethyl acetate reduces with increasing temperature for the same pressure, and increases with lowering temperature for the same pressure, indicating a physical dissolving process of CO2 in all three substances. However, CO2 solubility for the carbon dioxide + ether systems (1,4-dioxane, 1,2-dimethoxyethane) is better at low temperatures and pressures, and decreases with increasing pressures, leading to higher critical points for the mixtures. By contrast, the solubility of ethyl acetate in carbon dioxide is less dependent on temperatures and pressures, and the mixture has lower pressures critical points. In other words, the ethers offer better solubilization at low pressures; however, the ester has better overall miscibility in terms of lower critical pressures. Among the binary systems investigated, the 1,2-dimethoxyethane is the best solvent for CO2 absorption.
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OKONG'O, NORA A., and JOSETTE BELLAN. "Direct numerical simulation of a transitional supercritical binary mixing layer: heptane and nitrogen." Journal of Fluid Mechanics 464 (August 10, 2002): 1–34. http://dx.doi.org/10.1017/s0022112002008480.
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Direct numerical simulations (DNS) of a supercritical temporal mixing layer are conducted for the purpose of exploring the characteristics of high-pressure transitional mixing behaviour. The conservation equations are formulated according to fluctuation-dissipation (FD) theory, which is consistent with non-equilibrium thermodynamics and converges to kinetic theory in the low-pressure limit. According to FD theory, complementing the low-pressure typical transport properties (viscosity, diffusivity and thermal conductivity), the thermal diffusion factor is an additional transport property which may play an increasingly important role with increasing pressure. The Peng–Robinson equation of state with appropriate mixing rules is coupled to the dynamic conservation equations to obtain a closed system. The boundary conditions are periodic in the streamwise and spanwise directions, and of non-reflecting outflow type in the cross-stream direction. Due to the strong density stratification, the layer is considerably more difficult to entrain than equivalent gaseous or droplet-laden layers, and exhibits regions of high density gradient magnitude that become very convoluted at the transitional state. Conditional averages demonstrate that these regions contain predominantly the higher-density, entrained fluid, with small amounts of the lighter, entraining fluid, and that in these regions the mixing is hindered by the thermodynamic properties of the fluids. During the entire evolution of the layer, the dissipation is overwhelmingly due to species mass flux followed by heat flux effects with minimal viscous contribution, and there is a considerable amount of backscatter in the flow. Most of the species mass flux dissipation is due to the molecular diffusion term with significant contributions from the cross-term proportional to molecular and thermal diffusion. These results indicate that turbulence models for supercritical fluids should primarily focus on duplicating the species mass flux rather than the typical momentum flux, which constitutes the governing dissipation in atmospheric mixing layers. Examination of the passive-scalar probability density functions (PDFs) indicates that neither the Gaussian, nor the beta PDFs are able to approximate the evolution of the DNS-extracted PDF from its inception through transition. Furthermore, the temperature–species PDFs are well correlated, meaning that their joint PDF is not properly approximated by the product of their marginal PDFs; this indicates that the traditional reactive flow modelling based on replacing the joint PDF representing the reaction rate by the product of the marginal PDFs is not appropriate. Finally, the subgrid-scale temperature–species PDFs are also well correlated, and the species PDF exhibits important departures from the Gaussian. These results suggest that classic PDFs used in atmospheric pressure flows would not capture the physics of this supercritical mixing layer, either in an assumed PDF model at the larger scale, or at the subgrid scale.
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Prieto Jiménez, Natalia, and Germán González Silva. "Comparative Study of Equations of State for the Dew Curves Calculation in High Pressure Natural Gas Mixtures. [Estudio Comparativo de Ecuaciones de Estado para el Cálculo de Curvas de Rocío en Mezclas de Gas Natural a Alta Presión]." Revista Logos Ciencia & Tecnología 11, no. 1 (December 30, 2018): 152–64. http://dx.doi.org/10.22335/rlct.v11i1.743.
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he success during the operation of natural gas processing plants depends on the correct estimation of thermodynamic properties of the system. This paper calculates the equilibrium curves of real and synthetic natural gas mixtures means of three Equations of State (EOS). These equilibrium curves were constructed and compared with experimental data found in the literature covered. The results showed that, above 4 MPa the Peng-Robinson equation presented a considerable deviation with respect to the experimental data, reaching an absolute error of 4.36%; therefore, the GERG2008 equation is recommended for systems that operate at high pressures when the components present in the mixture apply.Keywords:Gas Mixtures, Dew curves, Equations of State; Peng-Robinson, Soave-Redlich-Kwong, GERG2008.ResumenEl éxito durante la operación de plantas de tratamiento de gas natural depende de la correcta estimación de las propiedades termodinámicas del sistema. Este artículo calcula las curvas de equilibrio de mezclas de gas natural reales y sintéticas por medio de tres ecuaciones de estado (EOS). Estas curvas de equilibrio fueron construidas y comparadas con datos experimentales presentes en la literatura. Los resultados mostraron que, por encima de 4 MPa la ecuación de Peng-Robinson presentó una desviación considerable con respecto a los datos experimentales, alcanzando un error absoluto de 4,36%; por lo cual se recomienda la ecuación de GERG2008 para sistemas que operen a altas presiones cuando los componentes presentes en la mezcla apliquen.Palabras clave: Mezclas de gas, Curvas de rocío, Ecuaciones de estado, Peng-Robinson, Soave-Redlich-Kwong, GERG2008.ResumoO sucesso na operação de usinas de tratamento de gás natural depende da correta estimação das propriedades termodinâmicas do sistema. Este artigo calcula as curvas de equilíbrio de misturas de gás natural reais e sintéticas por meio de três equações de estado (EOS). As curvas de equilíbrio foram construídas e comparadas com dados experimentais presentes na literatura. Os resultados mostraram que, acima de 4 Mpa a equação de Peng-Robinson apresentou um desvio considerável em relação aos dados experimentais, atingindo um erro absoluto de 4,36%; por tanto, é recomendável a equação de GERG2008 para sistemas que operam em alta pressão quando os componentes presentes no sistema apliquem.Palavras-chave:Misturas de gás, Curvas de orvalho, Equações de estado, Peng-Robinson, Soave-Redlich-Kwong, GERG2008.
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Hussain, B., and M. Ahsan. "A Numerical Comparison of Soave Redlich Kwong and Peng-Robinson Equations of State for Predicting Hydrocarbons’ Thermodynamic Properties." Engineering, Technology & Applied Science Research 8, no. 1 (February 20, 2018): 2422–26. http://dx.doi.org/10.48084/etasr.1644.
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Mixture phase equilibrium and thermodynamic properties have a significant role in industry. Numerical analysis of flash calculation generates an appropriate solution for the problem. In this research, a comparison of Soave Redlich Kwong (SRK) and Peng-Robinson (PR) equations of state predicting the thermodynamic properties of a mixture of hydrocarbon and related compounds in a critical region at phase equilibrium is performed. By applying mathematical modeling of both equations of states, the behavior of binary gases mixtures is monitored. The numerical analysis of isothermal flash calculations is applied to study the pressure behavior with volume and mole fraction. The approach used in this research shows considerable convergence with experimental results available in the literature.
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Palmer, S. C., and S. V. Shelton. "Sensitivity Analysis of Absorption Cycle Fluid Thermodynamic Properties." Journal of Energy Resources Technology 121, no. 2 (June 1, 1999): 137–41. http://dx.doi.org/10.1115/1.2795069.
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Absorption heat pump technology may be improved by new cycle configurations by new working fluids. In this study, the effect of hypothetical working fluids on performance improvement is explored. The performance of two cycles is studied using three fluid property sources for ammonia/water, i.e., curve-fit experimental data, an ideal solution model, and the Peng-Robinson equation of state model. The models require only minimal fundamental thermodynamic property data for the two pure components. This allows investigation into the influence of each fundamental property on cycle performance, providing insight into desirable properties for new absorption fluid pairs. Variations of fundamental fluid properties are used as input to the models, showing that the volatilities of the refrigerant and absorbent have the greatest effect on cycle performance.
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Khamukhin, Alexander A., and Eugenii V. Nikolayev. "Modeling of Gas Multistage Separation to Increase Stock Tank Oil." Advanced Materials Research 1040 (September 2014): 508–12. http://dx.doi.org/10.4028/www.scientific.net/amr.1040.508.
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The study gas multistage separation at the preliminary preparation of crude oil by means of computer simulation was performed. Different models have been used as the phase state equations in HYSYS software: Peng-Robinson, Grayson-Street-Choa-Seeder, Peng-Robinson-Twu, Suave-Redlich-Kwong, Twu-Sim-Tassone. The carry-over saving of liquid oil components into off gases approximately is 40–60% while optimizing thermobaric conditions of the separation was obtained. The semi-empirical model obtained on the basis statistical processing of the results of laboratory experiments was proposed. The proposed semi-empirical model has a slight deviation for the first and the second separators. There is a negative effect in the third separator, but it is not significant in comparison with the positive effect in the first and the second separators.
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Truc, George, Nejat Rahmanian, and Mahboubeh Pishnamazi. "Assessment of Cubic Equations of State: Machine Learning for Rich Carbon-Dioxide Systems." Sustainability 13, no. 5 (February 26, 2021): 2527. http://dx.doi.org/10.3390/su13052527.
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Carbon capture and storage (CCS) has attracted renewed interest in the re-evaluation of the equations of state (EoS) for the prediction of thermodynamic properties. This study also evaluates EoS for Peng–Robinson (PR) and Soave–Redlich–Kwong (SRK) and their capability to predict the thermodynamic properties of CO2-rich mixtures. The investigation was carried out using machine learning such as an artificial neural network (ANN) and a classified learner. A lower average absolute relative deviation (AARD) of 7.46% was obtained for the PR in comparison with SRK (AARD = 15.0%) for three components system of CO2 with N2 and CH4. Moreover, it was found to be 13.5% for PR and 19.50% for SRK in the five components’ (CO2 with N2, CH4, Ar, and O2) case. In addition, applying machine learning provided promise and valuable insight to deal with engineering problems. The implementation of machine learning in conjunction with EoS led to getting lower predictive AARD in contrast to EoS. An of AARD 2.81% was achieved for the three components and 12.2% for the respective five components mixture.
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Baseri, Hadi, Ali Haghighi-Asl, and Nader Lotfollahi. "Thermodynamic modeling of solid solubility in supercritical carbon dioxide: Comparison between mixing rules." Chemical Industry and Chemical Engineering Quarterly 19, no. 3 (2013): 389–98. http://dx.doi.org/10.2298/ciceq120203074b.
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In this paper, Peng Robinson equation of state is used for thermodynamic modeling of the solubility of various solid components in the supercritical carbon dioxide. Moreover, the effects of three mixing rules of Van der Waals mixing rules, Panagiotopoulos and Reid mixing rules and modified Kwak and Mansoori mixing rules on the accuracy of calculation results were studied. Good correlations between calculated and experimental data were obtained in the wide temperature and pressure range. A comparison between used models shows that modified Kwak and Mansoori mixing rules give better correlations in comparison with the other mixing rules.
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Sokolov, Mikhail, Nikolay Sadovsky, Anatoly Zuev, Lyubov Gileva, and Minh Hai Nguyen. "Real gas state equations comparative analysis for low-temperature calculations." E3S Web of Conferences 140 (2019): 05007. http://dx.doi.org/10.1051/e3sconf/201914005007.
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In this paper, various real gas state equations are considered and their comparative analysis is carried out. The following state equations are studied in the work: Benedict-Webb-Rubin modification equation, Ridlich-Kwong Real Gas equation, Peng-Robinson Real Gas equation, and the modified Ridlich-Kwong real gas state equations proposed by Barsuk S.D. We have made a direct comparison of these calculation methods with most accurate identification. In addition, the paper analyzes the equations features, with applicability limits definition of each state equations. For the chosen one, as the most universal and exact equation, the calculations were made for the liquid phase and the real gas two-phase state. Based on the data obtained, polynomials were developed for various parameters depending on the gas temperature, which can later be used to build various mathematical models. Our conclusions show main advantages of selected equation for real gases and the reasons for choosing it for modeling low-temperature heat and mass transfer processes.
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Colonna, Piero, and Paolo Silva. "Dense Gas Thermodynamic Properties of Single and Multicomponent Fluids for Fluid Dynamics Simulations." Journal of Fluids Engineering 125, no. 3 (May 1, 2003): 414–27. http://dx.doi.org/10.1115/1.1567306.
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The use of dense gases in many technological fields requires modern fluid dynamic solvers capable of treating the thermodynamic regions where the ideal gas approximation does not apply. Moreover, in some high molecular fluids, nonclassical fluid dynamic effects appearing in those regions could be exploited to obtain more efficient processes. This work presents the procedures for obtaining nonconventional thermodynamic properties needed by up to date computer flow solvers. Complex equations of state for pure fluids and mixtures are treated. Validation of sound speed estimates and calculations of the fundamental derivative of gas dynamics Γ are shown for several fluids and particularly for Siloxanes, a class of fluids that can be used as working media in high-temperature organic Rankine cycles. Some of these fluids have negative Γ regions if thermodynamic properties are calculated with the implemented modified Peng-Robinson thermodynamic model. Results of flow simulations of one-dimensional channel and two-dimensional turbine cascades will be presented in upcoming publications.
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Khan, Shadman H., Anupama Kumari, G. Dixit, Chandrajit B. Majumder, and Amit Arora. "Thermodynamic modeling and correlations of CH4, C2H6, CO2, H2S, and N2 hydrates with cage occupancies." Journal of Petroleum Exploration and Production Technology 10, no. 8 (September 14, 2020): 3689–709. http://dx.doi.org/10.1007/s13202-020-00998-y.
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Abstract The present work focuses on developing a framework for accurate prediction of thermodynamic conditions for single-component hydrates, namely CH4, CO2, N2, H2S, and C2H6 (coded in MATLAB). For this purpose, an exhaustive approach is adopted by incorporating eight different equations of states, namely Peng–Robinson, van der Waals, Soave–Redlich–Kwong, Virial, Redlich–Kwong, Tsai-Teja, Patel, and Esmaeilzadeh–Roshanfekr, with the well-known van der Waals–Platteeuw model. Overall, for I–H–V phase region, the Virial and van der Waals equation of state gives the most accurate predictions with minimum AAD%. For Lw–H–V phase region, Peng–Robinson equation of state is found to yield the most accurate predictions with overall AAD of 3.36%. Also, genetic programming algorithm is adopted to develop a generalized correlation. Overall, the correlation yields quick estimation with an average deviation of less than 1%. The accurate estimation yields a minimal AAD of 0.32% for CH4, 1.93% for C2H6, 0.77% for CO2, 0.64% for H2S, and 0.72% for N2. The same correlation can be employed for fitting phase equilibrium data for other hydrates too. The tuning parameter, n, is to be used for fine adjustment to the phase equilibrium data. The findings of this study can help for a better understanding of phase equilibrium and cage occupancy behavior of different gas hydrates. The accuracy in phase equilibria is intimately related to industrial applications such as crude oil transportation, solid separation, and gas storage. To date, no single correlation is available in the literature that can accurately predict phase equilibria for multiple hydrate species. The novelty of the present work lies in both the accuracy and generalizability of the proposed correlation in predicting the phase equilibrium data. The genetic programming generalized correlation is convenient for performing quick equilibrium prediction for industrial applications.
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GRINE, HICHEM, HAKIM MADANI, and SAIDA FEDALI. "Critical behaviour of binary mixtures: Calculation by the Heidemann-Khalil method." High Temperatures-High Pressures 48, no. 5-6 (2020): 497–525. http://dx.doi.org/10.32908/hthp.v48.799.
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The critical temperature and critical pressure are two important parameters to characterize a particular fluid. In this paper, we have studied the critical points of 24 binary mixtures containing hydrocarbon derivatives, carbon dioxide and alcohols. Computations were performed using the Heidemann-Khalil method, combined with the following equations of state (Eos): van der Waals (vdW), Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR). The Newton-Raphson method was used to solve a set of nonlinear equations in three independent variables (molar fraction x, temperature T and volume V). Comparisons between predicted and available reference data are given to evaluate the accuracy of the thermodynamic model employed. The average absolute relative error (AARE) of the simulated data was less than 0.2% for critical temperature and 3% for critical pressure. A good agreement has been found between model prediction and reference data.
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Fan, Xiaolin, Jisheng Kou, Zhonghua Qiao, and Shuyu Sun. "A Componentwise Convex Splitting Scheme for Diffuse Interface Models with Van der Waals and Peng--Robinson Equations of State." SIAM Journal on Scientific Computing 39, no. 1 (January 2017): B1—B28. http://dx.doi.org/10.1137/16m1061552.
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Touriño, A., M. Hervello, V. Moreno, G. Marino, and M. Iglesias. "Change of refractive indices in ternary mixtures containing chlorobenzene + n-hexane + (n-heptane or n-octane) at 298.15 K." Journal of the Serbian Chemical Society 69, no. 6 (2004): 461–75. http://dx.doi.org/10.2298/jsc0406461t.
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The refractive indices of ternary mixtures of chlorobenzene + n-hexane (n-heptane or n-octane) have been measured at 298.15 K and at atmospheric pressure over the whole composition diagram. Parameters of polynomial equations which represent the composition dependence of physical and derived properties are gathered. The experimental refractive indices and the ternary derived properties are compared with the data obtained using several predictive semi-empirical models. The use of the Soave?Redlich?Kwong (SRK) and the Peng?Robinson (PR) cubic equations of state with the Van der Waals one-fluid mixing rule, which incorporate different combining rules to predict refractive indices on mixing, are tested against the measured results, good agrement being obtained.
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Shoukry, Aktham E., Ahmed H. El-Banbi, and Helmy Sayyouh. "Enhancing asphaltene precipitation modeling by cubic-PR solid model using thermodynamic correlations and averaging techniques." Petroleum Science 17, no. 1 (October 15, 2019): 232–41. http://dx.doi.org/10.1007/s12182-019-00377-1.
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Abstract Cubic equation-of-state solid models are one of the most widely used models to predict asphaltene precipitation behavior. Thermodynamic parameters are needed to model precipitation under different pressures and temperatures and are usually obtained through tuning with multi asphaltene onset experiments. For the purpose of enhancing the cubic Peng–Robinson solid model and reducing its dependency on asphaltene experiments, this paper tests the use of aromatics and waxes correlations to obtain these thermodynamic parameters. In addition, weighted averages between both correlations are introduced. The averaging is based on reported saturates, aromatics, resins, asphaltene (SARA) fractions, and wax content. All the methods are tested on four oil samples, with previously published data, covering precipitation and onset experiments. The proposed wax-asphaltene average showed the best match with experimental data, followed by a SARA-weighted average. This new addition enhances the model predictability and agrees with the general molecular structure of asphaltene molecules.
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Debien, Isabel C. N., Aline A. Rigo, Marcos L. Corazza, Marcio A. Mazutti, and J. Vladimir Oliveira. "Thermodynamic Modeling of High-pressure Equilibrium Data for the Systems L-lactic Acid + (Propane + Ethanol) and L-lactic Acid + (Carbon Dioxide + Ethanol)." Open Chemical Engineering Journal 9, no. 1 (February 26, 2015): 1–6. http://dx.doi.org/10.2174/1874123101509010001.
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This short communication reports the thermodynamic modeling of high-pressure equilibrium data (cloud points) for the systems L-lactic acid + (propane + ethanol) and L-lactic acid + (carbon dioxide + ethanol) from 323.15 K to 353.15 K and at pressures up to 25 MPa.The experimental data were modeled using the Peng-Robinson equation of state with the classical van der Waals quadratic mixing rule (PR-vdW2) and with the Wong-Sandler mixing rule (PR-WS). It is shown that the PR-vdW2 and PR-WS models were both able to satisfactorily represent the phase behavior of the system L-lactic acid + (carbon dioxide + ethanol). However, for the system L-lactic acid + (propane + ethanol), the PR-vdW2 model was not able to appropriately describe its phase behavior.
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Yue, Zongyu, Randy Hessel, and Rolf D. Reitz. "Investigation of real gas effects on combustion and emissions in internal combustion engines and implications for development of chemical kinetics mechanisms." International Journal of Engine Research 19, no. 3 (December 13, 2017): 269–81. http://dx.doi.org/10.1177/1468087416678111.
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Real gas effects on combustion and emissions in internal combustion engines are investigated using three-dimensional computational fluid dynamics. The Peng–Robinson equation of state is implemented to describe pressure–volume–temperature relationships and to calculate thermodynamic properties and relevant partial derivatives. Four facilities are modeled, including non-reacting compression in a motoring engine, combustion in a conventional diesel combustion engine and in a reactivity controlled compression ignition engine, as well as for a non-reacting reflected wave in a shock tube. It is found that the real gas effects of gas mixtures in practical internal combustion engine operation are sensitive to the operating load and the amount of premixed fuel. Excellent agreement against experiments was found for engine simulations with the Peng–Robinson equation of state in terms of cylinder pressure and apparent heat release rate. However, discrepancies with predictions from the ideal gas law grow with increased load and larger amounts of premixed fuel. In particular, the predicted emissions of soot, NOx, CO and unburnt hydrocarbons show increasing sensitivity to real gas effects as a result of changes in combustion phasing. Fuel condensation is also modeled using a vapor–liquid phase equilibrium solver and significant dependency on the equation of state used is found. Therefore, it is recommended to include real gas effects in internal combustion engine modeling to capture combustion and emissions characteristics accurately. Additionally, the results emphasize the role of real gas effects on reaction rates. Shock tube simulations are used to demonstrate the importance of using the real gas equation of state in the interpretation of chemical kinetic measurements. Significantly different compressed gas temperatures behind the reflected shock are predicted when real gas effects are considered. This needs to be realized when developing chemical kinetic models and rate constants for engine applications from shock tube data.
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Setoodeh, Narjes, Parviz Darvishi, and Abolhasan Ameri. "A thermodynamic approach for correlating the solubility of drug compounds in supercritical CO2 based on Peng-Robinson and Soave-Redlich-Kwong equations of state coupled with van der Waals mixing rules." Journal of the Serbian Chemical Society 84, no. 10 (2019): 1169–82. http://dx.doi.org/10.2298/jsc181105043s.
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In the present study, the effect of equations of state and mixing rules in a thermodynamic approach has been investigated for the correlation of the solubility of four new solid pharmaceutical compounds, namely, benzamide, cetirizine, metaxalone and niflumic acid in supercritical CO2 at different temperatures and pressures. Two equations of state, the Peng?Robinson (PR) and Soave?Redlich?Kwong (SRK), coupled with mixing rules of one-parameter van der Waals (vdW1) and two-parameter van der Waals (vdW2) were used, where the binary interaction parameters for these sets of equations were evaluated. The approach correlations and the robustness of the numerical technique were validated with the experimental data previously reported for these compounds at different temperatures and pressures. The calculated average absolute relative deviations (AARD) were 7.51 and 5.31 % for PR/vdW1 and PR/ /vdW2 couples, and 11.05 and 10.24 % for SRK/vdW1 and SRK/vdW2 couples, respectively. It was also found that the PR equation of state results in modeling performance better than the SRK equation, and the vdW2 mixing rule better than the vdW1 one. These results obviously demonstrate that the combined approach used in this study is applicable for correlation of solid solubilities of some pharmaceutical compounds in supercritical CO2. Additionally, a semiempirical correlation is proposed for estimating the solubility of drug solids in supercritical CO2 as a function of pressure and temperature.
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Baramaki, Zargham, Zahra Arab Aboosadi, and Nadia Esfandiari. "Thermodynamic modeling of ternary systems containing imidazolium-based ionic liquids and acid gases using SRK, Peng-Robinson, CPA and PC-SAFT equations of state." Petroleum Science and Technology 37, no. 24 (October 3, 2019): 2420–28. http://dx.doi.org/10.1080/10916466.2019.1610774.
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Zainal, S. A., W. R. Daud, M. I. Rosli, S. Harun, Zulfan Adi Putra, and M. R. Bilad. "Development of An Integrated Surface and Sub-Surface Simulation Model in A Single Simulation Platform." Indonesian Journal of Science and Technology 5, no. 1 (January 29, 2020): 109–24. http://dx.doi.org/10.17509/ijost.v5i1.17439.
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An integrated model between surface and sub-surface is typically done by interconnecting many process modelling platforms. PROSPER and GAP are the common steady state modelling platforms for sub-surface while VMGSim and HYSYS are typical steady state surface modelling platforms. A major issue of using multiple simulation platforms is the compatibility of thermodynamic physical properties calculations among the platforms. This situation makes the simulations difficult to converge to a consistent thermo physical properties values. This is due to different interaction parameters applied in each platform that impact flashing and the physical property values even though the same property package such as Peng Robinson is used. To overcome this convergence problem, a single simulation platform within iCON (PETRONAS’s standard process simulation software, co-developed with VMG-Schlumberger) has been developed. This allows the use of one thermodynamic package across the integrated model. PROSPER sub-surface pressure-flow relationship results were automatically correlated and connected to surface models within the iCON environment. This integrated model was validated with data from operations and yielded about 1.23% average error tolerance. Based on this validated model, an optimization envelope can be developed with all possible well lineup configurations. This envelope covers set points for the operations where CAPEX free optimization can readily be applied.
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Jafari, Sajad, Hesham Gaballa, Chaouki Habchi, and Jean-Charles de Hemptinne. "Towards Understanding the Structure of Subcritical and Transcritical Liquid–Gas Interfaces Using a Tabulated Real Fluid Modeling Approach." Energies 14, no. 18 (September 7, 2021): 5621. http://dx.doi.org/10.3390/en14185621.
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A fundamental understanding and simulation of fuel atomization, phase transition, and mixing are among the topics researchers have struggled with for decades. One of the reasons for this is that the accurate, robust, and efficient simulation of fuel jets remains a challenge. In this paper, a tabulated multi-component real-fluid model (RFM) is proposed to overcome most of the limitations and to make real-fluid simulations affordable. Essentially, a fully compressible two-phase flow and a diffuse interface approach are used for the RFM model, which were implemented in the CONVERGE solver. PISO and SIMPLE numerical schemes were modified to account for a highly coupled real-fluid tabulation approach. These new RFM model and numerical schemes were applied to the simulation of different fundamental 1-D, 2-D, and 3-D test cases to better understand the structure of subcritical and transcritical liquid–gas interfaces and to reveal the hydro-thermodynamic characteristics of multicomponent jet mixing. The simulation of a classical cryogenic injection of liquid nitrogen coaxially with a hot hydrogen jet is performed using thermodynamic tables generated by two different equations of state: Peng–Robinson (PR) and Soave–Redlich–Kwong (SRK). The numerical results are finally compared with available experimental data and published numerical studies with satisfactory agreement.
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Saferna, Adam, Piotr Saferna, Szymon Kuczyński, Mariusz Łaciak, Adam Szurlej, and Tomasz Włodek. "Thermodynamic Analysis of CNG Fast Filling Process of Composite Cylinder Type IV." Energies 14, no. 17 (September 6, 2021): 5568. http://dx.doi.org/10.3390/en14175568.
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Due to ecological and economic advantages, natural gas is used as an alternative fuel in the transportation sector in the form of compressed natural gas (CNG) and liquefied natural gas (LNG). Development of infrastructure is necessary to popularize vehicles that use alternative fuels. Selected positive factors from EU countries supporting the development of the CNG market were discussed. The process of natural gas vehicle (NGV) fast filling is related to thermodynamic phenomena occurring in a tank. In this study, the first law of thermodynamics and continuity equations were applied to develop a theoretical model to investigate the effects of natural gas composition on the filling process and the final in-cylinder conditions of NGV on-board composite cylinder (type IV). Peng–Robinson equation of state (P-R EOS) was applied, and a lightweight composite tank (type IV) was considered as an adiabatic system. The authors have devised a model to determine the influence of natural gas composition on the selected thermodynamic parameters during fast filling: Joule–Thomson (J-T) coefficient, in-cylinder gas temperature, mass flow rate profiles, in-cylinder mass increase, natural gas density change, ambient temperature on the final natural gas temperature, influence of an ambient temperature on the amount of refueled natural gas mass. Results emphasize the importance of natural gas composition as an important parameter for the filling process of the NGV on-board composite tank (type IV).
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Mesbah, Mohammad, Sanaz Abouali Galledari, Ebrahim Soroush, and Masumeh Momeni. "Modeling Phase Behavior of Semi-Clathrate Hydrates of CO2, CH4, and N2 in Aqueous Solution of Tetra-n-butyl Ammonium Fluoride." Journal of Non-Equilibrium Thermodynamics 44, no. 2 (April 26, 2019): 155–67. http://dx.doi.org/10.1515/jnet-2018-0079.
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AbstractSemi-clathrate hydrates are members of the class of clathrate compounds. In comparison with clathrate hydrates, where the networks are formed only by H2O molecules, the networks of semi-clathrate hydrates are formed by mixtures of H2O and quaternary ammonium salts (QASs). The addition of QASs to the solution enables to improve the formation of semi-clathrate hydrates at much milder conditions comparing to clathrate hydrates. In this work, we study the phase equilibria of semi-clathrate hydrates of CH4, CO2, and N2gas in an aqueous solution of tetra-n-butyl ammonium fluoride (TBAF). An extension of the Chen–Guo model is proposed as a thermodynamic model. The Peng–Robinson equation of state (PREOS) was applied to calculate the fugacity of the gas phase and in order to determine the water activity in the presence of TBAF, a correlation between the system temperature, the TBAF mass fraction, and the nature of the guest molecules has been used. These equations were solved simultaneously and through optimizing tuning parameters via the Nelder–Mead simplex algorithm. The results are compared to experimental data and good agreement is observed.
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MILLER, RICHARD S., KENNETH G. HARSTAD, and JOSETTE BELLAN. "Direct numerical simulations of supercritical fluid mixing layers applied to heptane–nitrogen." Journal of Fluid Mechanics 436 (June 10, 2001): 1–39. http://dx.doi.org/10.1017/s0022112001003895.
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Direct numerical simulations (DNS) are conducted of a model hydrocarbon–nitrogen mixing layer under supercritical conditions. The temporally developing mixing layer configuration is studied using heptane and nitrogen supercritical fluid streams at a pressure of 60 atm as a model system related to practical hydrocarbon-fuel/air systems. An entirely self-consistent cubic Peng–Robinson equation of state is used to describe all thermodynamic mixture variables, including the pressure, internal energy, enthalpy, heat capacity, and speed of sound along with additional terms associated with the generalized heat and mass transport vectors. The Peng–Robinson formulation is based on pure-species reference states accurate to better than 1% relative error through comparisons with highly accurate state equations over the range of variables used in this study (600 [les ] T [les ] 1100 K, 40 [les ] p [les ] 80 atm) and is augmented by an accurate curve fit to the internal energy so as not to require iterative solutions. The DNS results of two-dimensional and three-dimensional layers elucidate the unique thermodynamic and mixing features associated with supercritical conditions. Departures from the perfect gas and ideal mixture conditions are quantified by the compression factor and by the mass diffusion factor, both of which show reductions from the unity value. It is found that the qualitative aspects of the mixing layer may be different according to the specification of the thermal diffusion factors whose value is generally unknown, and the reason for this difference is identified by examining the second-order statistics: the constant Bearman–Kirkwood (BK) thermal diffusion factor excites fluctuations that the constant Irwing–Kirkwood (IK) one does not, and thus enhances overall mixing. Combined with the effect of the mass diffusion factor, constant positive large BK thermal diffusion factors retard diffusional mixing, whereas constant moderate IK factors tend to promote diffusional mixing. Constant positive BK thermal diffusion factors also tend to maintain density gradients, with resulting greater shear and vorticity. These conclusions about IK and BK thermal diffusion factors are species-pair dependent, and therefore are not necessarily universal. Increasing the temperature of the lower stream to approach that of the higher stream results in increased layer growth as measured by the momentum thickness. The three-dimensional mixing layer exhibits slow formation of turbulent small scales, and transition to turbulence does not occur even for a relatively long non-dimensional time when compared to a previous, atmospheric conditions study. The primary reason for this delay is the initial density stratification of the flow, while the formation of strong density gradient regions both in the braid and between-the-braid planes may constitute a secondary reason for the hindering of transition through damping of emerging turbulent eddies.
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Burachok, О. V., D. V. Pershyn, S. V. Matkivskyi, Ye S. Bikman, Ye. S. Bikman, and О. R. Kondrat. "The Adjustment of EOS of Gas-condensate Mixture under the Condition of Input Data Shortage." Prospecting and Development of Oil and Gas Fields, no. 1(74) (June 2, 2020): 82–88. http://dx.doi.org/10.31471/1993-9973-2020-1(74)-82-88.
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The article characterizes the key difficulties which emerge during the simulation of phase behaviors described using the model of “black oil” or fully functional compositional model with the help of the equation-of-state (EOS) in order to create valid continuously operating geological-technological 3D models of gas-condensate reservoirs. The input data for 3D filtration reservoir modeling, the development of which started in the 1960s, are the results of initial gas-condensate and thermodynamic studies. Hydrocarbon component composition of reservoir gas in the existing gas-condensate studies is given only to fraction C5+. Taking into account the peculiarities of initial thermodynamic research with the use of the differential condensation experiment and the absence of such type of experiment in the list of standard experiments in commercially-available PVT-simulators, there appeared a need to develop rational approaches and techniques for correct integration of existing geological-production data in PVT modeling. This article describes the methods for adjusting Peng-Robinson equation-of-state under the condition of input data shortage. Depending on initial data availability and quality, the authors have suggested two different methods. The first PVT-modeling method, which makes it possible to adjust the equation-of-state, is based on the data of component composition of gases and fractional composition of the stable condensate. In case the data of fractional composition of the stable condensate are not available, the authors suggest the second method that is the splitting of fraction C5+ following Whitson volumetric methodology. The suggested methods and two different approaches to EOS adjustment allow effective PVT-modeling using available geological and production data. Study results are presented as the graphical dependencies of comparison of potential hydrocarbons C5+content change in reservoir gas before and after configuring the equation-of-state, as well as the synthetic “liquid saturation” loss curve of the CVD experiment.
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Rezaei, Farzaneh, Amin Rezaei, Saeed Jafari, Abdolhossein Hemmati-Sarapardeh, Amir H. Mohammadi, and Sohrab Zendehboudi. "On the Evaluation of Interfacial Tension (IFT) of CO2–Paraffin System for Enhanced Oil Recovery Process: Comparison of Empirical Correlations, Soft Computing Approaches, and Parachor Model." Energies 14, no. 11 (May 24, 2021): 3045. http://dx.doi.org/10.3390/en14113045.
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Carbon dioxide-based enhanced oil-recovery (CO2-EOR) processes have gained considerable interest among other EOR methods. In this paper, based on the molecular weight of paraffins (n-alkanes), pressure, and temperature, the magnitude of CO2–n-alkanes interfacial tension (IFT) was determined by utilizing soft computing and mathematical modeling approaches, namely: (i) radial basis function (RBF) neural network (optimized by genetic algorithm (GA), gravitational search algorithm (GSA), imperialist competitive algorithm (ICA), particle swarm optimization (PSO), and ant colony optimization (ACO)), (ii) multilayer perception (MLP) neural network (optimized by Levenberg-Marquardt (LM)), and (iii) group method of data handling (GMDH). To do so, a broad range of laboratory data consisting of 879 data points collected from the literature was employed to develop the models. The proposed RBF-ICA model, with an average absolute percent relative error (AAPRE) of 4.42%, led to the most reliable predictions. Furthermore, the Parachor approach with different scaling exponents (n) in combination with seven equations of state (EOSs) was applied for IFT predictions of the CO2–n-heptane and CO2–n-decane systems. It was found that n = 4 was the optimum value to obtain precise IFT estimations; and combinations of the Parachor model with three-parameter Peng–Robinson and Soave–Redlich–Kwong EOSs could better estimate the IFT of the CO2–n-alkane systems, compared to other used EOSs.
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Zhu, Di, and Ryosuke Okuno. "Robust Isenthalpic Flash for Multiphase Water/Hydrocarbon Mixtures." SPE Journal 20, no. 06 (December 18, 2015): 1350–65. http://dx.doi.org/10.2118/170092-pa.
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Summary Robust isenthalpic flash is important in compositional simulation of steam injection, which involves at least three phases—oleic, gaseous, and aqueous. However, multiphase isenthalpic flash is challenging because the total enthalpy can be substantially nonlinear, or even discontinuous, with respect to temperature. This type of phase behavior is referred to as narrow-boiling behavior in the literature. This paper presents robust isenthalpic flash for multiphase water-containing hydrocarbon mixtures. The algorithm developed is based on the direct substitution (DS) presented in our previous research for two phases. A detailed analysis is given for narrow-boiling behavior and its effects on the DS algorithm. A new method is also presented for K-value estimates for three phases for water-hydrocarbon mixtures. The thermodynamic model used is the Peng-Robinson equation of state with the van der Waals mixing rules. The narrow-boiling behavior in isenthalpic flash occurs when a small temperature change yields significant changes of equilibrium-phase compositions relative to the overall composition. The system of equations used in the DS algorithm becomes degenerate for narrow-boiling fluids. The multiphase DS algorithm developed in this paper adaptively switches between Newton's iteration step and the bisection step depending on the Jacobian condition number. The bisection algorithm solves for temperature, based solely on the enthalpy constraint only when narrow-boiling behavior is identified. The algorithm is tested with a number of different isenthalpic flash calculations for three and four phases formed by water-containing hydrocarbon mixtures at elevated temperatures. Results show the robustness of the algorithm for narrow-boiling fluids, including the cases with one degree of freedom.
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Bolotnova, R. Kh, E. F. Gainullina, and E. A. Nurislamova. "Modeling of the spherical explosion attenuation process using aqueous foam." Multiphase Systems 14, no. 2 (2019): 108–14. http://dx.doi.org/10.21662/mfs2019.2.015.
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The two-phase model of dry aqueous foam dynamic behavior under the strong shock wave influence is presented under assumption that the foam structure under shock loading is destroyed into a suspension of monodispersed microdrops with the formation of a gas-droplet mixture. The system of equations for the model of aqueous foam includes the laws of conservation of mass, momentum and energy for each phase in accordance with the single-pressure, two-speed, two-temperature approximations in a three-dimensional formulation, taking into account the Schiller–Naumann interfacial drag force and the Ranz–Marshall interfacial contact heat transfer. The thermodynamic properties of air and water forming a gas-droplet mixture are described by the Peng–Robinson and Mie–Grueneisen equations of state. The presence of non-uniform process in height of aqueous foam syneresis, which is due to gravitational forces, is taken into account by setting the distribution of the liquid volume fraction in the foam. An additional consideration of the syneresis process during calculating the intensity of interphase drag forces according to the Schiller–Naumann model was controlled by introducing the parameter depending on the spatial distribution of the initial liquid volume fraction of the foam. The spherical explosion is modeled in the form of the shock wave pulse whose energy coincided with the charge energy of the HE used in the experiments. The problem numerical solution is implemented using the OpenFOAM free software package based on the two-step PIMPLE computational algorithm. The numerical solution of the problem, obtained on the basis of the proposed gas-droplet mixture model, is in satisfactory agreement with the experimental data on a spherical explosion in aqueous foam. The analysis of the spherical shock wave dynamics while its propagation through aqueous foam is given. The causes of the significant decrease in the amplitude and velocity shock waves propagation in the medium under study are investigated.
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Gainullina, E. F. "Influence of aqueous foam syneresis on the shock wave propagation velocity." Multiphase Systems 15, no. 3-4 (2020): 159–66. http://dx.doi.org/10.21662/mfs2020.3.126.
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Numerical simulation of the spherical shock pulse propagation in aqueous foam with volumetric liquid fraction of 0.0083 has been carried out in accordance with the published experimental data on the explosion of HE in aqueous foam. The assumption is used that the foam structure is destroyed by the shock wave, which leads to the transformation of the foam into a monodisperse gas-droplet mixture. The system of equations for the two-phase gas-droplet model of aqueous foam includes the laws of conservation of mass, momentum, energy for each phase and the equation for the dynamics of the volumetric liquid fraction in a single-pressure, two-velocity, two-temperature approximations in a three-dimensional formulation and takes into account the forces of the Schiller-Naumann interfacial drag, the Ranz-Marshall interphase contact heat exchange and the effect of foam syneresis on the initial distribution of its volumetric liquid fraction. Realistic equations of state in the form of Peng-Robinson and Mie-Gruneisen are used to describe the thermodynamic properties of air and water that make up a gas-droplet mixture. Numerical modeling of the processes under consideration was carried out in the open software of computational fluid dynamics OpenFOAM using the finite volume method based on the iterative two-step PIMPLE algorithm. The analysis of the effect of foam syneresis on the dynamics of shock pulse in aqueous foam is given. It was found that the uneven distribution of the liquid fraction in the foam, caused by its sedimentation under the gravity, leads to the increase in the shock pulse velocity in upper layers of the foam. In comparative analysis of numerical solutions and experimental data at sensor locations, the importance of taking into account syneresis phenomena in modeling the dynamics of shock wave in aqueous foam is shown. The reliability of calculations obtained by the proposed model is confirmed by their agreement with experimental data.
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Malzi, Mohamed Jaouad, Aziz Ettahir, Christian Boned, Bernard Lagourette, Kamal Kettani, and Khaoula Amarray. "Critical Study of a Residual Viscosity Correlation of JOSSI: Pure Hydrocarbons Case." Materials Science Forum 986 (April 2020): 61–67. http://dx.doi.org/10.4028/www.scientific.net/msf.986.61.
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The most common residual viscosity correlation used in the petroleum models is JOSSI et al [1] where the residual viscosity is represented by a polynomial function of 4th degree involving the reduced density ρr ([(η-η*)ξ+10-4]1/4=Σ41=0(aiρri)). Based on this formula, it is possible to predict various uncertainties that can be accumulated and thus alter the performance of viscosity restitution which depends on several factors:The quality of the initial adjustment of the coefficients ai;The precision on the density;The accuracy with which are known the characteristics of the constituents of bases;The validity of the rule of the mixtures selected for the determination of the pseudo-critical coordinates Tcm and Pcm and the equivalent molar mass of the mixture.As far as the results are concerned, we reveal that with the new set of coefficients it is possible to obtain a more preciserepresentation compared to that of JOSSI. The method of JOSSI seems to be especially interesting for the viscosities restitution of systems containing light and close paraffins. However, for some pure substances, the opposite situation could be true. Among the four equations-of-state used, it has been found that the cubic equation-of-stateof PENG and ROBINSON should not be used since we would like to generate the density. Finally, we are not expecting a perfect systematic representation. As demonstrated in our model, if for light alkanes one can expect an average deviation ofless than 10%, for certain pure substances the deviation exceeds 20%.
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Wei, Zhijie, and Dongxiao Zhang. "A Fully Coupled Multiphase Multicomponent Flow and Geomechanics Model for Enhanced Coalbed-Methane Recovery and CO2 Storage." SPE Journal 18, no. 03 (April 8, 2013): 448–67. http://dx.doi.org/10.2118/163078-pa.
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Summary Enhanced coalbed-methane (ECBM) recovery by the injection of CO2 and/or N2 is an attractive method for recovering additional natural gas resources, while at the same time sequestering CO2 in the subsurface. For the naturally fractured coalbed-methane (CBM) reservoirs, the coupled fluid-flow and geomechanics effects involving both the effective-stress effect and the matrix shrinkage/swelling, are crucial to simulate the permeability change and; thus gas migration during primary or enhanced CBM recovery. In this work, a fully coupled multiphase multicomponent flow and geomechanics model is developed. The coupling effects are modeled by introducing a set of elaborate geomechanical equations, which can provide more fundamental understanding about the solid deformation and give a more accurate permeability/porosity prediction over the existing analytical models. In addition, the fluid-flow model in our study is fully compositional; considering both multicomponent gas dissolution and water volatility. To obtain accurate gas solubility in the aqueous phase, the Peng-Robinson equation of state (EOS) is modified according to the suggestions of Søreide and Whitson (1992). An extended Langmuir isotherm is used to describe the adsorption/desorption behavior of the multicomponent gas to/from the coal surface. With a fully implicit finite-difference method, we develop: a 3D, multiphase, multicomponent, dual-porosity CBM/ECBM research code that is fully compositional and has fully coupled fluid flow and geomechanics. It has been partially validated and verified by comparison against other simulators such as GEM, Eclipse, and Coalgas. We then perform a series of simulations/investigations with our research code. First, history matching of Alberta flue-gas-injection micropilot data is performed to test the permeability model. The commonly used uniaxial-strain and constant-overburden-stress assumptions for analytical permeability models are then assessed. Finally, the coupling effects of fluid flow and geomechanics are investigated, and the impact of different mixed CO2/N2 injection scenarios is explored for both methane (CH4) production and CO2 sequestration.
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Masi, Enrica, Josette Bellan, Kenneth G. Harstad, and Nora A. Okong’o. "Multi-species turbulent mixing under supercritical-pressure conditions: modelling, direct numerical simulation and analysis revealing species spinodal decomposition." Journal of Fluid Mechanics 721 (March 19, 2013): 578–626. http://dx.doi.org/10.1017/jfm.2013.70.
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AbstractA model is developed for describing mixing of several species under high-pressure conditions. The model includes the Peng–Robinson equation of state, a full mass-diffusion matrix, a full thermal-diffusion-factor matrix necessary to incorporate the Soret and Dufour effects and both thermal conductivity and viscosity computed for the species mixture using mixing rules. Direct numerical simulations (DNSs) are conducted in a temporal mixing layer configuration. The initial mean flow is perturbed using an analytical perturbation which is consistent with the definition of vorticity and is divergence free. Simulations are performed for a set of five species relevant to hydrocarbon combustion and an ensemble of realizations is created to explore the effect of the initial Reynolds number and of the initial pressure. Each simulation reaches a transitional state having turbulent characteristics and most of the data analysis is performed on that state. A mathematical reformulation of the flux terms in the conservation equations allows the definition of effective species-specific Schmidt numbers $(\mathit{Sc})$ and of an effective Prandtl number $(\mathit{Pr})$ based on effective species-specific diffusivities and an effective thermal conductivity, respectively. Because these effective species-specific diffusivities and the effective thermal conductivity are not directly computable from the DNS solution, we develop models for both of these quantities that prove very accurate when compared with the DNS database. For two of the five species, values of the effective species-specific diffusivities are negative at some locations indicating that these species experience spinodal decomposition; we determine the necessary and sufficient condition for spinodal decomposition to occur. We also show that flows displaying spinodal decomposition have enhanced vortical characteristics and trace this aspect to the specific features of high-density-gradient magnitude regions formed in the flows. The largest values of the effective species-specific $\mathit{Sc}$ numbers can be well in excess of those known for gases but almost two orders of magnitude smaller than those of liquids at atmospheric pressure. The effective thermal conductivity also exhibits negative values at some locations and the effective $\mathit{Pr}$ displays values that can be as high as those of a liquid refrigerant. Examination of the equivalence ratio indicates that the stoichiometric region is thin and coincides with regions where the mixture effective species-specific Lewis number values are well in excess of unity. Very lean and very rich regions coexist in the vicinity of the stoichiometric region. Analysis of the dissipation indicates that it is dominated by mass diffusion, with viscous dissipation being the smallest among the three dissipation modes. The sum of the heat and species (i.e. scalar) dissipation is functionally modelled using the effective species-specific diffusivities and the effective thermal conductivity. Computations of the modelled sum employing the modelled effective species-specific diffusivities and the modelled effective thermal conductivity shows that it accurately replicates the exact equivalent dissipation.
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Pa´dua, K. G. O. "Nonisothermal Gravitational Equilibrium Model." SPE Reservoir Evaluation & Engineering 2, no. 02 (April 1, 1999): 211–17. http://dx.doi.org/10.2118/55972-pa.
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Summary This work presents a new computational model for the non-isothermal gravitational compositional equilibrium. The works of Bedrikovetsky [Mathemathical Theory of Oil and Gas Recovery, Kluwer Academic Publishers, London, (1993)] (gravity and temperature) and of Whitson and Belery ("Compositional Gradients in Petroleum Reservoirs," paper SPE 28000, presented at the 1994 University of Tulsa Centennal Petroleum Engineering Symposium, Tulsa, 29-31 August) (algorithm) are the basis of the mathematical formulation. Published data and previous simplified models validate the computational procedure. A large deep-water field in Campos Basin, Brazil, exemplifies the practical application of the model. The field has an unusual temperature gradient opposite to the Earth's thermal gradient. The results indicate the increase of oil segregation with temperature decrease. The application to field data suggests the reservoir could be partially connected. Fluid composition and property variation are extrapolated to different depths with its respective temperatures. The work is an example of the application of thermodynamic data to the evaluation of reservoir connectivity and fluid properties distribution. Problem Compositional variations along the hydrocarbon column are observed in many reservoirs around the world.1–4 They may affect reservoir/fluid characteristics considerably leading to different field development strategies.5 These variations are caused by many factors, such as gravity, temperature gradient, rock heterogeneity, hydrocarbon genesis and accumulation processes.6 In cases where thermodynamic associated factors (gravity and temperature) are dominant (mixing process in the secondary migration), existing gravitational compositional equilibrium (GCE) models7,8 provide an explanation of most observed variations. However, in some cases8,9 the thermal effect could have the same order of magnitude as the gravity effect. The formulation for calculating compositional variation under the force of gravity for an isothermal system was first given by Gibbs10 $$\mu {ci}(p, Z, T)=\mu {i}(p {{\rm ref}}, Z {{\rm ref}}, T {{\rm ref}}) - m {i}g(h - h {{\rm ref}}),\eqno ({\rm 1})$$ $$\mu {ci}=\delta [nRT\,{\rm ln}(f {i})]/\delta x,\eqno ({\rm 2})$$ $$f {i}=f({\rm EOS}),\eqno ({\rm 3})$$where p =pressure, T=temperature, Z=fluid composition, m=mass, ? c=chemical potential, h=depth, ref=reference, EOS=equation of state, i=component indices, R=real gas constant, n=number of moles, f=fugacity, ln=natural logarithm, x=component concentration, and g=gravitational acceleration. In 1930 Muskat11 provided an exact solution to Eq. (1), assuming a simplified equation of state and ideal mixing. Because of the oversimplified assumptions, the results suggest that gravity has a negligible effect on the compositional variation in reservoir systems. In 1938, Sage and Lacey12 used a more realistic equation of state (EOS), Eq. (3), to evaluate Eq. (2). At that time, the results showed significant composition variations with depth and greater ones for systems close to critical conditions. Schulte13 solved Eq. (1) using a cubic equation of state (3) in 1980. The results showed significant compositional variations. They also suggested a significant effect of the interaction coefficients and the aromatic content of the oil as well as a negligible effect of the EOS type (Peng-Robinson and Soave-Redlich-Kwong) on the final results. A simplified formulation that included gravity and temperature separately was presented by Holt et al.9 in 1983. Example calculations, limited to binary systems, suggest that thermal effects can be of the same magnitude as gravity effects. In 1988, Hirschberg5 discussed the influence of asphaltenes on compositional grading using a simplified two component model (asphaltenes and non-asphaltenes). He concluded, that for oils with oil gravity <35°API, the compositional variations are mainly caused by asphalt segregation and the most important consequences are the large variations in oil viscosity and the possible formation of tar mats. Montel and Gouel7 presented an algorithm in 1985 for solving the GCE problem using an incremental hydrostatic term instead of solving for pressure directly. Field case applications of GCE models were presented by Riemens et al.2 in 1985, and by Creek et al.1 in 1988. They reported some difficulties in matching observed and calculated data but, in the end, it was shown that most compositional variations could be explained by the effect of gravity. Wheaton14 and Lee6 presented GCE models that included capillary forces in 1988 and 1989, respectively. Lee concluded that the effect of capillarity can become appreciable in the neighborhood of 1 ?m pore radius. In 1990, an attempt to combine the effects of gravity and temperature for a system of zero net mass flux was presented by Belery and Silva.15 The multicomponent model was an extension of earlier work by Dougherty and Drickamer16 that was originally developed in 1955 for binary liquid systems. The comparison of calculated and observed data from Ekofisk field in the North Sea is, however, not quantitatively accurate (with or without thermal effect). An extensive discussion and the formal mathematical treatment of compositional grading using irreversible thermodynamics, including gravitational and thermal fields, was presented by Bedrikovetsky17 in 1993. Due to the lack of necessary information on the values of thermal diffusion coefficients, which in general are obtained experimentally only for certain mixtures in narrow ranges of pressure and temperature, simplified models were proposed. In 1994, Hamoodi and Abed3 presented a field case of a giant Middle East reservoir with areal and vertical variations in its composition.
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Sheikhi, Reza, and Fatemeh Hadi. "Application of Scalar Filtered Density Function to Turbulent Flows Under Supercritical Condition." Journal of Energy Resources Technology, May 17, 2021, 1–25. http://dx.doi.org/10.1115/1.4051198.
Full textAbstract:
Abstract The scalar filtered density function (FDF) methodology is extended and employed for large eddy simulation (LES) of turbulent flows under supercritical condition. To describe real-fluid behavior, the extended methodology incorporates the generalized heat and mass diffusion models along with real fluid thermodynamic relations which are derived using the cubic Peng-Robinson equation of state. These models are implemented within the stochastic differential equations comprising the scalar FDF transport. Simulations are conducted of a temporally developing mixing layer under supercritical condition and the results are assessed by comparing with data generated by direct numerical simulation (DNS) of the same layer. The consistency of the proposed FDF methodology is assessed. The LES-FDF predictions are shown to agree favorably with the DNS data and exhibit several key features pertaining to supercritical turbulent flows.
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Botros, K. K., J. Geerligs, B. Rothwell, and T. Robinson. "Measurements of Decompression Wave Speed in Pure Carbon Dioxide and Comparison With Predictions by Equation of State." Journal of Pressure Vessel Technology 138, no. 3 (December 10, 2015). http://dx.doi.org/10.1115/1.4031941.
Full textAbstract:
Carbon dioxide capture and storage (CCS) is one of the technologies that have been proposed to reduce emissions of carbon dioxide (CO2) to the atmosphere. CCS will require the transportation of the CO2 from the “capture” locations to the “storage” locations via large-scale pipeline projects. One of the key requirements for the design and operation of pipelines in all jurisdictions is fracture control. Supercritical CO2 is a particularly challenging fluid from this point of view, because its thermodynamic characteristics are such that a very high driving force for fracture can be sustained for a long time. Even though CO2 is not flammable, it is an asphyxiating gas that is denser than air, and can collect in low-lying areas. Additionally, it is well known that any pipeline rupture, regardless of the nature of the fluid it is transporting, has a damaging reputational, commercial, logistic, and end user impact. Therefore, it is as important to control fracture in a CO2 pipeline as in one transporting a flammable fluid. With materials specified appropriately for the prevention of brittle failure, the key element is the control of propagating ductile (or tearing) fracture. The determination of the required toughness for the arrest of ductile fracture requires knowledge of the decompression behavior of the contained fluid, which in turn requires accurate knowledge of its thermodynamic characteristics along the decompression isentrope. While thermodynamic models based on appropriate EOS (equations of state) are available that will, in principle, allow determination of the decompression wave speed, they, in general, have not been fully validated for very rapid transients following a rupture. This paper presents experimental results of the decompression wave speed obtained from shock tube tests conducted on pure CO2 from different initial conditions, and comparison with predictions by models based on GERG-2008, Peng-Robinson, and BWRS equations of state (EOS). These tests were conducted as a baseline before introducing various impurities.
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Harinck, John, P. Colonna, A. Guardone, and S. Rebay. "Influence of Thermodynamic Models in Two-Dimensional Flow Simulations of Turboexpanders." Journal of Turbomachinery 132, no. 1 (September 11, 2009). http://dx.doi.org/10.1115/1.3192146.
Full textAbstract:
This paper presents a quantitative comparison of the effect of using thermodynamic models of various degrees of complexity if applied to fluid-dynamic simulations of turboexpanders operated at conditions affected by strong real-gas effects. The 2D flow field of a standard transonic turbine stator is simulated using the state-of-the-art inviscid ZFLOW computational fluid-dynamic solver coupled with a fluid property library containing the thermodynamic models. The considered thermodynamic models are, in order of increasing complexity, the polytropic ideal-gas (PIG) law, the Peng–Robinson–Stryjek–Vera (PRSV) cubic equation of state, and the highly accurate multiparameter equations of state (MPEoSs), which are adopted as benchmark reference. The fluids are steam, toluene, and R245fa. The two processes under scrutiny are a moderately nonideal subcritical expansion and a highly nonideal supercritical expansion characterized by the same pressure ratio. Using the PIG model for moderately nonideal subcritical expansions leads to large deviations with magnitudes of up to 18–25% in density, sound speed, velocity, and total pressure loss, and up to 4–10% in Mach number, pressure, temperature, and mass flow rate. The PIG model applied to highly nonideal supercritical expansions leads to a doubling of the deviations’ magnitudes. The advantage of the PIG model is that its computational cost is roughly 1/11 (or 1/3 if saturation-checks in the MPEoS are omitted) of the cost of the MPEoSs. For the subcritical expansion, adopting the physically more correct cubic PRSV model leads to comparatively smaller deviations, namely, <2% (toluene and R245fa) and <4% (steam) in all flow parameters, except for the total pressure loss error, which is comparable to that of the PIG model. The PRSV model is reasonably accurate even for the highly nonideal supercritical expansion, for which the errors are at most 4%. The computational cost of the PRSV model is roughly nine times higher than the cost of the PIG model (or twice as high if saturation-checks in the PRSV are omitted). Contrary to low-complexity fluids like water, for complex fluids like toluene and R245fa the deviations in density, speed of sound, and velocity ensuing from the use of the PIG model vary strongly along the isentropic expansions. This invalidates the approach commonly used in practice of correcting the PIG model with a properly chosen constant compressibility factor.
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Botros, K. K., J. Geerligs, B. Rothwell, and T. Robinson. "Measurements of Decompression Wave Speed in Simulated Anthropogenic Carbon Dioxide Mixtures Containing Hydrogen." Journal of Pressure Vessel Technology 139, no. 2 (September 27, 2016). http://dx.doi.org/10.1115/1.4034466.
Full textAbstract:
In order to determine the material fracture resistance necessary to provide adequate control of ductile fracture propagation in a pipeline, a knowledge of the decompression wave speed following the quasi-instantaneous formation of an unstable, full-bore rupture is necessary. The thermodynamic and fluid dynamics background of such calculations is understood, but predictions based on specific equations of state (EOS) need to be validated against experimental measurements. A program of tests has been conducted using a specially constructed shock tube to determine the impact of impurities on the decompression wave speed in carbon dioxide (CO2), so that the results can be compared to two existing theoretical models. In this paper, data and analysis results are presented for three shock tube tests involving anthropogenic CO2 mixtures containing hydrogen as the primary impurity. The first mixture was intended to represent a typical scenario of precombustion carbon capture and storage (CCS) technology, where typically the concentration of CO2 is around 95–97% (mole). The second mixture represents a worst case scenario of this technology with high level of impurities (with CO2 concentration around 85%). The third test represents a typical chemical-looping combustion process. It was found that the extent of the plateau on the decompression wave speed curves in these tests depends on the location of the phase boundary crossing along the bubble-point curve. The closer the phase boundary crossing to the critical point, the shorter the plateau. This is primarily due to the change in magnitude of the drop in the speed of sound at phase boundary crossing. For the most part, the predictions of the plateau pressure by both of the EOS that were evaluated, GERG-2008 and Peng–Robinson (PR), are in good agreement with measurements by the shock tube. This by no means reflects overall good performance of either EOS, but was rather due to the fact that the isentropes intersected the phase envelope near the critical point, or that the concentration of H2 was relatively low, either in absolute terms or relative to other impurity constituents. Hence, its influence in causing inaccurate prediction of the plateau pressure is lessened. An example of pipeline material toughness required to arrest ductile fracture is presented which shows that predictions by GERG-2008 are more conservative and are therefore recommended.
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Feroiu, Viorel, Dan Geana, and Catinca Secuianu. "Properties of Refrigerants from Cubic Equations of State." Revista de Chimie 59, no. 5 (June 9, 2008). http://dx.doi.org/10.37358/rc.08.5.1827.
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Vapour � liquid equilibrium, thermodynamic and volumetric properties were predicted for three pure hydrofluorocarbons: difluoromethane (R32), pentafluoroethane (R125) and 1,1,1,2 � tetrafluoroethane (R134a) as well as for binary and ternary mixtures of these refrigerants. Three cubic equations of state GEOS3C, SRK (Soave � Redlich � Kwong) and PR (Peng � Robinson) were used. A wide comparison with literature experimental data was made. For the refrigerant mixtures, classical van der Waals mixing rules without interaction parameters were used. The GEOS3C equation, with three parameters estimated by matching several points on the saturation curve (vapor pressure and corresponding liquid volumes), compares favorably to other equations in literature, being simple enough for applications.
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Cui, Zixuan, and Huazhou Li. "Toward accurate density and interfacial tension modeling for carbon dioxide/water mixtures." Petroleum Science, November 19, 2020. http://dx.doi.org/10.1007/s12182-020-00526-x.
Full textAbstract:
AbstractPhase behavior of carbon dioxide/water binary mixtures plays an important role in various CO2-based industry processes. This work aims to screen a thermodynamic model out of a number of promising candidate models to capture the vapor–liquid equilibria, liquid–liquid equilibria, and phase densities of CO2/H2O mixtures. A comprehensive analysis reveals that Peng–Robinson equation of state (PR EOS) (Peng and Robinson 1976), Twu α function (Twu et al. 1991), Huron–Vidal mixing rule (Huron and Vidal 1979), and Abudour et al. (2013) volume translation model (Abudour et al. 2013) is the best model among the ones examined; it yields average absolute percentage errors of 5.49% and 2.90% in reproducing the experimental phase composition data and density data collected in the literature. After achieving the reliable modeling of phase compositions and densities, a new IFT correlation based on the aforementioned PR EOS model is proposed through a nonlinear regression of the measured IFT data collected from the literature over 278.15–477.59 K and 1.00–1200.96 bar. Although the newly proposed IFT correlation only slightly improves the prediction accuracy yielded by the refitted Chen and Yang (2019)’s correlation (Chen and Yang 2019), the proposed correlation avoids the inconsistent predictions present in Chen and Yang (2019)’s correlation and yields smooth IFT predictions.
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Mohammadi, Mohammad-Reza, Fahime Hadavimoghaddam, Maryam Pourmahdi, Saeid Atashrouz, Muhammad Tajammal Munir, Abdolhossein Hemmati-Sarapardeh, Amir H. Mosavi, and Ahmad Mohaddespour. "Modeling hydrogen solubility in hydrocarbons using extreme gradient boosting and equations of state." Scientific Reports 11, no. 1 (September 9, 2021). http://dx.doi.org/10.1038/s41598-021-97131-8.
Full textAbstract:
AbstractDue to industrial development, designing and optimal operation of processes in chemical and petroleum processing plants require accurate estimation of the hydrogen solubility in various hydrocarbons. Equations of state (EOSs) are limited in accurately predicting hydrogen solubility, especially at high-pressure or/and high-temperature conditions, which may lead to energy waste and a potential safety hazard in plants. In this paper, five robust machine learning models including extreme gradient boosting (XGBoost), adaptive boosting support vector regression (AdaBoost-SVR), gradient boosting with categorical features support (CatBoost), light gradient boosting machine (LightGBM), and multi-layer perceptron (MLP) optimized by Levenberg–Marquardt (LM) algorithm were implemented for estimating the hydrogen solubility in hydrocarbons. To this end, a databank including 919 experimental data points of hydrogen solubility in 26 various hydrocarbons was gathered from 48 different systems in a broad range of operating temperatures (213–623 K) and pressures (0.1–25.5 MPa). The hydrocarbons are from six different families including alkane, alkene, cycloalkane, aromatic, polycyclic aromatic, and terpene. The carbon number of hydrocarbons is ranging from 4 to 46 corresponding to a molecular weight range of 58.12–647.2 g/mol. Molecular weight, critical pressure, and critical temperature of solvents along with pressure and temperature operating conditions were selected as input parameters to the models. The XGBoost model best fits all the experimental solubility data with a root mean square error (RMSE) of 0.0007 and an average absolute percent relative error (AAPRE) of 1.81%. Also, the proposed models for estimating the solubility of hydrogen in hydrocarbons were compared with five EOSs including Soave–Redlich–Kwong (SRK), Peng–Robinson (PR), Redlich–Kwong (RK), Zudkevitch–Joffe (ZJ), and perturbed-chain statistical associating fluid theory (PC-SAFT). The XGBoost model introduced in this study is a promising model that can be applied as an efficient estimator for hydrogen solubility in various hydrocarbons and is capable of being utilized in the chemical and petroleum industries.
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Robertson, Miles, Peter Newton, Tao Chen, Aaron Costall, and Ricardo Martinez-Botas. "Experimental and Numerical Study of Supersonic Non-ideal Flows for Organic Rankine Cycle Applications." Journal of Engineering for Gas Turbines and Power 142, no. 8 (July 31, 2020). http://dx.doi.org/10.1115/1.4046758.
Full textAbstract:
Abstract The organic Rankine cycle (ORC) is low-grade heat recovery technology, for sources as diverse as geothermal, industrial, and vehicle waste heat. The working fluids used within these systems often display significant real-gas effects, especially in proximity of the thermodynamic critical point. Three-dimensional (3D) computational fluid dynamics (CFD) is commonly used for performance prediction and flow field analysis within expanders, but experimental validation with real gases is scarce within the literature. This paper therefore presents a dense-gas blowdown facility constructed at Imperial College London, for experimentally validating numerical simulations of these fluids. The system-level design process for the blowdown rig is described, including the sizing and specification of major components. Tests with refrigerant R1233zd(E) are run for multiple inlet pressures, against a nitrogen baseline case. CFD simulations are performed, with the refrigerant modeled by ideal gas, Peng–Robinson, and Helmholtz energy equations of state. It is shown that increases in fluid model fidelity lead to reduced deviation between simulation and experiment. Maximum and mean discrepancies of 9.59% and 8.12% in nozzle pressure ratio with the Helmholtz energy EoS are reported. This work demonstrates an over-prediction of pressure ratio and power output within commercial CFD packages, for turbomachines operating in non-ideal fluid environments. This suggests a need for further development and experimental validation of CFD simulations for highly non-ideal flows. The data contained within this paper are therefore of vital importance for the future validation and development of CFD methods for dense-gas turbomachinery.