The Experts below are selected from a list of 18129 Experts worldwide ranked by ideXlab platform
Santiago Velasco - One of the best experts on this subject based on the ideXlab platform.
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Approximating the Temperature–Entropy Saturation Curve of ORC Working Fluids From the Ideal Gas Isobaric Heat Capacity
Energies, 2019Co-Authors: Juan A. White, Santiago VelascoAbstract:Recently, we proposed an approximate expression for the liquid–vapor Saturation Curves of pure fluids in a temperature–entropy diagram that requires the use of parameters related to the molar heat capacity along the vapor branch of the Saturation Curve. In the present work, we establish a connection between these parameters and the ideal-gas isobaric molar heat capacity. The resulting new approximation yields good results for most working fluids in Organic Rankine Cycles, improving the previous approximation for very dry fluids. The ideal-gas isobaric molar heat capacity can be obtained from most Thermophysical Properties databases for a very large number of substances for which the present approximation scheme can be applied.
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a simple semiempirical method for predicting the temperature entropy Saturation Curve of pure fluids
Industrial & Engineering Chemistry Research, 2019Co-Authors: Juan A. White, Santiago VelascoAbstract:In this work we propose an approximate analytical method to obtain the liquid–vapor Saturation Curve in a Tr–s* diagram, with Tr = T/Tc, s* = (s – sc)/R, Tc the critical temperature, s the molar entropy, sc the critical molar entropy, and R the gas constant, for a given fluid. The method uses a modified rectilinear diameter law for the saturated liquid and vapor entropies and an extended corresponding states equation for the entropy of vaporization. From this method, two approximations are derived. The first approximation requires the use of data obtained from RefProp or a similar program. The second approximation only needs Tc, the critical molar volume, vc, and the acentric factor, ω, of the fluid as input data. For most fluids, both approximations yield very good predictions.
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A Simple Semiempirical Method for Predicting the Temperature–Entropy Saturation Curve of Pure Fluids
Industrial & Engineering Chemistry Research, 2018Co-Authors: Juan A. White, Santiago VelascoAbstract:In this work we propose an approximate analytical method to obtain the liquid–vapor Saturation Curve in a Tr–s* diagram, with Tr = T/Tc, s* = (s – sc)/R, Tc the critical temperature, s the molar entropy, sc the critical molar entropy, and R the gas constant, for a given fluid. The method uses a modified rectilinear diameter law for the saturated liquid and vapor entropies and an extended corresponding states equation for the entropy of vaporization. From this method, two approximations are derived. The first approximation requires the use of data obtained from RefProp or a similar program. The second approximation only needs Tc, the critical molar volume, vc, and the acentric factor, ω, of the fluid as input data. For most fluids, both approximations yield very good predictions.
Juan A. White - One of the best experts on this subject based on the ideXlab platform.
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Approximating the Temperature–Entropy Saturation Curve of ORC Working Fluids From the Ideal Gas Isobaric Heat Capacity
Energies, 2019Co-Authors: Juan A. White, Santiago VelascoAbstract:Recently, we proposed an approximate expression for the liquid–vapor Saturation Curves of pure fluids in a temperature–entropy diagram that requires the use of parameters related to the molar heat capacity along the vapor branch of the Saturation Curve. In the present work, we establish a connection between these parameters and the ideal-gas isobaric molar heat capacity. The resulting new approximation yields good results for most working fluids in Organic Rankine Cycles, improving the previous approximation for very dry fluids. The ideal-gas isobaric molar heat capacity can be obtained from most Thermophysical Properties databases for a very large number of substances for which the present approximation scheme can be applied.
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a simple semiempirical method for predicting the temperature entropy Saturation Curve of pure fluids
Industrial & Engineering Chemistry Research, 2019Co-Authors: Juan A. White, Santiago VelascoAbstract:In this work we propose an approximate analytical method to obtain the liquid–vapor Saturation Curve in a Tr–s* diagram, with Tr = T/Tc, s* = (s – sc)/R, Tc the critical temperature, s the molar entropy, sc the critical molar entropy, and R the gas constant, for a given fluid. The method uses a modified rectilinear diameter law for the saturated liquid and vapor entropies and an extended corresponding states equation for the entropy of vaporization. From this method, two approximations are derived. The first approximation requires the use of data obtained from RefProp or a similar program. The second approximation only needs Tc, the critical molar volume, vc, and the acentric factor, ω, of the fluid as input data. For most fluids, both approximations yield very good predictions.
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A Simple Semiempirical Method for Predicting the Temperature–Entropy Saturation Curve of Pure Fluids
Industrial & Engineering Chemistry Research, 2018Co-Authors: Juan A. White, Santiago VelascoAbstract:In this work we propose an approximate analytical method to obtain the liquid–vapor Saturation Curve in a Tr–s* diagram, with Tr = T/Tc, s* = (s – sc)/R, Tc the critical temperature, s the molar entropy, sc the critical molar entropy, and R the gas constant, for a given fluid. The method uses a modified rectilinear diameter law for the saturated liquid and vapor entropies and an extended corresponding states equation for the entropy of vaporization. From this method, two approximations are derived. The first approximation requires the use of data obtained from RefProp or a similar program. The second approximation only needs Tc, the critical molar volume, vc, and the acentric factor, ω, of the fluid as input data. For most fluids, both approximations yield very good predictions.
Milan Zabranský - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic properties of dimethyl phthalate along the vapour liquid Saturation Curve
The Journal of Chemical Thermodynamics, 1999Co-Authors: Vladislav Roháč, Jana E Musgrove, Květoslav Ružicka, Vlastimil Ruzicka, Milan ZabranskýAbstract:Abstract Measurements of vapour pressurep, densityρ, and molar heat capacityCp,mare reported for dimethyl phthalate in the liquid phase. The methods of comparative ebulliometry, vibrating-tube densimetry, and heat conduction calorimetry were employed to determine these properties. A simultaneous correlation of vapour pressures and of enthalpy of vaporizationΔvapHmwas used to generate parameters for the Cox equation. Vapour pressure and enthalpies of vaporization derived from the fit are reported at the triple point temperatureTt, atT = 298.15 K, and at the normal boiling temperature. For inclusion into program packages, parameters of the Antoine equation were calculated by fitting the ebulliometric vapour pressures. A comparison of all measured properties with literature data is presented.
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Thermodynamic properties of dimethyl phthalate along the (vapour + liquid) Saturation Curve
The Journal of Chemical Thermodynamics, 1999Co-Authors: Vladislav Roháč, Jana E Musgrove, Květoslav Ružicka, Vlastimil Ruzicka, Milan ZabranskýAbstract:Abstract Measurements of vapour pressurep, densityρ, and molar heat capacityCp,mare reported for dimethyl phthalate in the liquid phase. The methods of comparative ebulliometry, vibrating-tube densimetry, and heat conduction calorimetry were employed to determine these properties. A simultaneous correlation of vapour pressures and of enthalpy of vaporizationΔvapHmwas used to generate parameters for the Cox equation. Vapour pressure and enthalpies of vaporization derived from the fit are reported at the triple point temperatureTt, atT = 298.15 K, and at the normal boiling temperature. For inclusion into program packages, parameters of the Antoine equation were calculated by fitting the ebulliometric vapour pressures. A comparison of all measured properties with literature data is presented.
Vladislav Roháč - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic properties of dimethyl phthalate along the vapour liquid Saturation Curve
The Journal of Chemical Thermodynamics, 1999Co-Authors: Vladislav Roháč, Jana E Musgrove, Květoslav Ružicka, Vlastimil Ruzicka, Milan ZabranskýAbstract:Abstract Measurements of vapour pressurep, densityρ, and molar heat capacityCp,mare reported for dimethyl phthalate in the liquid phase. The methods of comparative ebulliometry, vibrating-tube densimetry, and heat conduction calorimetry were employed to determine these properties. A simultaneous correlation of vapour pressures and of enthalpy of vaporizationΔvapHmwas used to generate parameters for the Cox equation. Vapour pressure and enthalpies of vaporization derived from the fit are reported at the triple point temperatureTt, atT = 298.15 K, and at the normal boiling temperature. For inclusion into program packages, parameters of the Antoine equation were calculated by fitting the ebulliometric vapour pressures. A comparison of all measured properties with literature data is presented.
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Thermodynamic properties of dimethyl phthalate along the (vapour + liquid) Saturation Curve
The Journal of Chemical Thermodynamics, 1999Co-Authors: Vladislav Roháč, Jana E Musgrove, Květoslav Ružicka, Vlastimil Ruzicka, Milan ZabranskýAbstract:Abstract Measurements of vapour pressurep, densityρ, and molar heat capacityCp,mare reported for dimethyl phthalate in the liquid phase. The methods of comparative ebulliometry, vibrating-tube densimetry, and heat conduction calorimetry were employed to determine these properties. A simultaneous correlation of vapour pressures and of enthalpy of vaporizationΔvapHmwas used to generate parameters for the Cox equation. Vapour pressure and enthalpies of vaporization derived from the fit are reported at the triple point temperatureTt, atT = 298.15 K, and at the normal boiling temperature. For inclusion into program packages, parameters of the Antoine equation were calculated by fitting the ebulliometric vapour pressures. A comparison of all measured properties with literature data is presented.
Juan C. Ordonez - One of the best experts on this subject based on the ideXlab platform.
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predicting the slope of the temperature entropy vapor Saturation Curve for working fluid selection based on lee kesler modeling
Industrial & Engineering Chemistry Research, 2020Co-Authors: Alejandro Riveraalvarez, Obie I. Abakporo, Julian D. Osorio, Rob Hovsapian, Juan C. OrdonezAbstract:This paper presents a general, novel, and accurate method to determine the shape of the temperature–entropy (T–S) vapor Saturation Curve for fluids, based on Lee–Kesler’s version of the corresponding states principle. The slope of the T–S vapor Saturation Curve and the location of isentropic points are successfully predicted for any fluid as a function of only three input variables: acentric factor (ω), ideal-gas ratio of specific heats at the critical temperature (kc), and the exponent of the heat capacity ratio vs temperature power relationship (m). The proposed method is then applied to a set of 120 commercially available fluids, and the results are validated with experimental data. As the method effectively distinguishes among dry, wet, and isentropic fluids, a simple semiempirical equation establishing the frontier between wet and dry fluid regions is discovered. The developed method can be used as an effective tool for working fluid selection for organic Rankine cycles (ORCs), refrigeration cycles, and heat pumps. It also has the potential to aid the development of new fluids with a proper set of characteristics for specific applications.
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Predicting the Slope of the Temperature–Entropy Vapor Saturation Curve for Working Fluid Selection Based on Lee–Kesler Modeling
Industrial & Engineering Chemistry Research, 2019Co-Authors: Alejandro Rivera-alvarez, Obie I. Abakporo, Julian D. Osorio, Rob Hovsapian, Juan C. OrdonezAbstract:This paper presents a general, novel, and accurate method to determine the shape of the temperature–entropy (T–S) vapor Saturation Curve for fluids, based on Lee–Kesler’s version of the corresponding states principle. The slope of the T–S vapor Saturation Curve and the location of isentropic points are successfully predicted for any fluid as a function of only three input variables: acentric factor (ω), ideal-gas ratio of specific heats at the critical temperature (kc), and the exponent of the heat capacity ratio vs temperature power relationship (m). The proposed method is then applied to a set of 120 commercially available fluids, and the results are validated with experimental data. As the method effectively distinguishes among dry, wet, and isentropic fluids, a simple semiempirical equation establishing the frontier between wet and dry fluid regions is discovered. The developed method can be used as an effective tool for working fluid selection for organic Rankine cycles (ORCs), refrigeration cycles, and heat pumps. It also has the potential to aid the development of new fluids with a proper set of characteristics for specific applications.
