International Journal of Thermophysics最新文献

{"title":"A Helmholtz Energy Equation of State for 3,3,3-Trifluoroprop-1-ene (R-1243zf)","authors":"Ryo Akasaka,&nbsp;Eric W. Lemmon","doi":"10.1007/s10765-024-03481-6","DOIUrl":"10.1007/s10765-024-03481-6","url":null,"abstract":"<div><p>A new fundamental equation of state expressed as a function of the Helmholtz energy is presented for 3,3,3-trifluoroprop-1-ene (R-1243zf). The equation is valid from the triple-point temperature (122.35 K) to 430 K at pressures up to 35 MPa. The expected uncertainties (<span>(k = 2)</span>) in calculated properties from the equation of state are 0.1 % for vapor pressures, 0.1 % for liquid densities, 1 % for vapor densities, 0.3 % for saturated liquid densities, 1 % for saturated vapor densities, 0.06 % for vapor-phase sound speeds, and 2 % for liquid-phase isobaric heat capacities. Differences between experimental and calculated vapor pressures are within 2 kPa in most cases. Uncertainties for caloric properties are particularly improved from the former equations of state. Various plots of constant-property lines demonstrate that not only does the equation exhibit correct behavior over all temperatures and pressures within the range of validity, but also that it shows reasonable extrapolation behavior at extremely low and high temperatures, and at high pressures.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"46 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Joule Effect in Electrically Aligned CNFs: Toward Fast Heating of Liquids","authors":"A. P. Franco-Bacca,&nbsp;I. Y. Forero-Sandoval,&nbsp;N. W. Pech-May,&nbsp;J. J. Alvarado-Gil,&nbsp;F. Cervantes-Alvarez","doi":"10.1007/s10765-024-03486-1","DOIUrl":"10.1007/s10765-024-03486-1","url":null,"abstract":"<div><p>Efficient use of heating systems is necessary from an environmental and economic perspective. This work analyses the Joule effect and the thermal transport properties of carbon nanofibers dispersed in ethylene–glycol aligned by applying a constant AC electric field. We tested several weight fraction concentrations from 0.1 % to 1 % wt of carbon nanofibers. The evolution of temperature and electric current as a function of time was analyzed. The amount of heat generated was quantified using Joule's law equation, and we estimated the thermal conductivity as a function of the concentration before and after the voltage application. The dependence of the temperature increase on the concentration of carbon nanofibers and electric voltage was investigated. Our work explores the viability of using carbon nanofiber dispersed in ethylene glycol in developing intelligent fluids useful for heat generation and release, with applications in heat management systems, such as those used for deicing.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"46 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10765-024-03486-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Density, Viscosity, and Refractive Index Variations in Diesel Fuel + Higher Alcohols Blends at Various Temperatures","authors":"Sibel Osman,&nbsp;Mert Gülüm,&nbsp;Amalia Stefaniu","doi":"10.1007/s10765-024-03475-4","DOIUrl":"10.1007/s10765-024-03475-4","url":null,"abstract":"<div><p>Understanding the physical properties of diesel fuel blends is essential for evaluating spray characteristics, engine performance, and exhaust emissions of internal combustion engines. Moreover, higher alcohols (n-butanol, n-pentanol, and n-octanol) have recently garnered attention as promising oxygenated additives for enhancing the fuel characteristics of diesel fuel in various combustion applications. For these reasons, in this study, density (ρ), kinematic viscosity (ν), and refractive index (n_D) values of pseudo-binary blends (diesel fuel + n-butanol, diesel fuel + n-pentanol, and diesel fuel + n-octanol) are measured at different temperatures (288.15 K–323.15 K with 5 K interval) and over the entire range of composition (mole fractions). Experimental results for n-butanol, n-pentanol, and n-octanol obtained in this study are consistent with literature values, showing average absolute percentage deviation less than 0.11 %, 3.94 %, and 0.14 % for density, viscosity, and refractive index, respectively. The studied blends meet density and kinematic viscosity limits imposed by the diesel fuel standard (EN 590). Derived from the experimental data, excess molar volumes, viscosity deviations, and refractive index deviations are calculated. These deviation from ideality are fitted using the Redlich–Kister polynomial equation. Refractive index data of pseudo-binary blends are predicted using different models (Lorentz–Lorenz, Gladstone–Dale, Newton, Eykman, Heller, and Edwards). These models have low average absolute percentage deviation (less than 0.67%) for all studied pseudo-binary blends and temperature ranges (293.15 K–308.15 K), which shows they give excellent fitting results between measured data and calculated values.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"46 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring Low-GWP Alternatives for Heat Pumps: A Drop-in Comparative Study of R1234yf/R600a and R134a","authors":"Giulia Lombardo,&nbsp;Davide Menegazzo,&nbsp;Laura Vallese,&nbsp;Michele De Carli,&nbsp;Fabio Poletto,&nbsp;Sergio Bobbo","doi":"10.1007/s10765-024-03495-0","DOIUrl":"10.1007/s10765-024-03495-0","url":null,"abstract":"<div><p>The progressive phase-out of high-GWP refrigerants as mandated by the Kigali Amendment to the Montreal Protocol and the EU F-gas Regulation necessitates the exploration of sustainable alternatives within the HVAC&amp;R industry. A recent proposal by the Council and the European Parliament aims to significantly reduce Hydrofluorocarbons (HFCs) consumption by 2050, including specific bans on high-GWP fluorinated gases in heat pumps and small air conditioning units. Heat pumps, pivotal in mitigating climate change, are expected to see a significant rise in residential applications. However, R134a, widely employed in these systems, has a high GWP of 1530, highlighting the need for more eco-friendly substitutes. Hydrofluoroolefins (HFOs) and natural fluids, particularly hydrocarbons (HCs), have emerged as promising fourth-generation refrigerants due to their negligible ozone depletion potential (ODP) and very low global warming potential (GWP). Despite the potential of these new refrigerants, an optimal replacement for R134a in heat pumps has yet to be found. In this regard, this study investigates the potential of the low-GWP HFO/HC mixture R1234yf/R600a (0.85/0.15) as a drop-in replacement for R134a in water-to-water heat pumps. The research conducts a comparative analysis between R134a and the nearly-azeotropic mixture, assessing their performance under identical heating conditions across 20 different combinations of heat sink and heat source temperatures, ranging from 35 °C to 70 °C and from 10 °C to 20 °C respectively. The R1234yf/R600a mixture exhibited a lower pressure ratio and higher mass flow rates compared to R134a. Additionally, the mixture showed favorable performance in terms of power consumption and compressor outlet temperatures, with slightly lower COP compared to the baseline fluid. These findings suggest that with proper optimization, the R1234yf/R600a mixture could be a viable and sustainable alternative to R134a in residential heat pump applications.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"46 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quest for a Single van der Waals Loop: A Four-Parameter Cubic Equation of State Tailored to a Reference Formulation for Propane","authors":"Jan Hrubý,&nbsp;Aleš Blahut","doi":"10.1007/s10765-024-03483-4","DOIUrl":"10.1007/s10765-024-03483-4","url":null,"abstract":"<div><p>Modern multiparameter equations of state (MP EOSs) enable accurate computation of thermodynamic properties of fluids in broad ranges of temperature and pressure. Between the saturated vapor and saturated liquid densities, a pressure vs. density isotherm computed with an MP EOS exhibits several oscillations with large amplitudes. This is not a problem for most engineering computations, because this portion of isotherm is replaced with a horizontal line, representing an equilibrium mixture of the vapor and liquid phases. However, for computing properties in metastable states, modeling phase interfaces with gradient theory, and certain models of fluid mixtures, an isotherm with a single maximum and a single minimum (single van der Waals loop) is needed. As a step toward an accurate, single-loop EOS, we propose a generalized four-parameter cubic (G4C) EOS. The four parameters are temperature functions which are fitted, at subcritical temperatures, to the second virial coefficient, saturation pressure, liquid density and compressibility, and, in the supercritical region, to the second virial coefficient and derivatives of pressure. Fitted data were generated from thermodynamic property formulation for propane (Lemmon et al. J Chem Eng Data 54:3141, 2009). The G4C EOS provides a representation of thermodynamic properties of propane in the gaseous, liquid, and supercritical regions, which is sufficiently accurate for the intended applications. The equation can be extrapolated to high temperatures. Between 85.5 K and 296 K, the density and compressibility of the saturated liquid are represented with an average absolute relative deviation (AARD) of, respectively, 0.04 and 0.25 percent, the density and compressibility of saturated vapor show AARD of 0.31 and 0.39 percent, and the saturation pressure deviates by 0.23 percent. Features to be improved in future are temperature dependencies of the third- and higher-order virial coefficients at low temperatures, the curvature of isotherms in the liquid region, liquid density at very high pressures, and the critical region. Developed G4C EOS was successfully used in a new mixture model (Hrubý Int J Thermophys 44:130, 2023) to model volumetric behavior and vapor–liquid equilibrium in asymmetric mixtures with propane as a low-volatile component.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"46 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Closed-Form Approximate Solution for Thermo-Mechanical Performance Analysis of Thermoelectric Generators with Temperature-Dependent Material Properties by Differential Transform Method","authors":"Zou-Qing Tan,&nbsp;Kun Tao,&nbsp;Han Sun","doi":"10.1007/s10765-024-03489-y","DOIUrl":"10.1007/s10765-024-03489-y","url":null,"abstract":"<div><p>Thermoelectric materials play a significant role in the electronic industry and energy production. However, temperature-dependent material properties make the theoretical analysis challenging. This paper investigates the thermo-mechanical performance of thermoelectric generators with temperature-dependent material properties by differential transform method (DTM). The nonlinear distribution of temperature-dependent thermal conductivity, Seebeck coefficient, and electric resistivity are considered. DTM is used to construct analytical approximate solutions of the nonlinear differential equation governing the temperature distribution of the thermoelectric element. The thermal performance of the thermoelectric element including temperature distribution, temperature gradient, heat flux, power output per area, and energy conversion efficiency are predicted by DTM. And, the proposed method is utilized to analyze the thermal stress of the thermoelectric element. Compared with numerical solutions, the results indicate that DTM has a fast convergence speed and a high accuracy. The findings reveal that the maximum energy conversion efficiency and thermal stress enhance with the increase of temperature difference.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"46 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of In-Plane Thermal Diffusivity of Polymer Films in Air Using Laser Periodic Heating Method","authors":"Maochao Lv,&nbsp;Jie Yang,&nbsp;Yanhui Zhang,&nbsp;Jianli Wang,&nbsp;Yi Zhou","doi":"10.1007/s10765-024-03491-4","DOIUrl":"10.1007/s10765-024-03491-4","url":null,"abstract":"<div><p>The laser periodic heating method is widely used to measure the thermal diffusivity of various thin films. In this technique, surface temperature responses are monitored using either an infrared (IR) camera or a thermocouple (TC) detector. Under air pressure, the impact of air heat loss on these two measurement methods warrants further examination. In this study, we measured the in-plane thermal diffusivity of a polyethylene terephthalate (PET) film under air pressure using both a non-research-grade IR camera and a microscale TC. Results indicate that air heat loss significantly influenced the TC measurements, yielding an abnormally high thermal diffusivity. Comparatively, the thermal diffusivity measured by the IR camera decreased slightly as modulation frequency increased from 0.1 Hz to 1 Hz. When the thermal diffusion length was approximately three times the film thickness, the diffusivity values from the IR camera closely matched those obtained under vacuum, indicating that the non-contact IR method can effectively suppress the impact of air heat loss.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"46 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Conductivity of Composite Materials Based on Microspheres and Fiberglass Binded by Styrene-Acrylic Emulsion","authors":"Ilgiz R. Gabitov,&nbsp;Lenar Yu. Yarullin,&nbsp;Il’nar Sh. Khabriev,&nbsp;Farizan R. Gabitov,&nbsp;Azat I. Khasanov,&nbsp;Vener F. Khairutdinov,&nbsp;Ilmutdin M. Abdulagatov","doi":"10.1007/s10765-024-03494-1","DOIUrl":"10.1007/s10765-024-03494-1","url":null,"abstract":"<div><p>In the present work, the thermal conductivity of composite materials based on glass, ceramic, and polystyrene microspheres, as well as fiberglass, bonded with a styrene-acrylic emulsion has been reported. The measurements were performed using a commercial SKZ1061C instrument manufactured by SKZ Industrial based on the transient plane source (TPS) method at room temperature and atmospheric pressure. The reliability of the measurements was confirmed through validation of two reference samples of extruded polystyrene foam with well-known thermal conductivity. The measured thermal conductivity values range between (0.0581 and 0.0905) W/(m⋅K) with an uncertainty of 2.5%.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"46 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Equation of State for Solid Argon Valid for Temperatures up to 760 K and Pressures up to 6300 MPa","authors":"Xiong Xiao,&nbsp;Sakimsan Sriskandaruban,&nbsp;Helen E. Maynard-Casely,&nbsp;Monika Thol,&nbsp;Peter Falloon,&nbsp;Roland Span,&nbsp;Eric F. May","doi":"10.1007/s10765-024-03469-2","DOIUrl":"10.1007/s10765-024-03469-2","url":null,"abstract":"<div><p>Thermodynamic property data for solid argon have been analysed to construct a new fundamental equation of state (EOS) based on the Helmholtz energy. This approach is based on methodologies previously applied to solid CO₂ and benzene (Trusler in J Phys Chem Ref Data 40:043105, 2011; Xiao et al. in J Phys Chem Ref Data 50:043104, 2021). The EOS is capable of predicting thermodynamic properties of solid argon up to 760 K and 6300 MPa, using temperature and cell volume as independent variables. The model incorporates the quasi-harmonic approximation with a Debye oscillator framework for vibrons, along with an anharmonic term to address deviations near the triple point. In addition to literature data, the model was regressed to new measurements of argon’s solid cell volume conducted from (8 to 50) K using a high-intensity neutron diffractometer, the results of which are reported here. This new EOS achieves a high degree of accuracy in representing experimental data, with uncertainties (<i>k</i> = 1) estimated of 0.1 %, 0.5 %, and 0.5 % for the cell volume along the sublimation curve, along the melting curve, and in the compressed solid phase, respectively; 2 % to 10 % for the heat capacity along the sublimation curve in different temperature regions; 1 % to 10 % for the thermal expansivity on the sublimation curve; 2 % for the isothermal bulk modulus, 1 % for the isentropic bulk modulus, 0.2 % for the enthalpy of sublimation, 0.5 % to 2 % for the enthalpy of melting, 1 % for the sublimation pressure (<i>T</i> &gt; 50 K), and 2 % to 5 % for melting pressure. The EOS maintains physically realistic behaviour across the range of conditions from absolute zero to high-pressure.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"46 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical Modeling and Experimental Study of Ester-Alcohol Interactions: Methyl Heptanoate and 1-Alkanols","authors":"Mohammad Almasi,&nbsp;Ariel Hernández","doi":"10.1007/s10765-024-03478-1","DOIUrl":"10.1007/s10765-024-03478-1","url":null,"abstract":"<div><p>This manuscript investigates different properties of binary mixtures composed of methyl heptanoate and a series of 1-alkanols (from 1-propanol to 1-hexanol) at atmospheric pressure (0.1 MPa) and temperatures ranging from 293.15 K to 323.15 K. Our experimental data shows that weak intermolecular interactions between the methyl heptanoate and 1-alkanol. Additionally, we employed the PC-SAFT equation of state to accurately predict the density of the mixtures. On the other hand, two viscosity correlations (Redlich–Kister and Belda) were also tested, both of which provided a good fit to the experimental viscosity data.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"46 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}