Thermal Properties of Water
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Effect of Glass Transition: Density and Thermal Conductivity Measurements of B2O3
High Temperatures-High Pressures, Vol. 49, pp. 125–142 ©2020 Old City Publishing, Inc. Reprints available directly from the publisher Published by license under the OCP Science imprint, Photocopying permitted by license only a member of the Old City Publishing Group DOI: 10.32908/hthp.v49.801 Effect of glass transition: density and thermal conductivity measurements of B2O3 DMITRY CHEBYKIN1*, HANS-PETER HELLER1, IVAN SAENKO2, GERT BARTZSCH1, RIE ENDO3 AND OLENA VOLKOVA1 1Institute of Iron and Steel Technology, TU Bergakademie Freiberg, Leipziger Straße 34, 09599 Freiberg, Germany 2Institute of Materials Science, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 5, 09599 Freiberg, Germany 3Department of Materials Science and Engineering, Tokyo Institute of Technology, 152–8552 Tokyo, Japan Received: May 28, 2019; Accepted: October 11, 2019. The role of B2O3 as a fluxing agent for developing fluoride free fluxes has been accentuated in the recent years. Therefore, knowledge about thermo- physical properties of the oxide are essential to find the optimal chemical composition of the mold fluxes. In the present study, the density and ther- mal conductivity of B2O3 were measured by means of the buoyancy method, the maximal bubble pressure (MBP) method and the hot-wire method in the temperature range of 295–1573 K. The results are discussed in the context of the chemical stability of the B2O3 as well as the effect of glass transition on the thermal conductivity. The density of the B2O3 decreases non-linearly with increasing temperature in the temperature range of 973–1573 K. The MBP method was successfully applied for the density measurements with a viscosity up to 91 Pa.s. -
Particular Characteristics of Transcritical CO2 Refrigeration Cycle with an Ejector
Applied Thermal Engineering 27 (2007) 381–388 www.elsevier.com/locate/apthermeng Particular characteristics of transcritical CO2 refrigeration cycle with an ejector Jian-qiang Deng a, Pei-xue Jiang b,*, Tao Lu b, Wei Lu b a Department of Process Equipment and Control Engineering, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China b Key Laboratory for Thermal Science and Power Engineering, Department of Thermal Engineering, Tsinghua University, Beijing 100084, China Received 4 April 2005; accepted 16 July 2006 Available online 26 September 2006 Abstract The present study describes a theoretical analysis of a transcritical CO2 ejector expansion refrigeration cycle (EERC) which uses an ejector as the main expansion device instead of an expansion valve. The system performance is strongly coupled to the ejector entrain- ment ratio which must produce the proper CO2 quality at the ejector exit. If the exit quality is not correct, either the liquid will enter the compressor or the evaporator will be filled with vapor. Thus, the ejector entrainment ratio significantly influences the refrigeration effect with an optimum ratio giving the ideal system performance. For the working conditions studied in this paper, the ejector expansion sys- tem maximum cooling COP is up to 18.6% better than the internal heat exchanger cycle (IHEC) cooling COP and 22.0% better than the conventional vapor compression refrigeration cycle (VCRC) cooling COP. At the conditions for the maximum cooling COP, the ejector expansion cycle refrigeration output is 8.2% better than the internal heat exchanger cycle refrigeration output and 11.5% better than the conventional cycle refrigeration output. -
Carbon Dioxide Heat Transfer Coefficients and Pressure
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Archivio della ricerca - Università degli studi di Napoli Federico II international journal of refrigeration 33 (2010) 1068e1085 available at www.sciencedirect.com www.iifiir.org journal homepage: www.elsevier.com/locate/ijrefrig Carbon dioxide heat transfer coefficients and pressure drops during flow boiling: Assessment of predictive methods R. Mastrullo a, A.W. Mauro a, A. Rosato a,*, G.P. Vanoli b a D.E.TE.C., Facolta` di Ingegneria, Universita` degli Studi di Napoli Federico II, p.le Tecchio 80, 80125 Napoli, Italy b Dipartimento di Ingegneria, Universita` degli Studi del Sannio, corso Garibaldi 107, Palazzo dell’Aquila Bosco Lucarelli, 82100 Benevento, Italy article info abstract Article history: Among the alternatives to the HCFCs and HFCs, carbon dioxide emerged as one of the most Received 13 December 2009 promising environmentally friendly refrigerants. In past years many works were carried Received in revised form out about CO2 flow boiling and very different two-phase flow characteristics from 8 February 2010 conventional fluids were found. Accepted 5 April 2010 In order to assess the best predictive methods for the evaluation of CO2 heat transfer Available online 9 April 2010 coefficients and pressure gradients in macro-channels, in the current article a literature survey of works and a collection of the results of statistical comparisons available in Keywords: literature are furnished. Heat exchanger In addition the experimental data from University of Naples are used to run a deeper Boiling analysis. Both a statistical and a direct comparison against some of the most quoted Carbon dioxide-review predictive methods are carried out. -
Advanced Organic Vapor Cycles for Improving Thermal Conversion Efficiency in Renewable Energy Systems by Tony Ho a Dissertation
Advanced Organic Vapor Cycles for Improving Thermal Conversion Efficiency in Renewable Energy Systems By Tony Ho A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering – Mechanical Engineering in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Ralph Greif, Co-Chair Professor Samuel S. Mao, Co-Chair Professor Van P. Carey Professor Per F. Peterson Spring 2012 Abstract Advanced Organic Vapor Cycles for Improving Thermal Conversion Efficiency in Renewable Energy Systems by Tony Ho Doctor of Philosophy in Mechanical Engineering University of California, Berkeley Professor Ralph Greif, Co-Chair Professor Samuel S. Mao, Co-Chair The Organic Flash Cycle (OFC) is proposed as a vapor power cycle that could potentially increase power generation and improve the utilization efficiency of renewable energy and waste heat recovery systems. A brief review of current advanced vapor power cycles including the Organic Rankine Cycle (ORC), the zeotropic Rankine cycle, the Kalina cycle, the transcritical cycle, and the trilateral flash cycle is presented. The premise and motivation for the OFC concept is that essentially by improving temperature matching to the energy reservoir stream during heat addition to the power cycle, less irreversibilities are generated and more power can be produced from a given finite thermal energy reservoir. In this study, modern equations of state explicit in Helmholtz energy such as the BACKONE equations, multi-parameter Span- Wagner equations, and the equations compiled in NIST REFPROP 8.0 were used to accurately determine thermodynamic property data for the working fluids considered. Though these equations of state tend to be significantly more complex than cubic equations both in form and computational schemes, modern Helmholtz equations provide much higher accuracy in the high pressure regions, liquid regions, and two-phase regions and also can be extended to accurately describe complex polar fluids. -
Analysis of a CO2 Transcritical Refrigeration Cycle with a Vortex Tube Expansion
sustainability Article Analysis of a CO2 Transcritical Refrigeration Cycle with a Vortex Tube Expansion Yefeng Liu *, Ying Sun and Danping Tang University of Shanghai for Science and Technology, Shanghai 200093, China; [email protected] (Y.S.); [email protected] (D.T.) * Correspondence: [email protected]; Tel.: +86-21-55272320; Fax: +86-21-55272376 Received: 25 January 2019; Accepted: 19 March 2019; Published: 4 April 2019 Abstract: A carbon dioxide (CO2) refrigeration system in a transcritical cycle requires modifications to improve the coefficient of performance (COP) for energy saving. This modification has become more important with the system’s more and more widely used applications in heat pump water heaters, automotive air conditioning, and space heating. In this paper, a single vortex tube is proposed to replace the expansion valve of a traditional CO2 transcritical refrigeration system to reduce irreversible loss and improve the COP. The principle of the proposed system is introduced and analyzed: Its mathematical model was developed to simulate and compare the system performance to the traditional system. The results showed that the proposed system could save energy, and the vortex tube inlet temperature and discharge pressure had significant impacts on COP improvement. When the vortex tube inlet temperature was 45 ◦C, and the discharge pressure was 9 MPa, the COP increased 33.7%. When the isentropic efficiency or cold mass fraction of the vortex tube increased, the COP increased about 10%. When the evaporation temperature or the cooling water inlet temperature of the desuperheater decreased, the COP also could increase about 10%. The optimal discharge pressure correlation of the proposed system was established, and its influences on COP improvement are discussed. -
R09 SI: Thermal Properties of Foods
Related Commercial Resources CHAPTER 9 THERMAL PROPERTIES OF FOODS Thermal Properties of Food Constituents ................................. 9.1 Enthalpy .................................................................................... 9.7 Thermal Properties of Foods ..................................................... 9.1 Thermal Conductivity ................................................................ 9.9 Water Content ........................................................................... 9.2 Thermal Diffusivity .................................................................. 9.17 Initial Freezing Point ................................................................. 9.2 Heat of Respiration ................................................................. 9.18 Ice Fraction ............................................................................... 9.2 Transpiration of Fresh Fruits and Vegetables ......................... 9.19 Density ...................................................................................... 9.6 Surface Heat Transfer Coefficient ........................................... 9.25 Specific Heat ............................................................................. 9.6 Symbols ................................................................................... 9.28 HERMAL properties of foods and beverages must be known rizes prediction methods for estimating these thermophysical proper- Tto perform the various heat transfer calculations involved in de- ties and includes examples on the -
THERMAL CONDUCTIVITY of CONTINUOUS CARBON FIBRE REINFORCED COPPER MATRIX COMPOSITES J.Koráb1, P.Šebo1, P.Štefánik 1, S.Kavecký 1 and G.Korb 2
1. THERMAL CONDUCTIVITY OF CONTINUOUS CARBON FIBRE REINFORCED COPPER MATRIX COMPOSITES J.Koráb1, P.Šebo1, P.Štefánik 1, S.Kavecký 1 and G.Korb 2 1 Institute of Materials and Machine Mechanics of the Slovak Academy of Sciences, Racianska 75, 836 06 Bratislava, Slovak Republic 2 Austrian Research Centre Seibersdorf, A-2444 Seibersdorf, Austria SUMMARY: The paper deals with thermal conductivity of the continuous carbon fibre reinforced - copper matrix composite that can be applied in the field of electric and electronic industry as a heat sink material. The copper matrix - carbon fibre composite with different fibre orientation and fibre content was produced by diffusion bonding of copper-coated carbon fibres. Laser flash technique was used for thermal conductivity characterisation in direction parallel and transverse to fibre orientation. The results revealed decreasing thermal conductivity as the volume content of fibre increased and independence of through thickness conductivity on fibre orientation. Achieved results were compared with the materials that are currently used as heat sinks and possibility of the copper- based composite application was analysed. KEYWORDS: thermal conductivity, copper matrix, carbon fibre, metal matrix composite, heat sink, thermal management, heat dissipation INTRODUCTION Carbon fibre reinforced - copper matrix composite (Cu-Cf MMC) offer thermomechanical properties (TMP) which are now required in electronic and electric industry. Their advantages are low density, very good thermal conductivity and tailorable coefficient of thermal expansion (CTE). These properties are important in the applications where especially thermal conductivity plays large role to solve the problems of heat dissipation due to the usage of increasingly powerful electronic components. In devices, where high density mounting technology is applied thermal management is crucial for the reliability and long life performance. -
Structural Transformation in Supercooled Water Controls the Crystallization Rate of Ice
Structural transformation in supercooled water controls the crystallization rate of ice. Emily B. Moore and Valeria Molinero* Department of Chemistry, University of Utah, Salt Lake City, UT 84112-0580, USA. Contact Information for the Corresponding Author: VALERIA MOLINERO Department of Chemistry, University of Utah 315 South 1400 East, Rm 2020 Salt Lake City, UT 84112-0850 Phone: (801) 585-9618; fax (801)-581-4353 Email: [email protected] 1 One of water’s unsolved puzzles is the question of what determines the lowest temperature to which it can be cooled before freezing to ice. The supercooled liquid has been probed experimentally to near the homogeneous nucleation temperature T H≈232 K, yet the mechanism of ice crystallization—including the size and structure of critical nuclei—has not yet been resolved. The heat capacity and compressibility of liquid water anomalously increase upon moving into the supercooled region according to a power law that would diverge at T s≈225 K,1,2 so there may be a link between water’s thermodynamic anomalies and the crystallization rate of ice. But probing this link is challenging because fast crystallization prevents experimental studies of the liquid below T H. And while atomistic studies have captured water crystallization3, the computational costs involved have so far prevented an assessment of the rates and mechanism involved. Here we report coarse-grained molecular simulations with the mW water model4 in the supercooled regime around T H, which reveal that a sharp increase in the fraction of four-coordinated molecules in supercooled liquid water explains its anomalous thermodynamics and also controls the rate and mechanism of ice formation. -
New Explicit Correlation for the Compressibility Factor of Natural Gas: Linearized Z-Factor Isotherms
J Petrol Explor Prod Technol (2016) 6:481–492 DOI 10.1007/s13202-015-0209-3 ORIGINAL PAPER - PRODUCTION ENGINEERING New explicit correlation for the compressibility factor of natural gas: linearized z-factor isotherms 1 2 3 Lateef A. Kareem • Tajudeen M. Iwalewa • Muhammad Al-Marhoun Received: 14 October 2014 / Accepted: 17 October 2015 / Published online: 18 December 2015 Ó The Author(s) 2015. This article is published with open access at Springerlink.com Abstract The compressibility factor (z-factor) of gases is Keywords Z-factor Á Explicit correlation Á Reduced a thermodynamic property used to account for the devia- temperature Á Reduced pressure Á Natural gas tion of real gas behavior from that of an ideal gas. Corre- lations based on the equation of state are often implicit, List of symbols because they require iteration and are computationally P Pressure (psi) expensive. A number of explicit correlations have been P Pseudo-critical pressure derived to enhance simplicity; however, no single explicit pc P Pseudo-reduced pressure correlation has been developed for the full range of pseudo- pr ÀÁ T Temperature (R) reduced temperatures 1:05 Tpr 3 and pseudo-reduced ÀÁ Tpc Pseudo-critical temperature (R) pressures 0:2 Ppr 15 , which represents a significant Tpr Pseudo-reduced temperature research gap. This work presents a new z-factor correlation Ppc Pseudo-critical pressure (psi) that can be expressed in linear form. On the basis of Hall Ppr Pseudo-reduced pressure and Yarborough’s implicit correlation, we developed the v Initial guess for iteration process new correlation from 5346 experimental data points Y Pseudo-reduced density extracted from 5940 data points published in the SPE z-factor Compressibility factor natural gas reservoir engineering textbook and created a linear z-factor chart for a full range of pseudo-reduced temperatures ð1:15 Tpr 3Þ and pseudo-reduced pres- sures ð0:2 Ppr 15Þ. -
Carbon Epoxy Composites Thermal Conductivity at 77 K and 300 K Jean-Luc Battaglia, Manal Saboul, Jérôme Pailhes, Abdelhak Saci, Andrzej Kusiak, Olivier Fudym
Carbon epoxy composites thermal conductivity at 77 K and 300 K Jean-Luc Battaglia, Manal Saboul, Jérôme Pailhes, Abdelhak Saci, Andrzej Kusiak, Olivier Fudym To cite this version: Jean-Luc Battaglia, Manal Saboul, Jérôme Pailhes, Abdelhak Saci, Andrzej Kusiak, et al.. Carbon epoxy composites thermal conductivity at 77 K and 300 K. Journal of Applied Physics, American Institute of Physics, 2014, 115 (22), pp.223516-1 - 223516-4. 10.1063/1.4882300. hal-01063420 HAL Id: hal-01063420 https://hal.archives-ouvertes.fr/hal-01063420 Submitted on 12 Sep 2014 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Science Arts & Métiers (SAM) is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. This is an author-deposited version published in: http://sam.ensam.eu Handle ID: .http://hdl.handle.net/10985/8502 To cite this version : Jean-Luc BATTAGLIA, Manal SABOUL, Jérôme PAILHES, Abdelhak SACI, Andrzej KUSIAK, Olivier FUDYM - Carbon epoxy composites thermal conductivity at 80 K and 300 K - Journal of Applied Physics - Vol. 115, n°22, p.223516-1 - 223516-4 - 2014 Any correspondence concerning this service should be sent to the repository Administrator : [email protected] Carbon epoxy composites thermal conductivity at 80 K and 300 K J.-L. -
New Explicit Correlation for the Compressibility Factor of Natural Gas: Linearized Z-Factor Isotherms
J Petrol Explor Prod Technol DOI 10.1007/s13202-015-0209-3 ORIGINAL PAPER - PRODUCTION ENGINEERING New explicit correlation for the compressibility factor of natural gas: linearized z-factor isotherms 1 2 3 Lateef A. Kareem • Tajudeen M. Iwalewa • Muhammad Al-Marhoun Received: 14 October 2014 / Accepted: 17 October 2015 Ó The Author(s) 2015. This article is published with open access at Springerlink.com Abstract The compressibility factor (z-factor) of gases is Keywords Z-factor Á Explicit correlation Á Reduced a thermodynamic property used to account for the devia- temperature Á Reduced pressure Á Natural gas tion of real gas behavior from that of an ideal gas. Corre- lations based on the equation of state are often implicit, List of symbols because they require iteration and are computationally P Pressure (psi) expensive. A number of explicit correlations have been P Pseudo-critical pressure derived to enhance simplicity; however, no single explicit pc P Pseudo-reduced pressure correlation has been developed for the full range of pseudo- pr ÀÁ T Temperature (R) reduced temperatures 1:05 Tpr 3 and pseudo-reduced ÀÁ Tpc Pseudo-critical temperature (R) pressures 0:2 Ppr 15 , which represents a significant Tpr Pseudo-reduced temperature research gap. This work presents a new z-factor correlation Ppc Pseudo-critical pressure (psi) that can be expressed in linear form. On the basis of Hall Ppr Pseudo-reduced pressure and Yarborough’s implicit correlation, we developed the v Initial guess for iteration process new correlation from 5346 experimental data points Y Pseudo-reduced density extracted from 5940 data points published in the SPE z-factor Compressibility factor natural gas reservoir engineering textbook and created a linear z-factor chart for a full range of pseudo-reduced temperatures ð1:15 Tpr 3Þ and pseudo-reduced pres- sures ð0:2 Ppr 15Þ. -
TABLE A-2 Properties of Saturated Water (Liquid–Vapor): Temperature Table Specific Volume Internal Energy Enthalpy Entropy # M3/Kg Kj/Kg Kj/Kg Kj/Kg K Sat
720 Tables in SI Units TABLE A-2 Properties of Saturated Water (Liquid–Vapor): Temperature Table Specific Volume Internal Energy Enthalpy Entropy # m3/kg kJ/kg kJ/kg kJ/kg K Sat. Sat. Sat. Sat. Sat. Sat. Sat. Sat. Temp. Press. Liquid Vapor Liquid Vapor Liquid Evap. Vapor Liquid Vapor Temp. Њ v ϫ 3 v Њ C bar f 10 g uf ug hf hfg hg sf sg C O 2 .01 0.00611 1.0002 206.136 0.00 2375.3 0.01 2501.3 2501.4 0.0000 9.1562 .01 H 4 0.00813 1.0001 157.232 16.77 2380.9 16.78 2491.9 2508.7 0.0610 9.0514 4 5 0.00872 1.0001 147.120 20.97 2382.3 20.98 2489.6 2510.6 0.0761 9.0257 5 6 0.00935 1.0001 137.734 25.19 2383.6 25.20 2487.2 2512.4 0.0912 9.0003 6 8 0.01072 1.0002 120.917 33.59 2386.4 33.60 2482.5 2516.1 0.1212 8.9501 8 10 0.01228 1.0004 106.379 42.00 2389.2 42.01 2477.7 2519.8 0.1510 8.9008 10 11 0.01312 1.0004 99.857 46.20 2390.5 46.20 2475.4 2521.6 0.1658 8.8765 11 12 0.01402 1.0005 93.784 50.41 2391.9 50.41 2473.0 2523.4 0.1806 8.8524 12 13 0.01497 1.0007 88.124 54.60 2393.3 54.60 2470.7 2525.3 0.1953 8.8285 13 14 0.01598 1.0008 82.848 58.79 2394.7 58.80 2468.3 2527.1 0.2099 8.8048 14 15 0.01705 1.0009 77.926 62.99 2396.1 62.99 2465.9 2528.9 0.2245 8.7814 15 16 0.01818 1.0011 73.333 67.18 2397.4 67.19 2463.6 2530.8 0.2390 8.7582 16 17 0.01938 1.0012 69.044 71.38 2398.8 71.38 2461.2 2532.6 0.2535 8.7351 17 18 0.02064 1.0014 65.038 75.57 2400.2 75.58 2458.8 2534.4 0.2679 8.7123 18 19 0.02198 1.0016 61.293 79.76 2401.6 79.77 2456.5 2536.2 0.2823 8.6897 19 20 0.02339 1.0018 57.791 83.95 2402.9 83.96 2454.1 2538.1 0.2966 8.6672 20 21 0.02487 1.0020