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ASHRAE handbook : fundamentals
01 Jan 2013-
About: The article was published on 2013-01-01 and is currently open access. It has received 2752 citations till now. The article focuses on the topics: ASHRAE 90.1.
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TL;DR: In this paper, a review of the properties of seawater is presented in terms of regression equations as functions of temperature and salinity, and the available correlations for each property are summarized with their range of validity and accuracy.
Abstract: Correlations and data for the thermophysical properties of seawater are reviewed. Properties examined include density, specific heat capacity, thermal conductivity, dynamic viscosity, surface tension, vapor pressure, boiling point elevation, latent heat of vaporization, specifi c enthalpy, specific entropy and osmotic coefficient. These properties include those needed for design of thermal and membrane desalination processes. Results are presented in terms of regression equations as functions of temperature and salinity. The available correlations for each property are summarized with their range of validity and accuracy. Best-fi tted new correlations are obtained from available data for density, dynamic viscosity, surface tension, boiling point elevation, specifi c enthalpy, specific entropy and osmotic coefficient after appropriate conversion of temperature and salinity scales to the most recent standards. In addition, a model for latent heat of vaporization is suggested. Comparisons are carried out amo...
1,008 citations
01 Apr 2010
TL;DR: In this article, a review of the properties of seawater is presented in terms of regression equations as functions of temperature and salinity, and the available correlations for each property are summarized with their range of validity and accuracy.
Abstract: Correlations and data for the thermophysical properties of seawater are reviewed. Properties examined include density, specific heat capacity, thermal conductivity, dynamic viscosity, surface tension, vapor pressure, boiling point elevation, latent heat of vaporization, specifi c enthalpy, specific entropy and osmotic coefficient. These properties include those needed for design of thermal and membrane desalination processes. Results are presented in terms of regression equations as functions of temperature and salinity. The available correlations for each property are summarized with their range of validity and accuracy. Best-fi tted new correlations are obtained from available data for density, dynamic viscosity, surface tension, boiling point elevation, specifi c enthalpy, specific entropy and osmotic coefficient after appropriate conversion of temperature and salinity scales to the most recent standards. In addition, a model for latent heat of vaporization is suggested. Comparisons are carried out amo...
859 citations
TL;DR: Experimental results on the viscosity of alumina-based nanofluids are reported for various shear rates, temperature, nanoparticle diameter, and nanoparticle volume fraction.
Abstract: Experimental results on the viscosity of alumina-based nanofluids are reported for various shear rates, temperature, nanoparticle diameter, and nanoparticle volume fraction. From the data it seems that the increase in the nanofluid viscosity is higher than the enhancement in the thermal conductivity as reported in the literature. It is shown, however, that the viscosity has to be increased by more than a factor of 4—relative to the increase in thermal conductivity—to make the nanofluid thermal performance worse than that of the base fluid.
735 citations
TL;DR: Rate constants for reactions of ozone with the more commonly identified indoor pollutants are summarized in this article and show that only a small fraction of the reactions occur at a rate fast enough to compete with air exchange, assuming typical indoor ozone concentrations.
Abstract: The concentration of indoor ozone depends on a number of factors, including the outdoor ozone concentration, air exchange rates, indoor emission rates, surface removal rates, and reactions between ozone and other chemicals in the air. Outdoor ozone concentrations often display strong diurnal variations, and this adds a dynamic excitation to the transport and chemical mechanisms at play. Hence, indoor ozone concentrations can vary significantly from hour-to-hour, day-to-day, and season-to-season, as well as from room-to-room and structure-to- structure. Under normal conditions, the half-life of ozone indoors is between 7 and 10 min and is determined primarily by surface removal and air exchange. Although reactions between ozone and most other indoor pollutants are thermodynamically favorable, in the majority of cases they are quite slow. Rate constants for reactions of ozone with the more commonly identified indoor pollutants are summarized in this article. They show that only a small fraction of the reactions occur at a rate fast enough to compete with air exchange, assuming typical indoor ozone concentrations. In the case of organic compounds, the “fast” reactions involve compounds with unsaturated carbon-carbon bonds. Although such compounds typically comprise less than 10% of indoor pollutants, their reactions with ozone have the potential to be quite significant as sources of indoor free radicals and multifunctional (−C=O, −COOH, −OH) stable compounds that are often quite odorous. The stable compounds are present as both gas phase and condensed phase species, with the latter contributing to the overall concentration of indoor submicron particles. Indeed, ozone/alkene reactions provide a link between outdoor ozone, outdoor particles and indoor particles. Indoor ozone and the products derived from reactions initiated by indoor ozone are potentially damaging to both human health and materials; more detailed explication of these impacts is an area of active investigation.
678 citations
TL;DR: In this article, the authors present recent developments and state-of-the-art for transcritical CO2 cycle technology in various refrigeration, air-conditioning and heat pump applications, including discussion of properties and characteristics of CO2, cycle fundamentals, methods of high-side pressure control, thermodynamic losses, cycle modifications, component/system design, safety factors, and promising application areas.
656 citations