1,720,979 research outputs found
Isothermal vapor-liquid equilibria for the binary system 1,1,1- trifluoroethane (R143a)+1,1,1,3,3,3-hexafluoropropane (R236fa) at 283.11, 298.16, and 313.21 K
No full textA recirculation apparatus in which the vapor phase was forced through the liquid was used to measure isothermal vapor - liquid equilibria (VLE) for the binary system 1,1,1-trifluoroethane (R143a) + 1,1,1,3,3,3-hexafluoropropane (R236fa) at 283.11, 298.16, and 313.21 K. The phase composition at equilibrium was measured with a gas chromatograph that was calibrated with gravimetrically prepared mixtures. The system shows a small deviation from Raoult's law. The data were reduced with the Carnahan-Starling-De Santis (CSD) equation of state. The deviations observed in vapor composition suggest a relatively good consistency of the experimental findings and the model used for their reduction
Le attività di ricerca italiane nel campo dei fluidi frigorigeni sostitutivi
No full text37° Convegno Annuale AICARR, Milano, Marzo 199
Obiettivo: sviluppo sostenibile. Le sfide dell'industria della refrigerazione e del condizionamento dell'aria, CDA 2003
No full textConsiderazioni sulla sostenibilità dello sviluppo del condizionamento dell’aria e della refrigerazione
No full text
Gas chromatographic measurements of activity coefficients at infinite dilution for refrigerants with a polyol ester oil as a stationary phase
No full textActivity coefficients at infinite dilution have been measured by gas chromatography for 14 refrigerants (R12, R22, R32, R124, R125, R134a, R142b, R143a, RE170, R236ea, R290, R600, R600a, and R236fa) as solutes, using a polyol ester oil (POE), EMKARATE by ICI, as a stationary phase (solvent). Instrumental analysis (NMR, IR) showed that the main components of the oil are pentaerithritol esters of carboxylic acids, and electrospray ionization spectrometry revealed an average molecular mass of the POE of 618 g·mol-1. The measurements were performed within a temperature range of 244 K to 313 K, but a specific temperature range for each refrigerant was adopted depending on its retention data. The experimental findings are well-represented by the equation: ln γi∞ = a1 - bi/T. Some refrigerants, i.e., R22, R124, R125, R236ea, and R236fa, show quite a considerable positive temperature dependence of their activity coefficients at infinite dilution, which can be attributed to hydrogen bonding with the POE, unlike other refrigerants that show a small, either positive or negative temperature dependence. To our knowledge, there are no data in the literature on activity coefficients at infinite dilution for refrigerant and oil (lubricant) systems, and details on the solubility of refrigerants in oils are also extremely scarce
Experimental study of the thermodynamic properties of difluoromethane (R32)
No full textDifluoromethane, R32, thermodynamic properties
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