A certain percentage of the vapor compression based refrigeration, air conditioning and heat pump systems continue to run on halogenated refrigerants due to its excellent thermodynamic and thermo-physical properties along with the low cost. However, the halogenated refrigerants have adverse environmental impacts such as ozone layer depletion potential and global warming. Hence, it is necessary ...

The impending prodllction limitations on the fully halogenated CFG refrigerants is causing an intense search for possible substitutes. This study reviews the historical development of the CFG refrigerants and the relationship between molecular structure and t:he ozone depletio11 and greenhouse warming potentials. It then demonstrates that the halogenated hydrocarbons (a class of compounds that:...

the examination of available vapor pressure data in the case of the methane, ethane, propane and butane halogenated refrigerants, allowed recommendations of standard equations for this property. in this study, three new models include a general correlation; a substance-dependent correlation and an artificial neural network (ann) approach have been developed to estimate the saturated vapor press...

The examination of available vapor pressure data in the case of the methane, ethane, propane and butane halogenated refrigerants, allowed recommendations of standard equations for this property. In this study, three new models include a general correlation; a substance-dependent correlation and an artificial neural network (ANN) approach have been developed to estimate the saturated vapor press...

In consideration of physical and chemical properties of pure substances, speed of sound is one of important quantity which can used to calculate many of other thermo-physical properties such as isothermal compressibility, Joule-Thomson coefficient, isobaric heat capacity and etc. These thermo-physical properties are the main parameters in industrial and chemical processes. Development of accura...

The thermal conductivity of refrigerants is needed to optimize and design the main components HVAC&R systems. Consequently, it crucial have reliable models that are able accurately calculate temperature pressure dependence refrigerants. For first time, this study presents a neural network specifically developed liquid various low-GWP-based In detail, feed-forward algorithm with 5 input para...

The paper deals with the use of R-290/600a(50/50) and R-600a, that are now considered as alternative to R-134a to substitute R-12 in domestic refrigeration. A theoretical analysis of the mixture performance shows that both hydrocarbon refrigerants may be used. Tests of certain hermetic compressors confrrm that the mixture can be used both for old and new equipment, while the isobutane must be u...

Vle have developed a predictive corresponding states model for the thermo· physical properties of pure refrigerants and refrigerant mixtures. The bulk phase properties such as the density, enthalpy and entropy are predicted using the prin· ciple of extended corresponding states. This theoretically based model uses shape factors to insure conformality among the various components and R134a is us...