To increase the power efficiency of refrigeration and air conditioning machinery it would be advantageous to be able to run the compressors without any lubricant added to the refrigerant. Without any added lubricant in the refrigerant it would also be possible to simplify the whole refrigeration machinery by excluding all oil handling systems, and there would not any longer be any risk for oil ...

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...

The vortex tube is an intriguing device that separates an incoming high-pressure fluid stream into a two low-pressure streams. Work interaction during the expansion process causes a temperature decrease in one of the two exit streams, while the other one experiences a temperature increase. The overall expansion process in a vortex tube therefore approaches isentropic rather than isenthalpic exp...

In this study, the energetic and exergetic performance merits of an automotive air condition-ing (AAC) system using R134a R1234yf have been investigated. For aim, a laboratory AAC was developed equipped with devices for mechanical measurements. The refrigeration circuit mainly had evaporator, condenser, liquid receiver, fixed capacity compressor, thermostatic expansion valve. tests were perform...

refrigerants that are used in refrigeration systems, cause environmental difficulties such as depletion of ozone layer and greenhouse effect. thus, we must find substitutes for such refrigerants, in this paper, the effect of refrigerant on the thermodynamics performance of refrigeration cycles are studied. to do this, a refrigerator that has designed for r12, is simulated. results show that pur...