The selection of lubricant is a key point in developing rotary compressor using R407C as a substitute for R22. The viscosity of oil, miscibility with refrigerant, thermal stability and compatibility with motor materials, etc, are all considerations. Furthermore, by reason of the POEs are more hygroscopic than mineral oils, hydrolytic stability and hygroscopicity of the selected oil must be cons...

Abstract—In present paper, the performance of various alternative refrigerants is compared to find the substitute of R22, the widely used hydrochlorofluorocarbon refrigerant in developing countries. These include the environmentally friendly hydrofluorocarbon (HFC) refrigerants such as R134A, R410A, R407C and M20. In the present study, a steady state thermodynamic model (includes both first and...

A cold room assisted vapor-compression refrigeration cycle is dynamically modeled in a year and optimized. Total annual cost (TACO) and coefficient of performance (COP) are selected as two objective functions. Both cold room and refrigeration cycle parameters are considered as design variables. Moreover, three working fluids included R22, R134a and R407c are examined. The optimum Pareto front r...

This paper presents irreversibility analysis using experimental data from vapor compression chiller system R22, R407C, R404A and R-134A as working fluids. The operated under cycling condition, which allowing the water to circulate in evaporator recording every ten minutes. Further, study was conducted at different ambient temperature identify parameter that cause energy deterioration. findings ...

In the present paper the heat exchange performance of a counter flow double-tube condenser for a ternary refrigerant mixture R407C, composed ofHFC32/HFC125/HFC134a, is calculated using a prediction method developed by the present authors. The axial distributions of vapor and liquid bulk mass fraction, temperature, heat flux, mass flux, etc., are obtained for both a smooth tube and a microfin tu...

The flow boiling heat transfer performance of R22 and R407c, in a microfin tube with helix angle 22° an apex 48°, was evaluated study. study is aimed at investigating the impact flux, mass saturation temperature, vapor quality on coefficient during boiling. Two different temperatures, 293.15 K 313.15 K, were used experiments, fluxes ranging from 25 to 85 kW.m-2 150 350 kg.m-2.s-1. To validate e...

This paper presents the experimental research into high mechanical efficiency at thrust bearings of low-side scroll compressors for air conditioners with the new refrigerant R407C and Polyolester (POE) lubricant. In order to examine the friction loss at the thrust bearing under a test condition which is close to the actual running condition of compressors, the authors developed a friction test ...

SERVICEABilllY ISSUES ASSOCIATED