An existing commercial scale low temperature R-502 refrigeration plant has been extensively instrumented for evaluating R-502 long term replacements R-404A, R-407A and R-507. This installation is part of the refrigeration plant located at the Thermal Technology Centre. The R-502 retrofit test facility has an internally compounded two stage 40 HP reciprocating compressor equipped with desuperhea...

For inverter heat pumps and multi-type heat pumps, conventional expansion devices such as capillary tubes, short tube orifices, and thermostatic expansion valves (TXVs) are being gradually replaced with electronic expansion valves (EEVs) because of the increasing focus on comfort and energy conservation. In this study, the effects of off-design refrigerant charge on the performance of a water-t...

INTRODUCTION Pulmonary vein (PV) isolation is considered as a key to atrial fibrillation (AF) treatment. Cryoballoon ablation is an effective therapy for PV isolation for AF with minimal side effects and was approved by the US Food and Drug Administration (FDA) several years ago. Successful isolation of PVs during cryoablation depends on the balloon temperature and helps in early identification...

Direct expansion (DX) refrigeration technology is almost exclusively used in multi-temperature transport refrigeration systems. Multi-temperature systems use up to three evaporators, requiring large refrigerant charges and system pressure control to operate over a wide range of set-point conditions. Despite incremental design improvements over the past decade, environmental and control issues c...

Performance of a reciprocating refrigerator compressor with mixed-refrigerants (MR) was investigated experimentally. The current, standard methods of testing compressors and presenting performance data were found unsuitable for MR, and a new experimental apparatus was designed for a ·direct flowrate measurement with MR. Representative test data for Refrigerant R-12 and for a mixture of R-22/R-1...

An analysis of transverse vibrations of a compressor, using the modified Mykle stad-Prohl method which is one of the transfer matrix methods, is explained. A 10 hp four-cylinder refrigerant compressor was used as an object. The shaft and the frame are modeled as beams which are coupled with the sets of a spring and a damper that are the models of bearing oil film, bearing pedestals or the magne...

To simulate the performance of unitary air conditioning and heat pumping equipment at design conditions, the amount of subcooling leaving the condenser is typically specified at design conditions and the required refrigerant charge necessary to achieve that subcooling is computed. For off-design conditions, the charge is fixed at the value determined for the design conditions and the amount of ...

in the present work, the integral equations method is used to calculate transport properties of polar fluids. for this goal, we use the stockmayer potential and examine theoretically the thermal conductivity of several refrigerant mixtures such as r125+r134a, r125+r32, r125+r152a, r134a+r32, r152a+r32, r134a+r143a, and r125+r143a. we solve numerically the ornstein-zernike (oz) equation using th...

Reuse and Recycling are difficult for blended HFC such as R-407C. Direct expansion system has high refrigerant leakage rate. Their continuous use may not be accepted in society near future.