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The aim of this work is to extend the investigation, to the influence of lubricating oil on R22-oil mixture in the heat pump and refrigeration system. The refrigerant-oil test bed was modified to accommodate R22-oil mixture investigation and R22-oil solubi ...
This review highlights the major advantages and challenges of mechanically driven heat pumps and refrigeration systems with focus on multi-temperature applications. Different design strategies are presented, including cycles with multi-stage compressors, e ...
Recent advances in refrigerant-oil flow boiling research are reviewed together with identification of the important trends in published experimental data, while shortcomings in data reduction methods used in most of these previous tests are also noted. New ...
Because of its non-toxicity and its availability steam is frequently used as an energy carrier in industrial processes. Steam is also the by-product of energy intensive processes such as drying, concentration, evaporation and distillation. Although the upg ...
As part of a comprehensive study on factors affecting flow boiling in horizontal tubes, local boiling heat transfer coefficients were measured for R- 134a evaporating inside the same 12.00 mm bore, plain tube for horizontal flow, vertical upflow and vertic ...
Two-phase flow pattern data were obtained with 12.0 mm bore sight glasses for five refrigerants: R-123, R-134a, R-502, R-402A and R-404A. The existing flow pattern maps of Taitel-Dukler and Hashizume poorly represented the data while the VDI map identified ...
The substitution of old refrigerants in refrigeration systems, heat pumps and organic Rankine cycles for heat recovery, request a good knowledge of heat transfer properties of substitute fluids. The test measurmements in LENI test facility (concentric tube ...
A very high accuracy, straight vibrating tube type of density flow meter has been used online to measure oil concentraiton of flowing R-134a/oil mixtures. The calibrations covered oil concentrations from 0-6 wt.% oil over the temperature range from -9.4 to ...
A new Thermodynamic Approach for modelling mixtures of refrigerants and lubricating oils is presented. The model includes generalized methods for predicting the following thermodynamic properties of refrigerant-oil mixtures: bubble point temperatures, loca ...
The conversion to the new alternative refrigerants caused by the greenhouse and ozone effects is now replacing nuclear reactor analysis and safety as the major driving force in two-phase heat transfer research. Extensive studies are underway on pool boilin ...