scholarly journals An experimental investigation of the saturated vapor pressure of solutions proL pane in compressor oils in the presence of fullerene C60 in oil

2021 ◽  
pp. 89-99
Author(s):  
V. Zhelezny ◽  
S. Korniievych ◽  
O. Khliyeva ◽  
D. Ivchenko
Keyword(s):  
Vapor Pressure ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Fullerene C60 ◽  
Working Fluid ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Concentration Dependences ◽  
Vapor Compression Refrigeration ◽  
Object Of Study

An investigation of the saturated vapor pressure for the solutions of propane in the two type of industrial compressor oils ProEco®RF22S and RENISO SP46, also as in oil ProEco®RF22S containing fullerene C60 6.837·10-4kg·kg-1is presented in this paper. The measurement of the saturated vapor pressure was conducted using a static method in a temperature range (273…333) K and thepropanemass fraction (0.11…0.595) kg·kg-1. An analysis revealed that the expanded uncertainties of the measured saturated vapor pressure do not exceed 0.0419·105Pafor solutionpropane/ProEco®RF22S,0.0716·105Pa for solution propane /RENISO SP46, and 0.0095·105Pa for solution propane/ProEco®RF22 Scontaining C60.The temperature and concentration dependences of the saturated vapor pressure for the object of study have been discussed. The excess of saturated vapor pressure for the solution of propane in oil ProEco®RF22S over the pressure of the solution of propane in oil RENISO SP46 reaches 1.5 105 Pa at a temperature of 330 K and propane fractionof 0.1 kg·kg-1. This effect decreases with temperature decreasing and propane fraction increasing.It was proven that the additive of the fullerene C60 increase the saturated vapor pressure of the solution propane/ProEco® RF22S up to 0.4·105Pa at low temperature and low propane mass fraction insolution. The results obtained proved the expediency of the introduction in the industry the solution of propane/compressor oil ProEco® RF22Scontaining the fullerene C60 as working fluid of vapor compression refrigeration system. The ability of C60additive in oil to increase the saturated vapor pressure of considered working fluid will contribute to increasing the energy efficiency of refrigeration systems.

scholarly journals Performance Analysis of Solar Combined Ejector-Vapor Compression Cycle Using Environmental Friendly Refrigerants

2013 ◽  
Vol 14 (1) ◽  
Author(s):  
A. B. Kasaeian ◽  
S. Daviran
Keyword(s):  
Internal Heat ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Working Fluid ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Environmental Friendly ◽  
Vapor Compression Cycle ◽  
Compression Cycle ◽  
Vapor Compression Refrigeration

In this study, a new model of a solar combined ejector-vapor compression refrigeration system has been considered. The system is equipped with an internal heat exchanger to enhance the performance of the cycle. The effects of working fluid and operating conditions on the system performance including COP, entrainment ratio (ω), compression ratio (rp) and exergy efficiency were investigated. Some working fluids suggested are: R114, R141b, R123, R245fa, R600a, R365mfc, R1234ze(e) and R1234ze(z). The results show that R114 and R1234ze(e) yield the highest COP and exergy efficiency followed by R123, R245fa, R365mfc, R141b, R152a and R600a. It is noticed that the COP value of the new solar ejector-vapor compression refrigeration cycle is higher than that of the conventional ejector cycle with R1234ze(e) for all operating conditions. This paper also demonstrates that R1234ze(e) will be a suitable refrigerant in the solar combined ejector-vapor compression refrigeration system, due to its environmental friendly properties and better performance. ABSTRAK: Kajian ini menganalisa model baru sistem penyejukan mampatan gabungan ejektor-wap solar.Sistem ini dilengkapi dengan penukar haba dalaman untuk meningkatkan prestasi kitaran.Kesan bendalir bekerja dan keadaan operasi pada prestasi sistem termasuk COP, nisbah pemerangkapan (ω), nisbah mampatan (rp) dan kecekapan eksergi telah disiasat.Beberapa bendalir bekerja yang dicadangkan adalah: R114, R141b, R123, R245fa, R600a, R365mfc, R1234ze(e) dan R1234ze(z).Hasil kajian menunjukkan R114 dan R1234ze(e) menghasilkan COP dan kecekapan eksergi tertinggi diikuti oleh R123, R245fa, R365mfc, R141b, R152a dan R600a.Didapati nilai COP kitaran penyejukan mampatan bagi ejektor-wap solar baru adalah lebih tinggi daripada kitaran ejektor konvensional dengan R1234ze(e) bagi semua keadaan operasi.Kertas kerja ini juga menunjukkan bahawa R1234ze(e) boleh menjadi penyejuk yang sesuai dalam sistem penyejukan mampatan gabungan ejektor -wap solar, kerana ianya mempunyai prestasi yang lebih baik serta sifatnya yang lebih mesra alam sekitar. KEYWORDS: environmental friendly refrigerants; solar combined ejector-vapor compression cycle; R1234ze(e)

Experimental Investigation of Vapor Compression Refrigeration System Performance Using Nano-Refrigerant

2014 ◽  
Vol 2 (2) ◽  
pp. 12-27
Author(s):  
Ahmed J. Hamad
Keyword(s):  
Experimental Investigation ◽  
System Performance ◽  
Cuo Nanoparticles ◽  
Working Fluid ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Test Rig ◽  
Vapor Compression Refrigeration ◽  
R 134A ◽  
Thermo Physical Properties

     Experimental investigation of vapor compression refrigeration system performance using Nano-refrigerant is presented in this work. Nano-refrigerant was prepared in current work by mixing 50 nanometers diameter of copper oxide CuO nanoparticles with Polyolester lubrication oil and added to the compressor of the refrigeration system to be mixed with pure refrigerant R-134a during its circulation through refrigeration system. Three concentrations (0.1%, 0.25%, and 0.4%) of CuO-R134 a Nano-refrigerant are used to study the performance of the refrigeration system test rig and to investigate the effect of using Nano-refrigerant as a working fluid compared with pure refrigerant R-134a. The results showed that, the increasing in concentration of CuO nanoparticles in the Nano-refrigerant will significantly enhance the performance of the refrigeration system, as adding nanoparticles will increase the thermal conductivity, heat transfer and improve the thermo-physical properties of Nano-refrigerant. Investigation of performance parameters for refrigeration system using Nano-refrigerant with 0.4% concentration compared with that for pure refrigerant R-134a shows that, Nano-refrigerant has reflect higher performance in range of 10% and 1.5% increase in COP and refrigeration effect respectively and 7% reduction in power consumption for refrigeration system. It can be concluded that, Nano-refrigerants can be efficiently and economically feasible to be used in the vapor compression refrigeration systems.

The Effect of Temperature on Water Cavitation Phenomena in Converging-Diverging Nozzle Flow

2017 ◽  
Author(s):  
Zayed Ahmed ◽  
B. Terry Beck ◽  
Mohammad H. Hosni
Keyword(s):  
Liquid Phase ◽  
Vapor Pressure ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
New Technology ◽  
Phase Region ◽  
Operating Conditions ◽  
Working Fluid ◽  
Absolute Pressure ◽  
Two Phase

A vapor-compression refrigeration cycle typically uses standard refrigerants as the working fluid. Traditional refrigerants, however, have been associated with Ozone level Depletion Potential (ODP) and significant Global Warming Potential (GWP). An innovative cooling technology has been investigated using sonic multi-phase flow in a critical-flow nozzle to create a low-pressure and low-temperature region for heat absorption. The strength of the new technology is its potential to produce cooling using water and/or other working fluids with low ODP and GWP. While the full potential for using water as the working fluid may not be fully-realized, because of property limitations still under investigation, water still provides a very useful media for investigating the underlying cavitation phenomena for the development of the new technology. As part of ongoing research into the potential cooling capacity of the cavitation phenomena, cavitation in a converging-diverging nozzle is being investigated using water as the working fluid. Cavitation in a fluid is the formation of the vapor phase from the liquid phase by reduction in the pressure of the fluid below its saturated vapor pressure. Due to the constricting nature of the throat of a converging-diverging nozzle, the liquid water velocity at the throat is increased and the local absolute pressure can drop to values below the saturated vapor pressure of water at a given temperature; thus, causing the fluid to cavitate. The effect of water temperature on both the onset of the cavitation within the nozzle, and the resulting length of the cavitation region within the nozzle, are the subject of the current paper. Flow Visualization using a high speed digital camera under these different operating conditions was aimed at investigating the region of cavitation onset, which also appears to be associated with the region of boundary layer separation just downstream of the throat of the nozzle. The length of the two phase region at different operating temperatures was measured and it was observed that as the temperature of the fluid was increased, the length of two-phase region before it condensed into single-phase liquid became longer. Experimental results and analysis are presented which also show that near the onset of cavitation, the flowrate can likely go well beyond a choking condition without cavitating, and can remain in this metastable state for an extended amount of time before nucleating (cavitating) into a stable state. In particular, analysis indicates that significantly negative absolute pressures can likely be achieved within the nozzle, suggesting the presence of tension in the liquid phase just prior to cavitation.

scholarly journals New HFC/HFO Blends as Refrigerants for the Vapor-Compression Refrigeration System (VCRS)

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 946
Author(s):  
Bartosz Gil ◽  
Anna Szczepanowska ◽  
Sabina Rosiek
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Mass Fraction ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Operational Parameters ◽  
Vapor Compression Refrigeration ◽  
Low Global Warming Potential ◽  
Triangular Design

In this work, which is related to the current European Parliament Regulation on restrictions affecting refrigeration, four new three-component refrigerants have been proposed; all were created using low Global Warming Potential(GWP) synthetic and natural refrigerants. The considered mixtures consisted of R32, R41, R161, R152a, R1234ze (E), R1234yf, R1243zf, and RE170. These mixtures were theoretically tested with a 10% step in mass fraction using a triangular design. The analysis covered two theoretical cooling cycles at evaporating temperatures of 0 and −30 °C, and a 30 °C constant condensing temperature. The final stage of the work was the determination of the best mixture compositions by thermodynamic and operational parameters. R1234yf–R152a–RE170 with a weight share of 0.1/0.5/0.4 was determined to be the optimal mixture for potentially replacing the existing refrigerants.

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