scholarly journals Effect of Titanium Oxide Nano Lubricants Applied to R134a Refrigeration System

2020 ◽  
Vol 8 (5) ◽  
pp. 5557-5559
Keyword(s):  
Steady State ◽  
Tio2 Nanoparticles ◽  
Titanium Oxide ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Compressor Work

In this work experiment is performed by using titanium oxide (Tio2) nanoparticles at three different nanoaparticles containing lubricants 0.2g/l,0.4g/l as well as 0.6g/l . An experiment was performed by dispersing titanium oxide (Tio2) nanoparticles and the variables such as compressor work, Coefficient of performance (C.O.P) and refrigeration has been analysed.The experiment was conducted with R134a refrigerant under steady state conditions.Inclusion of Tio2 nanoparticles improved the coefficient as well as cooling capacity of presentation and the compressor work is get reduced.

scholarly journals Effect of Titanium Oxide Nanoparticle Additives on R22 Refrigeration System

2019 ◽  
Vol 9 (2) ◽  
pp. 3458-3460
Keyword(s):  
Titanium Oxide ◽  
Tio2 Nanoparticle ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Heat Transfer Fluids ◽  
New Energy ◽  
Oxide Nanoparticle ◽  
Compressor Work ◽  
The Impact ◽  
Cooling Model

To explore the conservation technique for energy resources and making more efficient new energy systems has init iated the demand for usage of Nanoparticle in heat transfer fluids. The study explored the impact of Nanolubricants based on Mineral refrigeration oil and Tio2 Nanoparticle at three various mass concentrations 0.6g/l,024g/l and 046g/l in a vapour confining refrigeration system. Experiments are finalized out to read the important functions of cooling models, like as coefficient of performance (C.O.P), Compressor work and refrigeration effect when titanium oxide (Tio2 ) Nanoparticle are added to the lubricant. The experiment conduced using R22 refrigerant. The process of Tio2 Nanoparticle by the cooling model was raising the cooling level of accuracy and Collaborative of task and reduction of compressor work.

SIMULATION OF A SIMPLE VAPOUR-COMPRESSION REFRIGERATION SYSTEM USING R134a

2016 ◽  
Vol 78 (9-2) ◽  
Author(s):  
Mohd Yusoff Senawi ◽  
Farah Wahidah Mahmod
Keyword(s):  
Steady State ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Input Coefficient ◽  
Work Input ◽  
Compressor Work ◽  
Computerized Simulation ◽  
Steady State Simulation ◽  
Vapour Compression ◽  
Isentropic Efficiency

A computerized simulation of a simple single-stage vapour-compression refrigeration system has been made. The steady-state simulation uses the accurate property correlations developed by Cleland for refrigerant R134a. The inputs to the program are: evaporator pressure, condenser pressure, superheating at evaporator outlet, subcooling at condenser outlet and compressor isentropic efficiency. The program outputs are: refrigerating effect, compressor work input, coefficient of performance (COP) and suction vapour flow rate per kW of refrigeration. An increase in the evaporator pressure from 150 to 250 kPa improves the COP by 40%. The COP is decreased by 35% when the condenser pressure is increased from 1000 to 1500 kPa. Increasing the superheat at the evaporator outlet from 0 to 160C improves the COP by 2.6%. An increase in subcooling at the condenser outlet from 0 to 160C increases the COP by 20%. The COP is improved by 150% when the compressor isentropic efficiency is increased from 0.4 to 1.

scholarly journals Cop Enhancement of Vapour Compression Refrigeration System

2021 ◽  
pp. 1-6
Author(s):  
B Sairamakrishna ◽  
◽  
T Gopala Rao ◽  
N Rama Krishna ◽  
◽  
...  
Keyword(s):  
Tube Diameter ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Expansion Valve ◽  
Compressor Inlet ◽  
Work Input ◽  
Compressor Work ◽  
Vapour Compression ◽  
Design And Testing ◽  
Nozzle Inlet

This experimental investigation exemplifies the design and testing of diffuser at compressor inlet and nozzle at condenser outlet in vapour compression refrigeration system with the help of R134a refrigerant. The diffuser with divergence angle of 12°,14° and the nozzle with convergent angle 12°,14° are designed for same inlet and outlet diameters. Initially diffusers are tested at compressor inlet diffuser is used with inlet diameter equal to exit tube diameter of evaporator and outlet tube diameter is equal to suction tube diameter of the compressor. Diffuser helps to increases the pressure of the refrigerant before entering the compressor it will be helps to reduces the compression work and achieve higher performance of the vapour compression refrigeration system. Then nozzles are testing at condenser outlet, whereas nozzle inlet diameter equal to discharging tube diameter of condenser and outlet diameter equal to inlet diameter of expansion valve. Additional pressure drop in the nozzle helped to achieve higher performance of the vapour compression refrigeration system. The system is analyzes using the first and second laws of thermodynamics, to determine the refrigerating effect, the compressor work input, coefficient of performance (COP).

scholarly journals Investigation on the improvement of car air conditioning system performance using an ejector

2018 ◽  
Vol 197 ◽  
pp. 08013
Author(s):  
Enang Suma Arifianto ◽  
Ega Taqwali Berman ◽  
Mutaufiq Mutaufiq
Keyword(s):  
System Performance ◽  
Test Procedure ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
Compressor Work ◽  
R 134A

The purpose of this research is to know the improvement of car air conditioner system performance using an ejector. The study was conducted on a car engine with power 100 PS (74 kW) @ 5000 rpm. The test procedure is carried out under two conditions: the normal refrigeration cycle mode and the refrigeration cycle mode with the ejector. The working fluid used in the refrigeration cycle is R-134a. Performance data was measured on engine revolutions ranging from 1500 - 3000 rpm. Finally, the results showed that ejector usage on AC system generates an increase in the refrigeration effect and coefficient of performance (COP) of 25% and 22%, respectively. This has implications to better cooling capacity and compressor work that is lighter.

scholarly journals Evaporator Frosting in Refrigerating Appliances: Fundamentals and Applications

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5991
Author(s):  
Christian J. L. Hermes ◽  
Joel Boeng ◽  
Diogo L. da Silva ◽  
Fernando T. Knabben ◽  
Andrew D. Sommers
Keyword(s):  
First Principles ◽  
Simulation Models ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Trial And Error ◽  
Refrigeration System ◽  
Duty Cycles ◽  
Transfer Principles ◽  
Frost Layer

Modern refrigerators are equipped with fan-supplied evaporators often tailor-made to mitigate the impacts of frost accretion, not only in terms of frost blocking, which depletes the cooling capacity and therefore the refrigerator coefficient of performance (COP), but also to allow optimal defrosting, thereby avoiding the undesired consequences of condensate retention and additional thermal loads. Evaporator design for frosting conditions can be done either empirically through trial-and-error approaches or using simulation models suitable to predict the distribution of the frost mass along the finned coil. Albeit the former is mandatory for robustness verification prior to product approval, it has been advocated that the latter speeds up the design process and reduces the costs of the engineering undertaking. Therefore, this article is aimed at summarizing the required foundations for the design of efficient evaporators and defrosting systems with minimized performance impacts due to frosting. The thermodynamics, and the heat and mass transfer principles involved in the frost nucleation, growth, and densification phenomena are presented. The thermophysical properties of frost, such as density and thermal conductivity, are discussed, and their relationship with refrigeration operating conditions are established. A first-principles model is presented to predict the growth of the frost layer on the evaporator surface as a function of geometric and operating conditions. The relation between the microscopic properties of frost and their macroscopic effects on the evaporator thermo-hydraulic performance is established and confirmed with experimental evidence. Furthermore, different defrost strategies are compared, and the concept of optimal defrost is formulated. Finally, the results are used to analyze the efficiency of the defrost operation based on the net cooling capacity of the refrigeration system for different duty cycles and evaporator geometries.

Properties and Performance of Eco-Friendly Hydro-Fluoro-Olefin (HFO) Refrigerant-R1234yf: Part I

2021 ◽  
pp. 2130005
Author(s):  
B. S. Bibin ◽  
Edison Gundabattini
Keyword(s):  
Ozone Depletion ◽  
Past Research ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
General Effect ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Vapor Compression Refrigeration ◽  
Principal Points ◽  
And Performance

The creation of new age refrigerants might be the answer to the issue of an Earth-wide rise in temperature. Hence, while choosing new refrigerants a careful process is required. The general effect of any refrigerant substance on global warming, energy efficiency, ozone depletion, cost-effectiveness, chemical stability, and safety ought to be assessed. This paper sums up the experimental and numerical investigations directed with the globally accepted R1234yf refrigerant. The paper’s principal points are to assess the capability of the hydro-fluoro-olefin (HFO) refrigerant mainly R1234yf utilized in the refrigeration system (vapor compression systems, domestic refrigeration system) and to explore its utilization as an eco-friendly refrigerant. In the vapor compression refrigeration system, the cooling capacity and coefficient of performance of R1234yf are found to be less, 9% and 11%, respectively compared to that of R134a. But the power consumption of the system with R1234yf increased between 1.6% and 6.7% when compared to R134a. This paper likewise assists with recognizing the gap in the past research works and explores the possibilities for additional works.

scholarly journals COP enhancement of vapour compression refrigeration system using dedicated mechanical subcooling cycle

2020 ◽  
Vol 39 (3) ◽  
pp. 776-784
Author(s):  
T.S. Mogaji ◽  
A. Awolala ◽  
O.Z. Ayodeji ◽  
P.B. Mogaji ◽  
D.E. Philip
Keyword(s):  
System Performance ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Condensation Temperature ◽  
Refrigeration System ◽  
Wide Range ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration ◽  
Vapour Compression ◽  
Better Than

This study focused on development of an improved vapour compression refrigeration system (IVCR system). Dedicated mechanical subcooling cycle is employed in attaining the developed IVCR system. The system is composed of two cycles cascade refrigeration system working with R134a. It consists of a rectangular shape with total storage space of 0.582 m3, made of galvanized mild steel and internally insulated with 0.05 m polystyrene foam. Tests under a wide range operating temperature conditions were carried out on the developed IVCR system. Performance evaluation of the system was characterized in terms of cooling capacity and coefficient of performance (COP). Experimental results showed that the COP of the subcooled system improved better than that of the main system from 18.0% to about 33.5% over an evaporating temperature range of -10 to 30oC. It can be concluded that the use of dedicated sub cooling cycle in VCR system is more efficient and suitable for the betterment of thermal system performance. Keywords: Vapour compression Refrigeration system, Coefficient of performance, dedicated subcooled system, Condensation temperature, Evaporation temperature.

Effect of Hydrofluorocarbons and Hydrofluoroolefins in a Household Refrigerator as a Substitute for R134a

2019 ◽  
Vol 969 ◽  
pp. 199-204
Author(s):  
Shaik Mohammad Hasheer ◽  
Kolla Srinivas
Keyword(s):  
Cooling Capacity ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Condensation Temperature ◽  
Outlet Temperature ◽  
Refrigeration System ◽  
Volumetric Cooling ◽  
Work Done ◽  
Theoretical Results ◽  
Hfc 152A

Now a days R134a can be used in domestic refrigerators and in air conditioning of automobiles. As per Kyoto protocol the usage of R134a is restricted due to their higher GWP value. The GWP value of this refrigerant is around 1430. So in this article, thermodynamic analysis of HFC-152a, HFO refrigerants-1234ze(E) and 1234yf was done in a household refrigeration system as direct substitute to HFC-134a.The performance of the household refrigerator was compared in terms of outlet temperature of the compressor, volumetric cooling capacity (VCC), refrigeration effect, work done by the compressor and coefficient of performance (COP). The entire analysis is carried out at various operating conditions of condenser and evaporator temperatures i.e. condensation temperature of 25°C,35°C & 45°C and evaporating temperatures ranging between −20°C to 10°C.From the theoretical results, it can be concluded that R1234yf can be used as a direct substitute to R134a.

scholarly journals Numerical Study of Integrated Solar Photovoltaic–Thermal Module with a Refrigeration System for Air-Conditioning and Hot Water Production under the Tropical Climate Conditions of Singapore

2018 ◽  
Vol 26 (03) ◽  
pp. 1850021 ◽  
Author(s):  
Swapnil Dubey ◽  
Alison Subiantoro
Keyword(s):  
Air Conditioning ◽  
Numerical Study ◽  
Power Saving ◽  
Tropical Climate ◽  
Cooling Capacity ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Solar Photovoltaic ◽  
Refrigeration System ◽  
Climate Conditions

Thermal systems of buildings in the tropics are highly energy intensive. In this study, a novel integrated solar photovoltaic–thermal–refrigeration (PVTR) system used to produce hot water and air-conditioning in the tropical climate conditions of Singapore was analyzed. A dynamic simulation model was formulated for the analysis. Mathematical models were developed for the PV sandwich attached with a solar flat plate collector and for the main components of the refrigeration system. Thorough investigation of the electrical and thermal performances of the system were conducted through the analysis of coefficient of performance (COP), cooling capacity, water temperature and heat capacity in water heater, photovoltaic (PV) module temperature and PV efficiency. The results show that attractive electrical and thermal performance can be achieved with a maximum annual cooling COP of 9.8 and a heating COP of 11.3. The PV efficiency and power saving were 14% and 53%, respectively. The annual cooling, heating and PV energy produced were 9.7, 15.6 and 1.6[Formula: see text]MWh, respectively. The financial payback period of the system was 3.2 years and greenhouse gas (GHG) emission reduction annually was 12.6 tons of CO2 equivalents (tCO2e).

An Experimental Investigation of Steam Ejector Refrigeration Systems

2011 ◽  
Author(s):  
J. M. Dong ◽  
D. A. Pounds ◽  
P. Cheng ◽  
H. B. Ma ◽  
X. X. Pan
Keyword(s):  
Cooling Capacity ◽  
Back Pressure ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Operation Temperature ◽  
Steam Ejector ◽  
Mixing Chamber ◽  
Flow Mechanisms ◽  
Ejector System ◽  
Temperature And Pressure

A steam ejector refrigeration system with a movable primary nozzle was developed in order to determine the nozzle exit position (NXP) effect on the coefficient of performance (COP). Experimental results show that an optimum NXP exists for the ejector system investigated herein. In addition, the effects of the operation temperature, diffuser size, nozzle throat diameter, and structure of mixing chamber on the COP and cooling capacity were conducted experimentally. It was found that the critical condenser pressure and COP can be increased by increasing the low-temperature-evaporator (LTE) temperature and pressure. Although an increase of the high-temperature-evaporator (HTE) can increase the critical condenser pressure, the system COP did not increase as the HTE temperature increased. While the diffuser size significantly affected the critical back pressure, it had almost no effect on the system COP. A finned mixing chamber was tested at NXP = 0mm and NXP = 36mm. Compared with the regular mixing chamber, the finned mixing chamber can increase the critical back pressure. The results provide a better understanding of heat transfer and fluid flow mechanisms occurring in a steam ejector refrigeration system.

Sign in / Sign up

Export Citation Format

Share Document