The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a fast publication schedule whilst maintaining rigorous peer review the use of recommended electronic formats for article delivery expedites the process All submitted research articles are subjected to immediate rapid screening by the editors consultation with the Editorial Board or others working in the field as appropriate to ensure they are likely to be the level of interest and importance appropriate for the journal.
The document summarizes an experimental investigation on the performance of an air conditioner using R32 refrigerant. It begins with an abstract describing the refrigerant comparison experiment conducted on a 1.5 ton capacity air conditioning system using R22, R134a, and R32. Performance parameters like coefficient of performance, mass flow rate, and power to the compressor were calculated. The results and simulations showed R32 to be the most efficient refrigerant for retrofitting air conditioning systems due to its lower global warming potential and atmospheric lifetime compared to R22.
Thermodynamic analysis of vapour compression refrigeration system using alte...IOSR Journals
This document discusses thermodynamic analysis of alternative refrigerants for vapor compression refrigeration systems. It aims to analyze the environmental and energy consumption impacts of various refrigerants. The document defines key terms like ozone depletion potential and global warming potential. It then analyzes several potential refrigerant alternatives to R22 and R134a like propane, isobutane, R410a, R407c, and a mixture called MO9. The thermodynamic properties of these refrigerants are obtained from software and their coefficients of performance are compared. The analysis found that MO9 shows potential as a suitable substitute for R134a in new and retrofit systems due to its performance and lower environmental impact.
IRJET - Design and Development of Vapour Compression Refrigeration System usi...IRJET Journal
This document describes the design and development of a vapor compression refrigeration system using a liquid heat exchanger. The system uses refrigerant blends of R600a and R290 or HFO-1234yf to increase the system's coefficient of performance (COP) while reducing global warming and ozone depletion potential compared to traditional systems using R134a. Using a liquid heat exchanger reduces the load on the compressor, allowing for greater cooling effect with lower energy input and less environmental harm. Testing confirmed the new system achieved a COP increase while lowering global warming potential to around 4, compared to 1300 for R134a, and maintaining an ozone depletion potential of zero.
IJREI_Thermodynamic study of R134a in Vapour Compression Refrigeration System...Husain Mehdi
Thermodynamic analysis of an ideal vapour compression refrigeration system is done using refrigerants R134a.This Energy-Exergy analysis is carried out by developed mathematical model. Various parameters are numerically computed are first law efficiency in terms of coefficient of performance (COP) of the system both ideal case and actual experimental and exergetic efficiency and exergy destruction ratio have been computed . The eco-friendly R134a refrigerant gives lower COP than R22. Comparing with R22, R134a takes more compressor power and second law efficiency (exergetic efficiency) of VCRS is also lower than using R22. Due to higher GWP and ODP of R22, R134a can be used for domestic / commercial and industrial applications.
Performance Evaluation of Domestic Refrigerator Using Hc-12a Refrigerant as a...theijes
This document summarizes an experimental study that evaluated the performance of HC-12a (a hydrocarbon refrigerant mixture) as an alternative to R134a in a domestic refrigerator. The refrigerator's performance was tested using each refrigerant and results for temperature, coefficient of performance (COP), energy consumption, and other metrics were compared. Testing showed HC-12a had a higher COP, less energy consumption, and achieved temperature targets faster than R134a. Overall the study found HC-12a performed better than R134a and could be used as a replacement without system modifications.
This document compares the performance of eco-friendly refrigerants R-507, R-407c, and R404a for retrofitting an R-12 vapor compression refrigeration system. It provides thermodynamic property correlations for these refrigerants and analyzes the coefficient of performance (COP) and compressor volumetric efficiency of a 1-ton refrigeration unit using each refrigerant. The results show the COP and efficiency are nearly the same for R-134a, R-507, R404a and R-407c as for R-12, indicating these refrigerants' suitability for retrofitting existing R-12 systems. In conclusion, retrofitting with these refrigerants is a viable option to phase
IRJET- R134a Refrigerant in Vapour Compression Cycle: A Review PaperIRJET Journal
This document provides a review of R134a refrigerant used in vapor compression cycles. It discusses the properties and environmental impacts of R134a including its zero ozone depletion potential but relatively high global warming potential. The document then reviews potential alternative refrigerants to R134a such as CO2, HFC-152a, R32, and R152a. It evaluates their physical and chemical properties including boiling points, ozone depletion potentials, and global warming potentials. The document aims to identify efficient, eco-friendly, and safe refrigerants that can be used as alternatives to R134a in the future.
Performance Evaluation of Domestic Refrigerator Using Eco-Friendly Refrigeran...IRJET Journal
This document provides a review of research on using eco-friendly refrigerants in domestic refrigerators. It begins with an abstract that outlines comparing the performance of a refrigerator using R-134a, a mixture of propane R290 and isobutene R600a, and incorporating a condenser fan and acrylic door. The document then reviews literature on experiments evaluating the performance of refrigerators using alternative refrigerants like hydrocarbon mixtures, R152a, R600a, and HC-12a compared to R-134a. Key findings from the literature include improved COP and reduced energy consumption when using alternative refrigerants. The proposed work is to experimentally evaluate the performance of a refrigerator using a mixture of R290 and
The document summarizes an experimental investigation on the performance of an air conditioner using R32 refrigerant. It begins with an abstract describing the refrigerant comparison experiment conducted on a 1.5 ton capacity air conditioning system using R22, R134a, and R32. Performance parameters like coefficient of performance, mass flow rate, and power to the compressor were calculated. The results and simulations showed R32 to be the most efficient refrigerant for retrofitting air conditioning systems due to its lower global warming potential and atmospheric lifetime compared to R22.
Thermodynamic analysis of vapour compression refrigeration system using alte...IOSR Journals
This document discusses thermodynamic analysis of alternative refrigerants for vapor compression refrigeration systems. It aims to analyze the environmental and energy consumption impacts of various refrigerants. The document defines key terms like ozone depletion potential and global warming potential. It then analyzes several potential refrigerant alternatives to R22 and R134a like propane, isobutane, R410a, R407c, and a mixture called MO9. The thermodynamic properties of these refrigerants are obtained from software and their coefficients of performance are compared. The analysis found that MO9 shows potential as a suitable substitute for R134a in new and retrofit systems due to its performance and lower environmental impact.
IRJET - Design and Development of Vapour Compression Refrigeration System usi...IRJET Journal
This document describes the design and development of a vapor compression refrigeration system using a liquid heat exchanger. The system uses refrigerant blends of R600a and R290 or HFO-1234yf to increase the system's coefficient of performance (COP) while reducing global warming and ozone depletion potential compared to traditional systems using R134a. Using a liquid heat exchanger reduces the load on the compressor, allowing for greater cooling effect with lower energy input and less environmental harm. Testing confirmed the new system achieved a COP increase while lowering global warming potential to around 4, compared to 1300 for R134a, and maintaining an ozone depletion potential of zero.
IJREI_Thermodynamic study of R134a in Vapour Compression Refrigeration System...Husain Mehdi
Thermodynamic analysis of an ideal vapour compression refrigeration system is done using refrigerants R134a.This Energy-Exergy analysis is carried out by developed mathematical model. Various parameters are numerically computed are first law efficiency in terms of coefficient of performance (COP) of the system both ideal case and actual experimental and exergetic efficiency and exergy destruction ratio have been computed . The eco-friendly R134a refrigerant gives lower COP than R22. Comparing with R22, R134a takes more compressor power and second law efficiency (exergetic efficiency) of VCRS is also lower than using R22. Due to higher GWP and ODP of R22, R134a can be used for domestic / commercial and industrial applications.
Performance Evaluation of Domestic Refrigerator Using Hc-12a Refrigerant as a...theijes
This document summarizes an experimental study that evaluated the performance of HC-12a (a hydrocarbon refrigerant mixture) as an alternative to R134a in a domestic refrigerator. The refrigerator's performance was tested using each refrigerant and results for temperature, coefficient of performance (COP), energy consumption, and other metrics were compared. Testing showed HC-12a had a higher COP, less energy consumption, and achieved temperature targets faster than R134a. Overall the study found HC-12a performed better than R134a and could be used as a replacement without system modifications.
This document compares the performance of eco-friendly refrigerants R-507, R-407c, and R404a for retrofitting an R-12 vapor compression refrigeration system. It provides thermodynamic property correlations for these refrigerants and analyzes the coefficient of performance (COP) and compressor volumetric efficiency of a 1-ton refrigeration unit using each refrigerant. The results show the COP and efficiency are nearly the same for R-134a, R-507, R404a and R-407c as for R-12, indicating these refrigerants' suitability for retrofitting existing R-12 systems. In conclusion, retrofitting with these refrigerants is a viable option to phase
IRJET- R134a Refrigerant in Vapour Compression Cycle: A Review PaperIRJET Journal
This document provides a review of R134a refrigerant used in vapor compression cycles. It discusses the properties and environmental impacts of R134a including its zero ozone depletion potential but relatively high global warming potential. The document then reviews potential alternative refrigerants to R134a such as CO2, HFC-152a, R32, and R152a. It evaluates their physical and chemical properties including boiling points, ozone depletion potentials, and global warming potentials. The document aims to identify efficient, eco-friendly, and safe refrigerants that can be used as alternatives to R134a in the future.
Performance Evaluation of Domestic Refrigerator Using Eco-Friendly Refrigeran...IRJET Journal
This document provides a review of research on using eco-friendly refrigerants in domestic refrigerators. It begins with an abstract that outlines comparing the performance of a refrigerator using R-134a, a mixture of propane R290 and isobutene R600a, and incorporating a condenser fan and acrylic door. The document then reviews literature on experiments evaluating the performance of refrigerators using alternative refrigerants like hydrocarbon mixtures, R152a, R600a, and HC-12a compared to R-134a. Key findings from the literature include improved COP and reduced energy consumption when using alternative refrigerants. The proposed work is to experimentally evaluate the performance of a refrigerator using a mixture of R290 and
IRJET- Performance Analysis of R-134a with ECO Friendly Refrigerant in Va...IRJET Journal
This document summarizes research on alternatives to R134a refrigerant for vapor compression refrigeration systems. It begins with background on the phase-out of ozone-depleting and high-global warming potential refrigerants. The document then reviews literature on experimental analyses comparing R134a to potential replacement refrigerants like hydrocarbon and HFC mixtures. Two refrigerant mixtures, M1 and M2, are identified as having performance comparable to R134a but with lower global warming potential. M2 is suggested as the best replacement based on its performance and low global warming potential.
IRJET- CO2 as a Refrigerant in Supermarket Refrigeration Systems: A ReviewIRJET Journal
This document reviews the use of carbon dioxide (CO2) as a refrigerant in supermarket refrigeration systems. It discusses how CO2 is a natural refrigerant that offers advantages over conventional refrigerants like CFCs and HCFCs in terms of being non-toxic, non-flammable, and having no ozone depletion or low global warming potential. The document outlines the ideal properties of CO2 as a refrigerant, including its thermal, physical and chemical characteristics. It also discusses safety aspects and the advantages and disadvantages of using CO2, such as its low critical temperature and high working pressure. The document concludes by suggesting areas for future work to improve CO2 refrigeration technology.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a study on the parametric design of a plain fin and tube evaporator using CO2 as the refrigerant. The authors present a methodology to simulate the thermal performance of a cross-counter flow evaporator using Engineering Equation Solver. Operating conditions for an initial evaporator design are provided. Assumptions made in the simulation include steady-state heat transfer and negligible pressure drop. The overall conductance is calculated based on thermal resistances of refrigerant-side convection, tube conduction, and air-side convection. Refrigerant heat transfer coefficients are determined using an existing flow boiling model for CO2. Parameters like tube count, surface areas, and fin efficiency are also considered.
This document discusses refrigerants, including their classification and properties. It describes how refrigerants are selected based on their thermodynamic properties, environmental impact, and cost. Common refrigerants like CFCs, HCFCs, and HFCs are outlined along with their ozone depletion potential and global warming potential. Alternative natural refrigerants such as ammonia, hydrocarbons, and carbon dioxide are presented as more environmentally-friendly options.
This document reviews the performance enhancement of nano-refrigerants, which involve combining refrigerants with nanoparticles. Studies have shown that nano-refrigerants significantly enhance heat transfer capabilities compared to conventional refrigerants. Specifically, the document examines the dispersion of 50 nm alumina (Al2O3) nanoparticles within R-134a refrigerant to elevate its heat transfer efficiency and thermo-physical properties beyond conventional refrigerants. The results revealed a substantial increase in both cooling capacity and thermal efficiency of vapor compression refrigeration systems when using the R-134a/Al2O3 nano-refrigerant.
Walid Chakroun - ASHRAE - REFRIGERANTI E LORO USO RESPONSABILECentro Studi Galileo
The document discusses refrigerants and their responsible use according to ASHRAE's position. It provides an overview of refrigerants and alternative technologies like CO2, hydrocarbons, and ammonia. It addresses issues for consideration like high ambient temperatures challenges, remaining open questions, and recommendations for future research on balancing safety, efficiency, cost and environmental impacts of refrigerants.
This document presents a theoretical analysis of the performance of a vapor compression refrigeration system using different refrigerants: R-12, R134a, and R1234yf. The analysis uses a computational model based on the first law of thermodynamics to investigate the effects of evaporating temperature, subcooling, condenser temperature, and liquid-vapor heat exchanger effectiveness on the system's coefficient of performance and refrigerating capacity. The results show that R1234yf has the highest relative capacity increase with increased subcooling and the highest percentage increase in COP. R134a requires the most compressor work. R1234yf is identified as a promising alternative to R134a due to its low global warming potential
This document presents a theoretical analysis of a vapor compression refrigeration system using refrigerants R-22, R407C, and R410A. Equations are developed based on the first and second laws of thermodynamics to model the system and analyze parameters such as coefficient of performance (COP), exergetic efficiency, and exergy destruction ratio (EDR). Results show R410A has the highest relative capacity change with increased subcooling degree and COP increase with higher evaporator temperatures. Exergetic efficiency is maximized and EDR minimized at evaporator temperatures of -30 to -35°C. R410A performance is better than R407C based on the thermodynamic analysis.
This document reviews 10 research papers on alternative refrigerants to replace chlorofluorocarbons and hydrochlorofluorocarbons. The key points summarized are:
1) Various studies tested propane, propane/butane mixtures, and hydrofluorocarbon/hydrocarbon mixtures as potential refrigerants and found they provided performance similar to or better than CFC-12 in terms of coefficient of performance and cooling capacity.
2) Simulation and experimental studies identified propane/butane mixtures with 60% propane as the best drop-in replacement for R-134a, with higher performance under normal and tropical conditions.
3) Retrofitting domestic refrigerators with a hydrocarbon mixture of R-290 and
This document proposes and analyzes four new ternary refrigerant mixtures consisting of low GWP synthetic and natural refrigerants. The mixtures were theoretically tested in cooling cycles at evaporating temperatures of 0 and -30°C with a constant 30°C condensing temperature. The mixtures consisted of combinations of R32, R41, R161, R152a, R1234ze(E), R1234yf, R1243zf, and RE170. Thermodynamic and operational parameters were used to determine the optimal mixture composition, which was found to be R1234yf–R152a–RE170 with a weight share of 0.1/0.5/0.4. This mixture has the potential
Waste Heat Recovery From Refrigeration PlantIRJET Journal
This document summarizes waste heat recovery from a refrigeration plant condenser. It discusses how the waste heat from a condenser, which is currently released into the environment, can instead be captured and used for applications like water heating. The document then provides technical details on heat transfer methods, refrigerants, and vapor compression refrigeration systems. It analyzes using the condenser waste heat from a 30-ton refrigeration plant to heat water up to 50°C, which could then be used for low-temperature household or industrial purposes. Capturing this waste heat improves overall system efficiency and reduces environmental impacts.
Experimental Evaluation of Refrigerant Mixtures as Substitutes for HFC134aIOSRJMCE
The document describes an experimental evaluation of refrigerant mixtures as substitutes for HFC134a in a 200 liter domestic refrigeration system. The study tested mixtures of propane (R290) and butane (R600a) at different mass ratios, including R600a/R290 at ratios of 70/30, 60/40, and 50/50 by weight percent. The results showed that the R600a/R290 mixture at a ratio of 60/40 performed better than the other mixtures and HFC134a in terms of refrigerating effect and coefficient of performance. Specifically, the 60/40 mixture achieved a refrigerating effect 10% higher than HFC134a at -5°C and 35.
Experimental Study of R134a, R406A and R600a Blends as Alternative To Freon 12IOSR Journals
: In the vent of chlorofluorocarbons (CFCs) phase-out, identify long term alternative to meet
requirements in respect of system performance and service is an important area of research in the refrigeration
and are conditioning industry. This work focuses on experimental study of the performance of eco-friendly
refrigerant mixtures. Mixtures of three existing refrigerants namely: R600a (n-butane), R134a (1,1,
1,2,tetrafluoroethane) and R406A (55%R22/4%R600a/41%R142b)were considered for this research. These
refrigerants were mixed in various ratios, studied and compared with R-12 (dichlorodifluoromethane) which
was used as the control for the experimentation. The rig used in the experimentation is a 2 hp (1.492 kW)
domestic refrigerator, designed based on condensing and evaporating temperatures. The rig was
tested with R-12, and blends of the three refrigerants. During the experimentation, both evaporator and
condenser temperatures were measured. These were used to determine the heat absorbed in evaporator
and the heat rejected incondenser . The results show that R134a/R600a mixture in the ratio 50:50 can
be used as alternative to R-12 in domestic refrigerators, without the necessity of changing the compressor
lubricating oil. At and , R-12 gives a COP of 2.08 while 50:50 blend of R134a/R600a
gives a COP of 2.30 under the same operating conditions
CO2 As A Future Refrigerant - An Aranca ReportAranca
As CO2 based refrigeration technology grows in both viability and availability, it shows appreciable promise to reduce atmospheric pollution by Ammonia and other often potent greenhouse gases. Read this Aranca report to know how alternative energy sector is gearing for the challenge.
EFFECT OF CONCENTRATION OF LITHIUM BROMIDE MIXTURE ON COP FOR SINGLE EFFECT L...Editor IJMTER
In this paper effect of concentration of lithium bromide mixture on Co-efficient of
performance (COP) for single effect LiBr-H2O absorption chillers is calculated. Then find out how
the cop varies with the concentration of lithium bromide. For finding cop temperature of condenser
varies and the other parameter (temperature of generator, temperature of absorber, capacity of
evaporator, temperature of evaporator temperature of absorber) remains constant. Optimal value of
COP obtained 0.65 varying temperature of condenser.
This document discusses refrigerants used in refrigeration systems. It begins by defining refrigerants and their role in absorbing and transmitting heat. It then classifies refrigerants as primary or secondary and discusses their properties. The document outlines several criteria for selecting refrigerants, including thermodynamic, environmental, safety and economic factors. It also describes the numbering system used to designate refrigerants and compares common synthetic and natural refrigerants. The overall aim is to explain the important considerations for choosing suitable refrigerants.
Experimental Performance Evaluation of R152a to replace R134a in Vapour Compr...IJMER
The performance of heat transfer is one of the most important research areas in the field
of thermal engineering. There are a large number of refrigerants, which are used to transfer heat from
low temperature reservoir to high temperature reservoir by using vapour compression refrigeration
system. There are various obstacles faced in working of different refrigerants due to their environmental
impact (CFC, HCFC), toxicity (NH3), flammability (HC) and high pressure (CO2); which makes them
more hazardous than other working fluids according to safety and environmental issues.
Experimentation is conducted to observe the performance of Hydro-fluorocarbon (HFC) refrigerants
(R134a and R152a) in vapour compression refrigeration. Value of average refrigerating effect for R152a
is about 57% more than that of R134a . Average pressure ratio for R152a was 18.92% higher than that of
R134a. In this result, R152a has emerged as the most energy efficient refrigerant among both the
investigated refrigerants being the one that exhibited the lowest power consumption per ton of
refrigeration with the average value of 13.23% less than that of R134a.The COP of R152a obtain is
higher than R134a by 3.769% .As a result, R152a could be used as a drop-in replacement for R134a in
vapour compression refrigeration system. R152a offers the best desirable environmental requirements;
zero Ozone Depleting Potential (ODP) and 120 Global Warming Potential (GWP).
This document discusses replacing the refrigerant R134a with R152a in a vapor compression refrigeration system. It first provides background on vapor compression refrigeration systems and refrigerants such as R134a. It then summarizes an experiment comparing the performance of R134a and R152a. The results found that R152a had 57% higher refrigerating effect, 18.92% higher pressure ratio, and 13.23% lower power consumption than R134a. R152a also had a 3.769% higher COP than R134a. Therefore, the document concludes that R152a can be used as a drop-in replacement for R134a in vapor compression refrigeration systems as it has better environmental
Simulation of hydrodesulphurization (hds) unit of kaduna refining and petroch...Alexander Decker
This document summarizes a study that simulated a hydrodesulphurization (HDS) unit of Kaduna Refining and Petrochemical Company Limited using ASPEN HYSYS software. The simulation was based on parameters like mass flow rates, temperatures and pressures obtained from the Linear Alkyl Benzene plant. The simulation involved four reactors in series to remove impurities like sulfur, nitrogen and oxygen from raw kerosene. After simulation, the treated kerosene stream showed approximately zero mole fractions of these impurities. The simulation generated data on the reaction and stripping sections that were analyzed.
This document discusses the use of hydrocarbon refrigerants as an alternative to ozone depleting substances in Jamaica. It provides an overview of hydrocarbon refrigerant properties and safety considerations for use. Test results from refrigerant changeouts in Jamaica show average energy savings of 20% from switching to R-22a. Widespread adoption of natural refrigerants in Jamaica could yield significant economic benefits and annual cost savings for businesses through reduced cooling costs. Hydrocarbon refrigerants are presented as a viable long-term replacement for CFCs, HCFCs, and HFCs.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
IRJET- Performance Analysis of R-134a with ECO Friendly Refrigerant in Va...IRJET Journal
This document summarizes research on alternatives to R134a refrigerant for vapor compression refrigeration systems. It begins with background on the phase-out of ozone-depleting and high-global warming potential refrigerants. The document then reviews literature on experimental analyses comparing R134a to potential replacement refrigerants like hydrocarbon and HFC mixtures. Two refrigerant mixtures, M1 and M2, are identified as having performance comparable to R134a but with lower global warming potential. M2 is suggested as the best replacement based on its performance and low global warming potential.
IRJET- CO2 as a Refrigerant in Supermarket Refrigeration Systems: A ReviewIRJET Journal
This document reviews the use of carbon dioxide (CO2) as a refrigerant in supermarket refrigeration systems. It discusses how CO2 is a natural refrigerant that offers advantages over conventional refrigerants like CFCs and HCFCs in terms of being non-toxic, non-flammable, and having no ozone depletion or low global warming potential. The document outlines the ideal properties of CO2 as a refrigerant, including its thermal, physical and chemical characteristics. It also discusses safety aspects and the advantages and disadvantages of using CO2, such as its low critical temperature and high working pressure. The document concludes by suggesting areas for future work to improve CO2 refrigeration technology.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a study on the parametric design of a plain fin and tube evaporator using CO2 as the refrigerant. The authors present a methodology to simulate the thermal performance of a cross-counter flow evaporator using Engineering Equation Solver. Operating conditions for an initial evaporator design are provided. Assumptions made in the simulation include steady-state heat transfer and negligible pressure drop. The overall conductance is calculated based on thermal resistances of refrigerant-side convection, tube conduction, and air-side convection. Refrigerant heat transfer coefficients are determined using an existing flow boiling model for CO2. Parameters like tube count, surface areas, and fin efficiency are also considered.
This document discusses refrigerants, including their classification and properties. It describes how refrigerants are selected based on their thermodynamic properties, environmental impact, and cost. Common refrigerants like CFCs, HCFCs, and HFCs are outlined along with their ozone depletion potential and global warming potential. Alternative natural refrigerants such as ammonia, hydrocarbons, and carbon dioxide are presented as more environmentally-friendly options.
This document reviews the performance enhancement of nano-refrigerants, which involve combining refrigerants with nanoparticles. Studies have shown that nano-refrigerants significantly enhance heat transfer capabilities compared to conventional refrigerants. Specifically, the document examines the dispersion of 50 nm alumina (Al2O3) nanoparticles within R-134a refrigerant to elevate its heat transfer efficiency and thermo-physical properties beyond conventional refrigerants. The results revealed a substantial increase in both cooling capacity and thermal efficiency of vapor compression refrigeration systems when using the R-134a/Al2O3 nano-refrigerant.
Walid Chakroun - ASHRAE - REFRIGERANTI E LORO USO RESPONSABILECentro Studi Galileo
The document discusses refrigerants and their responsible use according to ASHRAE's position. It provides an overview of refrigerants and alternative technologies like CO2, hydrocarbons, and ammonia. It addresses issues for consideration like high ambient temperatures challenges, remaining open questions, and recommendations for future research on balancing safety, efficiency, cost and environmental impacts of refrigerants.
This document presents a theoretical analysis of the performance of a vapor compression refrigeration system using different refrigerants: R-12, R134a, and R1234yf. The analysis uses a computational model based on the first law of thermodynamics to investigate the effects of evaporating temperature, subcooling, condenser temperature, and liquid-vapor heat exchanger effectiveness on the system's coefficient of performance and refrigerating capacity. The results show that R1234yf has the highest relative capacity increase with increased subcooling and the highest percentage increase in COP. R134a requires the most compressor work. R1234yf is identified as a promising alternative to R134a due to its low global warming potential
This document presents a theoretical analysis of a vapor compression refrigeration system using refrigerants R-22, R407C, and R410A. Equations are developed based on the first and second laws of thermodynamics to model the system and analyze parameters such as coefficient of performance (COP), exergetic efficiency, and exergy destruction ratio (EDR). Results show R410A has the highest relative capacity change with increased subcooling degree and COP increase with higher evaporator temperatures. Exergetic efficiency is maximized and EDR minimized at evaporator temperatures of -30 to -35°C. R410A performance is better than R407C based on the thermodynamic analysis.
This document reviews 10 research papers on alternative refrigerants to replace chlorofluorocarbons and hydrochlorofluorocarbons. The key points summarized are:
1) Various studies tested propane, propane/butane mixtures, and hydrofluorocarbon/hydrocarbon mixtures as potential refrigerants and found they provided performance similar to or better than CFC-12 in terms of coefficient of performance and cooling capacity.
2) Simulation and experimental studies identified propane/butane mixtures with 60% propane as the best drop-in replacement for R-134a, with higher performance under normal and tropical conditions.
3) Retrofitting domestic refrigerators with a hydrocarbon mixture of R-290 and
This document proposes and analyzes four new ternary refrigerant mixtures consisting of low GWP synthetic and natural refrigerants. The mixtures were theoretically tested in cooling cycles at evaporating temperatures of 0 and -30°C with a constant 30°C condensing temperature. The mixtures consisted of combinations of R32, R41, R161, R152a, R1234ze(E), R1234yf, R1243zf, and RE170. Thermodynamic and operational parameters were used to determine the optimal mixture composition, which was found to be R1234yf–R152a–RE170 with a weight share of 0.1/0.5/0.4. This mixture has the potential
Waste Heat Recovery From Refrigeration PlantIRJET Journal
This document summarizes waste heat recovery from a refrigeration plant condenser. It discusses how the waste heat from a condenser, which is currently released into the environment, can instead be captured and used for applications like water heating. The document then provides technical details on heat transfer methods, refrigerants, and vapor compression refrigeration systems. It analyzes using the condenser waste heat from a 30-ton refrigeration plant to heat water up to 50°C, which could then be used for low-temperature household or industrial purposes. Capturing this waste heat improves overall system efficiency and reduces environmental impacts.
Experimental Evaluation of Refrigerant Mixtures as Substitutes for HFC134aIOSRJMCE
The document describes an experimental evaluation of refrigerant mixtures as substitutes for HFC134a in a 200 liter domestic refrigeration system. The study tested mixtures of propane (R290) and butane (R600a) at different mass ratios, including R600a/R290 at ratios of 70/30, 60/40, and 50/50 by weight percent. The results showed that the R600a/R290 mixture at a ratio of 60/40 performed better than the other mixtures and HFC134a in terms of refrigerating effect and coefficient of performance. Specifically, the 60/40 mixture achieved a refrigerating effect 10% higher than HFC134a at -5°C and 35.
Experimental Study of R134a, R406A and R600a Blends as Alternative To Freon 12IOSR Journals
: In the vent of chlorofluorocarbons (CFCs) phase-out, identify long term alternative to meet
requirements in respect of system performance and service is an important area of research in the refrigeration
and are conditioning industry. This work focuses on experimental study of the performance of eco-friendly
refrigerant mixtures. Mixtures of three existing refrigerants namely: R600a (n-butane), R134a (1,1,
1,2,tetrafluoroethane) and R406A (55%R22/4%R600a/41%R142b)were considered for this research. These
refrigerants were mixed in various ratios, studied and compared with R-12 (dichlorodifluoromethane) which
was used as the control for the experimentation. The rig used in the experimentation is a 2 hp (1.492 kW)
domestic refrigerator, designed based on condensing and evaporating temperatures. The rig was
tested with R-12, and blends of the three refrigerants. During the experimentation, both evaporator and
condenser temperatures were measured. These were used to determine the heat absorbed in evaporator
and the heat rejected incondenser . The results show that R134a/R600a mixture in the ratio 50:50 can
be used as alternative to R-12 in domestic refrigerators, without the necessity of changing the compressor
lubricating oil. At and , R-12 gives a COP of 2.08 while 50:50 blend of R134a/R600a
gives a COP of 2.30 under the same operating conditions
CO2 As A Future Refrigerant - An Aranca ReportAranca
As CO2 based refrigeration technology grows in both viability and availability, it shows appreciable promise to reduce atmospheric pollution by Ammonia and other often potent greenhouse gases. Read this Aranca report to know how alternative energy sector is gearing for the challenge.
EFFECT OF CONCENTRATION OF LITHIUM BROMIDE MIXTURE ON COP FOR SINGLE EFFECT L...Editor IJMTER
In this paper effect of concentration of lithium bromide mixture on Co-efficient of
performance (COP) for single effect LiBr-H2O absorption chillers is calculated. Then find out how
the cop varies with the concentration of lithium bromide. For finding cop temperature of condenser
varies and the other parameter (temperature of generator, temperature of absorber, capacity of
evaporator, temperature of evaporator temperature of absorber) remains constant. Optimal value of
COP obtained 0.65 varying temperature of condenser.
This document discusses refrigerants used in refrigeration systems. It begins by defining refrigerants and their role in absorbing and transmitting heat. It then classifies refrigerants as primary or secondary and discusses their properties. The document outlines several criteria for selecting refrigerants, including thermodynamic, environmental, safety and economic factors. It also describes the numbering system used to designate refrigerants and compares common synthetic and natural refrigerants. The overall aim is to explain the important considerations for choosing suitable refrigerants.
Experimental Performance Evaluation of R152a to replace R134a in Vapour Compr...IJMER
The performance of heat transfer is one of the most important research areas in the field
of thermal engineering. There are a large number of refrigerants, which are used to transfer heat from
low temperature reservoir to high temperature reservoir by using vapour compression refrigeration
system. There are various obstacles faced in working of different refrigerants due to their environmental
impact (CFC, HCFC), toxicity (NH3), flammability (HC) and high pressure (CO2); which makes them
more hazardous than other working fluids according to safety and environmental issues.
Experimentation is conducted to observe the performance of Hydro-fluorocarbon (HFC) refrigerants
(R134a and R152a) in vapour compression refrigeration. Value of average refrigerating effect for R152a
is about 57% more than that of R134a . Average pressure ratio for R152a was 18.92% higher than that of
R134a. In this result, R152a has emerged as the most energy efficient refrigerant among both the
investigated refrigerants being the one that exhibited the lowest power consumption per ton of
refrigeration with the average value of 13.23% less than that of R134a.The COP of R152a obtain is
higher than R134a by 3.769% .As a result, R152a could be used as a drop-in replacement for R134a in
vapour compression refrigeration system. R152a offers the best desirable environmental requirements;
zero Ozone Depleting Potential (ODP) and 120 Global Warming Potential (GWP).
This document discusses replacing the refrigerant R134a with R152a in a vapor compression refrigeration system. It first provides background on vapor compression refrigeration systems and refrigerants such as R134a. It then summarizes an experiment comparing the performance of R134a and R152a. The results found that R152a had 57% higher refrigerating effect, 18.92% higher pressure ratio, and 13.23% lower power consumption than R134a. R152a also had a 3.769% higher COP than R134a. Therefore, the document concludes that R152a can be used as a drop-in replacement for R134a in vapor compression refrigeration systems as it has better environmental
Simulation of hydrodesulphurization (hds) unit of kaduna refining and petroch...Alexander Decker
This document summarizes a study that simulated a hydrodesulphurization (HDS) unit of Kaduna Refining and Petrochemical Company Limited using ASPEN HYSYS software. The simulation was based on parameters like mass flow rates, temperatures and pressures obtained from the Linear Alkyl Benzene plant. The simulation involved four reactors in series to remove impurities like sulfur, nitrogen and oxygen from raw kerosene. After simulation, the treated kerosene stream showed approximately zero mole fractions of these impurities. The simulation generated data on the reaction and stripping sections that were analyzed.
This document discusses the use of hydrocarbon refrigerants as an alternative to ozone depleting substances in Jamaica. It provides an overview of hydrocarbon refrigerant properties and safety considerations for use. Test results from refrigerant changeouts in Jamaica show average energy savings of 20% from switching to R-22a. Widespread adoption of natural refrigerants in Jamaica could yield significant economic benefits and annual cost savings for businesses through reduced cooling costs. Hydrocarbon refrigerants are presented as a viable long-term replacement for CFCs, HCFCs, and HFCs.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
indian journal of pharmaceutical science 21 pdf.pdfnareshkotra
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
This document discusses the pathogenesis and diagnosis of schizophrenia from the perspective of mitochondrial dysfunction and nonlinear dynamics analysis. It summarizes that:
1) Schizophrenia is thought to result from an interplay between genetic and environmental factors that disrupt brain development, and recent research implicates mitochondrial dysfunction caused by disruption of multiple genes.
2) Studies using nonlinear dynamics analysis of EEG signals and other data have found reduced complexity and more linear/regular rhythms in schizophrenia patients compared to controls, indicating lower chaotic dynamics.
3) Quantum biophysical semeiotics clinical evaluation techniques can detect an inherited real risk of schizophrenia even in asymptomatic individuals by examining microvascular function and complexity of oscillations. This allows for early pre-clinical diagnosis
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
This document summarizes a study on job satisfaction among employees of SIDCO (State Industries Promotion Corporation) in Tamil Nadu, India. The study surveyed 254 employees across SIDCO units. It found that most employees were aged 18-36, had nuclear families of 3 or fewer members, lived in urban areas, earned Rs. 20,001-30,000 monthly, and had 0-20 years of experience. The study aimed to understand factors influencing job satisfaction and differences by socioeconomic characteristics. It used questionnaires and statistical analysis to assess relationships between job satisfaction, quality of work life, organizational culture, and employee performance.
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a speed publication schedule with the whilst maintaining rigorous proper review and the use of recommended electronic formats for an article delivery of expedites the process of All submitted research articles are subjected to immediate quick screening by the editors consultation with the Editorial Board or others working in the field as appropriate to ensure that they are alike to be the level of interest and importance of appropriate for the journal.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
international research journal of engineering and technology 3 nov.pdfnareshkotra
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a fast publication schedule whilst maintaining a proper peer review and the use of recommended electronic formats for an article delivery expedites the process of All submitted research articles are subjected to an immediate rapid screening by the editors consultation with the Editorial Board or others working in the field as assure that they are likely to be the level of interest and importance of appropriate for the journal.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
ugc list of approved journals 02 nov.pdfnareshkotra
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
This document summarizes a study on using computational fluid dynamics (CFD) to model and analyze the heat transfer performance of ceramic heat exchangers with different duct cross-sectional shapes (rectangular, elliptical, cylindrical). CFD was used to calculate parameters like temperature distribution, velocity distribution, heat transfer rate, and effectiveness. The predicted heat transfer rate from CFD analysis was found to be 15% higher than theoretical calculations. Analysis showed that cylindrical ducts had the highest effectiveness at 62%, followed by elliptical at 55% and rectangular at 52%. The document also provides background on the need to improve energy efficiency and reduce emissions, and discusses objectives, assumptions, and methodology of the CFD modeling and analysis.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
The International Journal of Mechanical Engineering Research and Technology is an international online journal published by Quarterly offers fast publication schedule with whilst maintaining rigorous peer review. The use of recommended electronic formats for article delivery expedites and the process of All submitted research articles are subjected to immediate rapid screening by the editors consultation with the Editorial Board or others working in the field of appropriate to ensure that they are likely to be the level of interest and importance of appropriate for the journal.
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published a Quarterly offers a fast publication schedule with maintaining a rigorous peer review and the use of recommended electronic formats and articles of delivery expedites and the process of All submitted research articles are subjected to the rapid screening by the editors consultation with the Editorial Board or others working in the field of appropriate to ensure that they are much a like to be the level of interest and importance of appropriate for the journal.
Neuro Quantology is an international, interdisciplinary, open-access, peer-reviewed journal that publishes original research and review articles on the interface between quantum physics and neuroscience. The journal focuses on the exploration of the neural mechanisms underlying consciousness, cognition, perception, and behavior from a quantum perspective. Neuro Quantology is published monthly.
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Many people wonder how long aluminum gutters last. In this ppt, we will cover the lifetime of aluminum gutters, appropriate maintenance procedures, and the advantages of using this material for gutter installation.
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2. Int. J. Mech. Eng. Res. & Tech 2019
ISSN 2454 – 535X www.ijmert.com
Vol. 11, Issue. 3, Sep 2019
PERFORMANCE AND ANALYSIS OF A CONDENSER WITH DIFFERENT
REFRIGERANTS USING CFD
Mr. Menda Santhan Kumar, Mr. P.Chinna ,
Dr. Chollangi Rajesh, Mr A. Anil Kumar
Abstract
R-22 is a very commonly used refrigerant having wide applications. We have a big challenge to
replace R-22 because of HCFCs, which deplete the ozone layer and harmful to the environment. As
per Montreal Protocol we promised to be banned by 2020. Since being an unconventional &non eco-
friendly product it is being replaced by R-134a. Nano Al2O3 gives better performance hence it is
succeeded after R-22. Refrigerant R-134a is currently being used in every sector of industries, as a
part of Nano element it was accepted having multipurpose use in less quantity. Being less in quantity
& economical aspect considered it to be an influencing refrigerant till date. Having Al2O3 a metal
component reduces its efficiency from being heated immediately, thus a new & more improved
world-wide experimented refrigerant R-744 is introduced. Various eco-friendly & non ozone
depleting refrigerant R-744 is manufactured by recycling the Co2 from atmosphere. It does not
consist of any CFCs, hazardous chemicals and also available at cheap rate. Hence it is proving an
efficient & sustainable refrigerant at current era. So, threw the present paper the highlighted study on
compression refrigeration system is discussed.
Keywords: R-22, R-134a, R-744, Co2, CFCs, Al2O3
Introduction
Condensers in use today may fall in either of
two categories: refrigerated or
nonrefrigerated. Non- refrigerated condensers
are widely used as raw material, product,
and/or solvent recovery devices in chemical
process industries. They are frequently used
prior to control devices (e.g., incinerators or
absorbers). Refrigerated condensers are used
as air pollution control devices for treating
emission streams with high VOC
concentrations (usually > 5,000 ppmv) in
applications involving gasoline bulk
terminals, storage, etc. Condenser control
technology is unique in that it not only
reduces emissions to the atmosphere but also
captures or recovers VOCs, potentially for
additional use. Condensation is a separation
technique in which one or more volatile
components of a vapor mixture are separated
from the remaining vapors through saturation
followed by a phase change. The phase
change from gas to liquid can be achieved in
two ways: (a) the system pressure can be
increased at a given temperature, or (b) the
temperature may be lowered at a constant
pressure. In a two-component system where
one of the components is non condensable
(e.g., air), condensation occurs at dew point
(saturation) when the partial pressure of the
volatile compound is equal to its vapor
pressure. The more volatile a compound is
(e.g., the lower the normal boiling point), the
larger the amount that can remain as vapor at
a given temperature; hence the lower the
temperature required for saturation
(condensation). Refrigeration is often
employed to obtain the low temperatures
required for acceptable removal efficiencies.
This chapter is limited to the evaluation of
refrigerated condensation at constant
(atmospheric) pressure.
Department of Mechanical Engineering, Pragati Engineering College,Surampalem ,India
3. The removal efficiency of a
condenser is dependent on the emission
stream characteristics including the nature of
the VOC in question (vapor
pressure/temperature relationship), VOC
concentration, and the type of coolant used.
Any component of any vapor mixture can be
condensed
if brought to a low enough temperature and
allowed to come to equilibrium. The vapor
pressure dependence on temperature for
selected compounds (Erikson, 1980). A
condenser cannot lower the inlet
concentration to levels below the saturation
concentration at the coolant temperature.
Removal efficiencies of approximately 50 to
90 percent can be achieved with coolants
such as chilled water and brine solutions, and
removal efficiencies above 90 percent can be
achieved with ammonia, liquid nitrogen,
chlorofluorocarbons,
hydrochlorofluorocarbons, or
hydrofluorocarbons, depending on the VOC
composition and concentration level of the
emission stream.
Objectives of the study
The main objective is to replace R22
refrigerant which ones released reacts
with the ozone layer,causing significant
damage.
And to analyze and identify better,
efficient & sustainable replacement of
R22 refrigerant among R134A and R
744.
Review of Literature
Dalkilic AS and Wongwises S[1] The study shows
that HCR134a hydrocarbon refrigerant could be an
alternative refrigerant for replacement the existing
R134a refrigerant. Harby K[2] Results of the study
showed that in spite of highly flammable
characteristics, hydrocarbons can offer proper
alternatives to the halogenated refrigerants from the
standpoint of environment impact, energy
efficiency, COP, refrigerant mass, and compressor
temperatures. Pearson SF [3] concluded that R-
134a have better performance than the R-22 also R-
134a have zero ozone depletion potential and less
global warming potential compare to R-22. The
Metal particle of Al2O3 present in R-134a makes
the Refrigerant efficient because of heated
immediately. Another side R-744 which is made by
recycling of CO2 from atmosphere does not have
any CFCs and also not hazardous to atmosphere
also is very efficient refrigerant. R-744 has zero
ODP, lowest GWP, non-toxic, and higher
refrigerant performance than other refrigerants
.Saleh B [4]The paper conclude that the
BACKONE equations of state give generally a good
accuracy for all thermodynamic data of refrigerants
with the advantage of needing only few
experimental data for the determination of its
substance specific parameter.Yoon SH et al. [5] the
paper that the heat transfer coefficients and pressure
drop during the evaporation process of carbon
dioxide in a horizontal tube have been investigated
and At a low mass quality region during
evaporation, heat transfer coefficient increases as
mass quality increases because convective boiling
becomes more dominant. But when mass quality is
greater than a certain value, heat transfer coefficient
tends to decrease.
4. It is because surface tension. Neksa P [6] The
paper concluded that CO2 is one of the
natural substances and it is an
environmentally benign, safe and economical
refrigerant used for heating and cooling
systems. Existing CO2 HPWHs both in
industrial and residential sectors have been
reviewed in this study, i.e. low-temperature
and high-temperature HPWHs (which are
classified by the heat delivery temperature
below and above 80 °C). The majority of
the existing systems are still not able to
deliver the water temperature above 100 °C
due to the temperature gliding matching
between water and sCO2, the limitations in
compressors, and the constraints in heat
exchangers. Hesse U [7] Taking in
consideration the current climate scenario
many researchers has done to develop a
refrigeration system that is both energy
efficient and has less impact on environment.
This environmental impact is directly and
indirectly related to the use of HCFC and
HFC refrigerants in refrigeration systems.
The amount of depletion of Ozone layer is
link to the use of HCF seeds and HFC
refrigerant whose consequence is measured
why the ODP index that is ozone depletion
potential. And also shows the potential
alternatives of the chlorofluorocarbons.
Suneel K Kalla [8] The Paper shows that the
performance of four refrigerants as possible
alternatives to R-22 was studied with the help
of cycled software. The values of COP were
nearer to those of R-22, e.g. at 25, 45 and 55
°C condensing temperature, COP of R432a is
lower than that of R22 by about 5.5%, 4%
and 4.38% respectively. By resorting to
hydrocarbon refrigerant as a substitute to R-
22 we can reduce global warming and avoid
ozone layer damage due to use of other
refrigerants. However, the drawback of
hydrocarbon refrigerants is their flammability
due to which safety measures during their use
is essential.
5. Research Methodology COMPUTATIONAL
FLUID DYNAMICS
:
Computational Fluid Dynamics (CFD) is a
branch of engineering and physics that
involves the use of computer algorithms and
numerical methods to simulate and analyse
the behaviour of fluids (liquids and gases)
and their interaction with physical objects.
CFD can be used to model and predict fluid
flow, heat transfer, chemical reactions, and
other related phenomena in a wide range of
applications such as aerodynamics,
hydrodynamics, weather forecasting,
combustion, and biomedical engineering.
CFD simulations involve breaking
down a complex fluid flow problem into
smaller, simpler components that can be
analysed using mathematical equations and
computational methods. These equations
describe the behaviour of the fluid under
various conditions, such as pressure,
temperature, velocity, and viscosity. CFD
software uses numerical methods to solve
these equations and generatea detailed visual
representation of the fluid flow behaviour,
such as velocity vectors, pressuredistribution,
and temperature gradients.
CFD simulations can help engineers
and scientists to optimize the design of fluid-
based systems, such as pumps, turbines, heat
exchangers, and air foils. By using CFD
simulations to study the fluid dynamics of a
system, engineers can identify potential
design improvements, reduce energy
consumption, and optimize performance.
CFD is also widely used in research and
development to gain a better understanding of
complex fluid flow phenomena and develop
new technologies.
Computational Fluid Dynamics
(CFD) is a numerical analysis process used to
simulate and analyse the behaviour of fluids
and gases in motion. It involves the use of
computational methods, algorithms, and
computer software to solve and analyse
complex fluid flow problems.
The CFD process typically involves the
following steps:
1. Problem Definition: In this step, the
problem is defined by specifying the
physical boundaries and initial
conditions of the fluid flow problem to
be solved. This includes defining the
geometryof the domain, the type of fluid,
and the boundary conditions.
2. Grid Generation: In this step, a mesh or
grid is generated over the geometry of
the domain. The grid is used to discretize
the fluid domain into a set of small cells
or elements. The quality of the grid has a
significant impact on the accuracy and
efficiency of the CFD simulation.
3. Mathematical Modelling In this step, the
governing equations of fluid dynamics,
such as the Navier-Stokes equations, are
discretized using numerical methods to
obtain a set of algebraic equations that
can be solved on a computer. The
mathematical model also includes any
additional physics, such as turbulence or
heat transfer, that need to be considered
in the simulation.
4. Solution Algorithm: In this step, a
numerical solution algorithm is chosen to
solve the discretized equations. This
can include various numerical
techniques such as finite volume,finite
element, or spectral methods.
5. Simulation Execution: In this step, the
CFD simulation is executed using the
solution algorithm and the grid generated
in the previous steps. The simulation
results are then computed and stored for
post-processing.
6. Post-Processing: In this step, the
simulation results are analysed and
visualized. This can include generating
graphs and charts, creating animations of
the fluid flow, and extracting
information about key parameters such
as pressure, velocity, and temperature.
7. Validation and Verification: In this step,
the CFD results are compared with
experimental or analytical data to
validate and verify the accuracy of the
simulation. This helps to ensure that the
CFD results are reliable and can be used
for engineering design and analysis.
The CFD process is iterative, and
several iterations may be required to
converge to a solution that is both
accurate and stable. The CFD process is
used in various fields, including
aerospace, automotive, energy, and
6. biomedical engineering.
Space claim:
Space Claim is a solid modeling CAD
(computer-aided design) software that runs
on Microsoft Windows and developed by
Space Claim Corporation. The company is
headquartered in Concord,
7. Massachusetts. Space Claim Corporation was
founded in 2005 to develop 3D solid
modeling software for mechanical
engineering. Its first CAD application was
launched in 2007 and used an approach to
solid modeling where design concepts are
created by pulling, moving, filling,
combining, and reusing 3D shapes. It was
acquired by Ansys in May 2014, Inc, and was
integrated in subsequent versions of Ansys
Simulation packages as a built-in 3D
modeler. Space Claim Corporation Markets
Space Claim Engineer directly to end-user
and indirectly by other channels. Space
Claim also licenses its software for OEMs,
such as ANSYS Flow International
Corporation Catal CAD, and Ignite
Technology which markets a version of
Space Claim for jewelry design. The below
figure shows the geometric modal of the
condenser as shown in Figure 1.
Fig:
1
Geo
met
ry
Pre-processor
Pre-processing consists of the input of a flow
problem to a CFD program by means of an
operator- friendly interface and the
subsequent transformation of this input into a
form suitable for use by the solver. The user
activities at the pre-processing stage involve:
• Definition of the geometry of the region of
interest: the computational domain
• Grid generation – the sub-division of
the domain into a number of smaller,
non-overlappingsubdomains: a grid (or mesh)
of cells (or control volumes or elements)
• Selection of the physical and chemical
phenomena that need to be modelled.
The solution to a flow problem (velocity,
pressure, temperature etc.) is defined at nodes
inside each cell. The accuracy of a CFD
solution is governed by the number of cells in
the grid. In general, the larger the number of
cells, the better the solution accuracy. Both
the accuracy of a solution and its cost in
terms of necessary computer hardware and
calculation time are dependent on the
fineness of the grid. Optimal meshes are
often non-uniform: finer in areas where large
variations occur from point to point and
coarser in regions with relatively little
change. Efforts are under way to develop
CFD codes with a (self-) adaptive meshing
capability. Ultimately such programs will
automatically refine the grid in areas of rapid
variations. At present it is still up to the skills
of the CFD user to design a grid that is a
suitable compromise between desired
accuracy and solution cost. The below
8. figures [2-12] represents the Meshing of the Model and parameters considered.
Fig:2 Mesh of the modal
Boundary conditions:
Fig:3 Boundary conditions of the model
RESULTS AND DISCUSSIONS:
R134a
A substantial amount of basic development work still needs to be done before these techniques are
robust enough to be incorporated into commercial CFD codes and simulation is shown in Figures [4-
12]
Fig:4 Temperature contour (R13a)
10. 450
400
350
300
250
200
150
100
50
0
R134A
R744
R22
TEMPERATURE
Fig:11 Pressure contour (R744) Fig:12 Eddy Viscosity(R744)
RESULTS: The Graph 1 shows the comparison of the temperatures of the three refrigerants, among
those R744 liberates less temperature to the environment than other refrigerants.
Graph: 1 Comparing temperature variations
CONCLUSION:
It is concluded that by observing the
temperature and pressure variations among
these three refrigerants R-134a have better
performance than the R-22 also R-134a have
zero ozone depletion potential and less global
warming potential compare to R-22. The
Metal particle of Al2O3 present in R-134a
makes the refrigerant inefficient because of
heated immediately. On other side R-744
which is made by recycling of CO2 from
atmosphere does not have any CFCs and also
not hazardous to atmosphere also is very
efficient refrigerant. R-744 has zero ODP,
lowest GWP, non-toxic, and higher
refrigerant performance than other
refrigerants.
REFERENCES:
1. Dalkilic AS and Wongwises S 2010 Int.
Commun. Heat Mass Transf.37 1340
2. Harby K 2017 Renew. Sustain. Energy
Rev. 73 1247.
3. Pearson SF.Natural refrigerants for heat
pumps. IEA Heat Pump Center
Newsletter 2004; 20:13–16.
4. Saleh B, Wendland M. Screening of
pure fluids as alternative refrigerants.
International Journal of Refrigeration
2006; 29: 260–269.
5. YoonSH, ChoES, HwangYW, KimMS,
MinK, KimY. Characteristics of
evaporative heat transfer and pressure
drop of carbon dioxide and correlation
development. International Journal of
Refrigeration 2004; 27 pages 111–119.
6. Neksa P.CO2 heat pump systems.
International Journal of Refrigeration
2002; 25:421 pages– 427.
7. Hesse U, Kruse H. Alternatives for
CFC’s and HCFC 22 based on CO 2.
IIF-IIR Commission B1/B2: Ghent,
Belgium, 1993 pages 317–325.
8. Suneel K Kalla, B B Arora
,Performance analysis of R22 and its
substitutes in air conditioners, Journal
of Thermal Engineering, Vol. 4, No. 1,
pp. 1724-1736, January, 2018