Alternative Refrigerants Research Articles

Computational Tool to Support the Decision in the Selection of Alternative and/or Sustainable Refrigerants

There have been consequences regarding the increment of the greenhouse effect, such as the rise in the planet’s global temperature, and climate change. Refrigerants have an important contribution to the aforementioned environmental impact. In particular, hydrofluorocarbons (HFCs) contribute to the destruction of the ozone layer and the increase of the greenhouse effect. Protocols, international agreements, and legislation were developed to slow down the emission of greenhouse gases. Prohibition and definition of deadlines for the gradual elimination of various refrigerants have been proposed to replace them with others that are environmentally sustainable. Soon, the refrigeration sector will have to replace some refrigerants with others that are alternative and/or sustainable with minimal or zero environmental impact. A computational tool to support decision-making regarding the selection of alternative and/or sustainable refrigerant to replace the old one is developed to be used by refrigeration companies, manufacturers, and installers. A suggestion of refrigerants with reduced environmental impact is provided, ensuring similar thermal performance and energy efficiency, considering the safety level and renovation cost of the installation and refrigerant itself. This decision support system (DSS) uses an objective function that includes the technical specifications and properties of alternative and sustainable refrigerants. The computational tool is applied in the agri-food sector in three case studies. The results show not only the consistency of the computational tool, but also its flexibility, objectivity, and simplicity. Its use allows companies to choose refrigerants with reduced environmental impact, reduced or zero ozone depletion potential and global warming impact, thus contributing to environmental sustainability.

Comparison of the performance of propane ([formula omitted]) and propene ([formula omitted]) as alternative refrigerants for cooling during expansion in a helical capillary tube: A CFD-based insight investigation

The current research compared the efficiency of the new generation refrigerants, propane (R290) and propene (R1270), for cooling applications. The refrigerants’ flow and phase change properties in a helical capillary tube are simulated using ANSYS Fluent 2021 R2 CFD software. For this virtual experiment, a helical capillary tube with an inner diameter of 1.2 mm and a total length of 2100 mm is used. The flashing phenomenon, in which the refrigerants undergo a phase change, is simulated using a finite volume-based mixture model. The Zwart–Gerber–Belamri model is utilized to estimate mass transfer during flashing, which adheres to a homogeneous equilibrium strategy. A set of user-defined functions (UDF) are created to access the refrigerant properties and implement the cavitation model. Bilinear interpolation is used to calculate the fluid’s characteristics at a particular cell pressure and temperature. Available numerical and experimental results are used to verify the constructed numerical model. The investigation shows that under the same operating conditions, R290 refrigerant maintains a higher mass flow through the helical capillary tube than R1270. R1270 produces a lower temperature vapour-liquid mixture at the exit of the capillary tube in comparison to R290. CFD simulations have generated information and data that are helpful in choosing proper refrigerants for different purposes.

Indirect Evaluation of the Electrocaloric Effect in PbZrTiO3 (20/80)-Based Epitaxial Thin Film Structures

Electrocaloric effect is the adiabatic temperature change in a dielectric material when an electric field is applied or removed, and it can be considered as an alternative refrigeration method. Materials with ferroelectric order exhibit large temperature variations in the vicinity of a phase transition, while antiferroelectrics and relaxors may exhibit a negative electrocaloric effect. In this study, the temperature variation in polarization was investigated for epitaxial ferroelectric thin film structures based on PbZrTiO3 materials in simple or complex multilayered structures. We propose the intriguing possibility of a giant negative electrocaloric effect (ΔT = −3.7 K at room temperature and ΔT = −5.5 K at 370 K) in a simple epitaxial Pb(ZrTi)O3 capacitor. Furthermore, it was shown that abnormal temperature variation in polarization is dependent on the non-FE component introduced in a multilayered structure. No significant variation in polarization with temperature was obtained for PZT/STON multilayered structures around room temperature. However, for PZT/BST or PZT/Nb2O5 multilayers, an abnormal temperature variation in polarization was revealed, which was similar to a simple PZT layer. The giant and negative ∆T values were attributed to internal fields and defects formed due to the large depolarization fields when the high polarization of the FE component was not fully compensated either by the electrodes or by the interface with an insulator layer. The presented results make Pb(ZrTi)O3-based structures promising for cooling applications operating near room temperature.

Experimental assessment of a low GWP nonflammable new refrigerant in a closed heat pump drying system

AbstractLow global warming potential (GWP) refrigerants are vital to mitigating the effect of heat systems on climate change. A low GWP mixture, RGT2 (R134a/R1234yf/R161, 54%/43%/3% weight), was proposed as an alternative refrigerant for R134a in heat pump systems. This article presented the results of an experimental investigation evaluating RGT2 as a possible replacement for R134a in a closed heat pump drying (CHPD) system and studying the drying characteristics of fig slices. The experiment concluded that RGT2 has a higher coefficient of performance (COPhp) value than R134a, on average, by 1.92%, achieving lower discharge temperature and pressure ratio at different condensing temperatures (45°C–70°C). Although the heating capacity of RGT2 was slightly lower, it still met the requirements of HPD. With careful consideration of the environment, performance, and safety, RGT2 was a suitable substitute for R134a in the drying field. In addition, the drying characteristics of fig slices were significantly affected by the air temperature. The effective diffusion coefficient (Deff) and specific moisture extracted ratio (SMER) are increased by increasing temperature and air flow rate. The two‐term model was the better model to accurately predict the fig slices drying process. The highest mean Deff and SMER of CHPDS were obtained as 6.4518 × 10−10 m2/s and 39.197 g/kWh, respectively, at the highest drying air temperature.Practical ApplicationA mixed refrigerant (RGT2) was proposed to replace R134a, and its GWP value was about 61% lower than that of R134a. Most of the studies on substituting R134a in the literature are simulations. This paper aims to evaluate the substitutions' feasibility theoretically and experimentally. The results have been assessed to provide better information about RGT2 as a potential substitute for R134a with superior comprehensive performance. Drying kinetics has also been determined experimentally, which helped to simulate fig drying. This study will provide a reference for refrigerants replacement in heat pump drying.

An Overview of Environment-Friendly Refrigerants for Domestic Air Conditioning Applications

Low global warming potential (GWP) refrigerants for the next-generation air conditioning systems have been investigated with target domestic applications. High-GWP refrigerants are mostly used in climate control applications such as heating, ventilation and air conditioning (HVAC) and refrigeration systems. The majority of refrigerants are responsible for significant environmental issues such as ozone layer depletion and global warming. The Montreal Protocol and the Kyoto Protocol have been implemented to address such issues. In the meantime, authorities in many countries have taken the initiative to phase out the usage of environmentally harmful refrigerants in vapor compression refrigeration systems. Following the global warming mitigation scheme by many signatory countries, research interest has been focused on finding alternative refrigerants with low or ultra-low GWP. This study considered the research trend and development of low-GWP refrigerants while examining system performance, safety issues, and the equivalent environmental impact as the critical assessment parameters. Here, the focus is primarily set on the potential of refrigerant blends (HFCs + HFOs) where the GWP value of 300 is set as the threshold value. Targeted for domestic heat pump systems, the performance of such systems using various refrigerant blends is collated and discussed. Many blends offer innovative drop-in replacements for R410A-conforming F-gas regulations. The technical difficulties and realistic remedies for the existing refrigerants are also discussed.

A review on analysis of Vapour Compression Refrigeration System (VCRS) for its performance using different ecofriendly refrigerants and nanofluids

From last many years Vapour Compression Refrigeration system (VCRS) was incorporated in most of refrigeration systems because of its favourable features like higher Coefficient of Performance (COP), higher Refrigerating Effect (RE) etc. VCRS Systems have wide range of applications including domestic and Industrial systems. In any refrigeration system refrigerant is the primary working fluid for absorbing as well as transmitting heat. Domestic and industrial refrigeration systems employ HFC’s due to their excellent thermodynamic properties but Kyoto protocol categorized HFCs as global warming gases due to their higher value of GWP (1300). To meet the needs of global standards and eco-friendliness, it is very essential to find out the alternative refrigerants to HFCs. Alternate refrigerants to be used should fulfil the required characteristics like energy efficient heat transfer, higher refrigerating effect, higher condenser heat rejection rate and higher COP as well as it should have lower GWP and zero ODP. From Research, it was found that Mixed Refrigeration Systems or blends are thermally efficient and different types of nanofluids can be utilized along with R134a for improving and achieving excellent performance of a Refrigeration system.

Thermodynamic performance optimization and analysis of an auto-cascade refrigeration cycle with vapor injection for ultra-low temperature freezer

To improve the performance of the conventional auto-cascade refrigeration cycle, a modified auto-cascade refrigeration cycle with vapor injection is proposed for the application of a -80 ℃ freezer in this study. The particle swarm optimization algorithm is used to obtain the cycle performance at different operation conditions. The mixture concentration, compression ratio and condenser outlet quality are optimized globally. The binary mixture selection is carried out among the R1150/R290, R150/R600 and R1150/R600a. The results indicate that R1150/R600 is proposed as the alternative refrigerant. The performance comparisons between conventional and vapor injection auto-cascade refrigeration cycles show that the vapor injection technique efficiently improves system performance, especially at high condensation and low evaporation temperatures. Compared with the conventional auto-cascade refrigeration cycle, the optimal COP in the modified auto-cascade refrigeration cycles show a 9.3∼53.8% improvement in COP and the maximum improvement in the volumetric refrigeration capacity reaches 58.2% at low evaporation temperature. The statistical results of the optimal concentration of the mixture R1150/R600 at the selected operating conditions show that 88% of the optimal R600 concentration in the VARC cycle is in the range of 0.657∼0.699. The optimal concentration of R600 in the CARC cycle varies in a wide range of 0.57∼0.75. The optimal intermediate pressure is 38.1∼13.4% lower than the geometric mean of discharge pressure and evaporation pressure. The exergetic analyses illustrate that the largest exergy destruction of the VARC cycle occurs in the recuperator-2 instead of the compressor in CARC, contributing to 22.6∼23.5% of the total exergy destruction.

Retrofit assessment of automobile air conditioners using hydrocarbon refrigerants

• R600a and HR12 were selected as alternative refrigerants for the R134a MAC. • Optimal charging amount of HR12 was 45% of that for R134a. • R600a was not suitable to directly replace R134a in the MAC. • Q c and DH were better than those of R134a at T oa of 30 to 40 °C. • T oa of 40 °C could cause a substantial decrease in the EER of HR12. In this study, hydrocarbons (R600a and HR12) were selected as alternative refrigerants to evaluate their performance and feasibility as direct replacements for the R134a used in automobile air conditioners (MACs). The MAC performance tests were performed under fixed indoor conditions (27 °C, 50% RH) and outdoor ambient temperatures ( T oa , 35 °C) to determine the optimum charging amount and availability of hydrocarbons. The results showed that the optimal charging amount of HR12 (247.5 g) was 45% of that for R134a, and its cooling capacity ( Q c ), dehumidification capacity ( DH ), and energy efficiency ratio (EER) were significantly better than those of R134a and R600a. Therefore, HR12 was more suitable for replacing R134a than R600a. In terms of the influence of T oa changes on MAC performance, the Q c , DH , and EER of HR12 used in MACs at a T oa of 30 °C were 5.96%, 6.62%, and 81.02% higher than those of R134a, respectively. The differences of the Q c , DH , and EER between the HR12 and R134a used in the MAC at a T oa of 40 °C were 1.02%, 7.59%, and −9.79%, respectively. The results showed that a T oa of 40 °C could cause a substantial decrease in the EER of HR12, mainly due to the increase in power consumption of MACs. However, in the T oa range (30–40 °C) of this study, the Q c and DH of HR12 were still higher than those of R134a, indicating that HR12 was suitable as a direct replacement for R134a in MACs.

Experimental evaluation of low-GWP refrigerants R513A, R1234yf and R436A as alternatives for R134a in a cascade refrigeration cycle with R744

This work presents an experimental analysis of the energy and environmental performance of low-GWP refrigerants R513A, R1234yf and R436A as alternatives for R134a in a cascade refrigeration system that operates with R744 in low-temperature cycle. An apparatus was built using a well-insulated room, where tests were carried out in a steady state condition. In addition to the typical components of a cascade cycle, an intermediate heat exchanger was used to thermally communicate the low and high temperature cycles, thus providing additional superheating and subcooling, respectively. The cooling capacity of the system ranged from 2.2 to 3.8 kW, the evaporation temperature varied from -34 to -24.5 °C and the air temperature inside the cold room ranged from -23.1 to -9.4 °C. The results revealed that the alternative refrigerants are potential substitutes for R134a in cascade refrigeration systems, showing an average increase in the CRC coefficient of performance of 3.1% for R436A, while R1234yf and R513A exhibited a reduction of 3.7% and 4.4%, respectively. The environmental impact analysis considered the scenarios of Chicago (USA) and Curitiba (Brazil), the latter being a southern Brazilian city with a wet climate throughout the year, a warm and mostly cloudy summer, and a short and cold winter. Total TEWI values, compared to those obtained with the originally designed R134a system, showed reductions in CO2 equivalent emission of 46%, 42.1% and 22.5% for refrigerants R436A, R1234yf and R513A, respectively, for the Curitiba scenario, while the values for Chicago were increments of 0.3%, 2.4% and 5.8%, respectively.

Multi-Objective Optimization of a Multilayer Wire-on-Tube Condenser: Case Study R134a, R600a, and R513A

This study presents the optimization of a multilayer wire-on-tube condenser exposed to forced convection, using the Optimized Multi-objective Particle Swarm Optimization (OMOPSO) algorithm. The maximization of the heat transfer and the minimization of the heat exchange area were defined as objective functions. In the optimization process, the variations of eight geometric parameters of the condenser were analyzed, and the Multi-objective Evolutionary Algorithm based on Decomposition (MOEAD), Non-dominated Sorting Genetic Algorithm-II (NSGAII), and OMOPSO algorithms were statistically explored. Furthermore, the condenser optimization analysis was extended to the use of alternative refrigerants to R134a such as R600a and R513A. Among the relevant results, it can be commented that the OMOPSO algorithm presented the best option from the statistical point of view compared to the other two algorithms. Thus, optimal designs for the wire-on-tube condenser were defined for three proposed study cases and for each refrigerant, providing an overview of compact designs. Likewise, the reduction of the condenser area was analyzed in more detail, presenting a maximum reduction of 15% for the use of R134a compared to for the current design. Finally, the crossflow condition was studied with respect to the current one, concluding in a greater heat transfer and a smaller heat exchange surface.

CO2 emissions and energy performance analysis of ground-source and solar-assisted ground-source heat pumps using low-GWP refrigerants

The energy consumption and CO2 emissions of heat pump systems can be reduced effectively by adopting an appropriate alternative refrigerant. However, investigation on alternative refrigerants for ground-source heat pump (GSHP) and solar-assisted ground-source heat pump (SGSHP) systems is limited although these systems still use conventional refrigerants. In this study, the life cycle climate performance (LCCP) and primary energy consumption (PEC) for GSHP and SGSHP systems using conventional and alternative refrigerants are compared to those for conventional boiler systems. Experiments are conducted to investigate the heating performance of selected refrigerants. For regions with low CO2 emission conversion factor for electricity (μCO2.elec), GSHP systems using R1234yf are the most suitable considering the LCCP, owing to its low GWP and high performance. However, SGSHP systems using R134a with a large system size are preferred in regions with high μCO2.elec, because system efficiency takes the priority in reducing the LCCP. For PEC, SGSHP systems using R134a are recommended owing to its high efficiency. However, in regions where oil or natural gas is used dominantly, either the system size of SGSHPs should be increased or the primary energy conversion factor of electricity should be reduced to guarantee the benefits of PEC reduction of SGSHP systems.

Evaluating the impact of refrigerated transport trucks in China on climate change from the life cycle perspective

With global increases in population and economic growth, refrigerated transport trucks play a critical role in human life, food quality and security, and environmental issues. However, little research has been done on the greenhouse gas (GHG) emissions arising from refrigerated trucks that are rapidly increasing in developing countries, such as China. As such, projecting GHG emissions associated with refrigerated trucks and exploring effective measures to mitigate its global warming impact is necessary to reach climate goals. This study presents a carbon footprint novel model for evaluating refrigerated trucks by considering the lifecycle impacts of their refrigeration systems (refrigerators and refrigerants), insulated truck bodies, and truck chassis, including these elements' production, transportation, installation, use and repair, and recycling phases. We then quantitatively evaluate refrigerated trucks' overall carbon footprint based on data from seven typical regions in China. Our results show that the carbon footprint is remarkably high in the use phase, accounting for approximately 96% of an refrigerated truck's total GHG emissions. The hotspots in the refrigerated truck lifecycle have been identified as fuel consumption and the temperature difference between the outside and inside of the insulated truck body during the use phase. Moreover, we prioritize four low-carbon management strategies to mitigate the refrigerated truck sector's climate change impact, including energy efficiency improvement, clean electricity grid supply, environmentally friendly refrigerants, and alternative refrigeration technologies.

Drop-in assessment of plug-in R404A refrigeration equipment using low-global warming potential mixtures

Abstract This study analyses the performance of plug-in refrigeration equipment, which has the condenser on the system and delivers heat to the indoor medium, using mixtures with low-global warming potential (GWP). The theoretical drop-in replacement of R404A that is widely used in the plug-in refrigeration equipment, is investigated utilizing refrigerants with GWP<150 such as R454C, R455A, R457A and R465A. In the study, four cases of evaporation temperatures (-25°C, -15°C, -5°C and 0°C) and two cases of condenser temperatures (30°C and 40°C) were considered for freezer and chiller modes of the equipment. According to the obtained results, the power consumption of R404A is determined to be higher than other refrigerants for both studied condenser temperatures. The mass flow rate circulating in the system decreases using R404A’s alternatives. Furthermore, the highest COP is reached with R457A which has a greater COP than R404A about by 8.5%. The compressor discharge pressures of alternative refrigerants are smaller compared to R404A as well. The reduction in CO2 emission is also presented in terms of total equivalent warming impact (TEWI) computations. The conducted analysis points out that it will be possible to use directly the investigated mixtures (especially R457A and R455A are most promising ones) in plug-in refrigeration devices as alternatives to R404A without performing any constructional modification in the system.

In tube condensation heat transfer and pressure drop for R454B and R32—Potential replacements for R410A

The heating, ventilation and air conditioning (HVAC) industry in the United States seeks near-term alternative refrigerants to replace R-410A in unitary equipment. Two potential replacement refrigerants are R-454B and R-32. It is of interest to investigate the capability and accuracy of existing heat exchanger design methods when applied to these replacement refrigerants. To that end, this work presents empirical condensation quasi-local heat transfer coefficient and pressure drop data for R-454B and R-32. These data were obtained in a 38 in. (9.52 mm) outside diameter (OD) smooth copper tube with a wall thickness of 0.032 in. (0.81 mm). The experimental variables and their ranges included refrigerant absolute pressure (1960≤Pabs≤3196 kPa), condensation temperature (35≤Tcond≤50oC), mass flux (100≤G≤200 kg m-2 s-1), vapor quality (0≤x≤1), and heat flux (32.9≤q″≤62.97 kW m-2). It was found that the heat transfer correlation developed by Cavallini et al. Cavallini et al. (2006) predicted the experimental condensation heat transfer data, for both R-454B and R-32, with the greatest accuracy. Using the Cavallini et al. correlation, it was found that the mean absolute percentage error (MAPE) was 10.5% and 15.1% for R-454B and R-32, respectively. Additionally, the pressure drop correlation developed by Friedel Friedel (1979) predicted the experimentally determined pressure gradient with a MAPE of 7.7% and 5.5% for R-454B and R-32, respectively. These results will assist the practicing thermal engineer to choose the most appropriate design correlation for these near-term replacement refrigerants.

THERMODYNAMIC ANALYSIS OF A RESIDENTIAL AIR CONDITIONING OPERATING WITH ODP FREE AND LOW GWP REFRIGERANTS

Throughout the evolution of air conditioning, the fluids commonly used have also undergone through changes. Firstly, the concern was chosing a refrigerant that allows the proper operation of the equipment. In the last forty years, the focus became environmental problems caused by refrigerants when released into the atmosphere. The search for an eco-friendly refrigerant that can result in air conditioning applications with satisfactory thermodynamic efficiency is an actual and developing field. The present work performs a thermodynamic analysis of a residential air conditioning operating with alternative refrigerants with ODP free and low GWP (less than 3). Computational modeling is developed in Python, focused on the thermodynamic analysis of the condenser and evaporator of the selected equipment, allowing a comparison between some promising fluids. The methodology developed allows selecting the best fluid to be used either in retrofitting old equipment to a new refrigerant or in developing a completely new refrigeration system. The performance and cooling capacity of the system working with ammonia (R717), isobutane (R600a), propane (R290), R1234yf, R1234ze(E), R22 and R134a for different operation conditions are studied. The results indicate that ammonia presents the best performance among the selected refrigerants for the conditions assumed here, although not suitable for residential applications due to its toxicity. Moreover, R290 and R1234yf showed to be thermodynamically suitable refrigerants to domestic air conditioning equipment.

Analytical and experimental study of two-phase ejectors considering the influence of lubricant oil

The use of traditional refrigerants such as HCFCs and HFCs has a significant impact on global warming. On the other hand, natural refrigerants have little environmental impact with essential characteristics such as low global warming potential (GWP) and zero ozone depletion potential (ODP). Among various natural refrigerants, carbon dioxide is used as an alternative natural refrigerant due to its excellent heat transfer efficiency in a supercritical state. However, its COP is low due to its inherent high compressor work. To reduce this high compressor work, additional components such as ejectors are used for carbon dioxide cycles. In this study, a two-phase ejector was investigated. In particular, ejector analysis was performed in consideration of the influence of lubricant oil. In vapor compression cycle, lubrication is essential. This lubricant oil is discharged to the system through a compressor. When oil flows to system and enters the ejector, it forms a layer that can obstruct the flow inside the ejector. Oil circulation ratio (OCR) change can affect the mass flow rate of the ejector as if the inner diameter of the ejector is reduced. Therefore, it is essential to consider effects of OCR in a two-phase ejector analysis. As a result of the simulation, considering the effect of oil, a lower mass flow rate was predicted compared to existing analysis. Compared to previous studies without considering oil, there was an average mass flow rate difference of 13.6%. This simulation result was validated through experiments.

Refrigeration property exploration of the superabsorbent hydrogel: Mechanism and application feasibility analysis

A novel phenomenon that the phase equilibrium temperature (PET) of the poly (sodium acrylate) based superabsorbent hydrogel was lower than that of water was found, and its application potential in refrigeration was analyzed in this study. In addition, relations between the unit refrigerating capacity and apparent properties of the superabsorbent hydrogel, such as swelling ratio, cross-linking degree and neutralization degree, were investigated. Experimental results show that the PET of the superabsorbent hydrogel was lower than that of water. The hydrogel can achieve lower temperature than water and potentially be used as alternative refrigerant. Based on this, the superabsorbent hydrogel may have obvious advantages in improving the efficiency of absorption refrigeration cycle. The swelling ratio and cross-linking degree of the superabsorbent hydrogel had significant influence on its refrigeration capacity, whereas the neutralization degree had minimal effect. Finally, the application of super absorbent hydrogel as the refrigerant was attempted, and existing problems were analyzed.

Heat pump 해석을 활용한 철도차량 HVAC 성능 시뮬레이션 연구

For heat pump system, in order to respond to regulations such as greenhouse gas reduction and carbon credits, it is necessary to conduct research such as selection of alternative refrigerants, system design and performance improvement, and the use of numerical simulation tools is inevitable. Therefore, it is very important to build a system suitable for each industrial field, and the HVAC system of railway vehicle is no exception to this. In this study, heat pump analysis was applied to the HVAC system of railway vehicles to analyze its performance.

Evaluation of a low-GWP and nonflammable blend as a new alternative for R134a in the heat pump system

R134a is a refrigerant widely used in heat pump systems, which has a high global warming potential (GWP) and cannot be used for a long time. In this study, a new mixed refrigerant, named RGT2 (GWP = 560), has been proposed as an alternative refrigerant to R134a in heat pump systems. RGT2 is a mixture composed of R134a/R1234yf/R161 (54%/43%/3% wt%) without toxicity. Firstly, the basic properties of RGT2 were tested, including flammability, miscibility, and saturated vapor pressure. The results showed that RGT2 is non-flammable and is well miscible with polyol ester (POE) oil and polyvinyl ether (PVE) oil. Moreover, the saturated vapor pressure curve of RGT2 is close to that of R134a in the range of -20∼80 °C. Secondly, the cycle performance of RGT2 and R134a were compared and analyzed by theoretical calculations and experiments. The cooling capacity of the heat pump system filled with RGT2 is close to R134a, and the coefficient of performance (COP) is 3.8% lower than that of R134a. Considering that RGT2 is more environmentally friendly and safer, and its thermophysical properties and cycle performance are close to R134a, it can be used as a substitute refrigerant for R134a in heat pump systems.

Investigation and Analysis of R438A as an Alternative Refrigerant to R22 with Lower Global Warming Potential

This research presents the R438A refrigerant that non-flammable refrigerant and develop for retrofit to R404A. The hydrofluorocarbons/hydrocarbon (HFCs/HCs) R463A (GWP=2,265) was zeotropic mixture of R125 (45%), R134a (44.2%), R32 (8.5%), R600 (1.7%) and R600a (0.6%). The R463A refrigerants is no frame propagation class A1 and lower toxicity and used polyol ester oil (POE). The results will investigation and analysis of the environmentally friendly refrigerant for R22 replacement. All refrigerant properties in this research were based on results from the REFPROP and CYCLE_D-HX software of NIST under CAN/ANSI/AHRI540. The results of this work show that HCs R170, R290, R600, R600a, R601, R601a, R1150 and R1270 can be mixed in HFCs R417A, R417B, R422A, R422B, R422C, R422D, R424A, R437A, R438A and R453A and able to be further developed in the future. All refrigerants are non-flammable refrigerants, non-toxic and zero ODP. The R438A mixed with HCs R600 (1.7%) and R601a (0.6%) and is the refrigerant cooling coefficient of performance close to that of R22 refrigerant. In conclusion, it can be used as an environmentally friendly and energy efficiency replacement for R22. The result of R438A normal boiling was lower than R404A 4% that high cooling capacity and zero ODP. All refrigerants are also refrigerants that are matched with the 4th generation refrigerants with the use of natural refrigerants.