Which refrigerant can be used as a retrofit refrigerant?
Hydrocarbon refrigerants can be used as a retrofit refrigerant. b. Propane cylinders for grilling contain impurities that can damage refrigerant equipment. Ozone depletion in the stratosphere is what type
What are hydrocarbons used for refrigeration?
They consist entirely of hydrogen and carbon. In the refrigeration and air conditioning world hydrocarbons can be used as refrigerants. Some of the most commonly used hydrocarbon refrigerants are Propane (R-290), Isobutane (R-600a), and Propylene (R-1270).
What is the difference between hydrocarbon refrigerant and propane refrigerant?
c. Refrigerant-grade hydrocarbon refrigerant is of lower quality than consumer propane cylinders. d. Hydrocarbon refrigerants can be used as a retrofit refrigerant. b. Propane cylinders for grilling contain impurities that can damage refrigerant equipment.
Should we consider the use of Natural refrigerants to replace synthetic refrigerants?
The use of natural refrigerants like CO2, NH3 and hydrocarbons such as R290, R600, R600a and blends of hydrocarbons are possible solution to this problem and are being used efficiently in many systems. In this paper the importance of reconsidering the use of natural refrigerants to replace the synthetic refrigerants has been discussed.
Are hydrocarbons approved for retrofit?
Remember that we cannot retrofit a system to operate on hydrocarbon refrigerants. This is because they are highly flammable and it would be dangerous if retrofit components failed. Hydrocarbons can only be factory charged.
What are hydrocarbon refrigerants?
What Are Hydrocarbon HC Refrigerants? Natural hydrocarbon (HC) refrigerants are natural, non-toxic refrigerants that have no ozone depleting properties and low global warming potential. Hydrocarbons are one of the most climate-friendly and cost-effective refrigerants to cool and freeze.
Which hydrocarbon refrigerant is approved for?
The United States Environmental Protection Agency (EPA) has approved hydrocarbon refrigerants R170 (ethane), R600a (isobutane), R290 (propane) and R441A (a blend of all four) for use in certain stationary refrigeration and air conditioning applications.
What is the major disadvantage of hydrocarbon refrigerants?
The disadvantages of these products are mainly toxicity (NH3), flammability (HC) and high pressures (CO2). However, with minimal skills and compliance with safety rules, they do not eventually prove to be more dangerous than other fluids.
Is hydrocarbon refrigerant flammable?
The use of flammable refrigerant gases, such as hydrocarbons, flammable hydrofluoroolefins (HFOs, eg R1234yf) and R32 has increased in recent years as organisations seek to minimise the use of ozone depleting gases and synthetic greenhouse gases with high global warming potential.
Is R410a a hydrocarbon?
Most air conditioners and refrigeration systems in use all over the world still rely on chemical refrigerants to provide cooling and heating. These chemical refrigerants are hydrofluorocarbons (HFC) and hydrochlorofluorocarbons (HCFC) which include R22, R134a and R410a.
Is there a difference between refrigerant grade hydrocarbon refrigerant and propane for grills?
There is no difference between refrigerant grade hydrocarbon refrigerant and propane for grills. Propane cylinders for grilling contain impurities that can damage refrigeration equipment. Refrigerant-grade hydrocarbon refrigerant is of lower quality than consumer propane cylinders.
Which refrigerants can be mixed?
The most commonly mixed refrigerants in the field are the replacements for R-22 — R-427A, R-438A, R-422D, and R-407C — which are often combined with the remaining R-22 in the system, said Maiorana.
Which refrigerant does not need to be recovered?
Co2 refrigerant R-744Co2 refrigerant R-744 (Carbon dioxide) is a very high-pressure refrigerant and generally does not need to be recovered.
What are the main advantages of using hydrocarbons as refrigerants?
The two main advantages of hydrocarbon refrigerants are lower environmental impact and economic gains. First, hydrocarbons do not damage the ozone layer. Moreover, hydrocarbons can significantly reduce emission of greenhouse gases from refrigeration and air conditioning equipment.
What are the disadvantages of hydrocarbons?
Some hydrocarbons can cause other effects, including coma, seizures, irregular heart rhythms or damage to the kidneys or liver. Examples of products that contain dangerous hydrocarbons include some solvents used in paints and dry cleaning and household cleaning chemicals.
What are some common HC refrigerants?
Hydrocarbon refrigerants include a number of products including R290 (propane), R600a (isobutane), R1150 (ethene/ethylene), R1270 (propene/propylene), R170 (ethane) and various blends of these products.
What are some common HC refrigerants?
Hydrocarbon refrigerants include a number of products including R290 (propane), R600a (isobutane), R1150 (ethene/ethylene), R1270 (propene/propylene), R170 (ethane) and various blends of these products.
Is R134a a hydrocarbon?
The Guide lists HFO R1234yf as A2L lower flammability, R12 and R134a as A1 not flammable and hydrocarbons as A3 higher flammability. The guide rightly states that both A2L and A3 categories fall under the same provisions when it comes to the Dangerous Goods classification – they are both classed as 2.1 Flammable.
Is R600a a hydrocarbon?
R600a (Iso-Butane) is a hydrocarbon that is becoming increasingly popular due to its low Global Warming Potential (GWP). It is the refrigerant of choice for domestic and light commercial refrigeration units, including fridges and freezers, drink dispensers and stand alone display units.
What are HFO refrigerants?
HFOs (hydrofluoro-olefins) are the fourth generation of fluorine-based gases. HFC refrigerants are composed of hydrogen, fluorine and carbon atoms connected by single bonds between the atoms.
What is the R134A refrigerator?
The R134a refrigerator used in this study was a single-cabinet refrigerator used for teaching and experiments. The specifications of the experimental equipment and those of the R134a refrigerator are shown in Fig. 4 and Table 4, respectively. The experimental measurements were conducted in an environment with controllable temperature and humidity. To improve the safety of the experiment, a contactless-type compressor starter was used, the other electrical parts were sealed, and the insulation was reinforced using insulating materials to reduce the risk of combustion and explosion. The measurement unit consisted of thermocouples, pressure transducers, a data-logger (TRM20, TOHO), and a power analyzer (WT230, Yokogawa), all of which were connected to a power source and personal computer. The T-type thermocouples were used to measure temperature with an accuracy of ±0.5 °C. Ten measurement points were used, including points for measuring the inlet and outlet temperatures of each refrigeration component, freezer temperature, and compressor casing temperature. Two pressure transducers were used for measuring the high-pressure range of −1 to 50 bars (JPT-131S-50 bar, Jetec) and the low pressure range of −1 to 5 bars (JPT-131S-5 bar, Jetec) at an accuracy of ±0.5%. Power consumption was recorded by using a power analyzer at an accuracy of ±0.1%.
What is R134A used for?
Such a material is R134a, a hydrofluorocarbon (HFC) that is used as a refrigerant in small- and medium-sized refrigerators and automotive air conditioners. R134a is a controlled substance under the Kyoto Protocol, and must be phased out in future [1], [2]. Many countries have not explicitly legislated to control the usage of R-134a but only to reduce the actual and potential emission of this refrigerant. Therefore, R134a should be replaced with the other refrigerants because this is the most efficient way to reduce the potential level of the emission of this refrigerant. Ideally, R134a must be replaced with a refrigerant that has no ozone depletion potential (ODP), low global warming potential (GWP), low toxicity, a low price, high chemical stability, and excellent thermodynamic properties. Some long-neglected natural refrigerants, such as ammonia, hydrocarbons (HCs), CO 2, water, and air, may be alternatives to hydrofluorocarbons (HFC) and hydrochlorofluorocarbon (HCFC) refrigerants. Many researchers have studied HC refrigerants as alternatives to traditional refrigerants in a variety of equipment [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14]; however, these studies were focused on medium and small-scale refrigerators or air-conditioners due to consideration of flammable property and safety.
What refrigerant is used in a R134A refrigerator?
This study used hydrocarbon (HC) refrigerants in a small R134a refrigerator to evaluate the refrigeration performance and feasibility of using these alternative refrigerants by conducting the no-load pull-down test and 24-hour on-load cycling test. The mixed mass ratios of the HC refrigerants, R290 and R600a, were 65% and 35% (HC 1 ), 50% and 50% (HC 2 ), and 0% and 100% (HC 3 ), respectively. The charged ratios were 30%, 40%, 50%, and 60% based on the charged mass of R134a for HC refrigerants. The results of the no-load pull-down test revealed that the optimal charged mass for all the HC refrigerants was 40% of that of R134a. Most of the experimental results of the HC refrigerators obtained using the optimal charged masses showed that freezer temperature and power consumption were higher than those of the R134a refrigerator. Therefore, the capillary tube lengths of R134a, HC 1, HC 2, and HC 3 were recalculated to be 2.77, 5.05, 5.34, and 5.60 m, respectively, and the recalculated capillary tube was used in the 24-hour on-load cycling test. The results of the 24-hour on-load cycling test showed that the freezer temperatures considerably decreased when the HC refrigerants were used, and that all of the HC refrigerants could be used in the R134a refrigerator after changing the capillary tube lengths. All of the HCs refrigerants yielded lower electricity consumption, lower on-time ratios, and higher energy factors (EFs) than R134a did. The EFs of HC 1, HC 2, and HC 3 were 9.1%, 12.2%, and 42.3% higher than that of R134a, respectively. Using a higher proportion of R600a in HC refrigerants can enhance the EFs of refrigerators.
What is refrigeration system?
Refrigeration systems play paramount roles in life quality of human beings and social development in terms of food security, environmental impact, and energy efficiency. The traditional CFC, HCFC, and HFC refrigerants have been in the process of phase-out and being replaced by the sustainable working fluids. In this paper, the experimental thermodynamic performance evaluation of the hydrocarbons R600a, R290 and their mixtures used in a vapour compression refrigeration system that utilizes R134a as a working fluid was carried out. Firstly, a theoretical analysis was developed to evaluate the feasibility of the retrofit by employing the vapour compression refrigeration cycle. The evaporation temperatures were ranging from −25 °C to 3 °C, and the condensation temperatures ranging from 25 °C to 65 °C with superheating and subcooling degrees constant at 5 °C. The thermodynamic and thermophysical properties were obtained using REFPROP software. Lastly, based on the results obtained from the theoretical analysis, the experimental comparison of the refrigeration cycle performance was conducted using a refrigeration system designed for R134a. The results show that both pure R600a and R290 cannot be recommended as drop-in substitutes for R134a due to their significant differences in thermophysical properties. A mixture of R600a/R290 50%/50% composition was found to be the most appropriate alternative refrigerant for the R134a system retrofit with a comparative thermal performance.
What is the most commonly used refrigerant in small hermetically sealed units?
The most commonly used refrigerant in small hermetically sealed units is R134a, but it has highGlobal Warming Potential (GWP). In this scenario, research has to be carried out to develop an eco-friendly refrigerant mixture with low ODP and low GWP values with performance that is as good as R134a . In present work, attempted to find a binary mixture of refrigerant R436A (R290/R600a) (54%/46%) which could be an alternative to R134a. Efforts have been made to specify a particular composition of binary mixtures and to study their performance compared to R134a.By using experimental values to generate the enthalpies values at a different processes are analysed using REFPROP 9.0 refrigerant software. It has been found that pure hydrocarbon refrigerants cannot replace R134a.Hence the binary mixtures of R436A (R290/R600a) (54%/46%) and CARE30 (50%R290/50%R600a) with the mass fractions are considered. The performance characteristics such as refrigeration effect, compressor power, Coefficient of Performance (COP) and pull down time of the proposed mixtures were compared with those of the R134a. Back Propagation Neural Network (BPNN) algorithm with bipolar sigmoid activation function is used for validation of experimental values. BPNN constructs with the input-output mapping based on both human knowledge and stipulated input-output data pairs. It is observed from the simulation results that the ANN approach gives accurate results in predicting the performance of Domestic Refrigeration System. The proposed mixture R436A seems to be an appropriate and ecofriendly alternate refrigerant for replacement of R134a.
What is a platelet incubator?
Platelet incubators are refrigerated laboratory storage devices aimed at preserving platelets in liquid form at close to ambient temperature. Quality and shelf life of the stored platelets strongly depend on the storage temperature uniformity and continuous movement of the platelets provided by an agitator to avoid coagulation. Incubator manufacturers usually provide assurance that temperature uniformity will be within +/-1°C from the set point. Such strict requirement of uniformity is achieved by continuously running a forced convection vapor compression refrigeration system and by balancing excess cooling capacity with a controlled pulse heater located inside the cabinet. Dominant refrigerants currently employed in refrigerated laboratory equipment are HFCs with high GWP. In the future, HFCs will be gradually replaced mostly by flammable natural refrigerants of the ASHRAE A3 group such as R600a (isobutane), R290 (propane) and R170 (ethane) depending on the cooler size and application temperature. Flammable refrigerant charges are limited to 150g or less which in some cases requires complete redesign of the refrigeration circuit. The focus of this study was to convert the refrigeration system of a platelet incubator to hydrocarbon refrigerant. The selected incubator is able to store 32 apheresis bags and based on the required cooling capacity R600a refrigerant was identified as most suitable replacement for R134a. The baseline R134a system performance was experimentally evaluated across the range of ambient temperatures allowed by the manufacturer, from 15°C to 35°C and at 3 different cabinet set points 20°C, 22°C and 27°C. Attention was given to the energy consumption by distinguishing between contributions of individual components (compressor, fans, pulse heater, agitator, condensate tray heater and controller). Temperature uniformity was determined from measurements at 17 locations inside the cabinet over a 24 hour period. Afterwards, the refrigeration system was converted to R600a refrigerant and its performance was optimized by capillary tube size selection, refrigerant charge amount, evaporator fan speed and by replacing the condensate heater with a discharge gas loop. The redesigned machine required only 50g of R600a refrigerant charge, an average 20% lower energy consumption, cabinet temperature uniformity within the required +/-1°C for all tested conditions, and uniformity of +/-0.5°C at 15°C and 25°C ambient temperatures.
What is the current use of hydrofluorocarbons?
The current use of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) as refrigerants will be phaseout and phasedown. Hydrocarbon (HC) refrigerants were introduced as potential replacements. These refrigerant grade hydrocarbons namely propane (R 290) and isobutane (R 600a) were on sale at premium prices. As Malaysia has capabilities to produce LPG, a study was conducted to find out the suitability of commercial liquefied petroleum gas (LPG) to be used as refrigerant. This study compares the efficiencies and cooling capacities of commercial grade LPG to refrigerant grade propane (C3H8) and chlorodifluoromethane (CHClF2) (R 22) in a split unit air conditioner installed in a psychrometric chamber. Results of experiments indicated that the commercial blends in the ratio of 80% propane and 20% butane provided the highest efficiency, but had the lowest cooling capacities; in contrast, the imported refrigerant grade propane despite value being purer, was not reflected in term of its efficiency; recorded the lowest. CHClF2 provided the highest efficiency and cooling capacity. LPG has the potential to replace R22 in split air conditioners despite losing 10 % in cooling capacities but instead gained 2.6% in energy efficiencies.
What refrigerant is used in a R134A refrigerator?
This study used hydrocarbon (HC) refrigerants in a small R134a refrigerator to evaluate the refrigeration performance and feasibility of using these alternative refrigerants by conducting the no-load pull-down test and 24-hour on-load cycling test. The mixed mass ratios of the HC refrigerants, R290 and R600a, were 65% and 35% (HC1), 50% and 50% (HC2), and 0% and 100% (HC3), respectively. The charged ratios were 30%, 40%, 50%, and 60% based on the charged mass of R134a for HC refrigerants. The results of the no-load pull-down test revealed that the optimal charged mass for all the HC refrigerants was 40% of that of R134a. Most of the experimental results of the HC refrigerators obtained using the optimal charged masses showed that freezer temperature and power consumption were higher than those of the R134a refrigerator. Therefore, the capillary tube lengths of R134a, HC1, HC2, and HC3 were recalculated to be 2.77, 5.05, 5.34, and 5.60 m, respectively, and the recalculated capillary tube was used in the 24-hour on-load cycling test. The results of the 24-hour on-load cycling test showed that the freezer temperatures considerably decreased when the HC refrigerants were used, and that all of the HC refrigerants could be used in the R134a refrigerator after changing the capillary tube lengths. All of the HCs refrigerants yielded lower electricity consumption, lower on-time ratios, and higher energy factors (EFs) than R134a did. The EFs of HC1, HC2, and HC3 were 9.1%, 12.2%, and 42.3% higher than that of R134a, respectively. Using a higher proportion of R600a in HC refrigerants can enhance the EFs of refrigerators.
Why are halocarbons being phased out?
Halocarbon refrigerants have been scheduled for total phase out because they contributed significantly to the two major global environmental problems -ozone layer depletion and global warming. In this study, the performances of the environmentally friendly R510A and R600a in a retrofitted domestic refrigerating system were investigated experimentally and compared with the performance of R134a. The results obtained showed that R510A has the lowest discharge pressure with an average value of 13.4 % lower than that of R134a. The average pressure ratios of R510A and R600a were 16.91 and 12.17 %, respectively, lower than that of R134a. The Volumetric Cooling Capacity obtained for R510A was 5.34 % higher than that of R134a. R510A and R600a exhibited higher refrigerating effect and Coefficient of Performance (COP) than R134a. The average COPs for R510A and R600a were 22.26 and 3.06 %, respectively, higher than that of R134a. Generally, R510A and R600a performed better than R134a and they can be used as retrofit substitute refrigerants for R134a in the existing domestic refrigerators. The best performance was obtained from the use of R510A in the retrofitted system.
What are the natural refrigerants?
The world is now looking for the refrigerants which do not contribute to the ozone layer depletion and global warming. The use of natural refrigerants like CO2, NH3 and hydrocarbons such as R290, R600, R600a and blends of hydrocarbons are possible solution to this problem and are being used efficiently in many systems. In this paper the importance of reconsidering the use of natural refrigerants to replace the synthetic refrigerants has been discussed. A review on the different systems where natural refrigerants are being used and modifications to such systems that could ensure better efficiency has been presented.