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Numerous investigations 12v heating element of the refrigerant R134a have been published. Besides experience with air conditioners in cars, the main tests have been limited to perform them in laboratories. This white paper some practical issues concerning the implementation of R134a refrigerant in commercial refrigeration systems for low power, equipped with hermetic compressors are presented.
Special production units such as: drinking fountains, coolers cabinets with electronic circuits, heat pump water heaters were considered to assess the results. The characteristics of capacity, energy efficiency, performance oil, moisture and other contaminants in the coolant, as well as the Retrofitting (conversion of a refrigeration 12v heating element system with R134a refrigerant R12) will be addressed in this white paper.
In context, 12v heating element should be understood in the commercial refrigeration as distinct from domestic refrigerators or fridges. The refrigeration systems with hermetic compressors (with a volume greater than 20 cm3 displacement), who frequently work with evaporation temperatures of -15 º to +15 º C, will be considered in this article. The particular interest is in units of mass production and troughs, units for the cooling of electronic circuits, commercial refrigerators and heat pumps designed to heat water. Performance of the refrigeration system with refrigerant R134a
Compared with the refrigerant R12, R134a has a reputation known for its lower required 12v heating element volume capacity and increased energy consumption. However, 12v heating element several tests have shown that this does not happen often. With applications 12v heating element including a hermetic compressor, the power characteristics appear to be similar to those of R12 and R134a refrigerant if the evaporating temperature is not very low.
Figure 1 shows a comparison between cooling capacity for a compressor with a volumetric displacement of 7.95 cm3 calorimeter testing between R12 and R134a refrigerant. Tests with R134a were made in this case without any alteration, but taking care to use the ester oil type. The known capacity decreases very low evaporation temperatures and increases 12v heating element at temperatures higher evaporation, as we noted in these tests. By lowering the temperature of condensation, the intersection of both curves changes at temperatures lower evaporation. 12v heating element This is due to the gradient of the line lower boiling R134a PH diagram (pressure enthalpy), 12v heating element which means that the reduction of the condensation temperature has a positive effect with R12 R134a.
In Figure 2, compares the COP of R12 and R134a. It is noted that the refrigerant R134a having a value greater than R12, except evaporation pressures below -25 degrees. In this comparison, the R134a does not win an energy disadvantage. Figure 3 is another 12v heating element comparison measurement COP for a hermetic compressor with a volumetric displacement of 12.9 cm3. R134a refrigerant measurements did not involve any alteration 12v heating element to the original 12v heating element compressor for refrigerant R12 in this case (the original compressor for R134a was not available). Again, there is evidence that the refrigerant R134a energy has disadvantages. On the contrary, in this case, even R134a shows low temperature energy advantages compared condensing refrigerant R12.
The different results shown in Figure 2 and 3, are not due to the properties of the refrigerant, but are influenced by the compressor used. This shows the limitations of making comparisons on energetic properties of the two refrigerants. It can be seen in the significant potential improvement from the energy viewpoint when R134a is used, and this involves the refrigeration system and the compressor, respectively. Moreover, especially when hermetic compressors are used, will depend to a greater degree of self-adaptation of the compressor and engine 12v heating element operating conditions of the system in its entirety. However, the variety of applications which must be taken into account in the design of commercial refrigeration systems, are the reason for such implementations which are only possible to a limited extend. Meanwhile, the optimizations of refrigerated systems in general should be carried out with the introduction of refrigerant R134a. An optimization of this type could, for example, replacement of the capillary tube or restrictor orifice 12v heating element or
Numerous investigations 12v heating element of the refrigerant R134a have been published. Besides experience with air conditioners in cars, the main tests have been limited to perform them in laboratories. This white paper some practical issues concerning the implementation of R134a refrigerant in commercial refrigeration systems for low power, equipped with hermetic compressors are presented.
Special production units such as: drinking fountains, coolers cabinets with electronic circuits, heat pump water heaters were considered to assess the results. The characteristics of capacity, energy efficiency, performance oil, moisture and other contaminants in the coolant, as well as the Retrofitting (conversion of a refrigeration 12v heating element system with R134a refrigerant R12) will be addressed in this white paper.
In context, 12v heating element should be understood in the commercial refrigeration as distinct from domestic refrigerators or fridges. The refrigeration systems with hermetic compressors (with a volume greater than 20 cm3 displacement), who frequently work with evaporation temperatures of -15 º to +15 º C, will be considered in this article. The particular interest is in units of mass production and troughs, units for the cooling of electronic circuits, commercial refrigerators and heat pumps designed to heat water. Performance of the refrigeration system with refrigerant R134a
Compared with the refrigerant R12, R134a has a reputation known for its lower required 12v heating element volume capacity and increased energy consumption. However, 12v heating element several tests have shown that this does not happen often. With applications 12v heating element including a hermetic compressor, the power characteristics appear to be similar to those of R12 and R134a refrigerant if the evaporating temperature is not very low.
Figure 1 shows a comparison between cooling capacity for a compressor with a volumetric displacement of 7.95 cm3 calorimeter testing between R12 and R134a refrigerant. Tests with R134a were made in this case without any alteration, but taking care to use the ester oil type. The known capacity decreases very low evaporation temperatures and increases 12v heating element at temperatures higher evaporation, as we noted in these tests. By lowering the temperature of condensation, the intersection of both curves changes at temperatures lower evaporation. 12v heating element This is due to the gradient of the line lower boiling R134a PH diagram (pressure enthalpy), 12v heating element which means that the reduction of the condensation temperature has a positive effect with R12 R134a.
In Figure 2, compares the COP of R12 and R134a. It is noted that the refrigerant R134a having a value greater than R12, except evaporation pressures below -25 degrees. In this comparison, the R134a does not win an energy disadvantage. Figure 3 is another 12v heating element comparison measurement COP for a hermetic compressor with a volumetric displacement of 12.9 cm3. R134a refrigerant measurements did not involve any alteration 12v heating element to the original 12v heating element compressor for refrigerant R12 in this case (the original compressor for R134a was not available). Again, there is evidence that the refrigerant R134a energy has disadvantages. On the contrary, in this case, even R134a shows low temperature energy advantages compared condensing refrigerant R12.
The different results shown in Figure 2 and 3, are not due to the properties of the refrigerant, but are influenced by the compressor used. This shows the limitations of making comparisons on energetic properties of the two refrigerants. It can be seen in the significant potential improvement from the energy viewpoint when R134a is used, and this involves the refrigeration system and the compressor, respectively. Moreover, especially when hermetic compressors are used, will depend to a greater degree of self-adaptation of the compressor and engine 12v heating element operating conditions of the system in its entirety. However, the variety of applications which must be taken into account in the design of commercial refrigeration systems, are the reason for such implementations which are only possible to a limited extend. Meanwhile, the optimizations of refrigerated systems in general should be carried out with the introduction of refrigerant R134a. An optimization of this type could, for example, replacement of the capillary tube or restrictor orifice 12v heating element or
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