Propane (R-290)
Propane is used as the working environment in large refrigeration systems for many years, especially in the petrochemical and processing industries. It has excellent thermodynamic properties are similar to the ammonia but the explosion and fire hazard are much more severe. This, of course, limits the possibility of its application in conventional refrigeration field, although this risk should not be exaggerated. Flammable gases, are commonplace in many technical applications, and does not cause many problems when simple precautions were observed. Propane has a special advantage for use in turbo compressors because it is almost perfect molar mass.
Another area where propane or mixtures of housing may have a future as a replacement for R-12 in the household refrigerators and freezers and, perhaps in smaller air conditioning systems. The charge in the normal refrigerator should not exceed 50 g, propane, being much lighter fluid than of R-12, and it is less than what can be used as a drive for gas in hair spray.
Recent large-scale study showed that the risk is minor (Lorentzen, 1993).
Several hundred grams needed in smaller air conditioning, seems to be quite acceptable with the right design. Propane-butane mixture may be advantageous to reach a temperature glide to fit the limited amount of air flow evaporator and capacitor.
In a study conducted by James Missenden (1992), the consequences of the use of propane refrigerators of the household type were considered with regard to energy consumption, compressor lubrication, cost, accessibility, environmental factors, and security, and compared with the results obtained for R-12, R-22 and R-134a. From the experiments, they found that propane may replacement for R-12 with a similar performance at a lower cost and came to the conclusion that propane is attractive and environmentally-friendly alternatives to ODSs. Although propane very stable and meets refrigeration (e.g., The COP, differential pressure, comparative discharge and other) is easy, the only concern is its reactive characteristics, such as incineration and halogenation...
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Refrigerants