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R-134a
R-134a is the refrigerant HFC, which has a boiling point of 26.2 C (-29.8 C to R-12) and latent heat 205 kJ/kg (159 kJ/kg for R-12) (Pearson, 1991). It is non-flammable and non-toxic replacement for R-12. R-134a is widely used in domestic refrigerators and in the automotive Air conditioning but, apparently of little use in its normal cooling or air-conditioning, where a moderate temperature of condensation may be specified. R-134a is proposed as a potential replacement of R-22 in area of complex systems. However, the volumetric displacement compressor for R-134a should be about 50% more than the volume of R-22 compressor same cooling capacity.
Pressure drops refrigerant tubing can have a significant impact on CA R-134a system, so more of the tube may be needed than R-22 systems. R-134a packaged systems tend to be physically larger and more expensive than their R-22 colleagues (Hickman, 1994). Currently, R-134a is not considered for widespread use in reciprocating chillers; however, it is offered by some manufacturers as an alternative to R-22 screw and centrifugal chillers with flooded испарители.
R-134a is also acceptable as a substitute for R-400 ((60/40), mass%) and R-114 in new industrial process air conditioning.
EPA recommends R-134a only be used at ambient temperatures lower than 70 C because of the very high pressure in the system. R-134a is not contribute to ozone depletion. R-134a is the GWP and atmospheric lifetime is close to what other alternatives that are acceptable in this end-use. While R-134a is compatible with most existing refrigeration and air-conditioning equipment, parts, it is not compatible with mineral oils, which are currently used in these...
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