As of 2011, R-134a systems were banned and applied to all new models, and as of 2017, to all cars in European countries because the indirect radioactive effect for GWP is 1300 as tabulated in Table 1. Table 1. Ozone depleting potential (ODP), global warming potential (GWP) and other ...
Detailed refrigerant properties for the alternatives in Table I are missing, however, except for a few. Here attention is drawn to HFC134a in particular, as this refrigerant is assumed to become one of the main refrigerants in the future. Figure 1 expresses theoretical COP relative to CFC-12 ...
R430A presents the closest values to R134a exceeding the COP for all working conditions. It is the most urgent for R404A replacement due to the differences in flammability, discharge temperature, temperature glide and performance reduction. It is not urgent for replacement of R410A due to the ...
In our case, we used as design parameters those shown in the legend of Table 4 where the calculated results (COP and density—ρ—at the suction of the first stage) are summarized. It has to be highlighted that: R22 is quite efficient, but it cannot no longer be used; R134A and R...
The evaluation of the optimal medium temperature in a space heating used transcritical air-source CO2 heat pump with an R134a subcooling device. Energy Convers Manag. 2018, 166, 409–423. [CrossRef] 12. Song, Y.; Cao, F. The evaluation of optimal discharge pressure in a water precooler-...
The study for the condensation process of the R134a and R404A refrigerants in pipe minichannels under the conditions of dynamic instabilities demonstrated that the velocity of the movement of the pressure change signal vp, remains in the range of 40–205 m/s, whereas the velocity of the front ...