2008, 2009), and do not cover flow condensation pressure drop characteristics.
These studies show that flow condensation pressure drop characteristics of refrigerant-oil mixtures are affected by the properties of refrigerant-oil mixtures.
In the case of conventional A/Cs, the minimum pressure ratio under which operations were possible (the "minimum allowable pressure ratio") was comparatively high, at about 1.5, so even when the outdoor temperature was low, it was necessary to maintain a high condensation pressure, which in turn resulted in extremely high power consumption in the compressor.
Furthermore, reducing the condensation pressure increases specific enthalpy for the refrigerant in the evaporator (Figure 4).
In the case of conventional A/Cs, the pressure ratio is high, and the compressor consumes large volumes of power, but the new A/C can operate at low condensation pressures, so the pressure ratio is lower, and the compressor's power consumption can be reduced.
The cycle's behavior with EEV has been simulated by using a lower superheating (Table 1) and a lower condensation pressure than TEV.
This result agrees with previous works, (6,7) where a high energy savings was claimed (due to the great modulation and adjustment capability of EEV with respect to TEV) at low condensation pressure (that implies low outside air temperature), while energy saving is decreasing with the increasing of condensation temperature.
In the reversed Rankine cycle the compressor outlet pressure is dictated by the condensation pressure
corresponding to the condenser temperature.
The increase in subcooling at the highest charges is due to increase of the saturation temperature at higher condensation pressures
and not to a decrease in the outlet refrigerant temperature.
As discussed earlier, due to the absence of pump oil and lubrication greases, the condensation pressures
of solvents in chemical scroll pumps are a few orders of magnitude higher than those in OSRVPs.