Abstract: Methods and systems provided for determining a phase state and/or for determining a degree of subcooling in a fluid. An exemplary method for operating a refrigeration cycle includes flowing a refrigerant through a metering device and calculating a pressure differential of the refrigerant across the metering device. Further, the method includes determining whether the refrigerant is a saturated liquid based on the pressure differential. The method includes, when the refrigerant is not a saturated liquid, cooling the refrigerant upstream of the metering device.

Abstract: Methods and systems provided for determining a phase state and/or for determining a degree of subcooling in a fluid. An exemplary method for operating a refrigeration cycle includes flowing a refrigerant through a metering device and calculating a pressure differential of the refrigerant across the metering device. Further, the method includes determining whether the refrigerant is a saturated liquid based on the pressure differential. The method includes, when the refrigerant is not a saturated liquid, cooling the refrigerant upstream of the metering device.

Abstract: A system includes a compressor outlet temperature module, a refrigerant quality module, and a correction factor module. The compressor outlet temperature module is configured to estimate a temperature at an outlet of a compressor in a thermal system of an electric vehicle. The refrigerant quality module is configured to estimate a quality of refrigerant at an inlet of the compressor based on an enthalpy at the compressor inlet and an inlet enthalpy correction factor. The refrigerant quality is a ratio of vapor refrigerant mass to total refrigerant mass. The correction factor module is configured to determine the inlet enthalpy correction factor based on the estimated compressor outlet temperature and a temperature measured at the compressor outlet.