CO2 refrigeration system with supercritical subcooling control

A refrigeration system comprising:

• a gas cooler/condenser configured to remove heat from a refrigerant and discharge the refrigerant into a high pressure conduit;
• a temperature sensor located along the high pressure conduit and configured to measure a temperature of the refrigerant leaving the gas cooler/condenser;
• a pressure sensor located along the high pressure conduit and configured to measure a pressure of the refrigerant leaving the gas cooler/condenser;
• a pressure control valve located along the high pressure conduit and operable to regulate the pressure of the refrigerant leaving the gas cooler/condenser;
• and
• a controller configured to determine whether the refrigerant leaving the gas cooler/condenser is in a subcritical region based on at least one of the measured temperature of the refrigerant or the measured pressure of the refrigerant and, in response to determining that the refrigerant leaving the gas cooler/condenser is not in the subcritical region:
• add a pseudo-subcooling temperature value to the measured temperature of the refrigerant to calculate a summed temperature;
• calculate a supercritical pseudo-saturated pressure as a function of the summed temperature;
• and
• operate the pressure control valve to drive the pressure of the refrigerant leaving the gas cooler/condenser to the supercritical pseudo-saturated pressure corresponding to the summed temperature.