Refrigeration system with emergency cooling using dedicated compressor

A refrigeration system, comprising:

• a high-pressure side, the high-pressure side comprising a gas cooler configured, while the refrigeration system is powered by a main power supply and is operating to provide refrigeration, to cool refrigerant on the high-pressure side;
• a low-pressure side comprising one or more evaporators, wherein each of the one or more evaporators is configured, while the refrigeration system is powered by the main power supply and is operating to provide refrigeration, to cool a corresponding space;
• an auxiliary compressor coupled to a backup power supply, wherein an input of the auxiliary compressor is coupled to fluid conduit of the low-pressure side and an output of the auxiliary compressor is coupled to fluid conduit of the high-pressure side;
• and
• a controller communicatively coupled to the auxiliary compressor, wherein the controller is configured to:
• determine that the main power supply is unavailable;
• and
• after determining that the main power supply is unavailable, cause the auxiliary compressor to turn on to move refrigerant from the low-pressure side to the high-pressure side;
• an expansion valve disposed between the high-pressure side and the low-pressure side, wherein:
• the expansion valve is at least partially open while the refrigeration system is powered by the main power supply and is operating to provide refrigeration;
• and
• the expansion valve is closed when the main power supply is unavailable, such that refrigerant flow from the high-pressure side to the low-pressure side is prevented.