C02 refrigeration system with isochoric compression

A refrigeration system, comprising:

• a heat exchanger configured to receive a portion of refrigerant from a low temperature (LT) compressor unit and a portion of refrigerant from a medium temperature (MT) compressor unit, wherein the heat exchanger is configured to transfer heat from the portion of the refrigerant received from the MT compressor unit to the portion of the refrigerant received from the LT compressor unit thereby producing a heated refrigerant stream and a cooled refrigerant stream;
• a first valve positioned between the LT compressor unit and the heat exchanger, wherein the first valve is configured to regulate the flow rate of the refrigerant from the LT compressor unit to the heat exchanger;
• a second valve positioned between the LT compressor unit and the MT compressor unit, wherein the second valve is configured to regulate the flow rate of the refrigerant from the LT compressor unit to the MT compressor unit;
• a parallel compressor unit configured to receive the heated refrigerant stream from the heat exchanger;
• and
• a third valve positioned between the heat exchanger and the parallel compressor unit, wherein the third valve is configured to regulate the flow rate of the heated refrigerant from the heat exchanger to the parallel compressor.

A method of operating a refrigeration system, the method comprising:

• compressing a refrigerant received from a medium temperature (MT) evaporator unit using a MT compressor unit, the MT compressor unit comprising at least one MT compressor;
• compressing the refrigerant received from a low temperature (LT) evaporator unit using a LT compressor unit, the LT compressor unit comprising at least one LT compressor;
• and
• transferring heat from a portion of the refrigerant provided by the MT compressor unit to a portion of the refrigerant provided by the LT compressor unit using a heat exchanger to produce a heated refrigerant stream and a cooled refrigerant stream.