A transcritical
refrigeration system (100, 300, 400, 500, 600, 700) includes a
gas cooler / condenser (102); a
receiver (108) configured to collect
refrigerant produced by the
refrigeration system (100, 300, 400, 500, 600, 700); a gas
bypass valve (110) fluidly coupled to the outlet of the
receiver (108) and operable to control a pressure of the
refrigerant in the
receiver (108); and a medium temperature subsystem (112, 504, 608, 704). The medium temperature subsystem (112, 504, 608, 704) includes one or more expansion valves (140); one or more medium temperature evaporators (142); and a suction group (514, 714) including one or more transcritical compressors (144, 516, 613, 616, 716) operable to compress gas
refrigerant and
discharge the compressed gas refrigerant into a
discharge line. The
system includes a superheat
control system (104, 304, 404, 506, 604, 706) that includes a
heat exchanger system (116, 520, 522, 610, 720, 722) including a first side configured to carry gas refrigerant passing between the
gas cooler / condenser (102) and an inlet of the receiver (108), and a second side in
heat transfer communication with the first side.