Two stage transcritical refrigeration system

A refrigeration system comprising:

• a low temperature refrigeration circuit configured to circulate a first refrigerant, the low temperature refrigeration circuit including a plurality of refrigerated display cases, each of the plurality of refrigerated display cases having a dedicated evaporator assembly adapted to cool return air from the respective refrigerated display case by at least partially evaporating the first refrigerant, and a dedicated first stage compressor assembly in fluid communication with the dedicated evaporator assembly to compress the first refrigerant from the dedicated evaporator assembly to a first pressure corresponding to a first temperature of the first refrigerant;
• a high temperature refrigeration circuit configured to circulate a second refrigerant, the high temperature refrigeration circuit including a second compressor assembly operable to compress the second refrigerant to a second pressure corresponding to a second temperature of the second refrigerant, and a heat exchanger configured to cool the second refrigerant;
• and
• a heat exchanger in communication with the low temperature refrigeration circuit and the high temperature refrigeration circuit to transfer heat from the first refrigerant to the second refrigerant to cool the first refrigerant without mixing the first refrigerant and the second refrigerant.

A refrigeration system comprising:

• a plurality of refrigerated display cases, each of the plurality of refrigerated display cases including a dedicated evaporator assembly adapted to cool return air from the respective refrigerated display case by at least partially evaporating a refrigerant;
• at least one first stage compressor assembly in fluid communication with the dedicated evaporator assemblies to compress the refrigerant from the dedicated evaporator assemblies to a first pressure corresponding to a first temperature of the refrigerant;
• a second stage compressor assembly in fluid communication with the at least one first stage compressor assembly to receive the compressed refrigerant and to compress the refrigerant to a second pressure that is higher than the first pressure, the second pressure corresponding to a second temperature of the refrigerant;
• a heat exchanger located remotely from the plurality of refrigerated display cases, the heat exchanger including an inlet in fluid communication with the second stage compressor assembly to receive the refrigerant from the second stage compressor assembly and to reject heat from the refrigerant to an environment;
• a vessel positioned between and in fluid communication with the dedicated evaporator assemblies and the heat exchanger to separate liquid and gaseous phases of the refrigerant;
• a liquid main fluidly coupled to the dedicated evaporator assemblies and to the vessel, the liquid main configured to supply liquid refrigerant to each dedicated evaporator assembly;
• and
• a gas main fluidly coupled to the second stage compressor assembly and to the vessel, the gas main configured to direct gaseous refrigerant from the vessel to the second stage compressor assembly without passing through the dedicated evaporator assemblies.

A refrigeration system comprising:

• a closed coolant loop configured to circulate a coolant fluid, the coolant loop including a supply main, a distribution main, a discharge main, a heat exchanger fluidly connected to the discharge main and the supply main and in communication with an environment to reject heat from the coolant fluid into the environment, and at least one coolant pump fluidly connected to the distribution main and the discharge main to pump the coolant fluid to the heat exchanger and through the coolant loop;
• and
• a plurality of refrigerated display cases coupled to the coolant loop, each of the plurality of refrigerated display cases including
• a dedicated evaporator assembly adapted to cool return air from the respective refrigerated display case by at least partially evaporating a refrigerant, and
• a dedicated refrigeration unit coupled to the evaporator assembly, the evaporator assembly and the refrigeration unit in fluid communication with each other and defining a closed transcritical refrigeration circuit, the refrigeration unit including a compressor assembly in fluid communication with the evaporator assembly to compress the refrigerant from the evaporator assembly, and a heat exchanger in fluid communication with the compressor assembly and with the evaporator assembly, the heat exchanger in heat exchange relationship with the coolant loop to reject heat from the refrigerant to the coolant fluid.