CO

1. An integrated CO 2 refrigeration and air conditioning (AC) system for use in a facility, the integrated system comprising:

one or more CO 2 compressors configured to discharge a CO 2 refrigerant at a higher pressure for circulation through a circuit to provide cooling to one or more refrigeration loads in the facility;

a gas cooler/condenser configured to receive the CO 2 refrigerant from the one or more CO 2 compressors;

a high pressure valve configured to receive the CO 2 refrigerant from the gas cooler/condenser via a CO 2 liquid line connecting the gas cooler/condenser to the high pressure valve;

a receiver configured to receive the CO 2 refrigerant at a lower pressure, the receiver having a CO 2 liquid portion and a CO 2 vapor portion;

an AC module that provides cooling for a chilled AC coolant different from the CO 2 refrigerant and delivers the chilled AC coolant to AC loads in the facility, the AC module comprising:

an AC evaporator having an inlet configured to receive CO 2 liquid from the high pressure valve and an outlet configured to discharge a CO 2 vapor, wherein the AC evaporator provides the cooling for the chilled AC coolant by transferring heat from the chilled AC coolant to the CO 2 liquid, thereby causing a portion of the CO 2 liquid to evaporate forming the CO 2 vapor; and

an AC compressor arranged in parallel with the one or more CO 2 compressors, the AC compressor configured to receive the CO 2 vapor from the receiver; and

a CO 2 vapor line connecting the AC evaporator to the CO 2 vapor portion of the receiver and configured to provide the CO 2 vapor discharged from the AC evaporator to the CO 2 vapor portion of the receiver;

wherein the high pressure valve is controllable to maintain a target pressure of the CO 2 refrigerant; and

wherein the one or more refrigeration loads are different from the AC loads.

2. The integrated system of claim 1 , further comprising:

a suction line heat exchanger disposed between the AC evaporator and the AC compressor, the suction line heat exchanger configured to receive the higher pressure CO 2 refrigerant as a heat source.

3. The integrated system of claim 2 , further comprising:

a CO 2 liquid accumulator disposed between the suction line heat exchanger and the AC compressor.

4. The integrated system of claim 1 , further comprising:

a control system operable to control an amount of CO 2 vapor directed from the receiver to a suction of the AC compressor and from the receiver to a suction of the CO 2 compressors.

5. The integrated system of claim 1 wherein the AC module is integrated into the CO 2 refrigeration system by three piping connections.

6. An integrated CO 2 refrigeration and air conditioning (AC) system for use in a facility, the integrated system comprising:

a CO 2 refrigeration circuit configured to circulate a CO 2 refrigerant to refrigeration loads in the facility, the CO2 refrigeration circuit including:

a plurality of parallel CO 2 compressors,

a gas cooler/condenser,

a receiver having a CO 2 vapor portion and a CO 2 liquid portion,

a high pressure valve positioned downstream of the gas cooler/condenser and upstream of the receiver;

a CO 2 liquid transport line coupled to the gas cooler/condenser and the high pressure valve, the CO 2 liquid transport line configured to receive CO 2 liquid from the gas cooler/condenser and to provide the CO 2 liquid to the high pressure valve;

a CO 2 liquid supply line coupled to the CO 2 liquid portion of the receiver and configured to direct CO 2 liquid to one or more refrigeration loads in the facility; and

an AC module that provides cooling for a chilled AC coolant different from the CO2 refrigerant and delivers the chilled AC coolant to AC loads in the facility, the AC module comprising:

an AC evaporator having an inlet configured to receive the CO 2 refrigerant from the high pressure valve and an outlet configured to discharge the CO 2 refrigerant, wherein the AC evaporator provides the cooling for the chilled AC coolant by transferring heat from the chilled AC coolant to the CO 2 refrigerant, thereby causing a portion of the CO 2 refrigerant to evaporate forming CO 2 vapor;

an AC compressor arranged in parallel with the plurality of parallel CO 2 compressors, the AC compressor configured to receive CO 2 vapor from the AC evaporator and from the receiver; and

a CO 2 vapor line connecting the AC evaporator to the CO 2 vapor portion of the receiver and configured to provide the CO 2 vapor from the AC evaporator to the CO 2 vapor portion of the receiver;

wherein the high pressure valve is controllable to maintain a target pressure of the CO 2 liquid; and

wherein the refrigeration loads are different from the AC loads.

7. The integrated system of claim 6 , wherein the AC compressor is configured to at least partially regulates a CO 2 pressure within the receiver.

8. The integrated system of claim 6 , wherein upon a loss of suction at the AC compressor, the CO 2 refrigerant is directed through a gas bypass valve to the plurality of parallel CO 2 compressors.

9. An integrated CO 2 refrigeration and air conditioning (AC) system for use in a facility, the integrated system comprising:

a CO 2 refrigeration circuit configured to circulate a CO 2 refrigerant to refrigeration loads in the facility, the CO 2 refrigeration circuit including:

a CO 2 compressor configured to discharge the CO 2 refrigerant at a first pressure into a first fluid line,

a receiver configured to receive the CO 2 refrigerant at a second pressure lower than the first pressure, the receiver having a CO 2 liquid portion and a CO 2 vapor portion, and

a high pressure valve disposed between the CO 2 compressor and the receiver, the high pressure valve configured to receive the CO 2 refrigerant at the first pressure from a second fluid line and discharge the CO 2 refrigerant at the second pressure;

a gas cooler/condenser located upstream of the high pressure valve and downstream of the CO 2 compressor, the gas cooler/condenser configured to receive the CO 2 refrigerant from the first fluid line, the gas cooler/condenser further configured to discharge the CO 2 refrigerant into the second fluid line;

an AC module integrated with the CO 2 refrigeration circuit, wherein the AC module provides cooling for a chilled AC coolant different from the CO 2 refrigerant and delivers the chilled AC coolant to AC loads in the facility, the AC module including:

an AC evaporator configured to receive CO 2 refrigerant from the high pressure valve, wherein the AC evaporator provides the cooling for the chilled AC refrigerant by transferring heat from the chilled AC coolant to the CO 2 refrigerant, thereby causing a portion of the CO 2 refrigerant to evaporate forming CO 2 vapor;

an AC compressor arranged in parallel with the CO 2 compressor, the AC compressor configured to receive CO 2 vapor from the CO 2 vapor portion of the receiver and to discharge vapor CO 2 refrigerant into the first fluid line; and

a CO 2 vapor line connecting the AC evaporator to the CO 2 vapor portion of the receiver and configured to provide the CO 2 vapor from the AC evaporator to the CO 2 vapor portion of the receiver;

wherein the high pressure valve is controllable to maintain a target pressure of the CO 2 refrigerant; and

wherein the refrigeration loads are different from the AC loads.

10. The integrated system of claim 9 , wherein the component of the CO 2 refrigeration circuit from which the AC evaporator receives CO 2 refrigerant is the second fluid line, the system further comprising:

a first CO 2 vapor line fluidly coupling the CO 2 vapor portion of the receiver to an outlet of the AC evaporator, and

a second CO 2 vapor line fluidly coupling the outlet of the AC evaporator to the inlet of the AC compressor.

11. The integrated system of claim 9 , wherein the component of the CO 2 refrigeration circuit from which the AC evaporator receives CO 2 refrigerant is the high pressure valve,

wherein the AC evaporator is arranged in an in line configuration to receive an entire mass flow of the CO 2 refrigerant from the high pressure valve.