Systems, controllers, and methods for controlling a CO2 refrigeration system
AssigneeCopeland Corporation
InventorsDonald R. Wiesmann, Diane B. Patrizio
Life of this patent
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Abstract
A method of controlling a CO2 refrigeration system includes obtaining a target exit pressure of refrigerant from a gas cooler/condenser, a measurement of a pressure of the flash tank, and an open percentage of a bypass valve (BGV). Whether or not to decrease the pressure of the flash tank is determined, based at least in part on the pressure of the flash tank and the open percentage of the BGV. When the controller determines to decrease the pressure of the flash tank, the target exit pressure is increased by an amount.
Claims20
A CO2 refrigeration system comprising:
- a compressor;
- a gas cooler/condenser that receives refrigerant discharged from the compressor and outputs a flow of refrigerant, the gas cooler/condenser operable as a gas cooler when the CO2 refrigeration system is operating in a transcritical mode and as a condenser when the CO2 refrigeration system is operating in a subcritical mode;
- a flash tank connected to receive refrigerant output from the gas cooler/condenser;
- a bypass valve (BGV) between the flash tank and a suction side of the compressor to control a flow of refrigerant from the flash tank to the suction side of the compressor;
- and
- a controller having a processor and a memory, the processor configured by instructions stored in the memory to perform the steps of:
- obtaining a target exit pressure of the refrigerant from the gas cooler/condenser, a measurement of a pressure of the flash tank, and an open percentage of the BGV;
- determining, based at least in part on the pressure of the flash tank and the open percentage of the BGV, whether or not to decrease the pressure of the flash tank;
- and
- increasing the target exit pressure by an amount when the controller determines to decrease the pressure of the flash tank.
A controller for a CO2 refrigeration system including a compressor, a gas cooler/condenser that receives refrigerant discharged from the compressor and outputs a flow of refrigerant, a flash tank connected to receive refrigerant output from the gas cooler/condenser, and a bypass valve (BGV) between the flash tank and a suction side of the compressor to control a flow of refrigerant from the flash tank to the suction side of the compressor, the controller comprising:
- a processor;
- and
- a memory, the processor configured by instructions stored in the memory to perform the steps of:
- obtaining a target exit pressure of the refrigerant from the gas cooler/condenser, a measurement of a pressure of the flash tank, and an open percentage of the BGV;
- determining, based at least in part on the pressure of the flash tank and the open percentage of the BGV, whether or not to decrease the pressure of the flash tank;
- and
- increasing the target exit pressure by an amount when the controller determines to decrease the pressure of the flash tank.
A method of controlling a CO2 refrigeration system including a compressor, a gas cooler/condenser that receives refrigerant discharged from the compressor and outputs a flow of refrigerant, a flash tank connected to receive refrigerant output from the gas cooler/condenser, and a bypass valve (BGV) between the flash tank and a suction side of the compressor to control a flow of refrigerant from the flash tank to the suction side of the compressor, the method comprising:
- obtaining a target exit pressure of the refrigerant from the gas cooler/condenser, a measurement of a pressure of the flash tank, and an open percentage of the BGV;
- determining, based at least in part on the pressure of the flash tank and the open percentage of the BGV, whether or not to decrease the pressure of the flash tank;
- and
- increasing the target exit pressure by an amount in response to the controller determining to decrease the pressure of the flash tank.
Dependencies are inferred from the claim text.