Cooling system

A vehicle including:

• a battery;
• a motor that drives the vehicle using electric power of the battery;
• and
• a cooling system that performs cooling inside the vehicle by circulating a refrigerant containing CO2, the cooling system comprising:
• a compressor that compresses the refrigerant, the refrigerant containing CO2;
• a first heat exchanger for cooling the refrigerant compressed by the compressor;
• a second heat exchanger for cooling a predetermined cooling target inside the vehicle using the refrigerant cooled by the first heat exchanger;
• a first refrigerant passage for supplying the refrigerant that has been used for cooling in the second heat exchanger to the battery inside the vehicle to further cool the battery using the refrigerant;
• a second refrigerant passage for supplying the refrigerant cooled by the first heat exchanger to the first refrigerant passage without passing the refrigerant through the second heat exchanger;
• an expansion valve for expanding the refrigerant, the expansion valve being provided on the first refrigerant passage;
• a flow control valve for adjusting a flow rate of the refrigerant, the flow control valve being provided on the second refrigerant passage;
• and
• processing circuitry configured to:
• obtain an enthalpy of the refrigerant supplied from the first refrigerant passage to the battery, and
• perform control to increase an opening degree of the flow control valve when the enthalpy exceeds a predetermine range and perform control to reduce the opening degree of the flow control valve when the enthalpy is below the predetermined range.

A method for performing cooling of a vehicle, comprising:

• compressing, by a compressor, a refrigerant containing CO2;
• cooling, by a first heat exchanger, the refrigerant compressed by the compressor;
• cooling the vehicle, by a second heat exchanger, a predetermined cooling target inside the vehicle, using the refrigerant cooled by the first heat exchanger;
• supplying, by a first refrigerant passage, the refrigerant that has been used for cooling in the second heat exchanger to a battery inside the vehicle to further cool the battery using the refrigerant;
• supplying, by a second refrigerant passage, the refrigerant cooled by the first heat exchanger to the first refrigerant passage without passing the refrigerant through the second heat exchanger;
• expanding, by an expansion valve, the refrigerant, the expansion valve being provided on the first refrigerant passage;
• adjusting, by a flow control valve, a flow rate of the refrigerant, the flow control valve being provided on the second refrigerant passage;
• and
• by processing circuitry:
• obtaining an enthalpy of the refrigerant supplied from the first refrigerant passage to the battery;
• and
• performing control to increase an opening degree of the flow control valve when the enthalpy exceeds a predetermine range and perform control to reduce the opening degree of the flow control valve when the enthalpy is below the predetermined range.