Adaptive trans-critical CO2 cooling system

A method of operating a cooling system, the method comprising:

• operating a set of valves to:
• cause a refrigerant to pass through a heat exchanger having a refrigerant inlet flow that is dependent on the ambient conditions;
• direct the refrigerant to a piping split point at a given pressure through a first cooling circuit that includes an expansion valve that receives the refrigerant at the given pressure, a second cooling circuit that includes a turbine that receives the refrigerant at the given pressure, or both depending on the ambient conditions;
• and,
• cause the refrigerant to pass in parallel and simultaneously through the first and second cooling circuits and rejoin after passing through the first and second cooling circuits;
• compressing the refrigerant in a first compressor to a first pressure;
• evaporating the refrigerant in an evaporator;
• cooling the refrigerant in a first fluid cooler;
• compressing the refrigerant in a second compressor to a second pressure that is less than the first pressure, prior to the refrigerant entering the first compressor;
• and
• cooling the refrigerant in a second fluid cooler, prior to the refrigerant entering the first compressor but after exiting the second compressor.

An aircraft comprising:

• a turbine engine;
• and
• a cooling system for the aircraft comprising:
• an evaporator configured to evaporate a refrigerant;
• a heat exchanger through which the refrigerant flows, in which heat is rejected to a fluid, the heat exchanger having the fluid passing therethrough such that heat is rejected to the fluid;
• and
• a first circuit comprising an expansion valve configured to receive the refrigerant at a given pressure;
• a second circuit comprising a first turbine coupled to a first compressor, wherein the first turbine receives the refrigerant at the given pressure;
• a refrigerant piping split point configured to:
• receive the refrigerant at the given pressure from the heat exchanger;
• and
• split the refrigerant flow into the first circuit and the second circuit through which the refrigerant flows simultaneously and in parallel;
• a piping rejoin point at which the first circuit and the second circuit rejoin;
• and
• a set of valves arranged to:
• direct the refrigerant through the first circuit, the second circuit, or both the first circuit and the second circuit based on ambient conditions of the cooling system;
• a first gas cooler configured to cool the refrigerant;
• a second compressor configured to, prior to entering the first compressor, compress the refrigerant to a second pressure that is less than the first pressure;
• and
• a second gas cooler configured to cool the refrigerant prior to entering the first compressor but after exiting the second compressor.