Trans-critical vapor cycle system with improved heat rejection

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

• receiving heated air in an evaporator from a compartment within an aircraft to heat a refrigerant that is operating trans-critically in the cooling system;
• compressing the refrigerant to a first pressure;
• cooling the refrigerant in a first gas cooler using air passing into an air intake of an aircraft;
• compressing the refrigerant to a second pressure that is greater than the first pressure;
• cooling the refrigerant in a second gas cooler using the air passing into the air intake;
• wherein the first and second pressures avoid temperature differences between the refrigerant and the air within each of the first and second heat exchangers below a set restriction and at least the second pressure is above the critical point.

A system for operating within an aircraft, comprising:

• a turbine engine having an air intake;
• an evaporator configured to receive heated air from a compartment within the aircraft and heat a refrigerant;
• a first heat exchanger configured to receive air passing into the air intake when the aircraft is operating at elevation, and configured to receive the refrigerant from a first compressor at a first pressure;
• a second compressor configured to receive the refrigerant from the first heat exchanger and compress the refrigerant to a second pressure that is greater than the first pressure;
• and
• a second heat exchanger configured to receive the refrigerant from the second compressor;
• wherein the first and second compressors are configured to operate at pressures that avoid temperature differences between the refrigerant and the air within each of the first and second heat exchangers below a set restriction, and pass the refrigerant to an expansion device and then to the evaporator.