Cooling system

A gas turbine engine comprising:

• a compressor section coupled to a turbine section by one or more shafts;
• a main lubrication system for providing lubrication to one or more components located in at least one of the compressor section or the turbine section;
• and
• a thermal management system including
• a thermal transport bus having a heat exchange fluid flowing therethrough;
• a plurality of heat source exchangers in thermal communication with the heat exchange fluid in the thermal transport bus, the plurality of heat source exchangers arranged along the thermal transport bus and including a heat exchanger for transferring heat from the main lubrication system to the heat exchange fluid in the thermal transport bus;
• at least one heat sink exchanger permanently or selectively in thermal communication with the heat exchange fluid in the thermal transport bus at a location downstream of the plurality of heat source exchangers;
• and
• a compressor in fluid communication with the heat exchange fluid at a location upstream of the at least one heat sink exchanger for compressing the heat exchange fluid in the thermal transport bus.