Cooling system and method employing a closed loop coolant path and micro-scaled cooling structure within an electronics subsystem of an electronics rack

A cooled electronics system comprising:

• at least one electronics rack comprising a plurality of electronics subsystems;
• and
• a cooling system comprising:
• a coolant distribution unit, the coolant distribution unit comprising a first heat exchanger, a first cooling loop and a plurality of second cooling loops, the first cooling loop receiving facility coolant and passing at least a portion thereof through the first heat exchanger, the plurality of second cooling loops providing system coolant to at least some of the plurality of electronics subsystems, and expelling heat in the first heat exchanger from the at least some electronics subsystems to the facility coolant in the first cooling loop;
• and
• multiple thermal dissipation units each associated with a respective one of the at least some electronics subsystems, each thermal dissipation unit comprising a second heat exchanger, a second cooling loop of the plurality of second cooling loops, and a third cooling loop, the second cooling loop providing system coolant to the second heat exchanger, the third cooling loop circulating conditioned coolant within the respective electronics subsystem and expelling heat in the second heat exchanger from the electronics subsystem to the system coolant in the second cooling loop.