Hermetically-sealed engine cooling system and related method of cooling

A heat transfer system, comprising:

• at least one heat-transfer fluid chamber formed adjacent to heat-rejecting components of the system and hermetically sealed to prevent exposure of coolant within the chamber to the system's ambient atmosphere;
• heat-transfer liquid received within the at least one heat-transfer fluid chamber and defining a first volume prior to system operation and a second volume greater than the first volume due to thermal expansion of the heat-transfer fluid during system operation;
• and
• an accumulator defining at least one hermetically-sealed chamber coupled in fluid communication with the at least one heat-transfer fluid chamber and receiving at least one of thermally-expanded heat-transfer fluid and gas from the at least one heat-transfer fluid chamber, wherein the at least one hermetically-sealed chamber defines a volume at least equal to or greater than the difference between the first and second volumes of the heat-transfer liquid, and the accumulator further defines at least one of:
• (i) a substantially liquid-free space coupled in fluid communication with the at least one hermetically-sealed chamber for receiving gas, and
• (ii) a movable wall coupled in fluid communication on one side with the at least one hermetically-sealed chamber and coupled in fluid communication on another side with ambient atmosphere and movable in response to the flow of at least one of thermally-expanded heat-transfer liquid and gas into the hermetically-sealed chamber,
• to thereby maintain the pressure within the at least one chamber of the accumulator within a predetermined pressure limit during system operation.