Method and apparatus for cooling with coolant at a subambient pressure

An apparatus, comprising heat-generating structure disposed in an environment having an ambient pressure, and a cooling system for removing heat from said heat-generating structure, said heat-generating structure disposed on a ship, said cooling system including:

• a first fluid coolant;
• structure which reduces a pressure of said first coolant to a subambient pressure at which said coolant has a boiling temperature less than a temperature of said heat-generating structure;
• structure which directs a flow of said first coolant in the form of a liquid at said subambient pressure in a manner causing said liquid coolant to be brought into thermal communication with said heat-generating structure, the heat from said heat-generating structure causing said liquid coolant to boil and vaporize so that said first coolant absorbs heat from said heat-generating structure as said coolant changes state, wherein said structure is configured to circulate said first coolant through a flow loop while maintaining the pressure of said first coolant within a range having an upper bound less than said ambient pressure;
• a first heat exchanger for exchanging heat between said first coolant flowing through said loop and a second coolant in an intermediary loop so as to condense said first coolant flowing through said loop to a liquid;
• and
• a second heat exchanger for exchanging heat between said second coolant in the intermediary cooling loop and a body of water on which the ship is disposed.

A method for cooling heat-generating structure on a ship on a body of water, the heat-generating structure disposed in an environment having an ambient pressure, the method comprising:

• providing a primary fluid coolant;
• reducing a pressure of said primary fluid coolant to a subambient pressure at which said primary coolant has a boiling temperature less than a temperature of said heat-generating structure;
• bringing said primary coolant at said subambient pressure into thermal communication with said heat-generating structure, so that said primary coolant boils and vaporizes to thereby absorb heat from said heat-generating structure;
• circulating said primary coolant through a flow loop while maintaining the pressure of said primary coolant within a range having an upper bound less than said ambient pressure, said flow loop in thermal communication with a heat exchanger for removing heat from said primary coolant so as to condense said primary coolant to a liquid;
• providing an intermediary cooling loop in thermal communication with said heat exchanger;
• exchanging, by the heat exchanger, heat from said primary coolant with an intermediary loop coolant in said intermediary cooling loop;
• and
• exchanging heat from said intermediary cooling loop coolant with a sink fluid.

A method for cooling a plurality of heat-generating structures on a ship on a body of water, the plurality of heat-generating structures each disposed in respective environments having a respective ambient pressure, the method comprising:

• for each heat-generating structure;
• providing a respective fluid coolant;
• reducing a pressure of said respective fluid coolant to a subambient pressure at which said respective coolant has a boiling temperature less than a temperature of said heat-generating structure;
• bringing said respective coolant at said subambient pressure into thermal communication with said heat-generating structure so that said coolant boils and vaporizes to thereby absorb heat from said heat-generating structure;
• and
• circulating said respective coolant through a respective flow loop while maintaining the pressure of said respective coolant within a range having an upper bound less than said respective ambient pressure, said respective flow loop in thermal communication with a respective heat exchanger for removing heat from said respective coolant so as to condense said respective coolant to a liquid;
• providing at least one intermediary cooling loop;
• exchanging, by each respective heat exchanger, heat from each respective coolant with said at least one intermediary cooling loop so as to condense at least a portion of said respective coolant to a liquid;
• and
• exchanging heat from said at least one intermediary cooling loop with the body of water.