| abstract |
In an engine cooling system, an upper coolant chamber and a lower coolant chamber of a typical engine, such as an internal combustion engine or fuel cell, are formed adjacent to the heat-rejecting components of the engine and are hermetically sealed to prevent exposure of coolant within the chambers to the engine's ambient atmosphere. The coolant is preferably a substantially anhydrous, boilable liquid coolant having a saturation temperature higher than that of water, and the coolant is pumped at a predetermined flow rate, and distributed through the coolant chambers so that the liquid coolant within the chambers substantially condenses the coolant vaporized by the heat-rejecting components of the engine. Thermally-expanded coolant, non-condensable gas, and trace amounts of vapor, if any, are received within a hermetically-sealed accumulator coupled in fluid communication with a relatively low-pressure area of the engine coolant chambers, and the accumulator defines at least one chamber, which may form a liquid-free space, for receiving the non-condensable gas and trace vapors. The at least one accumulator chamber defines a predetermined volume, which may be a variable volume, selected to maintain the pressure within the accumulator within a predetermined pressure limit (e.g., about 5 psig) during engine operation. |