Abstract: A two-phase liquid cooling system for an electronic component comprised of flexible sealed bag which is partially filled with a liquid coolant. Sufficient residual non-condensing gas is maintained in the bag so that some of the gas dissolves in the liquid coolant when the device is not operating and at ambient temperature. During warmup, the residual gas comes out of solution and creates nucleation sites that assist in initiating boiling. The bag is air and fluid-impermeable, and has sufficient flexibility such that as coolant vaporizes, the bag expands to maintain the internal bag pressure substantially the same as the ambient environmental pressure. The bag may also be provided with a metal heat spreader plate which passes through a wall of the bag an assists with transferring heat from the component to the coolant. The heat spreader plate may be specially treated to allow the flexible bag material to by directly heat sealed to the plate and to provide nucleation sites to enhance coolant boiling.

Abstract: A two-phase liquid cooling system has a container structure that has at least one wall with sufficient flexibility that the wall expands as the coolant vapor expands thereby maintaining the internal container pressure substantially the same as the ambient environmental pressure. Coolant boiling overshoot is reduced by allowing residual gases to remain in the cooling system. More particularly, sufficient residual gas is maintained in the system so that some of the gas dissolves in the liquid coolant when the device is not operating and is at ambient temperature. During warm-up, the residual gas comes out of solution and creates nucleation sites that initiate boiling and prevent overshoot. Additional nucleation sites can also be added to reduce overshoot by treating the inside surfaces of the container structure, for example by laser machining, to create nucleation sites.

Abstract: A two-phase cooling system for a portable computer, the system consisting of an evaporator and a condenser that are both included in either the lid or the base of the computer. The two-phase cooling system is positioned proximate to the computer's heat-producing circuitry, such that the system draws liquid coolant past the circuitry and heat is transferred from the circuitry to the coolant. A fan may also be included, to assist in heat rejection from the cooling system. In a preferred embodiment, the cooling system consists of a flattened heat pipe, with a first side operating as the evaporator and a second side operating as the condenser.

Abstract: A two-phase liquid cooling system utilizes and evaporator unit for vaporizing a liquid coolant and a condenser unit for condensing the coolant vapor. The unit is capable of operating in at least two orientations: in one orientation, the condenser is located vertically above the evaporator and condensed coolant returns from the condenser to the evaporator under the force of gravity. In another orientation, the evaporator is located vertically above the condenser and the liquid coolant is returned to the evaporator by a stream of bubbles rising in a tube connecting the evaporator and the condenser. The stream of bubbles is produced by a small heater which is operated by a gravity controlled switch. A check valve is provided to insure that the bubble stream moves in the proper direction.

Abstract: A heat pipe which is flexible and thus conformable to the space in which it is to be deployed consists of two or three layers, namely, a relatively thin, highly conductive plate as a bottom layer, a plastic sheet as a top layer and wicking as an optional middle layer. The bottom plate has a relatively high modulus of elasticity and it is stiff, yet ductile. It is preferably made of metal, such as aluminum, or a plastic sheet or plate. To manufacture the heat pipe, the bottom and top layers are aligned, with the wicking between them, and sealed together around three edges. Liquid coolant is then added and the fourth edge is sealed. The sealing is preferably performed by heat sealing. The heat pipe may include heat-dissipating fins or ridges on the end of the pipe that operates as a condenser. The opposing end of the pipe, which acts as the evaporator, is positioned proximate to a heat-generating component.

Abstract: A liquid crystal (LC) display monitor has a high luminosity light source to provide good visibility in brightly lit areas. To prevent overheating of the LC screen and other components of the monitor, a two-phase cooler is provided. The cooler consists of two translucent, flexible bag-like containers, each conforming to a different side of the light source. A low-boiling point coolant within the containers absorbs heat from the light source and is partially vaporized. The coolant vapor travels from the containers into a condenser which is external to the monitor cabinet. The condenser draws thermal energy out of the coolant vapor, causing it to condense and return to the containers. The containers provide shock absorption to protect the light source, and the containers or the coolant may have light-scattering properties to provide diffusion of the light.

Abstract: A two-phase liquid cooling system for an electronic component comprised of flexible sealed bag which is partially filled with a liquid coolant. Sufficient residual non-condensing gas is maintained in the bag so that some of the gas dissolves in the liquid coolant when the device is not operating and at ambient temperature. During warmup, the residual gas comes out of solution and creates nucleation sites that assist in initiating boiling. The bag is air and fluid-impermeable, and has sufficient flexibility such that as coolant vaporizes, the bag expands to maintain the internal bag pressure substantially the same as the ambient environmental pressure. The bag may also be provided with a metal heat spreader plate which passes through a wall of the bag an assists with transferring heat from the component to the coolant. The heat spreader plate may be specially treated to allow the flexible bag material to by directly heat sealed to the plate and to provide nucleation sites to enhance coolant boiling.

Abstract: A two-phase cooling apparatus uses a radioactive initiator to induce boiling in a liquid coolant, thus reducing thermal hysteresis. A radioactive source, such as spent uranium, is immersed in a liquid coolant bath to allow interaction between the emitted radiation and the liquid. A heat spreader plate may be used to conduct heat to the liquid from a unit to be cooled. An interior surface of a coolant chamber, such as the heat spreader plate, may be plated with a radioactive material to induce a high incidence of nucleation sites. A shielding material may also be used to shield the unit being cooled from the radioactive source. The radioactive source material may also be used to retrofit existing two-phase cooling systems.

Abstract: A two-phase liquid cooling system has a container structure that has at least one wall with sufficient flexibility that the wall expands as the coolant vapor expands thereby maintaining the internal container pressure substantially the same as the ambient environmental pressure. Coolant boiling overshoot is reduced by allowing residual gases to remain in the cooling system. More particularly, sufficient residual gas is maintained in the system so that some of the gas dissolves in the liquid coolant when the device is not operating and is at ambient temperature. During warmup, the residual gas comes out of solution and creates nucleation sites that initiate boiling and prevent overshoot. Additional nucleation sites can also be added to reduce overshoot by treating the inside surfaces of the container structure, for example by laser machining, to create nucleation sites.

Abstract: A two-phase cooling system for a portable computer which in one embodiment consists of an evaporator which is positioned within the base of the computer and a condenser which is positioned within or attached to the lid of the computer. The evaporator and the condenser are connected by flexible tubing. The tubing may run externally from the lid to the base or it may extend through one or more of the hinges that connect the base and the lid. In an alternative embodiment, both the evaporator and the condenser of the two-phase system are incorporated into either the base or the lid of the computer.