Abstract: A server can include a cooling line assembly to provide fluid cooling of one or more server components. The server can include a chassis, a circuit board positioned within the chassis, and a processor electrically connected to the circuit board. The cooling line assembly can include a heat sink module on a surface to be cooled that is in thermal communication with the processor. The heat sink module can include an inlet port fluidly connected to an inlet chamber, a plurality of orifices fluidly connecting the inlet chamber to an outlet chamber, and an outlet port fluidly connected to the outlet chamber. The orifices can deliver jet streams of coolant into the first outlet chamber and against the surface to be cooled when pressurized coolant is provided to the inlet chamber of the heat sink module.

Abstract: A microprocessor assembly adapted for fluid cooling can include a semiconductor die mounted on a substrate. The semiconductor die can include an integrated circuit with a two-dimensional and/or three-dimensional circuit architecture. The assembly can include a heat sink module in thermal communication with the semiconductor die. The heat sink module can include an inlet port fluidly connected to an inlet chamber, a plurality of orifices fluidly connecting the inlet chamber to an outlet chamber, and an outlet port fluidly connected to the outlet chamber. When pressurized coolant is delivered to the inlet chamber, the plurality of orifices can provide jet streams of coolant into the outlet chamber and against a surface to be cooled to provide fluid cooling suitable to control a semiconductor die temperature during operation.

Abstract: A redundant heat sink module can include a first independent coolant pathway and a second independent coolant pathway. The first independent coolant pathway can include a first inlet chamber, a first outlet chamber, and a first plurality of orifices extending from the first inlet chamber to the first outlet chamber and providing a first plurality of impinging jet streams of coolant against a first region of a surface to be cooled when pressurized coolant is provided to the first inlet chamber. The second independent coolant pathway can include a second inlet chamber, a second outlet chamber, and a second plurality of orifices extending from the second inlet chamber to the second outlet chamber and providing a second plurality of impinging jet streams of coolant against a second region of the surface to be cooled when pressurized coolant is provided to the second inlet chamber.

Abstract: A two-phase cooling system can include a primary cooling loop and a heat rejection loop. The primary cooling loop can include a reservoir, a first pump fluidly connected to the primary cooling loop downstream of the reservoir, and a heat sink module fluidly connected to the primary cooling loop downstream of the first pump and upstream of the reservoir. The first pump can draw dielectric coolant from the reservoir and provide a primary flow of pressurized dielectric coolant through the primary cooling loop, with a first portion flowing through the heat sink module and a second portion flowing through a bypass. The heat rejection loop can be fluidly connected to the same reservoir and can include a second pump and a heat exchanger. The second pump can draw dielectric coolant from the reservoir and provide a secondary flow of pressurized coolant through the heat exchanger and back to the reservoir.

Abstract: A heat exchanger can include a first helical gas passageway extending from a first side of the heat exchanger to a second side of the heat exchanger. The first helical gas passageway can extend along and wrap around a first liquid passageway within the heat exchanger. A second helical gas passageway can extend from the first side of the heat exchanger to the second side of the heat exchanger. The second helical gas passageway can extend along and wrap around a second liquid passageway within the heat exchanger. Along a length of the first helical gas passageway, the first helical gas passageway can merge with the second helical gas passageway and then subsequently separate from the second helical gas passageway. The heat exchanger can be a liquid-to-gas counter-flow heat exchanger suitable for a wide variety of applications, including computer cooling.

Abstract: A manifold can convey and distribute fluid within a cooling system. The manifold can include an inlet chamber and an outlet chamber. A first plurality of quick-connect fittings can fluidly connect to the inlet chamber, and a second plurality of quick-connect fittings can fluidly connect to the outlet chamber. The quick-connect fittings can allow one or more cooling line assemblies to be rapidly connected between the inlet chamber and the outlet chamber. The manifold can include a bypass fluidly connecting the inlet chamber to the outlet chamber. A valve can be positioned in the bypass. The valve can control a flow of pressurized coolant from the inlet chamber to the outlet chamber through the bypass to maintain a desired pressure differential between the inlet chamber and the outlet chamber. The valve can be a differential pressure bypass valve.

Abstract: A circuit board assembly, such as a motherboard, graphics card, sound card, or network card, can be adapted for fluid cooling. The circuit board assembly can include a processor electrically connected to a printed circuit board. The circuit board assembly can include a cooling line assembly with an inlet fitting, an outlet fitting, and a heat sink module fluidly connected between the inlet and outlet fittings by sections of tubing. The heat sink module can be mounted on a surface to be cooled that is a surface of, or a surface in thermal communication with, the processor. When fluidly connected to a cooling system, coolant flowing through the cooling line assembly can flow through a plurality of orifices in the heat sink module forming a plurality of jet streams that are projected against the surface to be cooled, resulting in heat transferring from the processor to the flowing coolant.

Abstract: Disclosed are methods and apparatuses for cooling a work piece surface using two-phase impingement, such as direct jet impingement. Preferred method include flowing a coolant through a chamber comprising a surface to be cooled by projecting a jet stream of coolant against the surface while maintaining pressure in the chamber to permit at least a portion of coolant contacting the surface to boil. Preferred apparatuses include a chamber comprising the surface and tubular nozzles configured to project a stream of coolant against the surface, a pump for forcing coolant through the tubular nozzles, a pressurizer for maintaining an appropriate pressure in the chamber, and a heat exchanger for cooling the coolant exiting the chamber. The apparatuses may further include a pressure regulator for detecting changes in temperature of the coolant exiting the chamber and communicating with the pressurizer to adjust the maintained pressure accordingly.

Abstract: A method of absorbing heat from two or more devices can employ a two-phase cooling apparatus that pumps low-pressure coolant through two or more fluidly-connected and series-connected heat sink modules. A flow of subcooled single-phase liquid coolant can be provided to an inlet of a first heat sink module in thermal communication with a first device. Within the first heat sink module, the flow of subcooled single-phase liquid coolant can absorb a first amount of heat from the first device as sensible heat. The flow of subcooled single-phase liquid coolant can be transported from an outlet of the first heat sink module to an inlet of a second heat sink module. Within the second heat sink module, the flow of subcooled single-phase liquid coolant can absorb a second amount of heat from the second device partially as sensible heat and partially as latent heat and thereby transform to two-phase bubbly flow.

Abstract: A method of cooling multiple processors of an electronic device can employ a two-phase cooling system with series-connected heat sink modules. A flow of dielectric single-phase liquid coolant can be provided to a first heat sink module on a first processor. A first amount of heat can be transferred from the first processor to the liquid coolant resulting in vaporization of a portion of the liquid coolant within the first heat sink module, thereby changing the flow of single-phase liquid coolant to two-phase bubbly flow and absorbing heat across the heat of vaporization of the coolant. The two-phase bubbly flow is then transferred from the first heat sink module to a second heat sink module mounted on a second processor. Within the second module, heat transfer from the second processor to the coolant can result in vaporization of a portion of the remaining liquid coolant, thereby further increasing vapor quality.

Abstract: A heat sink for cooling a heat source can include a thermally conductive base member configured to mount on, or be placed in thermal communication with, a heat source. The heat sink can include a heat sink module mounted on the thermally conductive base member. The heat sink module can include an inlet chamber formed within the heat sink module and an outlet chamber formed at least partially in the heat sink module and bounded by the surface of the thermally conductive base member. The heat sink module can include a first plurality of orifices extending from the inlet chamber to the outlet chamber. The first plurality of orifices can be configured to deliver a plurality of jet streams of coolant into the outlet chamber and against the surface of the thermally conductive base member when pumped coolant is provided to the inlet chamber.

Abstract: A method of providing stable pump operation in a two-phase cooling system is disclosed. The method can include providing a cooling system with a reservoir fluidly connected to a pump. The reservoir can include a liquid-vapor interface when partially filled with liquid coolant. The liquid-vapor interface can separate an amount of liquid coolant from an amount of vapor coolant. The method can include delivering two-phase bubbly flow to an upper portion of the reservoir above the liquid-vapor interface. The two-phase bubbly flow can include vapor bubbles of coolant dispersed in liquid coolant. The vapor bubbles can condense upon interacting with and transferring heat to subcooled liquid coolant in the reservoir. The method can include delivering a continuous outlet flow of single-phase liquid coolant from the reservoir to the pump, thereby ensuring stable pump operation despite the presence of two-phase flow in certain portions of the cooling system.

Abstract: A flexible two-phase cooling apparatus for cooling microprocessors in servers can include a primary cooling loop, a first bypass, and a second bypass. The primary cooling loop can include a reservoir, a pump, an inlet manifold, an outlet manifold, and flexible cooling lines extending from the inlet manifold to the outlet manifold. The flexible cooling lines can be routable within server housings and can be fluidly connected to two or more series-connected heat sink modules that are mountable on microprocessors of the servers. The flexible cooling lines can be configured to transport low-pressure, two-phase dielectric coolant. The first bypass can include a first pressure regulator configured to regulate a first bypass flow of coolant through the first bypass. The second bypass can include a second pressure regulator configured to regulate a second bypass flow of coolant through the second bypass.

Abstract: A heat sink module for cooling a heat providing surface can include an inlet chamber and an outlet chamber formed within the heat sink module. The outlet chamber can have an open portion that can be enclosed by the heat providing surface when the heat sink module is installed on the heat providing surface. The heat sink module can include a dividing member disposed between the inlet chamber and the outlet chamber. The dividing member can include a first plurality of orifices extending from a top surface of the dividing member to a bottom surface of the dividing member. The first plurality of orifices can be configured to deliver a plurality of jet streams of coolant into the outlet chamber and against the heat providing surface when the heat sink module is installed on the heat providing surface and when pressurized coolant is provided to the inlet chamber.

Abstract: A method of condensing vapor present in two-phase bubbly flow within a cooling apparatus can include mixing a first flow of coolant containing two-phase bubbly flow with a second flow of coolant containing single-phase liquid flow. The two-phase bubbly flow can have a first flow quality greater than zero and can include vapor bubbles dispersed in liquid coolant. The single-phase liquid flow can have a flow quality of about zero. Mixing the first flow of coolant and the second flow of coolant within the cooling apparatus can result in heat transfer from the first flow of coolant to the second flow of coolant and can cause vapor bubbles within first flow of coolant to condense, thereby providing a third flow of coolant with a third flow quality that is less than the first flow quality.

Abstract: A method of operating a cooling apparatus is described that allows flexible cooling lines connecting an inlet manifold to an outlet manifold to be safely added or removed during operation of the cooling apparatus without causing unstable two-phase flow. The method can include providing a cooling apparatus having an inlet manifold, an outlet manifold, and a bypass extending from the inlet manifold to the outlet manifold. Each manifold can include a plurality of connection ports, such as quick-connect couplers, to accommodate adding and removing cooling lines between the inlet manifold and the outlet manifold. The method can include providing a flow rate of single-phase liquid coolant to the inlet manifold and setting a pressure regulator in the bypass to provide a certain flow rate through the bypass. The flow rate through the bypass can be determined as a function of an average flow rate through each of the cooling lines.

Abstract: A method of cooling two or more heat-providing surfaces using a cooling apparatus having two or more fluidly connected heat sink modules in a series configuration can include providing a flow of single-phase liquid coolant to a first heat sink module mounted on a first heat-providing surface. The method can include projecting the flow of single-phase liquid coolant against the first heat-providing surface within the first heat sink module and causing phase change of a first portion of the liquid coolant and thereby forming two-phase bubbly flow with a first quality. The method can include transporting the two-phase bubbly flow to a second heat sink module and projecting the two-phase bubbly flow against a second heat-providing surface within the second heat sink module and causing phase change of a second portion of the coolant and formation of two-phase bubbly flow with a second quality greater than the first quality.

Abstract: A cooling system and method that significantly improves spray evaporative cooling by using arrays of slot or plane sprays to create coverage of the entire heated surface to be cooled without allowing interaction between plumes that are spraying from the nozzles. The sprays are directed at an angle to the surface to take advantage of the high droplet momentum possessed by the spray to direct a flow of coolant fluid across the surface toward desired draining points, thereby enabling drainage regardless of the orientation of the unit.

Abstract: Disclosed are methods and apparatuses for cooling a work piece surface using a dual-loop cooling system. The system includes a vapor-compression loop and a liquid-evaporation loop. The loops are configured to prepare a coolant at or approximately at saturation for delivery into a chamber for cooling the surface. A preferred liquid-evaporation loop includes a chamber, a phase separator, a liquid pressurizer, and a vapor mixer that heats the coolant to or near its saturation temperature. A preferred vapor-compression loop includes the phase separator, a compressor, a condenser, an expansion valve, and a return line. The vapor mixer preferably heats the coolant by mixing liquid coolant with vapor coolant derived from the vapor-compression loop. A two-phase flow detector may be disposed downstream of the vapor mixer and be in communication with a vapor valve disposed upstream of the vapor mixer to ensure that an appropriate amount of vapor is fed into the vapor mixer to induce evaporation.

Abstract: Disclosed are methods and apparatuses for cooling a work piece surface using two-phase impingement, such as direct jet impingement. Preferred methods include flowing a coolant through a chamber comprising a surface to be cooled by projecting a jet stream of coolant against the surface while maintaining pressure in the chamber to permit at least a portion of coolant contacting the surface to boil. Preferred apparatuses include a chamber comprising the surface and tubular nozzles configured to project a stream of coolant against the surface, a pump for forcing coolant through the tubular nozzles, a pressurizer for maintaining an appropriate pressure in the chamber, and a heat exchanger for cooling the coolant exiting the chamber. The apparatuses may further include a pressure regulator for detecting changes in temperature of the coolant exiting the chamber and communicating with the pressurizer to adjust the maintained pressure accordingly.