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 fluid distribution unit for a two-phase cooling system can include a reservoir configured to receive a two-phase flow of dielectric coolant. A first pump can be fluidly connected to a supply line extending from the reservoir. A heat rejection loop can be fluidly connected to the reservoir. The heat rejection loop can include a heat exchanger and a second pump. The second pump can be configured to circulate a flow of single-phase liquid coolant from the reservoir, through the heat exchanger, and back to the reservoir.

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 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 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 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 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 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.