A cooling arrangement for autonomous cooling of a rack hosting components and fans comprises a closed loop and an open loop. Liquid cooling is used in the closed loop to transfer heat from heat-generating units of the components to a primary side of a liquid-to-liquid heat exchanger. An air-to-liquid cooling unit is used in the open loop to absorb heat expelled from the rack by the fans. A liquid from a cold supply line is first heated to some degree in the air-to-liquid cooling unit before reaching a secondary side of the liquid-to-liquid heat exchanger. The primary side being hotter than the secondary side, heat is transferred from the primary side to the secondary side of the liquid-to-liquid heat exchanger. The liquid is expelled at a higher temperature from the secondary side to a hot return line.

A cooling arrangement for a rack hosting electronic equipment and at least one fan comprises first and second air-liquid heat exchangers. A first one is mounted to the rack so that heated air expelled from the rack by the fan flows therethrough. The second one is mounted to the first one so that air having flowed through the first heat exchanger flows through the second heat exchanger. Each heat exchanger comprises a frame, an inlet receiving liquid from a cold supply line, an outlet returning liquid to a hot return line, and a continuous internal conduit forming a plurality of interconnected parallel sections. The cooling arrangement is mounted to the rack so that the first and second frames are parallel and adjacent. One interconnected parallel section of the first heat exchanger nearest to its inlet is proximate one interconnected parallel section of the second heat exchanger nearest to its outlet.

A case heat dissipation structure is provided, which includes a case, a heat exchange assembly and a fan assembly. The case has a first heat dissipation chamber and a second heat dissipation chamber that are communicated with each other, and multiple heat sources are mounted in the first heat dissipation chamber and the second heat dissipation chamber, a liquid inlet for cooling liquid to flow in and a liquid outlet for cooling liquid to flow out are provided on the case. The heat exchange assembly is mounted in the first heat dissipation chamber, the heat exchange assembly comprises a heat exchanger, which is arranged between the liquid inlet and the liquid outlet. The fan assembly is mounted in the first heat dissipation chamber or the second heat dissipation chamber, and is used for driving the air in the first heat dissipation chamber and the second heat dissipation chamber to circulate mutually in operation.

A closed loop cooling system for electronic equipment. The system includes a cabinet having a top panel, walls, and a door defining an enclosure. A rack is within the enclosure, and the electronic equipment is mounted thereto. An evaporator is within the enclosure below the electronic equipment. Recirculated cabinet airflow warmed by the electronic equipment is directed to the evaporator, cooled by the evaporator, and directed back to the electronic equipment to cool the electronic equipment. A condenser is in fluid communication with the evaporator to circulate coolant therebetween. Ambient airflow from outside the cabinet flows across the condenser to cool coolant flowing therethrough. The recirculated cabinet airflow is maintained independent of the ambient airflow, thereby preventing introduction of added heat or contaminates into the recirculated cabinet airflow, and not affecting air pressure of the ambient airflow.

In one embodiment, an RF impedance matching network utilizing at least one electronically variable capacitors (EVC) is disclosed. Each EVC includes discrete capacitors operably coupled in parallel, the discrete capacitors including fine capacitors and coarse capacitors. A control circuit determines a parameter related to the plasma chamber and, based on the parameter, determines which of the coarse capacitors and which of the fine capacitors to have switched in to cause an impedance match. The increase of the variable total capacitance of each EVC is achieved by switching in more of the coarse capacitors or more of the fine capacitors than are already switched in without switching out a coarse capacitor that is already switched in.

A cooling system, in particular for electronics cabinets, is proposed, comprising a casing, wherein the casing comprises at least a cabinet side partitionment, wherein the cooling system comprises a first cooling circuit and a second cooling circuit, wherein the second cooling circuit is an active cooling circuit, wherein the first cooling circuit and the second cooling circuit are thermally coupled, wherein the second cooling circuit is not disposed in the cabinet side partitionment.

An apparatus includes an enclosure with a first data storage section, a second data storage section, a first cooling section positioned therebetween, and a second cooling section. The apparatus also includes an air-to-liquid heat exchanger positioned in the first cooling section and configured to cool air directed from the first data storage section towards the second data storage section and the second cooling section.

In one embodiment, an RF impedance matching circuit is disclosed. The matching circuit is coupled between a plasma chamber and an RF source providing an RF signal having a frequency. The matching circuit includes a first electronically variable capacitor having a first variable capacitance and a second electronically variable capacitor having a second variable capacitance. A control circuit determines a first parameter related to the plasma chamber, and then determines, based on the first parameter, a first capacitance value for the first electronically variable capacitor and a second capacitance value for the second electronically variable capacitor. The control circuit then generates a control signal to alter the first variable capacitance and the second variable capacitance accordingly, causing the RF power reflected back to the RF source to decrease while the frequency of the RF source is not altered.

In one aspect, a medium voltage power converter includes a cabinet having: a power cube bay to house a plurality of power cubes, each of the plurality of power cubes adapted within a corresponding enclosure and comprising a low frequency front end stage, a DC link and a high frequency back end stage, the plurality of power cubes to couple to a high speed machine; and a plurality of first barriers adapted to isolate and direct a first flow of cooling air through one of the plurality of power cubes; and a transformer bay having at least one transformer to couple between a utility connection and the plurality of power cubes, the transformer bay including a plurality of cooling fans to cool the at least one transformer.

A cooling assembly for cooling server racks includes a server rack enclosure sub-assembly that includes at least one panel member defining a volume for receiving one or more server racks having a front portion and a rear portion, at least one of the panel members is a rear panel member; at least one frame member defines an opening for receiving the rear portion of the server racks to form a hot space between the rear panel member and the combination of the frame member and the rear portion of the server racks; a cooling sub-assembly disposed in thermal communication with the hot space to cool at least one server supported in the server rack and including a chassis receiving at least one heat exchange member for exchanging heat between a refrigerant fluid flowing through the heat exchange member and fluid flowing through the hot space heated by the server.