Connection module for fluid management in liquid cooled electronics system

A design for servers and racks, includes a supply connector module including a supply connector connected to a first holder to connect a supply line connector, and a supply switch to engage the first holder when in a first position and to disengage with the second holder when in a second position, the second holder has a shape to disengage the supply switch and disconnect the supply connector from the supply line after a first time interval. The design further includes a return connector module a return connector connected to a second holder to connect a return line connector, and a return switch to engage the second holder when in a first position and to disengage when in a second position, the fourth holder has a shape to disengage the return switch and disconnect the return connector from the return line after a second time interval.

FIELD OF THE INVENTION

Embodiments of the present invention relate generally to data center and server electronics cooling. More particularly, minimizing the impact from fluid leaks in electronic rack systems.

BACKGROUND

Cooling is a prominent factor in a computer system and data center design. The number of high performance electronics components such as high performance processors packaged inside servers has steadily increased, thereby increasing the amount of heat generated and dissipated during the ordinary operations of the servers. The reliability of servers used within a data center decreases if the environment in which they operate is permitted to increase in temperature over time. Maintaining a proper thermal environment is critical for normal operations of these servers in data centers, as well as the server performance and lifetime. It requires more effective and efficient cooling solutions especially in the cases of cooling these high performance servers. Many such system are thermally managed by liquid cooling solutions that are often superior to air cooled solutions. However, care must be taken to properly manage coolant incidents, such as leaks, to prevent damage to equipment and downtime.

DETAILED DESCRIPTION

In one aspect, a fluid connector or connector module is connected to a manifold by a supply line including a supply line connector (also referred to as a rack supply connector), the supply line to receive cooling liquid from the cooling liquid source, and connected to the manifold by a return line including a return line connector (also referred to as a rack return connector), the return line to return warmer cooling liquid to a cooling liquid source. The fluid connector may include a supply connector module including a supply connector coupled or attached to a first holder to connect a supply line connector, and a supply switch to engage the first holder when in a first position and to disengage with the second holder when in a second position, the first holder may have a shape to disengage the supply switch and disconnect the supply connector from the supply line after a first time interval.

The system may further include a return connector module including a return connector connected or attached to a second holder to connect a return line connector, and a return switch to engage the second holder when in a first position and to disengage when in a second position, the second holder has a shape to disengage the return switch and disconnect the return connector from the return line after a second time interval that is different than the first time interval. In one embodiment, the second time interval is greater than the first time interval such that the supply connector disconnects before the return connector disconnects.

The fluid connector, in one embodiment, may further include a controller connected to a switch driver, the switch driver connected to the return switch and the supply switch, the switch driver to position the return switch and the supply switch to one of engage or disengage the second holder and the first holder, respectively. The switch driver may include an electric motor connected to the return switch and to the supply switch and configured to move the return switch to engage the second holder and to move the supply switch to engage the first holder when the electric motor is provided power. In one embodiment, a sensor may be connected to the controller, the controller may remove power to the electric motor to disengage the second holder and the first holder according to the second time interval and the first time interval, respectively, in response to a fluid leakage detected by the sensor. A pump may be connected to the controller, and the controller may increase the pump speed after the first time interval when the supply connector disconnects and signal the pump to resume normal speed after the second time interval when the return connector disconnects.

The switch driver may include a first electric motor connected to the return switch and, the first electric motor configured to move the return switch to engage the second holder when the first electric motor is provided power, and a second electric motor connected the supply switch, the second electric and configured to move the supply switch to engage the first holder when the second electric motor is provided power.

In one embodiment, the return line connector may disconnect from the return line when the second holder is disengaged after the second time interval, and the supply line connector to disconnect from the supply line when the first holder is disengaged after the first time interval. In one embodiment, the second time interval may be greater than the first time interval to disengage the first holder of the supply connector before second holder of the return connector.

In one embodiment, a return line spring may be connected to the second holder to provide a force to move the second holder away from the return line connector of the return line when the return switch is disengaged from the second holder, and a supply line spring connected to the first holder to provide a force move the first holder away from the supply line connector of the supply line when the supply switch is disengaged from the first holder. In one embodiment, the shape of the second holder to engage and disengage the return switch for the second time interval is a curve, wherein the one or more radii of the curve determines the second time interval.

According to another aspect, a sever chassis includes one or more cooling plates (e.g., cold plates) to provide liquid cooling to one or more electronic devices attached thereon (e.g., processors). The server chassis further includes a fluid connector module as described above, where the connector module is configured to connect and disconnect the cooling plates to and from a rack manifold of an electronic rack that contains the server chassis. According to a further aspect, an electronic rack includes a stack of server chassis as described above.

FIG.1is a block diagram illustrating an example of a data center or data center unit according to one embodiment. In this example,FIG.1shows a top view of at least a portion of a data center. According to one embodiment, data center system100includes one or more rows of electronic racks of information technology (IT) components, equipment or instruments101-102, such as, for example, computer servers or computing nodes that provide data services to a variety of clients over a network (e.g., the Internet). In this embodiment, each row includes an array of electronic racks such as electronic racks110A-110N. However, more or fewer rows of electronic racks may be implemented. Typically, rows101-102are aligned in parallel with frontends facing towards each other and backends facing away from each other, forming aisle103in between to allow an administrative person walking therein. However, other configurations or arrangements may also be applied. For example, two rows of electronic racks may back to back face each other without forming an aisle in between, while their frontends face away from each other. The backends of the electronic racks may be coupled to the room cooling liquid manifolds.

In one embodiment, each of the electronic racks (e.g., electronic racks110A-110N) includes a housing to house a number of IT components arranged in a stack operating therein. The electronic racks can include a cooling liquid manifold, a number of server slots (e.g., standard shelves or chassis configured with an identical or similar form factor), and a number of server chassis (also referred to as server blades or server shelves) capable of being inserted into and removed from the server slots. Each server chassis represents a computing node having one or more processors, a memory, and/or a persistent storage device (e.g., hard disk), where a computing node may include one or more servers operating therein. At least one of the processors is attached to a liquid cold plate (also referred to as a cold plate assembly) to receive cooling liquid. In addition, one or more optional cooling fans are associated with the server chassis to provide air cooling to the computing nodes contained therein. Note that the cooling system120may be coupled to multiple data center systems such as data center system100.

In one embodiment, cooling system120includes an external liquid loop connected to a cooling tower or a dry cooler external to the building/housing container. The cooling system120can include, but is not limited to evaporative cooling, free air, rejection to large thermal mass, and waste heat recovery designs. Cooling system120may include or be coupled to a cooling liquid source that provide cooling liquid.

In one embodiment, each server chassis is coupled to the cooling liquid manifold modularly, such that a server chassis can be removed from the electronic rack without affecting the operations of remaining server chassis in the electronic rack and the cooling liquid manifold. In another embodiment, each server chassis is coupled to the cooling liquid manifold through a quick-release coupling assembly having a server liquid intake connector and a server liquid outlet connector coupled to a flexible hose to distribute the cooling liquid to the processors. The server liquid intake connector is to receive cooling liquid via a rack liquid intake connector from a cooling liquid manifold mounted on a backend of the electronic rack. The server liquid outlet connector is to emit warmer or hotter liquid carrying the heat exchanged from the processors to the cooling liquid manifold via a rack liquid outlet connector and then back to a coolant distribution unit (CDU) within the electronic rack. In various embodiments, as discussed in detail herein below, the server liquid intake connector may include a supply connector module (not shown) and the server liquid outlet connector includes a return connector module (not shown) that disengages their respective connectors from the couplings at different time intervals to prevent leaks upon disconnect. In various embodiments, the time interval may be determined by the shape of one or more connector holders within each connector module.

In one embodiment, the cooling liquid manifold disposed on the backend of each electronic rack is coupled to a supply line132(also referred to as a room supply manifold) to receive cooling liquid from cooling system120. The cooling liquid is distributed through a liquid distribution loop attached to a cold plate assembly on which a processor is mounted to remove heat from the processors. A cold plate is configured similar to a heat sink with a liquid distribution tube attached or embedded therein. The resulting warmer or hotter liquid carrying the heat exchanged from the processors is transmitted via a return line131(also referred to as a room return manifold) back to cooling system120.

Liquid return/supply lines131-132return/supply lines131-132are referred to as data center or room liquid supply/return lines (e.g., global liquid supply/return lines), which supply cooling liquid to all of the electronic racks of rows101-102. The supply line132and return line131are coupled to a heat exchanger of a CDU located within each of the electronic racks, forming a primary loop. The secondary loop of the heat exchanger is coupled to each of the server chassis in the electronic rack to deliver the cooling liquid to the cold plates of the processors.

In one embodiment, data center system100further includes an optional airflow supply system135to generate an airflow to cause the airflow to travel through the air space of the server chassis of the electronic racks to exchange heat generated by the computing nodes due to operations of the computing nodes (e.g., servers) and to exhaust the airflow exchanged heat to an external environment or a cooling system (e.g., air-to-liquid heat exchanger) to reduce the temperature of the airflow. For example, air supply system135generates an airflow of cool/cold air to circulate from aisle103through electronic racks110A-110N to carry away exchanged heat.

The cool airflows enter the electronic racks through their frontends and the warm/hot airflows exit the electronic racks from their backends. The warm/hot air with exchanged heat is exhausted from room/building or cooled using a separate cooling system such as an air-to-liquid heat exchanger. Thus, the cooling system is a hybrid liquid-air cooling system, where a portion of the heat generated by a processor is removed by cooling liquid via the corresponding cold plate, while the remaining portion of the heat generated by the processor (or other electronics or processing devices) is removed by airflow cooling.

FIG.2is block diagram illustrating an electronic rack according to one embodiment. Electronic rack200may represent any of the electronic racks as described throughout this application. According to one embodiment, electronic rack200includes, but is not limited to, coolant distribution unit (CDU)201, rack management unit (RMU)202, and one or more server chassis203A-203E (collectively referred to as server chassis203). Server chassis203can be inserted into an array of server slots (e.g., standard shelves) respectively from frontend204or backend205of electronic rack200. Note that although there are five server chassis203A-203E shown here, more or fewer server chassis may be maintained within electronic rack200. Also note that the particular positions of CDU201, RMU202, and/or server chassis203are shown for the purpose of illustration only; other arrangements or configurations of CDU201, RMU202, and/or server chassis203may also be implemented. In one embodiment, electronic rack200can be either open to the environment or partially contained by a rack container, as long as the cooling fans can generate airflows from the frontend to the backend.

In addition, for at least some of the server chassis203, an optional fan module (not shown) is associated with the server chassis. Each of the fan modules includes one or more cooling fans. The fan modules may be mounted on the backends of server chassis203or on the electronic rack to generate airflows flowing from frontend204, traveling through the air space of the sever chassis203, and existing at backend205of electronic rack200.

In one embodiment, CDU201mainly includes heat exchanger211, liquid pump212, and a pump controller (not shown), and some other components such as a liquid reservoir, a power supply, monitoring sensors and so on. Heat exchanger211may be a liquid-to-liquid heat exchanger. Heat exchanger211includes a first loop with inlet and outlet ports having a first pair of liquid connectors coupled to external liquid return/supply lines131-132to form a primary loop. The connectors coupled to the external liquid return/supply lines131-132may be disposed or mounted on backend205of electronic rack200. The liquid return/supply lines131-132, also referred to as room liquid supply/return lines, may be coupled to an external cooling system.

In various embodiments, as discussed in detail herein below, each server chassis may include a server liquid intake connector that further includes a supply connector module (not shown) and a server liquid outlet connector that includes a return connector module (not shown) that disengages their respective connectors from the couplings at different time intervals to prevent leaks upon disconnect. In various embodiments, the time interval may be determined by the shape of one or more connector holders within each connector module.

In addition, heat exchanger211further includes a second loop with two ports having a second pair of liquid connectors coupled to liquid manifold225(also referred to as a rack manifold) to form a secondary loop, which may include a supply manifold (also referred to as a rack liquid supply line or rack supply manifold) to supply cooling liquid to server chassis203and a return manifold (also referred to as a rack liquid return line or rack return manifold) to return warmer liquid back to CDU201. Note that CDUs201can be any kind of CDUs commercially available or customized ones. Thus, the details of CDUs201will not be described herein.

Each of server chassis203may include one or more IT components (e.g., central processing units or CPUs, general/graphic processing units (GPUs), memory, and/or storage devices). Each IT component may perform data processing tasks, where the IT component may include software installed in a storage device, loaded into the memory, and executed by one or more processors to perform the data processing tasks. Server chassis203may include a host server (referred to as a host node) coupled to one or more compute servers (also referred to as computing nodes, such as CPU server and GPU server). The host server (having one or more CPUs) typically interfaces with clients over a network (e.g., Internet) to receive a request for a particular service such as storage services (e.g., cloud-based storage services such as backup and/or restoration), executing an application to perform certain operations (e.g., image processing, deep data learning algorithms or modeling, etc., as a part of a software-as-a-service or SaaS platform). In response to the request, the host server distributes the tasks to one or more of the computing nodes or compute servers (having one or more GPUs) managed by the host server. The compute servers perform the actual tasks, which may generate heat during the operations.

Electronic rack200further includes optional RMU202configured to provide and manage power supplied to server chassis203, and CDU201. RMU202may be coupled to a power supply unit (not shown) to manage the power consumption of the power supply unit. The power supply unit may include the necessary circuitry (e.g., an alternating current (AC) to direct current (DC) or DC to DC power converter, battery, transformer, or regulator, etc.) to provide power to the rest of the components of electronic rack200.

In one embodiment, RMU202includes optimization module221and rack management controller (RMC)222. RMC222may include a monitor to monitor operating status of various components within electronic rack200, such as, for example, computing nodes, CDU201, and the fan modules. Specifically, the monitor receives operating data from various sensors representing the operating environments of electronic rack200. For example, the monitor may receive operating data representing temperatures of the processors, cooling liquid, and airflows, which may be captured and collected via various temperature sensors. The monitor may also receive data representing the fan power and pump power generated by the fan modules and liquid pump212, which may be proportional to their respective speeds. These operating data are referred to as real-time operating data. Note that the monitor may be implemented as a separate module within RMU202.

Based on the operating data, optimization module221performs an optimization using a predetermined optimization function or optimization model to derive a set of optimal fan speeds for the fan modules and an optimal pump speed for liquid pump212, such that the total power consumption of liquid pump212and the fan modules reaches minimum, while the operating data associated with liquid pump212and cooling fans of the fan modules are within their respective designed specifications. Once the optimal pump speed and optimal fan speeds have been determined, RMC222configures the liquid pump212and cooling fans of the fan modules based on the optimal pump speeds and fan speeds.

As an example, based on the optimal pump speed, RMC222communicates with a pump controller of CDU201to control the speed of liquid pump212, which in turn controls a liquid flow rate of cooling liquid supplied to the liquid manifold225to be distributed to at least some of server chassis203. Similarly, based on the optimal fan speeds, RMC222communicates with each of the fan modules to control the speed of each cooling fan of the fan modules, which in turn control the airflow rates of the fan modules. Note that each of fan modules may be individually controlled with its specific optimal fan speed, and different fan modules and/or different cooling fans within the same fan module may have different optimal fan speeds.

Note that the rack configuration as shown is described for the purpose of illustration only; other configurations or arrangements may also be applicable. For example, CDU201may be an optional unit. The cold plates of server chassis203may be coupled to a rack manifold, which may be directly coupled to room manifolds without using a CDU. Although not shown, a power supply unit may be disposed within electronic rack200. The power supply unit may be implemented as a standard chassis identical or similar to a sever chassis, where the power supply chassis can be inserted into any of the standard shelves, replacing any of server chassis203. In addition, the power supply chassis may further include a battery backup unit (BBU) to provide battery power to server chassis203when the main power is unavailable. The BBU may include one or more battery packages and each battery package include one or more battery cells, as well as the necessary charging and discharging circuits for charging and discharging the battery cells.

FIG.3is block diagram illustrating an electronic rack300that disengages its connectors to manage a cooling liquid leak in the electronic rack. The electronic rack300may be included in any of the electronic rack embodiments as described in this application, such as electronic rack200ofFIG.2. According to one embodiment, electronic rack300, in a rear view in this example, includes one or more server chassis connected to a rack manifold302, for simplicity only two server chassis are illustrated, server chassis203A and server chassis203N. Each server chassis203A and203N include a leak sensor306A and306N, and controller308A and controller308N, respectively. In one embodiment, the supply line132is connected to the rack manifold302, which is connected to each server chassis203A and203N through supply connector module310A and310N through supply line connector312A and supply line connector312N, respectively. A supply line connector is also referred to as a rack supply connector.

Similarly, the return line131is connected to the rack manifold302, which may be connected to each server chassis203A and203N through return connector module314A and314N through return line connector316A and return line connector316N, respectively. A return line connector is also referred to as a rack return connector. In various embodiments, the supply line and return line connectors may be of any type that may be disengaged by their respective connector modules, such as blind mating connectors and the like.

In one embodiment, a liquid pump304is connected to the return line131and may be controlled by a controller, such as controller308A of server chassis203A. For example, to manage a leakage incident the leak sensor306A and the controller308A may work together to signal the supply connector module310A and the return connector module314A to disconnect from the supply line connector312A and the return line connector316A. In one embodiment, the supply line connector312A and the return line connector316A are disengaged according to different time intervals. For example, the supply line connector312A may be disengaged and disconnected first, and at some later time interval the return line connector316A may be disengaged and disconnected to allow the liquid pump304to clear the liquid coolant from server chassis203A and prevent leakage that may damage components within the electronic rack300. In various embodiments, the disengagement time interval may be dependent upon various component configurations within the supply connector module310A and return connector module314A, as discussed in further detail below with respect toFIGS.4and5. In one embodiment, the controller308A may vary the pump speed (e.g., increase the pump speed) for a time during the disengagement and disconnect process, for example, after the supply line connector312A is disconnected and before the return line connector314A is disconnected, or some variation around the disengagement time interval.

FIG.4is block diagram illustrating a server chassis400, according to one embodiment, to disengage its connectors to manage a cooling liquid leak. Server chassis400includes the return connector module314, the return line connector or rack return connector316, the supply connector module310, the supply line connector or rack supply connector312, and the controller308as described with respect toFIG.3. The return connector module314includes a holder402, a holder404, a return connector405, a return switch406, and a spring408. Note that holders402and404may be integrated as a single holder (e.g., a second holder). The supply connector module310includes a holder410, a holder412, a supply connector413, a supply switch414, and a spring416. Similarly, holders410and412may be integrated as a single holder (e.g., a first holder). In various embodiments, the return connector module314and the supply connector module310may various configurations of holders. For example, instead of two holders (e.g., holder402and holder404) there may be one holder or three or more holders. In an embodiment,402and404can be combined as one unit.402is mainly for holding the connector, and404is mainly for functioning with the switch.

The return switch406and the supply switch414are connected to a switch driver, such as a motor418, to engage and disengage with the holder404and the holder412, respectively. In one embodiment, the holder404is in contact with holder402that is under tension from spring408, and similarly, the holder412is contact with holder410that is under tension from spring416. The return connector405and the supply connector413, in one embodiment, may move together with their respective holders (e.g., holder402and404) to engage or release the return line connector316and supply line connector312based on the position of the return switch406and the supply switch414, respectively.

As discussed with respect toFIG.3, in one embodiment, the controller308may send a signal to motor418that results in the return switch406and supply switch414clockwise to disengage the return connector405and the supply connector413from their respective line connectors, return line connector316and supply line connector312. In one embodiment, the signal from the controller308shuts off the motor418and each switch (e.g., supply switch414and return switch406) may be under tension or force to rotate clockwise, for example, by a spring (not shown) connected to the switch. In another embodiment, the motor418may actively under power rotate each switch to engage and disengage with their respective holders.

To prevent leakage from cooling liquid remaining in the system the return connector405disengages after the supply connector413to provide a time interval for the pump (not shown) to clear the system. In one embodiment, the time interval, such as time interval420that includes t0and t1, may be determined by the shape of the holder404of the return connector module314. As shown in this embodiment, the holder404has a curved shape such that it disengages from the return switch406starting at time interval t0and continues to full disengagement at time interval t1. The supply switch begins disengaging from the holder412at time interval t0and thus disconnects the supply connector413at the time interval420before the return switch406.

Although the holder404is illustrated as having a curved or parabolic shape and radii in this embodiment, in other embodiments, the shape may be any shape that creates a time interval420between the disengagement of each switch with its respective holder to disconnect each connector. In one embodiment, the holder404and the holder412may be configurable in place or removable and replaced by another holder to lessen or increase the time interval420. Additionally, in another embodiment, the holder412may also have a shape similar to that of the holder404but still create a time interval420such that the return connector405is disconnected after the supply connector413. In other embodiments, the motor418may be a single electric motor connected to each switch or it may be an individual electric motors connected to each switch but controlled by the controller308as described herein.

FIGS.5A-Dare block diagrams of a rack system500that illustrate four switch positions the return connector module314and the supply connector module310as each disconnects from the return line connector316and the supply line connector312, according to one embodiment. Beginning atFIG.5A, in one embodiment, the motor418is powered on and the return switch406and the supply switch414are held at switch position #1, fully engaged with holder404and holder412, respectively, to engage the return connector405to connect to the return line connector316and the supply connector413to the supply line connector312.FIG.5Billustrates an embodiment when the controller308signals the motor418to power off, at which point the return switch406and the supply switch414begin to rotate clockwise, as shown in switch position #2. The return switch406is still engaged with the holder402and the holder404based on its shape, and the return connector405remains connected to the return line connector316. The supply switch414at switch position #2has started to disengage with the holder412and the spring416has forced the holders410and412along with the connector413away from the supply line connector312.

FIG.5Cillustrates the return switch406and the supply switch414at switch position #3. The return switch406has reached the end of the holder404and begins to disengage from the holder404. The supply switch414at switch position #3has disengaged with the holder412and the spring416has fully extended and the connector413has detached fully from the supply line connector312. In one embodiment, the controller308may signal the liquid pump (e.g., liquid pump304) to increase pump speed to expedite pumping the excess coolant fluid from the system to prevent leakage.FIG.5Dillustrates the return switch406and the supply switch414at switch position #4. The return switch406has fully disengaged from the holder404and the spring408has forced the holders402and404along with the connector405away from the return line connector316and thus disconnecting the return line connector316from the return connector405. In one embodiment, the controller308may signal the liquid pump (e.g., liquid pump304) to return to normal speed when the return connector405disconnects from the return line connector316.

In the foregoing specification, embodiments of the invention have been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of the invention as set forth in the following claims. While certain aspects have been described and shown in the accompanying drawings, it is to be understood that such aspects are merely illustrative of and not restrictive on the broad disclosure, and that the disclosure is not limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those of ordinary skill in the art. The description is thus to be regarded as illustrative instead of limiting.