Serial fluidic flow loop in liquid-assisted air cooled thermal control system

Systems and methods may provide for a serial fluidic flow loop in a liquid-assisted air cooled thermal control system, in order to balance thermal gradients in the thermal control system.

TECHNICAL FIELD

The present disclosure relates in general to information handling systems, and more particularly to liquid-assisted air-cooled thermal control systems in an information handling system.

BACKGROUND

As processors, graphics cards, random access memory (RAM) and other components in information handling systems have increased in clock speed and power consumption, the amount of heat produced by such components as a side-effect of normal operation has also increased. Often, the temperatures of these components need to be kept within a reasonable range to prevent overheating, instability, malfunction and damage leading to a shortened component lifespan. Accordingly, air movers (e.g., cooling fans and blowers) have often been used in information handling systems to cool information handling systems and their components.

To control temperature of components of an information handling system, an air mover may direct air over one or more heatsinks thermally coupled to individual components. Traditional approaches to cooling components may include a “passive” cooling system that serves to reject heat of a component to air driven by one or more system-level air movers (e.g., fans) for cooling multiple components of an information handling system in addition to the peripheral component. Another traditional approach may include an “active” cooling system that uses liquid cooling, in which a heat-exchanging cold plate is thermally coupled to the component, and a chilled fluid is passed through conduits internal to the cold plate to remove heat from the component.

FIG.1illustrates an information handling system102comprising a liquid-assisted air-cooled thermal control system118, as is known in the art. As shown inFIG.1, information handling system102may include one or more processors103, one or more memory modules104, and liquid-assisted air-cooled thermal control system118. Further, as shown inFIG.1, liquid-assisted air-cooled thermal control system118may include one or more air movers108, heat-rejecting media122, fluidic conduits126, cold manifold128, hot manifold130, and radiator132.

As shown inFIG.1, liquid-assisted air-cooled thermal control system118may be arranged in a parallel configuration, in that cooled liquid may be delivered from radiator132to cold manifold128, from where the cooled liquid may be distributed in parallel to both heat-rejecting media122(e.g., cold plates thermally coupled to respective processors103). Accordingly, heat generated by processors103may be transferred to their respective heat-rejecting media122, and from the heat-rejecting media122to the liquid. The liquid, now heated by heat transfer from processors103, may flow to hot manifold130and to radiator132. Air driven proximate to radiator132by air movers108may cool the liquid, which may re-emerge as cooled liquid flowing into cold manifold128, forming a liquid cooling loop.

While processors103may be cooled mainly through liquid cooling, other components of information handling system102, such as memory modules104, may be cooled entirely by airflow driven by air movers108. However, the arrangement ofFIG.1has disadvantages with respect to cooling of downstream components. To illustrate, because of the temperature gradient across radiator132from the left side ofFIG.1to the right side ofFIG.1, air passing over the left of radiator132may be warmed more than the air passing over the right of radiator132. Accordingly, as such airflow continues downward inFIG.1, a temperature of air being driven proximate to the memory module104on the left ofFIG.1may be warmer than a temperature of air being driven proximate to the memory module104on the right ofFIG.1.

Another disadvantage of liquid-assisted air-cooled thermal control system118depicted inFIG.1is that the liquid cooling loop comprises two triple valves with fluidic conduits126, which may require additional welding or other fluidic connectivity (which may lead to lower reliability) and may present a large liquid flow impedance.

A further disadvantage of the liquid-assisted air-cooled thermal control system118depicted inFIG.1is, due to the parallel routing of fluidic conduits126, processors103may see non-uniform thermal performance on account of uneven liquid flow distribution to heat-rejecting media122.

SUMMARY

In accordance with the teachings of the present disclosure, the disadvantages and problems associated with existing designs of thermal control systems for information handling system may be substantially reduced or eliminated.

In accordance with embodiments of the present disclosure, an information handling system may include a plurality of information handling resources comprising at least a first information handling resource and a second information handling resource and a thermal control system. The thermal control system may include one or more air movers, first heat-rejecting media thermally coupled to the first information handling resource, the first heat-rejecting media configured to receive a flow of cooling fluid through the first heat-rejecting media, second heat-rejecting media thermally coupled to the second information handling resource, the second heat-rejecting media configured to receive the flow of cooling fluid through the second heat-rejecting media, a first heat exchanger fluidically coupled to the first heat-rejecting media and located such that airflow driven by the one or more air movers flows proximate to the first heat exchanger, and a second heat exchanger fluidically coupled to the second heat-rejecting media and located such that airflow driven by the one or more air movers flows proximate to the second heat exchanger. Components of the thermal control system may be arranged such that the cooling fluid flows from the first heat exchanger to the first heat-rejecting media, from the first heat-rejecting media to the second heat exchanger, from the second heat exchanger to the second heat-rejecting media, and from the second heat-rejecting media to the first heat exchanger. The first heat exchanger and the second heat exchanger may be arranged relative to one another and relative to the one or more air movers such that as a result of mirrored thermal gradients across the first heat exchanger and the second heat exchanger, airflow driven by the one or more air movers proximate to the first heat exchanger and the second heat exchanger is of approximately uniform temperature once driven past the first heat exchanger and the second heat exchanger.

In accordance with these and other embodiments of the present disclosure, a thermal control system may include first heat-rejecting media configured to thermally couple to a first information handling resource, the first heat-rejecting media further configured to receive a flow of cooling fluid through the first heat-rejecting media, second heat-rejecting media configured to thermally couple to a second information handling resource, the second heat-rejecting media further configured to receive the flow of cooling fluid through the second heat-rejecting media, a first heat exchanger fluidically coupled to the first heat-rejecting media and located such that airflow driven by one or more air movers flows proximate to the first heat exchanger, and a second heat exchanger fluidically coupled to the second heat-rejecting media and located such that airflow driven by the one or more air movers flows proximate to the second heat exchanger. Components of the thermal control system may be arranged such that the cooling fluid flows from the first heat exchanger to the first heat-rejecting media, from the first heat-rejecting media to the second heat exchanger, from the second heat exchanger to the second heat-rejecting media, and from the second heat-rejecting media to the first heat exchanger. The first heat exchanger and the second heat exchanger may be arranged relative to one another and relative to the one or more air movers such that as a result of mirrored thermal gradients across the first heat exchanger and the second heat exchanger, airflow driven by the one or more air movers proximate to the first heat exchanger and the second heat exchanger is of approximately uniform temperature once driven past the first heat exchanger and the second heat exchanger.

In accordance with these and other embodiments of the present disclosure, a method may include fluidically coupling a first heat exchanger to first heat-rejecting media and locating the first heat exchanger such that airflow driven by one or more air movers flows proximate to the first heat exchanger, wherein the first heat-rejecting media is configured to thermally couple to a first information handling resource and is configured to receive a flow of cooling fluid through the first heat-rejecting media, fluidically coupling a second heat exchanger to second heat-rejecting media and locating the second heat exchanger such that airflow driven by the one or more air movers flows proximate to the second heat exchanger, wherein the second heat-rejecting media is configured to thermally couple to the a second information handling resource and is configured to receive a flow of cooling fluid through the second heat-rejecting media, arranging components of a thermal control system such that the cooling fluid flows from the first heat exchanger to the first heat-rejecting media, from the first heat-rejecting media to the second heat exchanger, from the second heat exchanger to the second heat-rejecting media, and from the second heat-rejecting media to the first heat exchanger, and arranging the first heat exchanger and the second heat exchanger relative to one another and relative to the one or more air movers such that as a result of mirrored thermal gradients across the first heat exchanger and the second heat exchanger, airflow driven by the one or more air movers proximate to the first heat exchanger and the second heat exchanger is of approximately uniform temperature once driven past the first heat exchanger and the second heat exchanger.

DETAILED DESCRIPTION

Preferred embodiments and their advantages are best understood by reference toFIG.2, wherein like numbers are used to indicate like and corresponding parts.

For the purposes of this disclosure, information handling resources may broadly refer to any component system, device or apparatus of an information handling system, including without limitation processors, buses, memories, I/O devices and/or interfaces, storage resources, network interfaces, motherboards, integrated circuit packages; electro-mechanical devices (e.g., air movers), displays, and power supplies.

FIG.2illustrates a block diagram of an example information handling system202, in accordance with embodiments of the present disclosure. In some embodiments, information handling system202may comprise a server or “blade” configured to be housed along with a plurality of other servers or “blades” within a rack, tower, or other enclosure. In other embodiments, information handling system202may comprise a personal computer (e.g., a desktop computer, laptop computer, mobile computer, and/or notebook computer). In yet other embodiments, information handling system202may be a storage appliance integral to a storage enclosure configured to house a plurality of physical disk drives and/or other computer-readable media for storing data. As shown inFIG.2, information handling system202may include a plurality of processors203, a plurality of memory modules204, and a liquid-assisted air-cooled thermal control system218.

A processor203may comprise any system, device, or apparatus operable to interpret and/or execute program instructions and/or process data, and may include, without limitation a microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), or any other digital or analog circuitry configured to interpret and/or execute program instructions and/or process data. In some embodiments, a processor203may interpret and/or execute program instructions and/or process data stored in memory modules204and/or another component of information handling system202.

A memory module204may be communicatively coupled to one or more processors203and may comprise any system, device, or apparatus operable to retain program instructions or data for a period of time. A memory modules204may comprise random access memory (RAM), electrically erasable programmable read-only memory (EEPROM), a PCMCIA card, flash memory, magnetic storage, opto-magnetic storage, or any suitable selection and/or array of volatile or non-volatile memory that retains data after power to information handling system202is turned off. In some embodiments, a memory module204may comprise a dual inline memory module (DIMM) or other similar memory module.

As shown inFIG.2, liquid-assisted air-cooled thermal control system218may include one or more air movers208, heat-rejecting media222(e.g., heat-rejecting media222A and222B) each thermally coupled to a respective processor203, fluidic conduits226, cold manifold228, hot manifold230, and a plurality of radiators232(e.g., radiators232A and232B).

An air mover208may include any mechanical or electro-mechanical system, apparatus, or device operable to move air and/or other gases in order to cool information handling resources of information handling system202. In some embodiments, air mover208may comprise a fan (e.g., a rotating arrangement of vanes or blades which act on the air). In other embodiments, air mover208may comprise a blower (e.g., a centrifugal fan that employs rotating impellers to accelerate air received at its intake and change the direction of the airflow). In these and other embodiments, rotating and other moving components of air mover208may be driven by a motor. The rotational speed of the motor may be controlled by an air mover control signal communicated from a thermal control system of information handling system202. In operation, air mover208may cool information handling resources of information handling system202by drawing cool air into an enclosure200housing the information handling resources from outside the chassis, expel warm air from inside the enclosure to the outside of such enclosure, and/or move air across one or more heat sinks (not explicitly shown) internal to the enclosure to cool one or more information handling resources.

Heat-rejecting media222may include any system, device, or apparatus configured to transfer heat from an information handling resource (e.g., processor203, as shown inFIG.2), thus reducing a temperature of the information handling resource. For example, heat-rejecting media222may include a solid thermally coupled to the information handling resource (e.g., heatpipe, heat spreader, heatsink, finstack, etc.) such that heat generated by the information handling resource is transferred from the information handling resource. In particular embodiments, heat-rejecting media222may comprise a cold plate through which cooling liquid may flow, such that heat may be transferred from an information handling resource (e.g., processor203) to the cooling liquid via heat-rejecting media222.

In operation, a cooled fluid may be received by cold manifold228from radiator232B. Although not shown inFIG.2for purposes of clarity and exposition, in some embodiments, liquid-assisted air-cooled thermal control system218may include components for driving flow of the fluid (e.g., a pump). As the fluid passes through heat-rejecting media222B proximate to a processor203, heat may be transferred from the processor to heat-rejecting media222B and from heat-rejecting media222B to the fluid flowing within heat-rejecting media222B, thus cooling the processor203. Such heated fluid may then be discharged from a fluidic conduit226to radiator232A.

As a result of airflow driven proximate to radiator232A by air movers208, the fluid may cool as it flows through radiator232A (e.g., flowing from right to left inFIG.2). The cooled fluid may then be conveyed to heat-rejecting media222A via a fluidic conduit226. As the fluid passes through heat-rejecting media222A proximate to a processor203, heat may be transferred from the processor to heat-rejecting media222A and from heat-rejecting media222A to the fluid flowing within heat-rejecting media222A, thus cooling the processor203. Such heated fluid may then be discharged from a fluidic conduit226to hot manifold230, after which it may flow to radiator232B.

As a result of airflow driven proximate to radiator232B by air movers208, the fluid may cool as it flows through radiator232B (e.g., flowing from left to right inFIG.2). After cooling, the fluid may again flow to cold manifold228, repeating the flow and cooling process.

In addition to processor203, memory204, and liquid-assisted air-cooled thermal control system218, information handling system202may include one or more other information handling resources. Furthermore, for the sake of clarity and exposition of the present disclosure,FIG.2depicts information handling system202including a liquid-assisted air-cooled thermal control system218for cooling of processors203. However, in some embodiments, approaches similar or identical to those used to cool processors203as described herein may be employed to provide cooling of any other information handling resources of information handling system202.

One notable difference between information handling system202depicted inFIG.2and information handling system102depicted inFIG.1is that radiators232and heat-rejecting media222are in a serial loop, as opposed to the parallel arrangement of heat-rejecting media122. Another notable difference is that radiator132ofFIG.1is effectively divided into two radiators232A and232B.

Because of a hot-to-cold temperature gradient from left to right in radiator232A and an approximately mirrored hot-to-cold temperature gradient from right to left in radiator232B, airflow driven by radiators232A and232B, once past radiators232A and232B, may be approximately uniform in temperature. Accordingly, the air flowing proximate to memory module204should be approximately uniform, potentially overcoming the disadvantages of the arrangement ofFIG.1.

In addition, routing of fluidic conduit networks for heat-rejecting media222A and222B may be approximately equal, potentially reducing or eliminating the mismatched cooling of processors103in the arrangement ofFIG.1.

Furthermore, the arrangement ofFIG.2may not require use of three-way valves needed in the arrangement ofFIG.1, potentially reducing fluid routing complexity and improving reliability compared to the arrangement ofFIG.1.

Although exemplary embodiments are illustrated in the figures and described above, the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the exemplary implementations and techniques illustrated in the figures and described above.

Unless otherwise specifically noted, articles depicted in the figures are not necessarily drawn to scale.