COMPUTER COOLING SYSTEM WITH DEFORMABLE DUCTS

A computing system includes a motherboard with an array of card connectors, circuit boards connected to the array of card connectors, wherein the circuit boards include electronic components, constraining walls positioned around the circuit boards to form a housing over the motherboard, and expandable ducts. One of the expandable ducts is positioned in contact with one of the electronic components and constrained by a constraining wall when expanded, and each of the expandable ducts includes an inlet, an outlet, and a fluid flow path from the inlet to the outlet that is parallel to other fluid flow paths of other expandable ducts.

BACKGROUND

The present disclosure relates to computing systems, and more specifically, to closed-circuit fluid cooling systems for circuit boards.

Many computing systems include circuit boards with electronic components that generate heat during operation. In order to better cool these components, various cooling structures can be thermally connected thereto. However, many computing systems have many different circuit boards, and many circuit boards have components with varying sizes, heights, and locations. Thereby, it can be difficult to design, manufacture, inventory, and install traditional solid cooling structures for each of the different circuit boards in a computing system.

SUMMARY

According to one embodiment of the present disclosure, a computing system includes a motherboard with an array of card connectors, circuit boards connected to the array of card connectors, wherein the circuit boards include electronic components, constraining walls positioned around the circuit boards to form a housing over the motherboard, and expandable ducts. One of the expandable ducts is positioned in contact with one of the electronic components and constrained by a constraining wall when expanded, and each of the expandable ducts includes an inlet, an outlet, and a fluid flow path from the inlet to the outlet that is parallel to other fluid flow paths of other expandable ducts.

According to one embodiment of the present disclosure, a heat transfer system includes a pump, a heat exchanger fluidly connected to the pump, and a computing system. The computing system includes a circuit board including an electronic component, another circuit board including another electronic component, wherein the circuit boards are positioned alongside each other, and an expandable duct. The expandable duct is positioned between the circuit boards and is in contact with at least one of the electronic components, and the expandable duct forms a path through the computing system that is fluidly connected to the pump and the heat exchanger to form a closed loop.

According to one embodiment of the present disclosure, a method of operating a heat transfer system for a computing system includes reading outputs of contact sensors positioned in the computing system, determining that there is a lack of contact of an expandable duct against at least one of the contact sensors based on the reading of the outputs of the contact sensors which indicates inadequate contact between the expandable duct and an electronic component of a circuit board in the computing system, and decreasing flow of a cooling fluid through the expandable duct in response to determining that there is a lack of contact of the expandable duct. The method also includes reading output of a temperature sensor of the electronic component, determining that the temperature of the electronic component is higher than an electronic component temperature threshold based on the reading of the output of the temperature sensor, and increasing flow from a cooling fluid pump in response to determining that the temperature of the electronic component is higher than the electronic component temperature threshold.

DETAILED DESCRIPTION

Various embodiments of the present disclosure are described herein with reference to the related drawings. Alternative embodiments can be devised without departing from the scope of the present disclosure. It is noted that various connections and positional relationships (e.g., over, below, adjacent, etc.) are set forth between elements in the following description and in the drawings. These connections and/or positional relationships, unless specified otherwise, can be direct or indirect, and the present disclosure is not intended to be limiting in this respect. Accordingly, a coupling of entities can refer to either a direct or an indirect coupling, and a positional relationship between entities can be a direct or indirect positional relationship.

For purposes of the description hereinafter, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” and derivatives thereof shall relate to the described structures and methods, as oriented in the drawing Figures. The terms “overlying,” “atop,” “on top,” “positioned on,” or “positioned atop” mean that a first element, such as a first structure, is present on a second element, such as a second structure, wherein intervening elements such as an interface structure can be present between the first element and the second element.

FIG.1is a perspective view of heat transfer system100. In the illustrated embodiment, heat transfer system100includes computing system102, pump104, heat exchanger106, and controller108that are fluidly connected to one another via lines110. Lines110carry cooling fluid, for example, water, between the components of heat transfer system100in a closed loop. This cooling fluid is pressurized in pump104, heated in computing system102, and cooled in heat exchanger106so that heat can be removed from computing system102.

In the illustrated embodiment, computing system102has several parallel flow paths (as indicated by inlets112and outlets114), so inlet manifold116is positioned upstream of computing system102, and outlet manifold118is positioned downstream of computing system102. In order to control flow through the parallel flow paths of computing system102, valves120are positioned between each outlet114and outlet manifold118. Valves120are communicatively connected to and controlled by controller108. Similarly, pump104is communicatively connected to and controlled by controller108. Controller108is also communicatively connected to sensors placed throughout heat transfer system100, for example, in computing system102and heat exchanger106. Controller108can automatically adjust parameters of heat transfer system100(e.g., the output of pump104and the flow through valves120) based on data from the sensors and predetermined operating thresholds (e.g., the maximum allowable temperature of the cooling fluid and/or electronic components).

Depicted inFIG.1is one embodiment of the present disclosure, to which there are alternative embodiments. For example, heat exchanger106can be directly upstream of computing system102, and pump104can be directly downstream of computing system102. For another example, there can be more than three parallel flow paths through computing system102. For another example, controllable flow valves can be positioned between inlet manifold116and inlets112instead of or in addition to valves120.

FIG.2is an exploded perspective view of computing system102. In the illustrated embodiment, computing system102includes motherboard122, circuit boards124A-124D (collectively “circuit boards124”), ducts126A-126C (collectively “ducts126”), constraining walls128A-128D (collectively “constraining walls128”), and restrictor band130. When assembled, circuit boards124are plugged into the array of card connectors132on motherboard122so circuit boards124are positioned alongside each other (i.e., extending in parallel planes to one another and perpendicular to motherboard122).

In the illustrated embodiment, circuit boards124include electronic components134A-134H (collectively “electronic components134”), respectively. Circuit boards124can have different functions (e.g., at least some can be memory cards) and/or configurations from one another, so the sizes, locations, and orientations of electronic components134can vary board-to-board. In addition, electronic components134can generate heat during operation, and this heat can be removed by operating heat transfer system100(shown inFIG.1). Thereby, ducts126are positioned between circuit boards124(e.g., when they are empty), and then ducts126are filled with cooling fluid. Ducts126are made from expandable, stretchable, and/or flexible materials (such as, for example, high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, and polyvinyl chloride), so ducts126come into contact with and conform to electronic components134when filled. The cooling fluid flows through ducts126via inlets112and outlets114, so there are several parallel flow paths to evacuate heat from computing system102.

In the illustrated embodiment, electronic component134H would not benefit from contact with duct126C, which can be for a reason such as fragility, lack of heat generation, or need for heat retention. Thereby, restrictor band130can be positioned around a portion of duct126C to locally prevent expansion. Restrictor band130can be, for example, an elastomeric rubber component. However, to generally prevent over expansion of ducts126and keep ducts126in place, constraining walls128A-128D (collectively “constraining walls128”) are strategically positioned in computing system102. For example, constraining walls128are positioned where there is an open side around one or more ducts126to form a housing over motherboard122. Thereby, constraining walls128assist in maintaining contact between ducts126and electronic components134.

FIG.3Ais a cross-sectional view of computing system102along line A inFIG.1.FIG.3Bis a cross-sectional view of computing system102along line B inFIG.1.FIGS.3A and3Bwill be discussed in conjunction with one another. It should be noted that ducts126have been illustrated such that their sides are straight unless otherwise impinged upon. While ducts126could be constructed in such a manner that would encourage this quality (i.e., made of six flat sections welded together), ducts126could be constructed as a single piece (à la a balloon). In such embodiments, ducts126may bulge further to more generously fill the space. This may cause ducts126to contact motherboard122, circuit boards124, and/or constraining walls128more than is shown inFIGS.3A and3B.

In the illustrated embodiment, duct126A is positioned between motherboard122, circuit board124A, and constraining walls128A-128D; duct126B is positioned between motherboard122, circuit boards124A and124B, and constraining walls128A,128B, and128D; and duct126C is positioned between motherboard122, circuit boards124C and124D, and constraining walls128A,128B, and128D. Duct126C can cool both electronic components134F and134G despite them being on circuit boards124C and124D, respectively, since circuit boards124C and124D face each other. On the other hand, because there are no electronic components134between circuit boards124B and124C, there isn't a duct126positioned between circuit boards124B and124C. In some embodiments, a duct126may be placed in between circuit boards124B and124C but restrictor bands130may be positioned around it. This would prevent unnecessary expansion of the duct126to preserve its lifespan, but allow it to be plumbed in during initial assembly in case the configuration of circuit boards124was changed later on.

In the illustrated embodiment, computing system102includes sensors136A-136Q (collectively “sensors136”). Sensors136are positioned on motherboard122, circuit boards124, and constraining walls128, respectively. Sensors136can detect contact with ducts126, which can be read by controller108(shown inFIG.1). During operation of heat transfer system100(shown inFIG.1), ducts126expand and come into contact with at least some of sensors136. For example, duct126B contacting sensors136C,136D,136E,136L,136M (which is positioned on pedestal138),136N, and136O can indicate to controller that duct126B is properly conforming to the geometry that constrains it. However, as stated previously, restrictor band130prevents duct126C from contacting electronic component134H. If restrictor band130fails, duct126C will expand and contact at least one of sensors136G and136H, which can alert controller108of the problem. In some embodiments, sensors136can also sense temperature. This data can also be read by controller108and added to any other temperature sensors present in heat transfer system100(e.g., sensors that are installed on circuit boards124to measure temperatures of electronic components134, for example, sensor136G on circuit board124D, and/or sensors that are in direct contact with the cooling fluid such as, for example, at pump104, heat exchanger106, and/or valves120, shown inFIG.1to measure temperatures of the cooling fluid).

FIG.4is a side view of duct126. Because ducts126are expandable, they can all be manufactured the same regardless of their placement in computing system102or the configurations of circuit boards124and electronic components134(shown inFIG.2). Thereby, duct126can represent any of ducts126A-126C.

In the illustrated embodiment, duct126includes dividers140A-140B (collectively “dividers140”). Dividers140can extend across the interior of duct126, and dividers140can be additional material added to duct126or they can be formed by local melting/welding of the sides of duct126together. Dividers140define a flow path for the cooling fluid from inlet112to outlet114(as indicated by the arrows) to increase the uniformity of flow in duct126, which increases the cooling capacity at the corners of duct126opposite from inlet112and outlet114.

FIG.5is a flowchart of method200of operating heat transfer system100. During the discussion of method200, references may be made to components and features described previously with respect toFIGS.1-4. Method200can be performed regularly or continuously to ensure proper operation of heat transfer system100since the demands on computing system102can change rapidly, which can change the amount of cooling required.

In the illustrated embodiment, method200starts at operation202where the contact sensors (i.e., sensors136) are read by controller108. At operation204, controller108determines whether ducts126are contacting the correct electronic components134based on the reading of sensors136. If there is not contact where there should be or if there is contact where there shouldn't be, then the flow in the affected ducts is adjusted at operation206. For example, if there was insufficient contact of a duct126, the corresponding valve120can be restricted (e.g., closed to an extent). For another example, if there was inappropriate contact of a duct126, the corresponding valve120can be expanded (e.g., opened to an extent). However, if the contact was correct, then method200moves to operation208.

In the illustrated embodiment, at operation208, the temperature sensors (e.g., sensors136) are read by controller108. At operation210, controller108determines whether the temperatures of electronic components134cooled by ducts126are acceptable based on the reading of the temperature sensors. If any of the temperatures (either direct measurements of electronic components134and/or proxy measurements thereof from ducts126) is above a threshold, then the flow from pump104is increased (e.g., by increasing pump speed) at operation212. However, if the temperatures were below the threshold, then method200moves to operation214where controller108determines that the operation of heat transfer system100is acceptable.

Depicted inFIG.5is one embodiment of the present disclosure, to which there are alternative embodiments. For example, sensors136can be non-binary in that they can measure the force of contact (e.g., pressure). For another example, instead of or in addition to restricting or expanding the corresponding valve120at operation206, pump flow can be adjusted. For another example, instead of or in addition to increasing pump flow at operation212, the valves120for the non-affected ducts126can be restricted to effectively increase flow in the affected duct126. The latter two alternative embodiments can be aided by the initial alternative embodiment in that controller108would be able to determine how close to the acceptable thresholds each duct126was when deciding how remedy the unacceptable operation of a duct126.