Methodology for electronic equipment to self-identify submersion in mineral oil

An information handling system (IHS) automatically responds to a change in cooling medium that cools functional components. A cooling medium sensor senses a material characteristic of the cooling medium. A thermal management controller determines whether the material characteristic received from the cooling medium sensor is in one of a first range that is associated with the air cooling medium and a second range that is associated with the liquid cooling medium. In response to determining that the material characteristic is within the second range, the thermal management controller disables a thermal mitigation component that reduces a temperature of the functional components of the IHS.

BACKGROUND

1. Technical Field

This disclosure generally relates to information handling systems (IHS), and more particular to cooling an IHS by submersion in a liquid cooling medium.

2. Description of the Related Art

Liquid cooling media such as mineral oil are being used as an alternative for cooling electronic equipment due to its cost effectiveness in comparison to traditional air cooling methodology. Empirical data indicates that using a liquid cooling medium and removing fans significantly reduces power consumption in data centers. One problem with using a liquid cooling medium such as mineral oil is that fans have to be disabled because the increased viscosity as compared to air creates a back pressure that tends to burn out the fans.

One approach to avoid fan burn out is to remove the fans and install a special circuit board to mimic the tachometer signal that is output by the fans. The IHS operates without disruption or reverting to a degraded mode due to the special circuit board preventing the IHS from sensing a failed or missing fan. This approach adds additional costs and requires a separate process in manufacturing of the electronic equipment. When not performed by an original equipment manufacturer, this approach can void a warranty as well as create a situation where inadvertent damage can be caused to other components of the IHS.

BRIEF SUMMARY

The illustrative embodiments of the present disclosure provide an information handling system (IHS) that automatically responds to a change in cooling medium. In one or more embodiments, the IHS includes functional components that are disposed within an interior space of a chassis and that require cooling. A cooling medium sensor is positioned to sense a material characteristic of a cooling medium that is present in the interior space. The cooling medium is one of an air cooling medium and a liquid cooling medium. A thermal mitigation component is provided to reduce a temperature of the functional components that are operating in an air cooling medium. The IHS includes a thermal management controller in communication with the thermal mitigation component and the cooling medium sensor. The thermal management controller determines whether the material characteristic received from the cooling medium sensor is in one of a first range that is associated with the air cooling medium or a second range that is associated with the liquid cooling medium. In response to determining that the material characteristic is within the second range, the thermal management controller disables the thermal mitigation component.

According to at least one aspect of the present disclosure, a power supply unit (PSU) of an IHS automatically responds to a change in cooling medium. In one or more embodiments, the PSU includes a housing that has an interior space. The PSU includes electrical conversion components that are disposed within the housing and that supply electrical power to functional components of the IHS. A thermal mitigation component is provided to reduce a temperature of one of the functional components of the IHS and the electrical conversion components of the PSU that are operating in an air cooling medium. A cooling medium sensor is positioned to sense a material characteristic of a cooling medium present in the interior space from among the air cooling medium and a liquid cooling medium. A thermal management controller is placed in communication with the thermal mitigation component and the cooling medium sensor. The thermal controller determines whether the material characteristic received from the cooling medium sensor is in one of a first range that is associated with the air cooling medium and a second range that is associated with the liquid cooling medium. In response to determining that the material characteristic is within the second range, the thermal management controller disables the thermal mitigation component.

According to at least one aspect of the present disclosure, a method is provided of automatically responding to a change in cooling medium in an IHS. In one or more embodiments, the method includes sensing, via a cooling medium sensor, a material characteristic of a cooling medium that is present in an interior space of a chassis of an IHS. The method includes a thermal management controller determining whether a material characteristic that is received from a cooling medium sensor is in one of a first range that is associated with the air cooling medium and a second range that is associated with a liquid cooling medium. The method includes, in response to determining that the material characteristic is within the second range, the thermal management controller disabling a thermal mitigation component utilized to cool components of the IHS operating in an air cooling medium.

The above presents a general summary of several aspects of the disclosure in order to provide a basic understanding of at least some aspects of the disclosure. The above summary contains simplifications, generalizations and omissions of detail and is not intended as a comprehensive description of the claimed subject matter but, rather, is intended to provide a brief overview of some of the functionality associated therewith. The summary is not intended to delineate the scope of the claims, and the summary merely presents some concepts of the disclosure in a general form as a prelude to the more detailed description that follows. Other systems, methods, functionality, features and advantages of the claimed subject matter will be or will become apparent to one with skill in the art upon examination of the following figures and detailed written description.

DETAILED DESCRIPTION

An information handling system (IHS) automatically responds to a change in cooling medium that cools functional components. A cooling medium sensor senses a material characteristic of the cooling medium. A thermal management controller determines whether the material characteristic received from the cooling medium sensor is in one of a first range that is associated with the air cooling medium and a second range that is associated with the liquid cooling medium. In response to determining that the material characteristic is within the second range, the thermal management controller disables a thermal mitigation component that reduces a temperature of the functional components of the IHS. Thereby, the present disclosure can reduce power consumption in customer data centers with minimum impact to the reliability and maintainability of the IHS.

FIG. 1illustrates an IHS100with thermal mitigation components102that are intended to operate in an air cooling medium104to reduce a temperature of functional components106. For clarity,FIG. 1illustrates two thermal mitigation components102of an air mover108to move an air flow110to cool the functional components106and a power throttle112to reduce an amount of heat generated by the functional components106. Examples of the latter include a variable system clock. For purposes of this disclosure, an information handling system, such as IHS100, may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a handheld device, personal computer, a server, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components.

In one or more embodiments, the IHS100includes functional components106that are disposed within an interior space114of a chassis116and that require cooling. The functional components can be are communicatively interconnected, but are not necessarily so. A cooling medium sensor118is positioned to sense a material characteristic of a cooling medium that is present in the interior space. The cooling medium can be one of (a) an air cooling medium104and (b) a liquid cooling medium120(FIG. 2). A thermal management controller122is provided in communication with the cooling medium sensor118and the thermal mitigation components102, specifically the air mover108and the power throttle112. The thermal management controller122determines whether the material characteristic received from the cooling medium sensor118is in one of a first range that is associated with the air cooling medium104and a second range that is associated with the liquid cooling medium120(FIG. 2). In response to determining that the material characteristic is within the first range (i.e., identifying the cooling medium as an air cooling medium), the thermal management controller enables the thermal mitigation components102.

FIG. 2illustrates the IHS100ofFIG. 1submersed in the liquid cooling medium120such as mineral oil that is held within a tank124. In response to determining that the material characteristic is within the second range (i.e., identifying the cooling medium as an air cooling medium), the thermal management controller122disables one or more of the thermal mitigation components102.

FIG. 3illustrates an example IHS200with a power supply unit (PSU)201that incorporates aspects of the present disclosure, while economically reduces or avoids changes to a system controller203of the IHS200. For example, the system controller203can be a Baseboard Management Controller (BMC). The IHS200includes functional components206that are disposed within an interior space214of a chassis216and that require cooling. The PSU201can accomplish the benefits of disabling thermal mitigation components202when in a liquid cooling medium220(FIG. 4). The thermal mitigation components202are intended to operate in an air cooling medium204.

In one or more embodiments, the PSU201can include a housing205that has a PSU interior space207. Electrical conversion components209are disposed within the housing205and supply electrical power to the functional components206of the IHS200. The thermal mitigation component202can reduce a temperature of at least one of the functional components206of the IHS200and the electrical conversion components209of the PSU201when these components are operating in the air cooling medium204. In one or more embodiments, the PSU201can include a PSU fan211to cool the electrical conversion components209with a PSU air flow213. In one or more embodiments, the IHS200can include a system fan208to cool the functional components206with a chassis air flow210. The IHS200can include a power throttle212, such as a variable system clock, to control an amount of heat generated by the functional components206.

A cooling medium sensor218is positioned to sense a material characteristic of a cooling medium that is present in the PSU interior space207from among the air cooling medium204and a liquid cooling medium220(FIG. 4). A thermal management controller222is in communication with the thermal mitigation components202and the cooling medium sensor218. The thermal management controller222determines whether the material characteristic received from the cooling medium sensor is in one of a first range that is associated with (or which indicates operation in) the air cooling medium204and a second range that is associated with (or which indicates operation in) the liquid cooling medium220(FIG. 4). In response to determining that the material characteristic is within the first range, the thermal management controller222can enable the thermal mitigation components202.

FIG. 4illustrates the example IHS200and PSU201submersed in the liquid cooling medium220contained within a tank224. In response to determining that the material characteristic is within the second range, the thermal management controller222can disable the thermal mitigation components202.

The exemplary embodiments ofFIGS. 3-4illustrate the cooling medium sensor218including a parallel plate capacitor225that is energized by an electrical stimulus driver227. The change in the cooling medium from air or mineral oil and back can be detected by measuring a corresponding change in the capacitance detected by the cooling medium sensor218. A parallel plate capacitor225can be similar to those used in radio frequency (RF) circuits can be mounted on a printed circuit board (PCB) of the PSU201. The electrical stimulus driver227can include digital signal processing (DSP) capability than can inject an electrical stimulus across the parallel plate capacitor215and measure the capacitance. The capacitance is given by the equation C=E*A/d, where E is the dielectric constant of the medium, A is the area of the parallel plate, and d is the distance between the plates. The capacitance measured in the mineral oil will be more than twice as much as in air as the dielectric constant of mineral oil is 2.2 and that of air is 1. Alternatively, electrical stimulus driver227can also inject a direct current (DC) current (i) and measure the voltage across the parallel plate capacitor225. Capacitance can be determined from a relationship i=c*dv/dt) by measuring a rate of change in voltage over a time interval (dv/dt).

In another embodiment, the cooling medium sensor218can also detect a difference between air and oil by using a magnetic circuit that includes an inductor or a transformer. An air core solenoid can be mounted on the PCB of the PSU201, and the inductance can be measured with the air core and with the mineral oil. The permeability (u) of the cooling medium will impact the inductance, and this can be used to differentiate between air and oil.

In one or more embodiments, during in-circuit test (ICT) testing of the PSU201when the cooling medium is air cooling medium204(FIG. 3), the measured capacitance, which is the change in voltage across the parallel plate capacitor225, can be measured and stored in PSU nonvolatile memory (NVM)229as a threshold231. When the system build is complete, the stimulus is applied and the capacitance measured each time the IHS200is powered on. In one embodiment, processor233of the thermal management controller222then compares the capacitance (or voltage) to the stored value of the threshold231in the NVM229.

In a particular embodiment, in addition to the NVM229and processor233, the thermal management controller222can include (i) a memory communicatively coupled to processor233, (ii) storage media, (iii) a network interface communicatively coupled to processor233, and (iv) a power source electrically coupled to processor233. These components are not specifically illustrated but are known to those skilled in the art as components of IHS. Processor233may include any system, device, or apparatus configured to interpret and/or execute program instructions and/or process data. Processor233may also 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, processor233may interpret and/or execute program instructions and/or process data stored in memory and/or another component of IHS200. Memory may be communicatively coupled to processor233and may include any system, device, or apparatus configured to retain program instructions and/or data for a period of time (e.g., computer-readable media). By way of example without limitation, memory may include RAM, 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 PSU201is turned off or power to PSU201is removed. Network interface may include any suitable system, apparatus, or device operable to serve as an interface between PSU201and a network. Network interface may enable the PSU201to communicate over network using any suitable transmission protocol and/or standard, including without limitation all transmission protocols and/or standards enumerated herein or generally known.

FIG. 5illustrates a method500(performed by and/or within an IHS) of automatically responding to a change in cooling medium within an IHS. According to one or more embodiments, a thermal mitigation component reduces a temperature of functional components that are operating in an air cooling medium of the IHS (block502). A cooling medium sensor senses a material characteristic of a cooling medium that is present in an interior space of a chassis of an IHS (block504). A thermal management controller determines whether a material characteristic that is received from the cooling medium sensor is in one of a first range that is associated with the air cooling medium and a second range that is associated with a liquid cooling medium (block506). The thermal management controller, in response to determining that the material characteristic is within the first range, enables the thermal mitigation component (block508). The thermal management controller, in response to determining that the material characteristic is within the second range, disables the thermal mitigation component (block510). In one or more embodiments, the thermal mitigation component includes a power throttle to reduce heat generation by the functional components. In one or more embodiments, the thermal mitigation component includes an air mover that is positioned to move air within at least a portion of the interior space.

FIG. 6illustrates a method600of a PSU performing a standalone measurement of a material characteristic of the cooling medium during a first-time system power up condition. For example, an original equipment manufacturer (OEM) can operate a test unit in order to determine a setting to provision a class of devices such as a PSU. In one or more embodiments, each device can have a degree of variability in a sensor such that each device is calibrated during a first time use. According to one or more embodiments, the method600includes placing a PSU in air (block602). The method600includes powering on the PSU for the first time (block604). A thermal management controller of the PSU determines whether a calibration condition exists, such as by accessing a memory to see if a first range or the second range has been provisioned (decision block606). In response to determining in decision block606that a calibration condition does not exist, method600exits. In response to determining in decision block606that a calibration condition exists, method600includes sensing the material characteristic of a cooling medium by applying an electrical stimulus across a parallel plate capacitor to measure a capacitance. The amount of capacitance measured/detected correlates to the cooling medium in which the parallel plate capacity is exposed (block608). The method600includes storing, in memory, the material characteristic that is currently sensed by the cooling medium sensor as one of the first range and the second range. The method also includes storing the other of the first and second range that is separated from the one by a threshold (block610). Then method600exits.

In one embodiment, calibration is performed on one device at an original equipment manufacturer (OEM). The device detects that it is in a calibration mode and stores the detected material characteristic to a default one of the first and second range. For example, operators can procedurally ensure that the device is in a cooling medium that corresponds to the default range. In another example, the device incorporates an approximate value for air cooling medium or liquid cooling medium. Calibration provides an adjustment to the closer of the two approximate values. In an additional example, the device can be selectably configured to one of the first and second ranges, such as by a test pin or user interface. One of the first and second ranges can be deterministically set based upon an empirical value for the other. In one or more embodiments, both values can be empirically determined in sequential tests. In one or more embodiments, each device can be calibrated upon first power up. In one or more embodiments, the OEM can be provisioned with values obtained on a representative test article.

FIG. 7illustrates a method700of a PSU providing electrical power to functional components of an IHS in either air or liquid cooling media. In one or more embodiments, the method700includes a thermal management controller monitoring a power up condition of the PSU (block702). The thermal management controller determines whether the power up condition is detected (decision block704). In response to determining in decision block704that a power condition is not detected, then method700returns to block702to wait for a power up condition where the PSU is called upon to provide electrical power to functional components. In response to the thermal management controller determining that a PSU power up condition exists in decision block704, then the method700includes the thermal management controller sensing the material characteristic by injecting an electrical stimulus across a parallel plate capacitor to measure a capacitance, which correlates to the cooling medium to which the parallel plate capacitor is exposed (block706). A determination is made by the thermal management controller as to whether the material characteristic sensed indicates an air cooling medium (decision block708). In response to the determination in decision block708that the sensed material characteristic indicates air cooling medium, then the method700includes communicating with a system controller to enable a system fan (block710). Method700includes enabling a PSU fan (block712). Then, method700includes PSU supplying electrical power to the functional components. In response to the determination in decision block708that the material characteristic does not indicate an air cooling medium and is thus indicating a liquid cooling medium, then the method700includes communicating with the system controller to disable a system fan (block716). Method700includes disabling the PSU fan (block718). Then method700returns to block714to continue supplying electrical power. Then method700ends.

In the above described flow charts ofFIGS. 5-7, one or more of the methods may be embodied in an automated controller that performs a series of functional processes. In some implementations, certain steps of the methods are combined, performed simultaneously or in a different order, or perhaps omitted, without deviating from the scope of the disclosure. Thus, while the method blocks are described and illustrated in a particular sequence, use of a specific sequence of functional processes represented by the blocks is not meant to imply any limitations on the disclosure. Changes may be made with regards to the sequence of processes without departing from the scope of the present disclosure. Use of a particular sequence is therefore, not to be taken in a limiting sense, and the scope of the present disclosure is defined only by the appended claims.

One or more of the embodiments of the disclosure described can be implementable, at least in part, using a software-controlled programmable processing device, such as a microprocessor, digital signal processor or other processing device, data processing apparatus or system. Thus, it is appreciated that a computer program for configuring a programmable device, apparatus or system to implement the foregoing described methods is envisaged as an aspect of the present disclosure. The computer program may be embodied as source code or undergo compilation for implementation on a processing device, apparatus, or system. Suitably, the computer program is stored on a carrier device in machine or device readable form, for example in solid-state memory, magnetic memory such as disk or tape, optically or magneto-optically readable memory such as compact disk or digital versatile disk, flash memory, etc. The processing device, apparatus or system utilizes the program or a part thereof to configure the processing device, apparatus, or system for operation.

For example, in one or more embodiments the thermal mitigation components102can disable an air operating mode by reverting to a liquid operating mode. Certain thermal mitigation components can be capable of efficiently and reliably operate in the liquid cooling medium120albeit at a different performance level. For example, the air mover108can provide a benefit by operating a reduced duty cycle that is appropriate for its motive capabilities, the viscosity of the liquid cooling medium, and the reduced convective flow rates required by the functional components106.