Abstract:
The present disclosure includes a method for regenerating power in an information handling system. The method includes circulating a cooling fluid through a fluid flow loop connecting a thermosiphon, a turbine, and a condenser. The method further includes removing heat from a heated component of the information handling system, converting the cooling fluid from a liquid state to a gaseous state in the thermosiphon, and extracting energy from the cooling fluid in the gaseous state in the turbine. The method additionally includes removing thermal energy from the cooling fluid in the condenser, converting the cooling fluid from a gaseous state to a liquid state as the thermal energy is removed from the cooling fluid, and returning the cooling fluid in the liquid state to the thermosiphon. The disclosure also includes associated systems and apparatuses.

Description:
TECHNICAL FIELD 
     The present disclosure relates in general to information handling systems, and more particularly to power regeneration for an information handling system. 
     BACKGROUND 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
     An information handling system may include one or more microprocessors or other electronic components configured to perform the functions of a central processing unit (CPU). One or more heat sinks may be associated with an electronic component to increase the effective thermal mass and heat dissipation associated with the component. Electronics designers and users may find that a greater cooling rate allows increased operating speeds of the components so cooled. Some benefits of increased operating speeds may include, for example, an increase in how quickly and/or efficiently information may be processed, stored, and/or communicated. 
       FIG. 1  illustrates the use of a prior art heat sink  14  that may be used to increase the rate of heat transfer away from an electronic component associated with an information handling system. Electronic component  10  may include processing resources (e.g., one or more central processing units, a graphics processing unit, and/or a digital signal processor), storage units (e.g., a hard disk drive, flash memory, etc.), and/or any device configured to control data, to process data, to convert electric power (e.g., sensors, transducers, and actuators), and/or to distribute electric power. 
     Electronic component  10  includes pins  12  providing an electrical connection between electronic component  10  and the circuitry present on an associated circuit board. For example, pins  12  may include a connector configured to attach electronic component  10  to a CPU socket and/or CPU slot (e.g., to plug into a known “socket  478 ”, “socket T”, or any of the many CPU sockets provided to interface with one or more available CPUs). As another example, pins  12  may include a ball grid array (e.g., a fine ball grid array, a plastic ball grid array, a land grid array, a pin grid array, a dual in-line surface mount, and/or any other method of providing electrical connections to electronic component  10 ). 
     Heat sink  14  includes a mass  16  and a set of fins  18 . Mass  16  is formed from an appropriate material with relatively high thermal conductivity (e.g., a metal block or aluminum and/or copper alloy). Fins  18  increase the surface area of heat sink  14  and, therefore, increase the rate of heat transfer through convection, conduction, and/or radiation between mass  16  and the environment. Extended Fins  18  define a primary flow direction, shown by arrow  20 . In most information handling systems, the cooling fluid is room air drawn across fins  18  by a fan mounted in the case of the system. 
     The heat transfer from electronic component  10 , mass  16 , and/or fins  18  depends on the velocity of the cooling fluid, the specific heat of the cooling fluid, the surface area of fins  18 , and the temperature difference between the cooling fluids and electronic component  10 , mass  16 , and/or fins  18 . The heat removed from electronic component  10  is generally rejected to room air by the action of the fan, raising the cooling load in the surrounding air. 
     SUMMARY 
     In accordance with one embodiment of the present disclosure, an power regeneration system for use with an information handling system is disclosed. The power regeneration system may include a thermosiphon in thermal communication with a heated component of the information handling system, a turbine, a condenser, and a fluid flow loop. The thermosiphon may be configured to convert a cooling fluid from a liquid to a gaseous state as the cooling fluid absorbs heat from the heated component of the information handling system. The turbine may be configured to extract energy from the cooling fluid in the gaseous state after it leaves the thermosiphon. The condenser may be configured to remove thermal energy from the cooling fluid after it leaves the turbine, the condenser fluid converting the cooling fluid from a gaseous state to a liquid state as thermal energy is removed. The fluid flow loop may connect the thermosiphon, the turbine, and the condenser in order so that the cooling fluid flows in a closed loop through the power regeneration system. 
     In accordance with another embodiment of the present disclosure, an information handling system is disclosed. The information handling system may include a processor, a memory communicatively coupled to the processor, and a thermosiphon in thermal communication with the one or more processors, a turbine, a condenser, and a fluid flow path. The thermosiphon may be configured to convert a cooling fluid from a liquid to a gaseous state as the cooling fluid absorbs heat from the one or more processors. The turbine may be configured to extract energy from the cooling fluid in the gaseous state after it leaves the thermosiphon. The condenser may be configured to remove thermal energy from the cooling fluid after it leaves the turbine. The condenser may convert the cooling fluid from a gaseous state to a liquid state as thermal energy is removed. The fluid flow path may connect the thermosiphon, the turbine, and the condenser in order so that the cooling fluid flows in a closed loop through the power regeneration system. 
     In accordance with yet another embodiment of the present disclosure, a method for power regeneration in an information handling system is disclosed. The method may include circulating a cooling fluid through a fluid flow loop connecting a thermosiphon, a turbine, and a condenser, removing heat from a heated component of the information handling system, converting the cooling fluid from a liquid state to a gaseous state in the thermosiphon, extracting energy from the cooling fluid in the gaseous state in the turbine, removing thermal energy from the cooling fluid in the condenser, converting the cooling fluid from a gaseous state to a liquid state as the thermal energy is removed from the cooling fluid, and returning the cooling fluid in the liquid state to the thermosiphon. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein: 
         FIG. 1  illustrates a prior art heat sink for increasing the rate of cooling for an electronic component in an information handling system; 
         FIG. 2  illustrates a portion of an example power regeneration loop for use with an information handling system, in accordance with teachings of the present disclosure; 
         FIG. 3  shows a cross-section of the power regeneration system of  FIG. 2 , in accordance with teachings of the present disclosure; 
         FIG. 4  is chart of temperature versus entropy showing an example cooling cycle that may be used in a power regeneration system for use with an information handling system, in accordance with teachings of the present disclosure; and 
         FIG. 5  illustrates an example method for regenerating power in an information handling system, in accordance with teachings of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Preferred embodiments and their advantages are best understood by reference to  FIGS. 2 through 5 , wherein like numbers are used to indicate like and corresponding parts. For the purposes of this disclosure, an information handling system 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, entertainment, or other purposes. For example, an information handling system may be a personal computer, a PDA, a consumer electronic device, 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 memory, one or more processing resources such as a central processing unit (CPU) or hardware or software control logic. Additional components or the information handling system may include one or more storage devices, one or more communications 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 communication between the various hardware components. 
       FIG. 2  illustrates a portion of an example power regeneration system  30  for use with an information handling system, in accordance with teachings of the present disclosure. Power regeneration system  30  may be mounted, as shown in  FIG. 2 , in association with an electronic component  10  of the information handling system. Power regeneration system  30  may be configured to remove heat from electronic component  10  using a cooling fluid entering at point  70   b  and exiting at point  70   a . Electronic component  10  may include processing resources (e.g., one or more central processing units, a graphics processing unit, and/or a digital signal processor), storage units (e.g., a hard disk drive, flash memory, etc.), and/or any device configured to control data, to process data, to convert electric power (e.g., sensors, transducers, and actuators), and/or to distribute electric power. 
     Electronic component  10  may include pins  12  providing an electrical connection between electronic component  10  and the circuitry present on an associated circuit board. For example, pins  12  may include a connector configured to attach electronic component  10  to a CPU socket and/or CPU slot (e.g., to plug into a known “socket  478 ”, “socket T”, or any of the many CPU sockets provided to interface with one or more available CPUs). As another example, pins  12  may include a ball grid array (e.g., a fine ball grid array, a plastic ball grid array, a land grid array, a pin grid array, a dual in-line surface mount, and/or any other method of providing electrical connections to electronic component  10 ). 
     Power regeneration system  30  may include a thermosiphon  40  and a turbine  50 . Thermosiphon  40  may include any component, device, and/or subsystem of the information handling system configured to circulate the cooling fluid from point  70   b  to point  70   a  using the heat removed from electronic component  10  rather than an associated mechanical pump. For example, thermosiphon  40  may allow convective movement of the cooling fluid. In such embodiments, cooling fluid at the bottom  32  of thermosiphon  40  may absorb the heat transferred from electronic component  10 . As the cooling fluid heats up, it expands and its density reduces. Convection acts to move the heated cooling fluid upward and allows cooler liquid to settle at the bottom  32  of the thermosiphon  40 . 
     As shown in  FIG. 2 , thermosiphon  40  may receive a cooling fluid at point  70   b , entering at the bottom  32  of power regeneration system  30 . As heat is transferred from electronic component  10  into thermosiphon  40 , that cooling fluid may heat up and rise within Power regeneration system  30 . If the cooling fluid heats up enough, it rises from thermosiphon  40  through turbine  50  and exits turbine  50  at point  70   a.    
       FIG. 3  is a cross-section of power regeneration system  30 . Power regeneration system  30  may include thermosiphon  40 , turbine  50 , condenser  60 , and fluid flow loop  70 . The circulation of a cooling fluid through power regeneration system  30  may depend on the effects of convection described in relation to  FIG. 2 . In embodiments depending on convective fluid flow, condenser  60  must be physically located above the inlet  45  of thermosiphon  40  so that condensing cooling fluid may return to thermosiphon  40  by the effects of gravity. 
     Thermosiphon  40  may include a boiling plate  42  and a reservoir  44 . Boiling plate  42  may be direct thermal communication with electronic component  10  (as shown in  FIG. 2 ). Boiling plate  42  may be any device, component, and/or feature of thermosiphon  40  configured to transfer heat from electronic component  10  into the cooling fluid in reservoir  44 . For example, boiling plate  42  may include a plate of material with high thermal conductivity (e.g., copper) configured to match the shape of electronic component  10 . In some embodiments, boiling plate  42  may include a cutout or indentation configured to rest on top of electronic component  10 . In some embodiments, boiling plate  42  may be configured to collect heat from a plurality of heat sources associated with the information handling system. For example, multiple processors may share a cooling loop which feeds into plate in contact with boiling plate  42 . 
     Reservoir  44  may include a portion of thermosiphon  40  configured to hold the cooling fluid in thermal communication with boiling plate  42 . The cooling fluid may enter the reservoir at inlet  45  and collect at the bottom of reservoir  44  adjacent boiling plate  42 . As shown in  FIG. 3 , the cooling fluid may enter reservoir  44  in a liquid phase  46 . The cooling fluid may undergo phase transformation as heat is added, resulting in boiling and changing the cooling fluid into a gaseous phase  48 . Because the gaseous phase  48  has a lower density than the liquid phase  46 , bubbles will form adjacent boiling plate  42  and rise to the top of reservoir  44 . 
     Turbine  50  may include any component, device, and/or feature of power regeneration system  30  configured to remove energy from a fluid passing through turbine  50 . For example, turbine  50  may include a rotor assembly  54  with blades  52  mounted thereon. In such embodiments, the passage of the cooling fluid in its gaseous state through turbine  50  may cause rotor assembly  54  to rotate. The rotational energy of rotor assembly  54  may be converted into electrical power and/or used as rotational energy as needed. Rotor assembly  54  of  FIG. 3  may be mounted vertically so that the cooling fluid rising from thermosiphon  40  will pass over blades  52 . 
     In some embodiments, turbine  50  may be configured based on the properties of the cooling fluid used in power regeneration system  30 . For example, blades  52  may have an increased lifetime if they are not subject to impact from liquid. If turbine  50  is designed to operate at a relatively high speed with a relatively low pressure drop, the cooling fluid may pass over blades  52  without condensing into its liquid phase. In such embodiments, the cooling fluid may leave turbine  50  still in a completely gaseous state at point  70   a.    
     The cooling fluid may continue along fluid flow loop  70  in its gaseous state and eventually reach condenser  60 . Condenser  60  may include any device, component, and/or feature of power regeneration system  30  configured to remove heat from the cooling fluid until it condenses into a liquid phase. For example, condenser  60  may include a radiator. In one embodiment condenser  60  may include a microchannel tube heat exchanger with fins configured to maximize the ratio of surface area on the fins to the volume of the heat exchanger. Power regeneration system  30  may include a fan  64  disposed to induce air flow  62  across condenser  60 . 
     As the cooling fluid condenses to the liquid phase  46 , the effect of gravity will draw the cooling fluid to the bottom  66  of condenser  60 . If condenser  60  is physically above the inlet  45  of reservoir  44 , cooling fluid will flow through fluid flow loop  70  at point  70   b  from condenser  60  to reservoir  44 . Fluid flow loop  70  may include any conduit, tubing, and/or channel configured to transport the liquid cooling fluid  46  from condenser  60  to reservoir  44  and the gaseous phase  48  cooling fluid from turbine  50  to condenser  60 . 
     The phase change properties of the cooling fluid may be chosen to match the configuration of power regeneration system  30 . The selection of a cooling fluid may drive the configuration of turbine  50 . For example, the change in boiling point of the cooling fluid based on the pressure drop (e.g., as it passes through turbine  50 ) may control whether the cooling fluid condenses within turbine  50 . In some embodiments, the cooling fluid may stay in a fully gaseous state until after it has fully passed through turbine  50 . 
     For example, one embodiment may use 3M NOVEC 7000 Engineered Fluid as the cooling fluid because it may include good dielectric properties, flammability, corrosive effects, and/or toxicity in the event of leakage. 3M NOVEC 7000 Engineered Fluid may allow boiling at ambient and/or near-ambient temperatures. 
       FIG. 4  is chart of temperature versus entropy showing an example cooling cycle  80  that may be used in power regeneration system  30 , in accordance with teachings of the present disclosure. As shown in  FIG. 4 , cycle  80  begins at point  81 . In practice, however, cycle  80  may be a continuous cycle with no particular starting point. 
     Heat (Q in ) is added to the cooling fluid along legs  82  and  84  of cycle  80 . Leg  84  shows the cooling fluid boiling (e.g., transforming from a liquid to a gaseous state at a constant temperature). Legs  82  and  84  of cycle  80  may take place within thermosiphon  40 . At the end of leg  84 , the cooling fluid may have reached a fully saturated gaseous state. 
     During leg  86 , energy is removed from the cooling fluid (e.g., while passing through turbine  50 ). As shown in  FIG. 4 , cycle  80  is designed so that, even as the cooling fluid drops in temperature, it stays above line  83 , indicating the condensation point as enthalpy varies. During leg  88   a , the cooling fluid continues to reduce temperature, until it reaches the condensation point at the beginning of leg  88   b . During leg  88   b  (e.g., in condenser  60 ), additional heat is removed from the cooling fluid until it reaches a fully condensed state and the cycle begins again at point  81 . In one embodiment, power regeneration system  30  may be used in association with an electronic processor generating 100 watts of heat. If the temperature gradient between the entrance to turbine  50  and the exit of turbine  50  is 6 degrees Celsius, 11.3 watts of energy can be gathered from turbine  50 . 
     The energy recovered by power regeneration system  30  may be used for any of several purposes. For example, many information handling systems include a powered cooling system to maintain the temperature of certain components within an acceptable range. Power regeneration system  30  may use the regenerated power to drive fan  64 , reducing and/or eliminating the need to supply additional power for cooling. 
     In another example, the energy regenerated by power regeneration system  30  may be used to increase the total power available to the information handling system. For example, if a power supply associated with an information handling system supplies 1.2 kilowatts of energy, the addition of the energy regenerated by power regeneration system  30  may increase the total available energy to 1.4 kilowatts. In another example, the energy regenerated by power regeneration system  30  may provide auxiliary power for other components of the information handling system (e.g., external hard drives, racks, memory, CPUs, graphics cards, and/or any integrated circuit component associated with the information handling system). 
     In other embodiments, the energy regenerated by power regeneration system  30  may improve the acoustic performance and/or the thermal performance of the information handling system. Because some of the heat generated by electronic component  10  may be converted to energy rather than ejected from the information handling system as heat, the cooling load of the information handling system may be reduced. A reduced cooling load may result in lower noise generation (e.g., if fans are run at a lower speed and/or reduced in size), and/or a lower temperature external to the information handling system (e.g., less heat transferred to the surrounding space). 
       FIG. 5  illustrates an example method  100  for regenerating power in an information handling system, in accordance with teachings of the present disclosure. Although method  100  is discussed herein as beginning at step  102 , method  100  may include a continuous loop which may begin at any step. 
     At step  102 , a power regeneration system may circulate a cooling fluid through a fluid flow loop connecting a thermosiphon, a turbine, and a condenser. The fluid flow loop may include fluid flow loop  70 . 
     At step  104 , a power regeneration system may remove heat from a heated component of an information handling system. Thermosiphon  40  may perform step  104 . 
     At step  106 , a power regeneration system may convert the cooling fluid from a liquid state to a gaseous state. Step  106  may take place within reservoir  44 . 
     At step  108 , a power regeneration system may extract energy from the cooling fluid in the gaseous state. Turbine  50  may perform step  108 . 
     At step  110 , a power regeneration system may remove thermal energy from the cooling fluid. Condenser  60  and associated fan  64  may perform step  110 . 
     At step  112 , a power regeneration system may convert the cooling fluid from a gaseous state to a liquid state as the thermal energy is removed from the cooling fluid. Condenser  60  may perform step  112 . 
     At step  114 , a power regeneration system may return the cooling fluid in the liquid state to the thermosiphon. Fluid flow loop  70  may use the effects of gravity to perform step  114 . 
     Although the figures and embodiments disclosed herein have been described with respect to display screens for information handling systems, it should be understood that various changes, substitutions and alternations can be made herein without departing from the spirit and scope of the disclosure as illustrated by the following claims.