Patent Publication Number: US-11665865-B1

Title: Dynamic control of two-phase thermal management systems for servers

Description:
BACKGROUND 
     A datacenter typically contains a collection of datacenter electronic components such as computer servers and components for the management, operation and connectivity of those datacenter electronic components. Even in isolation, these datacenter electronic components may generate sufficient heat that temperature management is important for prolonging the life of the datacenter electronic components and ensuring smooth and continuous operation of the datacenter. Typically, such datacenter electronic components are installed equipped with onboard cooling equipment, such as heat sinks and fans or even liquid cooling systems attached to components that produce the most heat, like processors. 
     Datacenter electronic components are often arranged together. For example, datacenter electronic components can be vertically arranged in racks or within cabinets. Datacenter cooling systems often include air cooling of individual datacenter electronic components, for example by circulating air through the casings of respective rack-mounted datacenter electronic components. Alternatively, or in combination with air cooling, heat rejection of rack-mounted datacenter electronic components can be achieved by direct liquid cooling of components of the datacenter electronic components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments in accordance with the present disclosure will be described with reference to the drawings, in which: 
         FIG.  1    illustrates an example system with a datacenter component rack and an associated datacenter component shown in an open configuration to illustrate a simplified example of a thermal management system including thermoelectric regulation, according to at least some embodiments; 
         FIG.  2    illustrates a block diagram showing elements of the thermal management system with thermoelectric regulation, according to at least some embodiments; 
         FIG.  3    illustrates a block diagram showing elements of a control system for the thermal management system with thermoelectric regulation, according to at least some embodiments; 
         FIG.  4    illustrates a block diagram showing elements of a multi-zone thermal regulation system with thermoelectric regulation, according to at least some embodiments; 
         FIG.  5    illustrates an example process for thermally regulating elements of a datacenter component, according to at least some embodiments; 
         FIG.  6    illustrates an example process for initializing a thermal regulation system with a thermoelectric cooler, according to at least some embodiments; 
         FIG.  7    illustrates an example process for initializing a thermosiphon system using a thermoelectric cooler, according to at least some embodiments; and 
         FIG.  8    illustrates an environment in which various embodiments can be implemented. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments and techniques described herein are directed to thermal regulation systems and methods associated with the same for managing heat generation and buildup in electronic datacenter components. Datacenter electronic components generate and reject heat during operation and management of heat removal systems is important to properly maintain the electronic datacenter components in operation. Some thermal regulation systems are active relying on pumping of a coolant fluid and some are passive, with passive systems often relying on convection of fluid. One particular style of heat removal system is a two-phase coolant system that removes heat by absorbing heat and causing a working fluid to boil and subsequently condensing the working fluid at a condenser. A thermosiphon is one example of a heat transfer system that relies on natural convection and temperature differences to provide for flow of a working fluid between an evaporator and a condenser in a two-phase coolant system. The use of natural convection instead of pumping of the working fluid results in an efficient thermal management system that consumes little to no additional energy during steady state to maintain operation as compared to systems using pumped working fluids which introduce additional complexity, components, potential breakdown locations, and consume additional resources. The use of the thermosiphon also enables transfer and rejection of heat at a greater distance than typical systems and methods, such as natural convective cooling that is often implemented in electronic datacenter components. Due to the lack of active pumping of the working fluid, it is possible for a thermosiphon to produce a vapor bubble at the evaporator during startup of the system as the working fluid present in the evaporator begins to vaporize that may initially travel backwards through a cold line and therefore prevent use of the thermosiphon due to the lack of initial direction provided to the working fluid until the convective process begins. 
     Aspects of the present disclosure define a system and methods for regulating operation of a two-phase thermal management system for electronic datacenter components that is capable of overcoming the transient issues during initialization of the thermosiphon. Two-phase cooling (thermosiphons) are excellent heat removal devices for steady heat rates due to their high heat transfer efficiency from the surface of an electronic datacenter component. However, non-steady heating rates, such as during initialization and when workloads are variable, causes issues due to uneven boiling and changes in internal pressures that drive the direction of the working fluid. The present disclosure uses a thermoelectric cooling module and associated control system to dynamically control heating and cooling exchanges to ensure positive control of two-phase cooling systems in an electronic datacenter component without introducing additional moving or complex components. By eliminating the risks of startup dryout, the present disclosure enables positive vapor direction for a wider range of different applications previously unsuited for thermosiphon cooling systems including processors (CPUs, GPUs, and ASICs). As noted above, electronic devices, e.g., computer components, such as processors and memories, generate heat. A thermosiphon system can be used to remove heat from such an electronic device. Although some systems have been proposed for removing heat from computer components, the limited space available in the datacenter component rack environment introduces an additional challenge to thermosiphon system design. 
     In an illustrative example, a datacenter rack may include a number of datacenter components, e.g., servers, arranged together, with each datacenter component including components that reject heat during operation, such as processors and other such components. A two-phase heat management system according to the present disclosure enables heat transfer at a greater distance due to the use of a working fluid while also remaining energy efficient, thereby enabling use of the two-phase cooling system in a datacenter component to cool components that may be placed at one end of the datacenter component with the heat from such components rejected at the far end of the datacenter component. 
     The two-phase cooling system includes a thermoelectric cooler adjacent the evaporator of the system, the thermoelectric cooler positioned to remove heat from a cold line of the cooling system or add heat to a hot line of the cooling system, thereby biasing the flow of the working fluid from the evaporator into the hot line and preventing formation of a vapor bubble or reverse flow, where the working fluid may initially travel from the evaporator through the cold line. By applying power to the thermoelectric cooler (TEC), and dynamically monitoring the temperature difference between the hot and cold lines, a temperature difference can be maintained across the evaporator to bias flow during startup and continue flow of the working fluid in the proper direction to continue the cooling cycle in the event of variable heat rejection by the processor. 
     In the following description, various embodiments will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to one skilled in the art that the embodiments may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the embodiment being described. 
       FIG.  1    illustrates an example system with a datacenter component rack and an associated datacenter component shown in an open configuration to illustrate a simplified example of a thermal management system including thermoelectric regulation, according to at least some embodiments.  FIG.  1    illustrates a system with a datacenter component rack  100  and an associated datacenter component  102  shown in an open configuration. The system illustrates simplified components in a datacenter component rack  100  that enable techniques and methods described herein for providing dynamic regulation of a two-phase thermal management system. 
     The system includes a datacenter component rack  102  designed to accommodate a plurality of datacenter components  102 . The datacenter component rack  100  may be designed to accept datacenter components  102  at varying locations, heights, and/or of varying sizes. In the example shown in  FIG.  1   , the datacenter components  102  are shown having the same size, though in some examples other and different sizes of datacenter components are envisioned. For instance, a datacenter component  102  located within the datacenter component rack  100  is of a first size, which may be sized according to a rack unit (RU) size system to be any size, such as ½ RU and/or 1 RU. Additional datacenter components  102  may be of the same size or RU as the datacenter component  102  or may be of a different size. Other datacenter components (not shown) may be installed in the datacenter component rack  100 . The datacenter components  102 , may be distributed at any height along the datacenter component rack  100 . The datacenter components  102  may be, for example, servers, JBODs, network switches, automatic transfer switches (ATSes), power distribution units (PDUs), or any other electronic equipment that is mountable in a datacenter component rack  100 , such as a server rack. 
     As illustrated in the datacenter component  102  shown in an open configuration, a simplified interior illustrating elements of the system described herein is shown. In particular, the datacenter component  102  includes an electronic component  104  that rejects heat during operation such as a processor, integrated circuit, power supply, storage device, or other such component. The electronic component  104  is coupled to an evaporator  106  where a working fluid may be vaporized by the heat extracted from the electronic component  104 . The evaporator  106  has a hot conduit  110  and a cold conduit  112  that carry the working fluid to and away from the evaporator  106 . The hot conduit  110  carries hot working fluid, sometimes a vapor, away from the evaporator  106  to a condenser  114  at the rear of the datacenter component  102 . The condenser  114  condenses the working fluid, thereby ejecting heat that may be removed from the datacenter in other means, including additional working fluids, active cooling, passive cooling, and such other systems. The condenser  114  is connected to the evaporator  106  through the cold conduit  112  that carries the cold working fluid to the evaporator  106  where it may absorb heat and return to the condenser  114 . 
     Adjacent the evaporator  106  and the hot conduit  110  and the cold conduit  112  is a thermoelectric cooler (TEC)  108 . The TEC  108  may include any thermoelectric elements and devices and may produce a temperature difference between different locations on the TEC  108  in response to applying power to the TEC  108 . The TEC  108  may provide heat to the hot conduit  110  and/or may remove heat from the cold conduit  112  to initially bias flow of the working fluid in the proper direction and may also be used to regulate a variable heat load generated by the electronic component  104 , which may not produce heat at a steady state but may instead produce varying amounts of heat depending on a workload. As noted above, the TEC  108  may provide for dynamic regulation of a variable load of heat energy produced by the electronic component  104  and also prevents stalling working fluid or reverse flow problems during a transient phase of the cooling system. Additional details of the cooling system are provided with respect to  FIGS.  2 - 4    below. 
       FIG.  2    illustrates a block diagram showing elements of the thermal management system  200  with thermoelectric regulation, according to at least some embodiments. As described above with respect to  FIG.  1   , the thermal management system  200  serves to remove heat from a CPU  202  and expel the removed heat at a distance from the CPU  202 . The CPU  202  is thermally connected to an evaporator  204 , which may include any known evaporator design or materials, including aluminum, copper, and other such materials or combinations thereof to enable transfer of heat from the CPU  202  to the working fluid of the thermal management system  200 . The TEC  206 , as noted above, provides for regulation of the thermal management system  200  to maintain the system in operation during variable loading from the CPU  202 . As noted earlier, typical two-phase thermosiphon systems are highly efficient for displacement of heat from steady state systems, but typical systems may not be capable of handling variable loads and have therefore been unsuited for cooling of datacenter components, which may be switched off for periods of time, may operate at varying capacity, and may not produce a constant amount of heat. The TEC  206  may be coupled to the hot conduit  210  and/or the cold conduit  212 . In some examples, the TEC  206  may be coupled to both the hot conduit  210  and the cold conduit  212  so as to remove heat from the working fluid within the cold conduit  212  and provide heat to the working fluid within the hot conduit  210 . The TEC  206  may be coupled to the hot conduit  210  and the cold conduit  212  through contact, including through a thermal conductor such as a thermal paste or may be integrally formed together in some examples. In some examples, the TEC  206  may be any device that implements the Peltier effect (the thermoelectric effect) to create a heat flux at a junction of two different materials. In some embodiments, the TEC  206  may include more than one TEC  206 , for example including a first TEC  206  connected to the cold conduit  212  and a second TEC  206  connected to the hot conduit  210 . Additional configurations of TECs  206  are envisioned and intended to be covered through this description including multiples of the TEC  206 , arrangements at different locations such as a midpoint of the hot conduit  210  and the cold conduit  212 , and other such variations are all within the spirit of the present disclosure. 
     During operation, the hot conduit  210  carries the working fluid as vapor  216  from the evaporator  204  to the condenser  208  and the working fluid may return as a liquid  218  from the condenser  208  to the evaporator  204 . In some examples, the evaporator  204  and the condenser  208  may be positioned at a distance of over 600 millimeters from one another, for example at a distance of up to 600 to 1200 millimeters or at a distance of up to 800 to 1000 millimeters. Such distancing, which is not possible with typical passive heat removal systems, enables additional configurations for electronic datacenter components that would otherwise be impossible without compromising the performance of the electronics therein. 
     The hot conduit  210  is fluidly coupled to the evaporator  204  at or adjacent an upper portion of the evaporator  204 . In this manner, as the working fluid vaporizes in the evaporator  204 , it will naturally rise to the hot conduit  210 . The cold conduit  212  is similarly coupled to or adjacent a bottom of the evaporator  204 , as the cold conduit  212  contains liquid  218  that will vaporize in the evaporator  204 . Additionally, the hot conduit  210  may enter the condenser at or near an upper portion of the condenser  208  with the cold conduit  212  connected at or near the bottom of the condenser  208  such that liquid  218  will naturally flow through the cold conduit  212  due to a natural convection cycle. The hot conduit  210  and the cold conduit  212  are vertically displaced from one another such that the hot conduit  210  is vertically above the cold conduit  212 . The hot conduit  210  may be at a distance of three to five millimeters vertically higher than the cold conduit  212 . In some embodiments, the displacement may be greater than three to five millimeters. The vertical displacement enables the vapor  216 , which will naturally rise due to convection and expansion as a vapor, to preferentially travel through the hot conduit  210 , especially when the hot conduit  210  is biased through the use of the TEC  206  as described herein. In some examples, the condenser  208  may be a traditional condenser unit that dissipates heat to the environment or to another system through a heat exchanger and condenses the working fluid. in some examples, the condenser  208  may include a coldplate heat exchanger and may therefore operate inside of a sealed datacenter component. The use of a coldplate or other heat exchanger that transfers heat from a first working fluid in a closed loop to a second working fluid through a coldplate enables the datacenter component to be sealed against the environment and prevent foreign material such as dust or moisture from entering into the datacenter component and potentially damaging the datacenter component or elements thereof. 
     During a startup or a variable load of the heat from the CPU  202 , the TEC  206  may be supplied with power to transfer heat from the cold conduit  212  to the hot conduit  210  to maintain a temperature gradient and preserve the operation of the natural convection. Additionally, the initial startup vapor bubble may be biased or forced to advance through the hot conduit  210  due to the temperature gradient presented as a result of the operation of the TEC  206 . 
       FIG.  3    illustrates a block diagram showing elements of a control system  300  for the thermal management system with thermoelectric regulation, according to at least some embodiments. The elements of  FIG.  3    illustrate basic components that may be used to control the operation of the TEC  206  of  FIG.  2    to dynamically regulate operation of the two-phase thermal management system and maintain the thermosiphon that continues the cycling of the working fluid between the evaporator  204  and the condenser  208 . In particular, the control system  300  includes a baseboard management controller (BMC)  302  which may be a component of the datacenter component and control operations within the datacenter component. In some examples, the BMC  302  may instead be a computing device, such as described with respect to  FIG.  8    or may be application specific for management of the thermal regulation system and include components such as an ASIC for controlling the operations of control system  300 . The BMC  302  may control operation of a power switch  304  that provides power from a power supply to the TEC  306 , which may be the same as the TEC  206 . The TEC  306 , upon receiving power from the power switch  304 , provides heat transfer to and/or away from the two-phase cooling system  308 , which may be the thermal management system  200  of  FIG.  2   . The TEC  306  may transfer heat to a hot conduit, to an upper end of an evaporator, to an upper end of a condenser, or anywhere along a hot portion of the two-phase cooling system  308 . The TEC  306  may also remove heat in a similar manner from any portion of the cold portion of the two-phase cooling system  308  including the cold conduit, the bottom of the evaporator, or the bottom of the condenser. 
     The BMC  302  may control the power switch  304  based on an open loop control system or a closed loop control system using inputs from temperature sensors  310 ,  312 , and  314 . The temperature sensor  310  may include an ambient temperature sensor. The temperature sensors  312  and  314  may provide temperature data from the electronic component being cooled and temperature at the evaporator. In some examples, the temperature sensors  312  and  314  may provide temperatures at an inlet and an outlet of the evaporator. In some examples, the temperature sensor  310  may provide a temperature of the electronic component. The BMC  302  receives temperature data from the temperature sensors  310 ,  312 ,  314 , and determines when to apply power to the TEC  306  through the power switch  304 . The temperature data may, for example, indicate that the temperature of the evaporator, the electronic component, and/or the ambient temperature exceed a predetermined threshold temperature. In some examples, the temperature data may, for example indicate a difference in pressure between the cold conduit and the hot conduit or across the evaporator. Such temperature data may be useful for determining when to apply power to the TEC  306 , for example to increase a temperature difference across the evaporator or between the hot and cold conduits, to bias the flow of the working fluid and preferentially begin flow in the proper direction. 
     In some examples, the BMC  302  may receive other signals, such as startup signals for electronic components indicating when an electronic component is started up or begins processing. In some examples the BMC  302  may receive workload data indicating a present workload or upcoming workload for different electronic components and may begin to transfer heat via the TEC  306  to begin the convective movement of the working fluid associated with those electrical components to begin the cooling process before a threshold temperature is reached. The BMC  302  may control when the TEC  306  is disabled via the power switch  304 . The BMC may, for example identify that the two-phase cooling system is operating at steady state and therefore the TEC  306  is no longer needed to maintain the flow of the working fluid. The BMC  302  may, for example identify that a temperature difference across the evaporator or between the hot and cold conduits is steady or within a predetermined percentage for a predetermined time period, indicating the system is operating at steady state. In some examples, the regulation provided by the BMC  302  is iterative, with instructions to power or cut off power to the TEC  306  provided at regular intervals, such as once per second or every few seconds. 
       FIG.  4    illustrates a block diagram showing elements of a multi-zone thermal regulation system  400  with thermoelectric regulation, according to at least some embodiments. The multi-zone thermal regulation system  400  may operate in a similar manner to the thermal regulation system described above with respect to  FIGS.  1 - 3   . The multi-zone thermal regulation system  400  may provide a single condenser  402  with several evaporators  404  to thermally regulate multiple CPUs  406  with a single system rather than with individual systems for each. The multi-zone thermal regulation system  400  may provide uniform or non-uniform cooling to the various CPUs  406  and may provide such cooling without the use of controlled valves, thereby providing for a branched cooling system capable of meeting different cooling needs on different branches without the addition of complex components such as switching valves that may fail or provide complication to the system. 
     In particular, the multi-zone thermal regulation system  400  relies on the same principles described above but uses a cold conduit coupled, in parallel, to multiple different evaporators as well as a hot conduit connected, in parallel, to each of the different evaporators to provide a single system capable of on-demand temperature regulation. The multi-zone thermal regulation system  400  includes the condenser  402 , evaporators  404 , TECs  408 , CPUs  406  (which may be any electronic or heat rejecting component), hot conduit  414 , cold conduit  416 , and joints  410  and  412 . The hot conduit  414  receives working fluid from each evaporator  404  and returns the hot working fluid to the condenser  402 , similarly, the cold conduit  416  delivers cold working fluid to each evaporator  404 . Joints  410  and  412  provide for the conduits to branch into the three parallel branches as illustrated, though other numbers and configurations of branches for the conduits are envisioned that will operate according to the present disclosure. 
     In operation, CPU  406 A, CPU  406 B, and CPU  406 C may each have different workloads and different heat transfer needs based on the different workloads and different types of electrical components that may be placed in place of the CPUs  406 . The multi-zone thermal regulation system  400  does not require valves to meter working fluid to each of the evaporators but will naturally meter based on the heat transferred through each evaporator due to natural convection. For example if CPU  406 B is producing significantly more heat than the other CPUs  406 A and  406 C, then evaporator  404 B will cause more working fluid to vaporize and return through the hot conduit  414 . The convective movement of the working fluid traveling at a greater rate through the evaporator with the greater heat flux, evaporator  404 B, will result in greater working fluid flowing through the cold conduit flowing to evaporator  404 B than to the other evaporators  404 A and  404 C. 
     In a similar manner, the regulation of the TECs  408  may be individual to each component and provide for individual regulation of cooling for each evaporator  404 . For example during a variable phase of operation, any of CPUs  406  may experience downtime or reduced workloads compared to other CPUs  406  and therefore associated evaporators  404  may reduce in temperature and may cease convective flow. The TECs  408  may be used to transfer heat and maintain a temperature difference to preserve the convective flow through each branch and ensure no portion of the multi-zone thermal regulation system  400  becomes stagnant or experiences backflow that may impact other elements of the system. 
       FIG.  5    illustrates an example process  500  for thermally regulating elements of a datacenter component, according to at least some embodiments; Some or all of the process  500  (or any other processes described herein, including processes  600  and  700 , or variations, and/or combinations thereof) may be performed under the control of one or more computer systems, such as the BMC or a remote computing system, configured with executable instructions and may be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications) executing collectively on one or more processors, by hardware or combinations thereof. The code may be stored on a computer-readable storage medium, for example, in the form of a computer program comprising a plurality of instructions executable by one or more processors. The computer-readable storage medium may be non-transitory. The process  500  may be implemented using any of the systems described herein including systems  200 ,  300 , and  400 . 
     At  502 , process  500  includes transferring heat from an electronic component to a working fluid. The transfer of heat from the electronic component to the working fluid may take place in an evaporator, such as evaporator  204  of  FIG.  2   . The heat may be transferred through the evaporator being in contact with the electrical component and the working fluid traveling through the evaporator. 
     At  504 , the process includes operating a TEC to transfer heat. The TEC may be a TEC  206  or any other TEC described herein and may transfer heat from a cold conduit of a thermal regulation system to a hot conduit of a thermal regulation system. In some examples, the TEC may transfer heat away from a cold conduit and a TEC may also separately transfer heat to a hot conduit to generate or maintain a temperature difference between a hot conduit and a cold conduit. 
     At  506 , the process  500  includes transporting the working fluid from the evaporator of the thermal regulation system to the condenser of the thermal regulation system. The working fluid may be transported with aa forced system, such as with a pump or other driving feature or may be driven due to natural convection within the thermal regulation system along the hot conduit as described above. 
     At  508 , the process  500  includes transferring heat from the working fluid. The heat may be transferred from the working fluid at the condenser, which may include any typical condenser unit, a coldplate, a heat exchanger, active and passive cooling systems, and other such heat dissipation and removal systems. This may include condensing the working fluid from a vapor to a fluid at the condenser. 
     At  510 , the process  500  includes transporting the working fluid from the condenser to the evaporator. As with the transport of the working fluid to the evaporator, the working fluid may be forced with a pump or other such device or may be allowed to flow due to natural convection within the thermal regulation system and due to the thermosiphon system of the two-phase thermal regulation system. 
     At  512 , the process  500  includes disabling operation of the thermoelectric cooler. The TEC may be disabled based on the system operating at a steady state, due to sufficient temperature difference existing between the hot and cold conduits, or may be partially disabled or reduced. In some examples, the operation of the TEC may be reduced when only alight additional heat transfer is needed to maintain the system in a steady state, effectively providing similar heat flows through the working fluids as though the system were operating in steady state, even when operation or demand for heat removal is variable. 
       FIG.  6    illustrates an example process  600  for initializing a thermal regulation system with a thermoelectric cooler, according to at least some embodiments. The process  600  may be performed using any of the systems described herein, and may be implemented, at least in part on a computing device, such as BMC  302 . 
     At  602 , the process  600  includes receiving first temperature data. The first temperature data may be ambient temperature data within the electronic datacenter component, may be temperature data indicating a temperature of the hot conduit or the cold conduit and may be a temperature of the electronic component. The first temperature data may be received at the BMC or other computing device. 
     At  604 , the process  600  includes receiving second temperature data. The second temperature data may be from a different location of the system than the first temperature data and may include a number of potential sources. The second temperature data may be ambient temperature data within the electronic datacenter component, may be temperature data indicating a temperature of the hot conduit or the cold conduit and may be a temperature of the electronic component. The second temperature data may be received at the BMC or other computing device. 
     At  606 , the process  600  includes determining a difference between the first temperature data and the second temperature data. The difference may indicate a difference across the evaporator, between the hot and cold conduits, between ambient temperature and the temperature of the electronic component, or other such temperatures. 
     At  608 , the process  600  includes providing a signal to cause a TEC to transfer heat from the working fluid in the cold conduit or to the working fluid in the hot conduit. In response to determining that the temperature difference exceeds a predetermined threshold, for example when the difference between ambient and the electronic component is too large or when the difference is below a threshold, for example when a difference across the evaporator or between the hot and cold conduits is insufficient to provide for convective flow or the working fluid, the TEC may begin to transfer heat as controlled by the BMC. 
     At  610 , the process  600  includes receiving third temperature data. The third temperature data may be the temperature of the electronic component or the ambient temperature and may indicate that the system is operating at a steady state or other such condition. 
     At  612 , the process  600  includes disabling operation of the TEC. The TEC may be disabled based on the system operating at a steady state, due to sufficient temperature difference existing between the hot and cold conduits, or may be partially disabled or reduced. In some examples, the operation of the TEC may be reduced when only alight additional heat transfer is needed to maintain the system in a steady state, effectively providing similar heat flows through the working fluids as though the system were operating in steady state, even when operation or demand for heat removal is variable. In some examples, the operation may be disabled based on the third temperature data indicating that the electronic component is cooling or is at a steady state and additional input from the TEC is no longer needed. 
       FIG.  7    illustrates an example process  700  for initializing a thermosiphon system using a thermoelectric cooler, according to at least some embodiments. The process  700  may be performed using any of the systems described herein, and may be implemented, at least in part on a computing device, such as BMC  302 . 
     At  702 , the process  700  includes receiving first temperature data. The first temperature data may be ambient temperature data within the electronic datacenter component, may be temperature data indicating a temperature of the hot conduit or the cold conduit and may be a temperature of the electronic component. The first temperature data may be received at the BMC or other computing device. 
     At  704 , the process  700  includes receiving second temperature data. The second temperature data may be from a different location of the system than the first temperature data and may include a number of potential sources. The second temperature data may be ambient temperature data within the electronic datacenter component, may be temperature data indicating a temperature of the hot conduit or the cold conduit and may be a temperature of the electronic component. The second temperature data may be received at the BMC or other computing device. 
     At  706 , the process  700  includes determining to initialize a two-phase thermal management system. The determination may be based on a startup signal for an electronic component, for example indicating that the electronic component is beginning operation or is beginning a large workload, or is substantially increasing workload such that cooling resources may be required. The determination may also be based on the first and second temperature data, for example by identifying that the electronic component has exceeded a predetermine threshold temperature or that a temperature difference between a hot and cold conduit is less than a threshold amount and the electronic component is beginning operation or has started up as previously indicated. 
     At  708 , the process  700  includes causing power to be supplied to a TEC of the two-phase thermal management system. The TEC may be a TEC  206  or any other TEC described herein and may transfer heat from a cold conduit of a thermal regulation system to a hot conduit of a thermal regulation system. In some examples, the TEC may transfer heat away from a cold conduit and a TEC may also separately transfer heat to a hot conduit to generate or maintain a temperature difference between a hot conduit and a cold conduit. 
     At  710 , the process  700  includes determining the two-phase thermal management system has passed an initialization stage. After an initial startup phase, for example if the system is operating at a steady state with non-variable heat removal requirements, the BMC may determine that the startup phase is passed and therefore may proceed to  712 . 
     At  712 , the process  700  includes disabling operation of the TEC in response to passing the initialization phase. The TEC may be disabled based on the system operating at a steady state, due to sufficient temperature difference existing between the hot and cold conduits, or may be partially disabled or reduced. In some examples, the operation of the TEC may be reduced when only alight additional heat transfer is needed to maintain the system in a steady state, effectively providing similar heat flows through the working fluids as though the system were operating in steady state, even when operation or demand for heat removal is variable. In some examples, the operation may be disabled based on the third temperature data indicating that the electronic component is cooling or is at a steady state and additional input from the TEC is no longer needed. 
       FIG.  8    illustrates aspects of an example environment  800  for implementing aspects in accordance with various embodiments. As will be appreciated, although a Web-based environment is used for purposes of explanation, different environments may be used, as appropriate, to implement various embodiments. The environment includes an electronic client device  802 , which can include any appropriate device operable to send and receive requests, messages, or information over an appropriate network  804  and convey information back to a user of the device. Examples of such client devices include personal computers, cell phones, handheld messaging devices, laptop computers, set-top boxes, personal data assistants, electronic book readers, and the like. The network can include any appropriate network, including an intranet, the Internet, a cellular network, a local area network, or any other such network or combination thereof. Components used for such a system can depend at least in part upon the type of network and/or environment selected. Protocols and components for communicating via such a network are well known and will not be discussed herein in detail. Communication over the network can be enabled by wired or wireless connections and combinations thereof. In this example, the network includes the Internet, as the environment includes a Web server  806  for receiving requests and serving content in response thereto, although for other networks an alternative device serving a similar purpose could be used as would be apparent to one of ordinary skill in the art. 
     The illustrative environment includes at least one application server  808  and a data store  810 . It should be understood that there can be several application servers, layers, or other elements, processes, or components, which may be chained or otherwise configured, which can interact to perform tasks such as obtaining data from an appropriate data store. As used herein the term “data store” refers to any device or combination of devices capable of storing, accessing, and retrieving data, which may include any combination and number of data servers, databases, data storage devices, and data storage media, in any standard, distributed, or clustered environment. The application server can include any appropriate hardware and software for integrating with the data store as needed to execute aspects of one or more applications for the client device, handling a majority of the data access and business logic for an application. 
     The data store  810  can include several separate data tables, databases or other data storage mechanisms and media for storing data relating to a particular aspect. For example, the data store illustrated includes mechanisms for storing production data  812  and user information  816 , which can be used to serve content for the production side. The data store also is shown to include a mechanism for storing log data  814 , which can be used for reporting, analysis, or other such purposes. It should be understood that there can be many other aspects that may need to be stored in the data store, such as for page image information and to access right information, which can be stored in any of the above listed mechanisms as appropriate or in additional mechanisms in the data store  810 . The data store  810  is operable, through logic associated therewith, to receive instructions from the application server  808  and obtain, update or otherwise process data in response thereto. In one example, a user might submit a search request for a certain type of item. In this case, the data store might access the user information to verify the identity of the user and can access the catalog detail information to obtain information about items of that type. The information then can be returned to the user, such as in a results listing on a Web page that the user is able to view via a browser on the user device  802 . Information for a particular item of interest can be viewed in a dedicated page or window of the browser. 
     Each server typically will include an operating system that provides executable program instructions for the general administration and operation of that server and typically will include a computer-readable storage medium (e.g., a hard disk, random access memory, read only memory, etc.) storing instructions that, when executed by a processor of the server, allow the server to perform its intended functions. Suitable implementations for the operating system and general functionality of the servers are known or commercially available and are readily implemented by persons having ordinary skill in the art, particularly in light of the disclosure herein. 
     The environment in one embodiment is a distributed computing environment utilizing several computer systems and components that are interconnected via communication links, using one or more computer networks or direct connections. However, it will be appreciated by those of ordinary skill in the art that such a system could operate equally well in a system having fewer or a greater number of components than are illustrated in  FIG.  8   . Thus, the depiction of the system  800  in  FIG.  8    should be taken as being illustrative in nature and not limiting to the scope of the disclosure. 
     The various embodiments further can be implemented in a wide variety of operating environments, which in some cases can include one or more user computers, computing devices or processing devices which can be used to operate any of a number of applications. User or client devices can include any of a number of general purpose personal computers, such as desktop or laptop computers running a standard operating system, as well as cellular, wireless, and handheld devices running mobile software and capable of supporting a number of networking and messaging protocols. Such a system also can include a number of workstations running any of a variety of commercially-available operating systems and other known applications for purposes such as development and database management. These devices also can include other electronic devices, such as dummy terminals, thin-clients, gaming systems, and other devices capable of communicating via a network. 
     Such devices also can include a computer-readable storage media reader, a communications device (e.g., a modem, a network card (wireless or wired)), an infrared communication device, etc.), and working memory as described above. The computer-readable storage media reader can be connected with, or configured to receive, a computer-readable storage medium, representing remote, local, fixed, and/or removable storage devices as well as storage media for temporarily and/or more permanently containing, storing, transmitting, and retrieving computer-readable information. The system and various devices also typically will include a number of software applications, modules, services, or other elements located within at least one working memory device, including an operating system and application programs, such as a client application or Web browser. It should be appreciated that alternate embodiments may have numerous variations from that described above. For example, customized hardware might also be used and/or particular elements might be implemented in hardware, software (including portable software, such as applets), or both. Further, connection to other computing devices such as network input/output devices may be employed. 
     Storage media computer readable media for containing code, or portions of code, can include any appropriate media known or used in the art, including storage media and communication media, such as but not limited to volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage and/or transmission of information such as computer readable instructions, data structures, program modules, or other data, including RAM, ROM, Electrically Erasable Programmable Read-Only Memory (“EEPROM”), flash memory or other memory technology, Compact Disc Read-Only Memory (“CD-ROM”), digital versatile disk (DVD), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage, or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a system device. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will appreciate other ways and/or methods to implement the various embodiments. 
     The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the disclosure as set forth in the claims. 
     Other variations are within the spirit of the present disclosure. Thus, while the disclosed techniques are susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof are shown in the drawings and have been described above in detail. It should be understood, however, that there is no intention to limit the disclosure to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the disclosure, as defined in the appended claims. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosed embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the disclosure and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure. 
     Disjunctive language such as the phrase “at least one of X, Y, or Z,” unless specifically stated otherwise, is intended to be understood within the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present. 
     Various embodiments of this disclosure are described herein, including the best mode known to the inventors for carrying out the disclosure. Variations of those embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate and the inventors intend for the disclosure to be practiced otherwise than as specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.