Phase immersion cooling system based on pressure

Abstract

Techniques are disclosed for dynamically changing the pressure within a pressurized cooling system to allow for cooling electronic devices using different cooling rates. A pressurized cooling system uses a dielectric heat transfer fluid disposed within a two-phase immersion cooling vessel to cool an electronic heat generating component. The container is operable to maintain different pressure levels. The pressurized cooling system includes a pressure system configured to modify a pressure within the vessel. The system operates in a first state when the pressure is above a threshold pressure. The system operates in a second state when the pressure is at a threshold pressure. The system operates in either a first state or a second state based on an operating state of the heat generating component.

Description

Background Art

[0001] Electronic products generate a lot of heat. If this heat is not transferred away from the electronic device, the performance of the electronic device may be degraded. Therefore, it is very desirable to provide a cooling mechanism to cool the electronic device.

[0002] There are various mechanisms available for cooling electronic devices. For example, consider a data center that includes many different servers. The data center is likely equipped with a climate control system that includes air conditioning and a number of different fans. The fans circulate the cool air produced by the air conditioning throughout the room that includes the servers. When the cooler air blows over the servers, the servers are cooled. Therefore, some cooling technologies include air cooling.

[0003] Another interesting cooling technology is to place a sealed environment deep in the seawater. This environment is sealed to prevent water leaks. Servers are placed in this environment. Due to the low temperature of the deep water, the walls remain very cool. Heat can be transferred from the servers to the walls and into the water.

[0004] Another interesting cooling technology is single-phase or two-phase immersion cooling. With this technology, the server is immersed in a dielectric heat transfer fluid. This liquid has a very low boiling point. Due to the low boiling point, heat can be transferred via evaporative cooling.

[0005] As mentioned above, there are many technologies that can be used to cool electronic devices. However, each of these technologies comes with challenges. For example, air cooling technology is relatively inefficient and provides a "one size fits all" approach. Deep water cooling presents challenges in terms of maintenance. Immersion cooling is challenging because traditionally, there are a limited number of different types of dielectric heat transfer fluids that can be used. Therefore, an improved technology is needed to transfer heat away from electronic devices in an efficient and scalable manner.

[0006] The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as described above. Rather, this background is provided merely to illustrate one exemplary technology area in which some embodiments described herein may be practiced. Summary of the invention

[0007] Embodiments disclosed herein relate to systems, apparatus, and methods for dynamically changing pressure within a pressurized cooling system.

[0008] Some embodiments relate to a pressurized cooling system for cooling one or more electronic heat generating components using a dielectric heat transfer fluid disposed in a two-phase immersion cooling vessel. The pressurized cooling system includes a two-phase immersion cooling vessel operable to maintain different pressure levels. The system includes a pressure system configured to modify the pressure within the two-phase immersion cooling vessel. When the pressure within the two-phase immersion cooling vessel changes, the low-temperature boiling point of the dielectric heat transfer fluid changes, thereby enabling the use of different cooling rates to cool the heat generating components. When the pressure of the two-phase immersion cooling vessel is higher than a threshold pressure (e.g., 1 atmosphere), the pressurized cooling system operates in a first state. When the pressure of the two-phase immersion cooling vessel is at a threshold pressure, the pressurized cooling system operates in a second state. The pressurized cooling system operates in either the first state or the second state based on the operating state of the heat generating component.

[0009] Some embodiments dynamically adjust the pressure within a pressurized cooling system, thereby enabling the use of multiple different cooling fluids within the pressurized cooling system. When the pressurized cooling system is operated in a first state, the embodiment maintains the pressure within the pressurized cooling system above a threshold pressure. The pressurized cooling system includes a two-phase immersion cooling vessel; a dielectric heat transfer fluid is disposed within the two-phase immersion cooling vessel; and one or more electronic heat generating components are completely immersed in the dielectric heat transfer fluid within the two-phase immersion cooling vessel. The embodiment determines that one or more electronic heat generating components are or will subsequently transition from a first operating state to a second operating state. In response to determining that one or more electronic heat generating components are currently or will subsequently transition from a first operating state to a second operating state, the embodiment operates the pressurized cooling system in the second state by reducing the pressure within the pressurized cooling system to a threshold pressure. The process of reducing the pressure causes the low temperature boiling point of the dielectric heat transfer fluid to decrease. As a result, heat is transferred from the one or more heat generating components at a faster rate when the pressurized cooling system is operated in the second state than when heat is transferred from the heat generating components when the pressurized cooling system is operated in the first state. Later, an embodiment operates the pressurized cooling system in a first state by increasing the pressure within the pressurized cooling system to maintain it above a threshold pressure.

[0010] This Summary is provided to introduce a series of concepts in a simplified form, which are further described in the Detailed Description below. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0011] Additional features and advantages will be set forth in the following description, and in part will be apparent from the description, or may be learned by practice of the teachings herein. The features and advantages of the present invention may be realized and obtained by the instruments and combinations particularly pointed out in the appended claims. The features of the present invention will become more apparent from the following description and the appended claims, or may be learned by practice of the present invention as described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to describe the manner in which the above-recited and other advantages and features may be obtained, a more particular description of the subject matter briefly described above will be rendered by reference to specific embodiments that are illustrated in the accompanying drawings. Understanding that these drawings depict only typical embodiments and are therefore not to be considered limiting in scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0013] Figure 1 An example pressurized cooling system is illustrated in which the internal pressure of the system may be dynamically modified.

[0014] Figure 2 It illustrates how changes in pressure can result in changes in the cooling rate of the system in accordance with the disclosed principles.

[0015] Figure 3 Illustration of how to monitor the level of a dielectric heat transfer fluid.

[0016] Figure 4 An example technique for controlling pressure is illustrated, where the technique relies on a pressure reducing valve.

[0017] Figure 5 Another example technique for controlling pressure is illustrated, where the technique relies on varying the coolant flow rate of the coolant pumped through the condenser.

[0018] Figure 6 Another example technique for controlling pressure is illustrated, where the technique relies on a pressure diaphragm.

[0019] Figure 7 A flow chart of an example method for dynamically changing pressure within the system is illustrated.

[0020] Figure 8 An example computer system capable of performing any of the disclosed operations is illustrated. DETAILED DESCRIPTION

[0021] Embodiments disclosed herein relate to systems, apparatus, and methods for dynamically changing pressure within a pressurized cooling system.

[0022] Some embodiments relate to a pressurized cooling system for cooling electronic heat generating components using a dielectric heat transfer fluid disposed in a two-phase immersion cooling vessel. The system also enables the use of multiple dielectric heat transfer fluids. In some cases, a mixture of multiple different dielectric cooling fluids can be used simultaneously to produce an azeotropic mixture.

[0023] The system includes a two-phase immersion cooling vessel operable to maintain different pressure levels. The system also includes a pressure system configured to modify the pressure within the two-phase immersion cooling vessel. When the pressure within the two-phase immersion cooling vessel changes, the low-temperature boiling point of the dielectric heat transfer fluid also changes. When the pressure of the two-phase immersion cooling vessel is above a threshold pressure (e.g., 1 atm), the pressurized cooling system operates in a first state. When the pressure of the two-phase immersion cooling vessel is at a threshold pressure, the pressurized cooling system operates in a second state. The pressurized cooling system operates in either the first state or the second state based on the operating state of the heat generating component.

[0024] Some embodiments dynamically adjust the pressure within the pressurized cooling system, thereby enabling the use of multiple different cooling fluids in the pressurized cooling system. Multiple different cooling fluids can be used simultaneously, such as in the case of an azeotropic mixture. Alternatively, one fluid can be replaced with another fluid at different times to provide different cooling temperatures, or more precisely, different evaporative cooling temperatures.

[0025] When the pressurized cooling system is operated in a first state, some embodiments maintain the pressure within the pressurized cooling system above a threshold pressure. By making the pressure (or pressure "level") above the threshold pressure, the pressure does not necessarily remain constant or static. Instead, the pressure can optionally fluctuate above the threshold pressure. In some cases, the pressure can be static, at least for a period of time, above the threshold pressure. The pressurized cooling system includes a two-phase immersion cooling container; a dielectric heat transfer fluid is disposed in the two-phase immersion cooling container; and the electronic heat generating component is completely immersed in the dielectric heat transfer fluid. The embodiment determines that the electronic heat generating component transitions from a first operating state or will subsequently transition from the first operating state (e.g., a planned transition or a predicted transition) to a second operating state. In response, the embodiment operates the pressurized cooling system in a second state by reducing the pressure within the pressurized cooling system to a threshold pressure. Reducing the pressure causes the low-temperature boiling point of the dielectric heat transfer fluid to decrease. When the pressurized cooling system is operated in the second state due to the lower evaporation boiling point, heat is transferred away from the heat generating component at a faster rate. Then, the embodiment operates the pressurized cooling system in the first state by increasing the pressure within the pressurized cooling system to maintain it above the threshold pressure.

[0026] The following section summarizes some example improvements and practical applications provided by the disclosed embodiments. However, it should be understood that these are only examples and the embodiments are not limited to these improvements.

[0027] The disclosed embodiments advantageously employ the use of pressure to dynamically change the boiling point of a dielectric heat transfer fluid. By doing so, a wider or more diverse range of different types of dielectric heat transfer fluids can be used to cool electronic devices. Traditionally, immersion cooling techniques have been hampered or limited because only a select set of dielectric heat transfer fluids can be used. These limitations are due in part to the limited range of boiling points of these fluids. Now, by applying pressure to these fluids, embodiments can dynamically change the boiling point of these fluids, thereby enabling the use of different fluids, where these different fluids have different boiling points.

[0028] Traditionally, the types of fluids used have not been ideal for overclocking scenarios, where significantly reducing the junction temperature of the CPU chip is beneficial. Now that a more diverse set of fluids can be used (due to dynamic pressure variations), embodiments can provide benefits that were previously unavailable, particularly when the chip is overclocked.

[0029] Another benefit relates to the ability to modify the cooling rate of an electronic device. As mentioned above, in some cases, an electronic device may be "overclocked." The term "overclocking (and its variations) refers to a scenario in which a processor or other electronic device is set to run at a speed higher than it was originally intended. In other words, overclocking refers to a scenario in which the clock rate of a computer is increased to exceed its certified operating capabilities. A device can be overclocked for a period of time to increase the amount of processing it performs. Overclocking causes the device to generate more heat, which needs to be dissipated to ensure that the device is not damaged.

[0030] These embodiments can advantageously dynamically reduce the boiling temperature of the dielectric heat transfer fluid. Doing so allows the system to increase the cooling rate that the fluid can provide. Such features are particularly beneficial when the device is overclocked. That is, by reducing the boiling point of the dielectric heat transfer fluid (thereby increasing the cooling rate provided by the fluid), the embodiments enable the junction temperature of the CPU chip to be significantly reduced, and changing the junction temperature helps to improve the processing power or overclocking capability of the processor. Therefore, the embodiments provide a kind of adjustable technology for improving the processing of the chip when the chip is overclocked by reducing the junction temperature of the chip.

[0031] Another benefit relates to the ability to finely control the cooling rate for a specific server or a specific pressurized cooling system. Previously, an entire data center could be cooled using an air conditioning (AC) unit, resulting in a "one size fits all" approach to cooling various servers. Because each pressurized cooling system can be independently controlled relative to the other systems, an embodiment provides a technique that enables fine-grained or fine control of cooling technology.

[0032] Another benefit relates to reduced energy consumption of the system, particularly the condenser. As will be mentioned later, the condenser can be used to condense a dielectric heat transfer fluid in vapor form. When the system is operated at a higher pressure, the boiling point of the dielectric heat transfer fluid will increase. Embodiments can advantageously reduce energy consumption in the system because the coolant in the condenser (e.g., which may be water) does not need to be cooled as when the system is operated at 1 atm. In other words, the coolant used for the condenser can be maintained at a higher temperature, thereby improving energy efficiency. Allowing the temperature to rise, thereby achieving improved efficiency and energy consumption.

[0033] Another benefit relates to the ability to keep all electronic devices at the same temperature due to the boiling temperature of the dielectric heat transfer fluid. Notably, the two-phase immersion fluid has a higher heat transfer coefficient compared to air. This results in a reduced thermal resistance to heat transfer. A large amount of heat can be dissipated with minimal (or zero) temperature rise. The disclosed pressure relief system enables improved system performance and provides a method for adjusting overclocking based on server workload. The disclosed two-phase immersion cooling system can be coupled with various pressure control systems (e.g., pressure relief or steam release mechanisms) to achieve intelligent load-driven overclocking and performance improvements. Therefore, these and many other benefits will now be discussed in more detail in subsequent sections of the present disclosure.

[0034] Pressurized cooling system

[0035] Now turn your attention to Figure 1 , which illustrates an example pressurized cooling system 100 that can provide the above benefits. The pressurized cooling system 100 is shown to include a two-phase immersion cooling vessel 105. Such a vessel is a sealable pressure vessel that can be used to contain a desired pressure therein. The two-phase immersion cooling vessel 105 is called a "two-phase" unit because it is configured so that the dielectric heat transfer fluid can exist in liquid form and in gaseous form.

[0036] Inside the two-phase immersion cooling container 105, one or more electronic devices, such as a server 110, are disposed. Depending on the size of the two-phase immersion cooling container 105, any number of servers may be disposed therein. Note the positioning and orientation of the server 110. The server 110 is oriented vertically within the container 105, and the other servers are also arranged or oriented vertically. This orientation is particularly beneficial because it prevents air bubbles from being trapped under a flat surface. If air bubbles are trapped on the surface of the server 110, the exposed surface may become overheated and may potentially be melted or damaged.

[0037] Server 110 is shown to include one or more heat generating components, such as heat generating component 115. As used herein, the term "heat generating component" may be any type of hardware or physical component. Examples of such components include, but are not limited to, processors, graphics processing units (GPUs), memory, capacitors, resistors, inductors, or even heat sinks. In fact, any type of hardware component that generates, produces, or may absorb (e.g., a heat sink) heat on an electronic device may be classified under the category of a heat generating component.

[0038] A dielectric heat transfer fluid 120 is also disposed inside the two-phase immersion cooling vessel 105. The dielectric heat transfer fluid 120 is a non-conductive substance that may be in liquid form at a given pressure or temperature (e.g., such as HFE7000, nitrogen, etc.). Figure 1 As shown, the heat generating component is completely immersed in the dielectric heat transfer fluid 120, and the heat generating component is in direct contact with the dielectric heat transfer fluid 120. In some cases, multiple different dielectric heat transfer fluids can be mixed together in the two-phase immersion cooling vessel 105. In this way, one, two, or more than two different fluids can be present in the pressure vessel.

[0039] The dielectric heat transfer fluid 120 has a low temperature boiling point 125. It is noteworthy that when no additional pressure is added, the pressure within the two-phase immersion cooling vessel 105 will be approximately 1 atm. When no additional pressure is added (i.e., when operating at about 1 atmosphere (atm)), the low temperature boiling point 125 is typically between about 30 degrees Celsius (C) and about 40C. If other types of dielectric heat transfer fluids (e.g., such as nitrogen) are used, these boiling point ranges may be different. However, in most scenarios, the ranges are as described above. As will be described in more detail later, the default (which may also be referred to as "normal") operating condition of the two-phase immersion cooling vessel 105 is to operate at a high pressure greater than 1 atm. As used herein, when the pressure within the two-phase immersion cooling vessel 105 is not at 1 atm, the two-phase immersion cooling vessel 105 is in a first state (e.g., a default state). When the pressure within the two-phase immersion cooling vessel 105 is 1 atm, the two-phase immersion cooling vessel 105 is in a second state.

[0040] Heat generating components of electronic devices typically reach temperatures above 40°C. Heat can be transferred from the heat generating component 115 to the dielectric heat transfer fluid 120 and then dissipated via an evaporation process. That is, "phase change heat transfer" (e.g., evaporative cooling or alternatively condensation) refers to the process of liquid changing to gas (evaporation) or alternatively gas changing to liquid (condensation), both of which are convective processes.

[0041] Evaporation can be used to cool a material (eg, heat generating component 115) because the latent heat of the dielectric heat transfer fluid is used to transfer heat from the heat generating component 115 by absorbing the energy required to evaporate the dielectric heat transfer fluid 120. The absorbed heat can then be released during condensation.

[0042] For example, Figure 1 It is shown how the dielectric heat transfer fluid 120 near the heat generating component 115 undergoes evaporation 130 as the temperature of the heat generating component 115 equals or exceeds the low temperature boiling point 125 of the dielectric heat transfer fluid 120 . Figure 1 The bubbles shown represent the process of evaporation 130. When the bubbles reach the surface of the dielectric heat transfer fluid 120, the vapor 135 enters the surrounding air or "head space" of the two-phase immersion cooling vessel 105.

[0043] The pressurized cooling system 100 also includes a condenser 140. The coolant flows through the tubes, and the heat in the steam 135 can be transferred to the coolant, causing the steam 135 to condense into a condensed fluid 145. The coolant can be cooled by an external cooler. In this way, the heat generated by the heat generating component 115 can be transferred away.

[0044] The disclosed embodiments are also configured to include a pressure system 150. The pressure system 150 is designed to modify the pressure 155 within the two-phase immersion cooling vessel 105. By modifying the pressure 155, the embodiments can dynamically control the boiling point of the dielectric heat transfer fluid 120. By controlling the boiling point (and thereby the evaporation rate), the embodiments enable the cooling rate of the heat generating component 115 to be controlled. Figure 2 is illustrative.

[0045] Figure 2 Shows that by dynamically modifying Figure 1 The difference in cooling rate 200 that can be achieved is due to the pressure within the two-phase immersion cooling vessel 105 changing the boiling point of the dielectric heat transfer fluid 120.

[0046] In the first scenario, the internal pressure in the container is set to a level greater than 1 atm. It is worth noting that this is the default state 205 (i.e., the first state) of the pressure. In other words, the first state of the pressurized cooling system refers to a state in which the internal pressure exceeds 1 atm. In other words, the default operating pressure (i.e., the pressure when operating in the first state) of the two-phase immersion cooling container is higher than 1 atmospheric pressure (atm), so that by default or under typical operating conditions, the dielectric heat transfer fluid will be subject to "increased pressure" (increased relative to atmospheric pressure or 1 atm). Due to operation at a higher pressure, the low-temperature boiling point will also increase. In this regard, the low-temperature boiling point of the dielectric heat transfer fluid is maintained at a relatively high temperature compared to when the dielectric heat transfer fluid is not subject to increased pressure.

[0047] Typically, the default operating pressure is between about 1.5 atm to about 3.5 atm (when the system is operated in the first state). In some cases, the range is between about 2 atm to about 3 atm. Due to the higher pressure, the boiling point of the dielectric heat transfer fluid rises. For illustration, when the dielectric heat transfer fluid is subjected to increased pressure (for example, between 2-3 atm), the low temperature boiling point of the dielectric heat transfer fluid is generally between about 45C to about 55C. In contrast, when the dielectric heat transfer fluid is not subjected to increased pressure, the low temperature boiling point of the dielectric heat transfer fluid is approximately 30C to 40C.

[0048] When in the default state 205 (i.e., pressure above 1 atm), the pressurized cooling system operates at a relatively low cooling rate 210 (e.g., note that there are fewer bubbles, reflecting a scenario where there is less evaporative cooling). The term "cooling rate" refers to the amount of heat dissipated over time. When the boiling temperature of the dielectric heat transfer fluid is higher, the cooling rate is lower. When the boiling temperature is lower, the cooling rate is higher.

[0049] When the electronic device is caused to operate in the overclocked state 215 (or possibly an increased load state), the pressure within the pressurized cooling system drops or may be completely released, thereby lowering the boiling point of the dielectric heat transfer fluid and thereby increasing the cooling rate (eg, due to the lower boiling point). Figure 2 The right side of shows a scenario where the internal pressure is now less than or equal to 1 atm, resulting in a relatively higher cooling rate 220 (eg, note the more bubbles). The response time for modifying the pressure can be substantially instantaneous.

[0050] Once an embodiment detects that an electronic device is currently or will subsequently be in an overclocked state 215 or a state of increased load (e.g., a threshold level of processor usage or memory usage can also be a triggering factor), an embodiment can react (in real time and on demand) by modifying the pressure within the system. In some cases, the overclocked state 215 is pre-planned, so an embodiment can prepare for the state. In some cases, the overclocked state 215 is predicted, such as may be predicted by a machine learning engine. An embodiment can then cycle the pressure based on the prediction. In some cases, an embodiment monitors the workload of the CPU chip in real time and can respond based on fluctuations in these workloads.

[0051] Thus, in some embodiments, the pressure system is configured to modify the pressure based on a situation where one or more servers including one or more heat generating components are operating in an overclocked state. In some cases, the pressure system modifies the pressure within the two-phase immersion cooling vessel based on the load applied to the one or more heat generating components. In such a scenario, the load may not be sufficient to cause the components to operate in an overclocked state, but the load may still cause the components to operate at a high rate. Thus, dynamically controlling the cooling rate is beneficial even though the CPU chip may not be overclocked.

[0052] A data center may have any number of discrete pressurized cooling systems for any number of different servers. For example, a data center may be organized to include discrete pressurized cooling systems for each server area, each server channel, each server rack, or even potentially each individual server. Therefore, a pressurized cooling system may be manufactured to accommodate any size requirement. Each pressurized cooling system may be independently controlled. Therefore, an embodiment has very fine or very fine-grained control of the cooling conditions for a particular server. This fine-grained control cannot be achieved using conventional cooling techniques based on air conditioning (AC). By following the disclosed principles, an embodiment may dynamically modify the cooling rates of these particular servers when a particular server is overclocked. One can understand how this control can produce substantial benefits, including the ability to help extend the life of electronic equipment by ensuring that the electronic equipment is adequately cooled, and cost savings by allowing fine control of the cooling rate (e.g., this is in contrast to cooling the entire data center via AC based on the increased demand of a single server).

[0053] Thus, in some embodiments, the pressure system is configured to drive the pressure within the two-phase immersion cooling vessel to a pressure above 1 atm (e.g., a first state), 1 atm (e.g., a second state), and / or even below 1 atm (e.g., a third state). In some cases, the pressure remains at 1 atm (i.e., the system operates in the second state).

[0054] Figure 3 A pressurized cooling system 300 is shown that represents the system discussed thus far. The pressurized cooling system 300 is shown to include a monitor 305 for monitoring the level 310 of the dielectric heat transfer fluid. Monitoring the level 310 is advantageous because it helps prevent scenarios where the dielectric heat transfer fluid in the pressure vessel (i.e., the two-phase immersion cooling vessel) is too low.

[0055] If there is too little fluid, components of the electronic device may be exposed to the air / head space and may not be cooled via evaporative cooling techniques. Therefore, some embodiments monitor the liquid level 310 and can optionally trigger the addition of additional dielectric heat transfer fluid to the container if the liquid level 310 drops below a threshold level or buffer level. It may be desirable to maintain a buffer or threshold amount of fluid above the servers to ensure that they are not inadvertently exposed and cooled. Modifying the pressure can also be advantageously used to modify the amount of dielectric heat transfer fluid in the pressure vessel (e.g., by controlling the evaporation rate). That is, a pressure modification can be performed to modify the buffer level. The higher the pressure, the higher the boiling temperature and the less evaporation. Reduced evaporation can result in an increase in the liquid form of the fluid. Therefore, in some embodiments, the liquid level of the dielectric heat transfer fluid within the two-phase immersion cooling container is monitored.

[0056] Thus, some embodiments are directed to a pressurized cooling system for cooling one or more electronic heat generating components using a dielectric heat transfer fluid disposed within a two-phase immersion cooling vessel. The pressurized cooling system includes a two-phase immersion cooling vessel operable to maintain different pressure levels.

[0057] The pressurized cooling system also includes a pressure system configured to modify the pressure within the two-phase immersion cooling vessel. It is noteworthy that when the pressure within the two-phase immersion cooling vessel changes, the low temperature boiling point of the dielectric heat transfer fluid will also change. Changing the pressure enables different cooling rates to be used to cool the heat generating components.

[0058] When the pressure of the two-phase immersion cooling vessel is above a threshold pressure (eg, 1 atm), the pressurized cooling system operates in a first state. When the pressurized cooling system operates in the first state, the low temperature boiling point of the dielectric heat transfer fluid is relatively high, so that less evaporative cooling occurs.

[0059] When the pressure of the two-phase immersion cooling vessel is at a threshold pressure (eg, 1 atm), the pressurized cooling system operates in a second state. When the pressurized cooling system operates in the second state, the low temperature boiling point of the dielectric heat transfer fluid is relatively low, so that more evaporative cooling occurs.

[0060] The pressurized cooling system operates in either a first state or a second state based on the operating state of one or more heat generating components. The operating state of the heat generating components may include an overclocked state, an increased load state (e.g., such as when processor usage or memory usage exceeds a predefined threshold), or a default load state (e.g., such as when processor usage or memory usage does not exceed a predefined threshold). For example, when the server transitions to or subsequently transitions to an overclocked state, the pressurized cooling system may transition from the first state to the second state.

[0061] In some cases, the heat generating component includes a processor, and the operating state of the process includes (i) a first operating state in which a processor usage of the processor is below a threshold level, and (ii) a second operating state in which a processor usage of the processor is above a threshold level.

[0062] When the pressurized cooling system is operated in the first state, it is typically the case that the low temperature boiling point of the dielectric heat transfer fluid is between about 45° C. and about 55° C. When the pressurized cooling system is operated in the second state, the low temperature boiling point is between about 30° C. and about 40° C.

[0063] Techniques for dynamically modifying pressure levels

[0064] Now pay attention Figure 4 , Figure 5 and Figure 6 These figures illustrate various techniques for dynamically modifying the pressure within a pressure vessel, such as Figure 1 , Figure 2 and Figure 3 As shown, in order to achieve the benefit of being able to vary the cooling rate of a heat generating component.

[0065] Figure 4 A pressurized cooling system 400 is shown that includes a two-phase immersion cooling vessel 400A and a heat generating component 405. In this example scenario, the system also includes a flow meter 410 and a pump 415. The flow meter 410 and the pump 415 can be used to cause the dielectric heat transfer fluid (in liquid form) to fluctuate, cycle, or circulate within the system. Circulating the dielectric heat transfer fluid helps prevent bubbles from being trapped (e.g., the circulation can disturb the fluid).

[0066] The system also includes a condenser 420, which represents Figure 1 4. A cooler 425 is also shown for cooling a coolant included in a pipe between the condenser 420 and the cooler 425. The coolant can be any type of coolant or refrigerant. In some cases, the coolant is water. In some cases, the coolant can be a Freon refrigerant.

[0067] One example technique for dynamically controlling the pressure within the system is through the use of a steam container 430, a pressure gauge 435, and a pressure relief valve 440. As used herein, the term "steam container" refers to a structure that is distinct from the two-phase immersion cooling vessel 400A (also referred to as a "vessel"). The steam container 430 is a chamber that allows gas to escape from the two-phase immersion cooling vessel 400A, such as Figure 4As shown, the container accommodates the heating component 405. As previously mentioned, the default pressure level of the system is higher than 1 atm. In order to reach this pressure level, the embodiment can be configured to allow the dielectric heat transfer fluid to evaporate to form steam. The accumulation of steam in the container also increases the pressure in the container. The pressure in the container can be monitored via a pressure gauge 435. The pressure gauge 435 can be incorporated into the two-phase immersion cooling container, or combined with the pipeline connected to the two-phase immersion cooling container, such as between the steam container 430 and the two-phase immersion cooling container. Optionally, pressure can be measured at multiple different locations in the system, such as in the container and / or outside the container via an attached pipeline. Different pressure measurement sensors can also be used. If the pressure does not reach a threshold or a default pressure level (e.g., typically 2-3 atm), the pressure reducing valve 440 remains closed, thereby allowing pressure to accumulate. Once the pressure reaches the threshold level, the pressure reducing valve 440 can be selectively opened or closed to ensure that the pressure remains at or near the threshold level.

[0068] When the pressure reducing valve 440 is opened, the steam may be released, such as into the steam container 430, where the steam will condense and may then be transported back to the container (in liquid form). Optionally, the condensed liquid in the steam container 430 may be retained in the steam container 430 for a period of time, or alternatively, the liquid may be returned or drained back to the two-phase immersion cooling container without delay. In some cases, a liquid level monitor is provided in the two-phase immersion cooling container. When the monitor indicates that the liquid in the two-phase immersion cooling container is below a threshold level, then an embodiment may optionally trigger a valve, thereby causing the liquid in the steam container 430 to flow into the two-phase immersion cooling container to increase the level in the two-phase immersion cooling container. Thus, in this example scenario, the pressure system (e.g., Figure 1 The pressure system 150 of the two-phase immersion cooling vessel can be configured to modify the pressure within the two-phase immersion cooling vessel via the pressure reducing valve 440 (and the accompanying pressure gauge 435). When the pressure reducing valve 440 is opened, the increased pressure within the vessel can be selectively released or controlled. Opening or closing the pressure reducing valve 440 can depend on what state the pressurized cooling system is in. For example, when the pressurized cooling system transitions from a first state to a second state, the pressure reducing valve 440 can be opened. When the pressurized cooling system transitions from the second state to the first state, the pressure reducing valve 440 can be closed.

[0069] Thus, in some scenarios, the pressurized system is configured to include a steam vessel 430. The pressurized cooling system transitions from the first state to the second state when the pressure in the two-phase immersion cooling vessel is relieved (e.g., possibly by opening a pressure relief valve 440), and when the vapor form of the dielectric heat transfer fluid escapes to the steam vessel 430 and is condensed.

[0070] In some scenarios, when the increased pressure in the two-phase immersion cooling vessel is eliminated, the vapor form of the dielectric heat transfer fluid can be allowed to escape. In some optional scenarios, some of the vapor form is allowed to escape into the steam vessel 430.

[0071] Figure 5 Another example technique for dynamically controlling pressure within a container is illustrated. Figure 5 An example pressurized cooling system 500 is illustrated, which includes a two-phase immersion cooling vessel 500A and a heat generating component 505 immersed in a dielectric heat transfer fluid, the flow of which is monitored via a flow meter 510 and circulated via a pump 515. As previously described, the system also includes a condenser 520 and a cooler 525. A coolant 530 is provided to transfer heat from the vapor form of the dielectric heat transfer fluid so that the fluid can condense back into a liquid form. As previously described, the coolant 530 can be water or other types of refrigerants.

[0072] Embodiments enable dynamically controlling the coolant flow rate 535 of the coolant 530 passing through the condenser 520 to dynamically control the pressure within the container. That is, by controlling the flow rate of the coolant, embodiments can increase or decrease the condensation rate of the dielectric heat transfer fluid when it is in the form of vapor. Slowing down the flow rate of the coolant will reduce the condensation rate, which will increase the amount of vapor in the container, thereby also increasing the pressure level. In some cases, environmental conditions such as temperature and pressure can be monitored. Embodiments can dynamically control the coolant flow rate 535 based on detected environmental conditions. On the other hand, increasing the flow rate of the coolant will increase the condensation rate, which will reduce the amount of vapor in the container, thereby also reducing the pressure level. Therefore, there is an inverse relationship between the coolant flow rate and the pressure level. The higher the flow rate, the lower the pressure; a lower flow rate results in a higher pressure. The flow rate of the coolant can be controlled via a pump 540.

[0073] Figure 6 Another pressurized cooling system 600 configured to dynamically control pressure within a vessel is illustrated. The system includes a two-phase immersion cooling vessel 600A and a heat generating component 605 immersed in a dielectric heat transfer fluid, a flow meter 610, a pump 615, a condenser 620, and a cooler 625. The system also includes a pressure diaphragm 630.

[0074] The pressure diaphragm 630 can be any type of movable structure designed to modify the pressure within the container. Examples of such structures include, but are not limited to, an inflatable bladder, a piston, or any other type of thin flexible membrane that can be moved to change the pressure by modifying the internal volume in the container.

[0075] For example, assuming that the pressure diaphragm 630 is in the form of an inflatable airbag, it can be part of a pressurized cooling system. When the airbag is inflated, the pressure in the container will increase. When the airbag is deflated, the pressure in the container will decrease. In some cases, the pressure can even be reduced to a level below 1 atm (e.g., such as when the piston is retracted to create a vacuum) (e.g., the third state). Setting the pressure below 1 atm will also affect the boiling point of the dielectric heat transfer fluid.

[0076] Thus, a variety of different techniques can be used to dynamically change the pressure within the container. In one example scenario, the pressure is modified via the use of a pressure reducing valve. In another example scenario, the pressure system is configured to modify the pressure within the two-phase immersion cooling container by modifying the coolant flow rate of the coolant within the condenser. In another example scenario, the pressure system includes a diaphragm configured to modify the pressure within the two-phase immersion cooling container. Each of these techniques can be performed individually, or alternatively, these techniques can be performed in various combinations with each other. Therefore, no one technique should be considered mutually exclusive with any other technique.

[0077] In another example, the temperature of the dielectric heat transfer fluid can also be cooled via the use of a cooler. For example, a pipe can pass through a pressure vessel and can come into contact with a liquid form of the dielectric heat transfer fluid. The pipe can be filled with a refrigerant, which can also be used to cool the dielectric heat transfer fluid. This method can be considered a hybrid single-phase and two-phase cooling technique. Therefore, there are a variety of different methods to provide cooling functionality.

[0078] Example Method

[0079] The following discussion now relates to a number of methods and method actions that can be performed. Although the method actions may be discussed in a particular order or illustrated in a flowchart as occurring in a particular order, no particular order is required unless specifically stated or required because one action depends on another action being completed before the action is performed.

[0080] Now turn your attention to Figure 7 , which illustrates a flow chart of an example method 700 for dynamically adjusting the pressure within a pressurized cooling system to enable the use of multiple different cooling fluids in the pressurized cooling system. The method may use Figure 1 The pressurized cooling system 100 is implemented.

[0081] As described above, the pressurized cooling system 100 includes a two-phase immersion cooling vessel, wherein the two-phase immersion cooling vessel is a pressure vessel configured to maintain different pressure levels. The system also includes one or more electronic heat generating components disposed within the two-phase immersion cooling vessel. The system also includes a dielectric heat transfer fluid disposed within the two-phase immersion cooling vessel.

[0082] The two-phase immersion cooling vessel is filled with a dielectric heat transfer fluid at a level such that one or more electronic heat generating components are completely immersed in the dielectric heat transfer fluid and such that the one or more electronic heat generating components are in direct contact with the dielectric heat transfer fluid. The dielectric heat transfer fluid has a low temperature boiling point, which enables heat to be transferred from the one or more heat generating components by evaporation of the dielectric heat transfer fluid under the following conditions: (i) when in contact with the one or more heat generating components and (ii) when the temperature of the one or more heat generating components reaches at least the low temperature boiling point of the dielectric heat transfer fluid.

[0083] The system also includes a condenser configured to condense the dielectric heat transfer fluid when the dielectric heat transfer fluid is in vapor form due to evaporation. The system includes a pressure system configured to modify the pressure within the two-phase immersion cooling vessel. When the pressure within the two-phase immersion cooling vessel changes, the low-temperature boiling point of the dielectric heat transfer fluid will also change, thereby enabling different cooling rates to be used to cool the heat-generating components. In the case where a plurality of different types of dielectric heat transfer fluids are provided in the two-phase immersion cooling vessel 105, each of these fluids may have a different boiling point. Therefore, different cooling rates may be achieved via the presence of different boiling points. Therefore, Figure 7 Method 700 can be used Figure 1 The structure of the pressurized cooling system 100 is implemented.

[0084] Method 700 includes an action (action 705) of maintaining the pressure within the pressurized cooling system above a threshold pressure (e.g., 1 atmosphere (atm)) when the pressurized cooling system is operated in a first state. In some cases, the pressure may selectively fluctuate by a threshold amount as long as it remains above 1 atm. For example, a range (also referred to as a "buffer" or "buffer range") may be defined, wherein the pressure may be anywhere within the defined range, such as between 2.2 atm and 2.7 atm (or any other defined range). Fluctuations within the pressure range may be allowed without the system performing corrective measures (e.g., triggering the pressure system to increase or decrease pressure). If the pressure exceeds the defined range, the system may be triggered to correct the pressure. Small fluctuations (e.g., fluctuations occur, but the pressure remains within the range) may not be a triggering condition for the system to perform a pressure correction action (e.g., increase or decrease the pressure so that the pressure is within the range again). For example, the pressure level may be maintained between about 1.5 atm and about 3.5 atm. When at such a higher or increased pressure, the boiling point of the dielectric heat transfer fluid may increase. Typically, the boiling point is raised from a normal (non-pressurized) point of about 30C to 40C to a new or elevated (pressurized) boiling point of about 45C to 55C.

[0085] Act 710 includes determining that one or more electronic heat generating components are or will subsequently transition from a first operating state (e.g., a load reduced state, or a state in which a processor or memory operates below a threshold level) to a second operating state (e.g., an overclocked state or a load increased state, such as when a processor or memory operates below a threshold level). Embodiments may determine that a component will enter an overclocked state within a threshold time period.

[0086] In response to determining that the one or more electronic heat generating components are or will subsequently transition from the first operating state to the second operating state, act 715 includes operating the pressurized cooling system in the second state by reducing the pressure within the pressurized cooling system to a threshold pressure (e.g., 1 atm). Reducing the pressure causes the low temperature boiling point of the dielectric heat transfer fluid to decrease, so that heat is transferred away from the one or more heat generating components at a faster rate when the pressurized cooling system is operated in the second state than when heat is transferred away from the heat generating components when the pressurized cooling system is operated in the first state.

[0087] The pressure may be reduced by opening a pressure reducing valve to allow pressure to escape from the two-phase immersion cooling vessel of the pressurized cooling system. Additionally or alternatively, the pressure reduction may be performed by modifying the coolant flow rate in the condenser of the pressurized cooling system. Additionally or alternatively, the pressure reduction may be performed by moving a diaphragm within the pressurized cooling system.

[0088] Then, action 720 includes causing the pressurized cooling system to operate in a first state by increasing the pressure within the pressurized cooling system above a threshold pressure (e.g., 1 atm). For example, after the electronic components have returned to a normal state so that they are not in an overclocked state, embodiments may again increase the pressure in the pressure vessel, thereby increasing the boiling point of the dielectric heat transfer fluid.

[0089] By dynamically modifying the pressure, the system is not only able to modify the cooling rate of the electronic device, but the system also allows the use of a more diverse range of fluids. Now, fluids with a wide range of boiling temperatures can be used. Previously, fluids with boiling points of approximately 50C were used. This embodiment can advantageously deviate from this limitation, and fluids with different boiling points can be used. In some cases, a mixture of multiple different fluids can be used to produce an azeotropic mixture. Therefore, substantial benefits can be achieved by following the disclosed principles.

[0090] Example Computer / Computer System

[0091] Now turn your attention to Figure 8, which illustrates an example computer system 800 that may include and / or be used to perform any of the operations described herein. For example, computer system 800 may be used to help perform various operations in method 700. Computer system 800 may be used to control reduced pressure values, coolant flow rates, or even the pressure diaphragms mentioned previously. Computer system 800 may also monitor the level of a dielectric heat transfer fluid. Computer system 800 may be used in a larger sense to independently control the pressure of multiple different pressurized cooling systems within a data center.

[0092] Computer system 800 can take a variety of different forms. For example, computer system 800 can be embodied as a tablet computer 800A, a desktop or laptop computer 800B, a wearable device 800C, a mobile device, or any other stand-alone device, as shown by ellipsis 800D. Computer system 800 can also be a distributed system that includes one or more connected computing components / devices that communicate with computer system 800.

[0093] In its most basic configuration, computer system 800 includes a variety of different components. Figure 8 As shown, computer system 800 includes one or more processors 805 (also referred to as “hardware processing units”) and storage device 810 .

[0094] With respect to processor(s) 805, it should be understood that the functionality described herein may be performed, at least in part, by one or more hardware logic components (e.g., processor(s) 805). For example, and without limitation, illustrative types of hardware logic components / processors that may be used include field programmable gate arrays (“FPGAs”), program-specific or application-specific integrated circuits (“ASICs”), programming-specific standard products (“ASSPs”), systems on chips (“SOCs”), complex programmable logic devices (“CPLDs”), central processing units (“CPUs”), graphics processing units (“GPUs”), or any other type of programmable hardware.

[0095] As used herein, the terms "executable module," "executable component," "component," "module," or "engine" may refer to a hardware processing unit or a software object, routine, or method that can be executed on the computer system 800. The term "heat generating component" refers to a physical or hardware device. The different components, modules, engines, and services described herein may be implemented as objects or processors that execute on the computer system 800 (e.g., as separate threads).

[0096] Storage device 810 may be physical system memory, which may be volatile, non-volatile, or some combination of the two. The term "memory" may also be used herein to refer to non-volatile mass storage devices, such as physical storage media. If computer system 800 is distributed, processing, memory, and / or storage capabilities may also be distributed.

[0097] Storage device 810 is shown as including executable instructions 815. Executable instructions 815 represent instructions executable by processor(s) 805 of computer system 800 to perform disclosed operations, such as those described in various methods.

[0098] The disclosed embodiments may include or utilize a special-purpose or general-purpose computer including computer hardware, such as, for example, one or more processors (such as (multiple) processors 805) and system memory (such as storage device 810), as discussed in more detail below. Embodiments also include physical and other computer-readable media for carrying or storing computer-executable instructions and / or data structures. Such computer-readable media can be any available media that can be accessed by a general-purpose or special-purpose computer system. A computer-readable medium that stores computer-executable instructions in the form of data is a "physical computer storage medium" or a "hardware storage device." In addition, computer-readable storage media (including physical computer storage media and hardware storage devices) do not include signals, carriers, and propagating signals. On the other hand, a computer-readable medium that carries computer-executable instructions is a "transmission medium" and includes signals, carriers, and propagating signals. Therefore, by way of example and not limitation, the current embodiments may include at least two distinct computer-readable media: computer storage media and transmission media.

[0099] Computer storage media (also called "hardware storage devices") are computer-readable hardware storage devices such as RAM, ROM, EEPROM, CD-ROM, solid-state drives ("SSD") based on RAM, flash memory, phase change memory ("PCM") or other types of memory, or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other media that can be used to store desired program code in the form of computer-executable instructions, data or data structures and that can be accessed by a general purpose or special purpose computer.

[0100] The computer system 800 may also be connected (via a wired or wireless connection) to external sensors (e.g., one or more remote cameras) or devices via the network 820. For example, the computer system 800 may communicate with any number of devices or cloud services to acquire or process data. In some cases, the network 820 itself may be a cloud network. In addition, the computer system 800 may also be connected to a remote / separate (multiple) computer system via one or more wired or wireless networks that is configured to perform any of the processing described with respect to the computer system 800.

[0101] A "network" (such as network 820) is defined as one or more data links and / or data switches that can transmit electronic data between computer systems, modules and / or other electronic devices. When information is transmitted or provided to a computer through a network (hardwired, wireless, or a combination of hardwired and wireless), the computer will correctly regard the connection as a transmission medium. Computer system 800 will include one or more communication channels for communicating with network 820. Transmission media include networks that can be used to carry data or desired program codes in the form of computer executable instructions or in the form of data structures. In addition, these computer executable instructions can be accessed by general or special computers. The combination of the above items should also be included in the scope of computer-readable media.

[0102] After reaching various computer system components, program code means in the form of computer executable instructions or data structures may be automatically transferred from transmission media to computer storage media (or vice versa). For example, computer executable instructions or data structures received over a network or data link may be buffered in RAM within a network interface module (e.g., a network interface card or "NIC"), and then ultimately transferred to computer system RAM and / or less volatile computer storage media at the computer system. Thus, it should be understood that computer storage media may be included in computer system components that also (or even primarily) utilize transmission media.

[0103] For example, computer executable (or computer interpretable) instructions include instructions that cause a general-purpose computer, a special-purpose computer, or a special-purpose processing device to perform a specific function or group of functions. Computer executable instructions can be, for example, binary files, intermediate format instructions such as assembly language, or even source code. Although the subject matter has been described in a language specific to structural features and / or method actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the features or actions described above. On the contrary, the described features and actions are disclosed as example forms of implementing the claims.

[0104] Those skilled in the art will appreciate that the embodiments can be implemented in a network computing environment with many types of computer system configurations, including personal computers, desktop computers, laptop computers, message processors, handheld devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, mobile phones, PDAs, pagers, routers, switches, etc. The embodiments can also be implemented in a distributed system environment, where local and remote computer systems linked by a network (by a hardwired data link, a wireless data link, or a combination of hardwired and wireless data links) each perform tasks (e.g., cloud computing, cloud services, etc.). In a distributed system environment, program modules can be located in both local and remote memory storage devices.

[0105] The present invention may be embodied in other specific forms without departing from its characteristics. The described embodiments are considered in all respects to be illustrative only and not restrictive. Therefore, the scope of the present invention is indicated by the appended claims rather than by the above description. All changes within the equivalent meaning and scope of the claims should be included within the scope of the claims.

Claims

1. A pressurized cooling system for cooling one or more electronic heat generating components using a dielectric heat transfer fluid disposed in a two-phase immersion cooling vessel, the pressurized cooling system comprising: The two-phase immersion cooling vessel is operable to maintain different pressure levels; as well as a pressure system configured to modify the pressure within the two-phase immersion cooling vessel, when the pressure within the two-phase immersion cooling vessel changes, the low temperature boiling point of the dielectric heat transfer fluid changes, thereby enabling different cooling rates to be used to cool the one or more heat generating components, in: the pressurized cooling system operates in a first state when the pressure of the two-phase immersion cooling vessel is above a threshold pressure, When the pressure of the two-phase immersion cooling vessel is at the threshold pressure, the pressurized cooling system operates in a second state, and The pressurized cooling system operates in either the first state or the second state based on an operating state of the one or more heat generating components.

2. The pressurized cooling system of claim 1 , wherein the one or more heat generating components comprises a processor, and wherein the operating state of the processor comprises (i) a first operating state in which a processor usage of the processor is below a threshold level, and (ii) a second operating state in which the processor usage of the processor is above the threshold level.

3. The pressurized cooling system of claim 2, wherein the threshold pressure is 1 atmosphere (atm), and wherein when the pressurized cooling system is operated in the first state, the pressure of the two-phase immersion cooling vessel is between about 1.5 atm and about 3.5 atm.

4. The pressurized cooling system of claim 2, wherein the low temperature boiling point of the dielectric heat transfer fluid is between about 45 degrees Celsius (C) and about 55C when the pressurized cooling system is operated in the first state.

5. The pressurized cooling system of claim 4, wherein the low temperature boiling point of the dielectric heat transfer fluid is between about 30°C and about 40°C when the pressurized cooling system is operated in the second state.

6. The pressurized cooling system of claim 2, wherein the pressure system is configured to modify the pressure within the two-phase immersion cooling vessel via a pressure relief valve, and wherein when the pressurized cooling system transitions from the first state to the second state, the pressure is released when the pressure relief valve is opened.

7. The pressurized cooling system of claim 2, wherein the pressure system is configured to modify the pressure within the two-phase immersion cooling vessel by modifying a coolant flow rate of coolant within a condenser included as part of the pressurized cooling system.

8. The pressurized cooling system of claim 1, wherein the dielectric heat transfer fluid comprises HFE7000 or nitrogen.

9. The pressurized cooling system of claim 1, wherein the one or more heat-generating components include one or more servers, wherein the operating state of the one or more servers includes an overclocked state, and wherein when the one or more servers are in the overclocked state, the pressurized cooling system transitions from the first state to the second state.

10. The pressurized cooling system of claim 1, wherein the pressure system comprises a diaphragm configured to modify the pressure within the two-phase immersion cooling vessel.

11. The pressurized cooling system of claim 1 , wherein the pressure system modifies the pressure within the two-phase immersion cooling vessel based on a load imposed on the one or more heat generating components.

12. The pressurized cooling system of claim 2, wherein the pressure system includes a steam vessel, and wherein the pressurized cooling system transitions from the first state to the second state when the dielectric heat transfer fluid in vapor form escapes into the steam vessel and is condensed.

13. The pressurized cooling system of claim 1, wherein the pressure system is configured to drive the pressure within the two-phase immersion cooling vessel to a pressure above 1 atmosphere (atm) or to a pressure below 1 atm.

14. The pressurized cooling system of claim 13, wherein the pressure system is further configured to drive the pressure to 1 atm.

15. The pressurized cooling system of claim 1 wherein the level of the dielectric heat transfer fluid within the two-phase immersion cooling vessel is monitored.

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