Full immersion heat sink

Abstract

This application relates to a fully immersion heat dissipation device for cooling power components. The device includes a main chamber, a balancing channel, a telescopic cavity, and a condensation assembly. The balancing channel connects the main chamber and the telescopic cavity, forming a sealed cavity free of non-condensable gases. The heating surface of the power component is immersed in liquid working fluid within the main chamber. The condensation surface of the condensation assembly is located at the upper end of the main chamber. Gaseous working fluid can force the liquid working fluid in the main chamber into the telescopic cavity through the balancing channel, causing the cavity to expand. When the gaseous working fluid rises and contacts the condensation surface, it liquefies. The liquid working fluid in the telescopic cavity can then enter the main chamber through the balancing channel. The fully immersion heat dissipation device provided by this application solves the problem of large pressure fluctuations within the cooling system, which is detrimental to maintaining a stable heat dissipation range for the power components.

Description

Technical Field

[0001] This application relates to the field of heat pipe device technology, and in particular to a fully immersion heat dissipation device. Background Technology

[0002] With the rapid development of artificial intelligence technology, the computing power required for chips is also continuously increasing. However, this is accompanied by higher energy consumption and heat generation. The heat flux density of power components such as chips is growing exponentially. It is estimated that in the near future, a single chip will generate more than 2500W of heat power in a package area of ​​26×33 (mm), with a heat flux density of about 300W / cm². Obviously, traditional water cooling technology can no longer meet such high-density heat dissipation requirements.

[0003] Currently, there are two main solutions: Solution A involves modifying the liquid cooling plate by replacing the coolant with a coolant possessing phase change properties. The latent heat of vaporization of the coolant is used to rapidly dissipate heat from the chip. It's important to note that in this solution, the coolant and the chip are not in direct contact; that is, the chip and the coolant are separated by the liquid cooling plate. Therefore, Solution A's heat dissipation capacity is relatively limited. Solution B involves directly immersing the chip in the coolant, with all exposed surfaces of the chip in direct contact with the coolant. Highly efficient heat dissipation is achieved through the phase change boiling of the coolant. Clearly, in this solution, the coolant and the chip are in direct contact.

[0004] Most importantly, regardless of whether it's Option A or Option B, the vaporization or reliquefaction of the coolant causes significant pressure fluctuations within the cooling system. These pressure fluctuations lead to substantial changes in the boiling point (or condensation point) of the coolant. For example, when the internal pressure increases, the boiling point of the coolant might rise from 30°C to 40°C. This means that below 40°C, the coolant will not undergo a phase change. In this case, the heat generated by the chip will be difficult to dissipate using the latent heat of vaporization of the coolant. Therefore, significant pressure fluctuations within the cooling system are detrimental to maintaining stable heat dissipation for power components such as chips. This could even lead to damage to the chip due to insufficient heat dissipation, or cause the chip to operate at excessively low temperatures, impacting its performance.

[0005] It should be noted that the application of immersion liquid cooling technology is already quite common, and its sealing problem has long been effectively solved. A leading domestic automotive testing platform published an article on October 20, 2023, titled "Unlocking Battery Thermal Management Technology: A Comparison of Four Cooling Technologies." The article introduced the four current battery cooling technologies, including air cooling, liquid cooling, phase change material cooling, and thermoelectric cooling. In the second part of the liquid cooling section—immersion liquid cooling—the article detailed the technology of completely immersing the battery in coolant. The article also revealed the following two key points through text and images: ① Immersion liquid cooling mainly uses insulating oil and fluorinated liquid as coolants, meaning that the coolant will not cause the battery to short-circuit; ② As shown in the attached diagram, the battery transmits power to the outside through copper busbars, which are sealed through the external liquid storage container, preventing leakage. Therefore, it can be concluded that immersing the battery in coolant will not affect the electrical connection between the battery and external components. Summary of the Invention

[0006] Therefore, it is necessary to provide a fully immersion heat dissipation device to solve the problem that large pressure fluctuations inside the cooling system are not conducive to maintaining a stable heat dissipation range for power components such as chips.

[0007] The fully immersion heat dissipation device provided in this application is used to dissipate heat from one or more power components. The device includes a main chamber, a balancing channel, a telescopic cavity, and a condensation assembly. The balancing channel connects the main chamber and the telescopic cavity, forming a sealed cavity free of non-condensable gases. The sealed cavity is filled with a liquid working fluid, with at least the heating surface of the power component immersed in it. The condensation assembly has a condensation surface located at the upper end of the main chamber. When the liquid working fluid in the sealed cavity vaporizes, the gaseous working fluid can force the liquid working fluid in the main chamber into the telescopic cavity through the balancing channel, causing the telescopic cavity to expand. When the gaseous working fluid rises and contacts the condensation surface, it liquefies, and the liquid working fluid in the telescopic cavity can enter the main chamber through the balancing channel.

[0008] In one embodiment, the fully immersion heat dissipation device further includes a sub-chamber, a telescopic cavity is installed inside the sub-chamber, the sub-chamber is connected to the external space, and the sub-chamber is a rigid structure.

[0009] In one embodiment, the sub-chamber is provided with an adjusting baffle that can be adjusted to move toward or away from the telescopic cavity to increase or decrease the maximum expansion space of the telescopic cavity within the sub-chamber.

[0010] In one embodiment, the fully immersion heat dissipation device further includes a power element, a pressure sensor, and a controller. The pressure sensor is disposed in the sealed cavity, the power element is disposed on the side of the adjusting baffle away from the telescopic cavity, and the controller can control the power element to drive the adjusting baffle to move toward or away from the telescopic cavity according to the pressure value of the working medium in the sealed cavity measured by the pressure sensor, so as to adjust the pressure of the working medium in the sealed cavity.

[0011] In one embodiment, the main chamber and the auxiliary chamber are distributed along the same horizontal plane, or the main chamber and the auxiliary chamber are distributed along the same vertical direction.

[0012] In one embodiment, the fully immersion heat dissipation device further includes a second liquid pump and a jet pipe assembly, both of which are disposed in the main chamber. The second liquid pump can drive the jet pipe assembly to spray liquid working fluid toward the heating surface of the power element, so that the liquid working fluid forms a liquid flow on the heating surface of the power element.

[0013] In one embodiment, there are multiple power elements, which are spaced apart in the main chamber. The injection pipe assembly includes a main pipe, branch pipes, and nozzles. One end of the main pipe is connected to a second liquid pump, and the other end is connected to each branch pipe. The nozzles are located at the ends of the corresponding branch pipes away from the main pipe. Each power element has at least one nozzle, so that the liquid working fluid can be sequentially sprayed onto the heating surface of the corresponding power element through the main pipe, branch pipes, and nozzles.

[0014] In one embodiment, the nozzle has a plurality of arrayed nozzles, the spray direction of which is perpendicular to the heating surface of the power element, or the spray direction of which is inclined relative to the heating surface of the power element.

[0015] In one embodiment, the telescopic cavity is a flexible structure with a built-in return spring, and the spring constant is a fixed value.

[0016] In one embodiment, the telescopic cavity is an elastic bag or a corrugated tube.

[0017] In one embodiment, the vertical height of the telescopic cavity is greater than the vertical height of the main chamber, and the liquid working fluid in the telescopic cavity can flow back into the main chamber by gravity.

[0018] In one embodiment, the power element is embedded in the bottom or side wall of the main chamber, the heating surface of the power element is exposed inside the main chamber and completely immersed in the liquid working fluid of the main chamber, and the external terminals of the power element are located outside the main chamber.

[0019] In one embodiment, the power element is completely submerged in the main chamber, and the connecting wires of the power element are sealed through the inner wall of the main chamber.

[0020] In one embodiment, the distance A between the condensation assembly and the top surface of the main chamber inner wall satisfies 1mm≤A≤5mm.

[0021] Compared with existing technologies, the fully immersion heat dissipation device provided in this application actively compensates for volume changes caused by the phase change of the working fluid through the volume adjustment function of the telescopic cavity, thereby stabilizing the system pressure within a set threshold range. The sealed cavity filled with working fluid eliminates external environmental pressure interference, and the balance channel ensures the directional flow of the liquid working fluid, forming a closed-loop pressure regulation system.

[0022] Through the above technical solution, this application effectively suppresses pressure fluctuations during the working fluid phase change process, keeping the boiling point of the liquid working fluid stable. The heat continuously generated by the power components can be promptly converted into the latent heat of the working fluid phase change, avoiding performance degradation caused by excessively high local temperatures. The elastic deformation characteristics of the telescopic cavity enable adaptive pressure regulation, effectively maintaining the stable operation of the fully immersion heat dissipation device. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A partial structural schematic diagram of a fully immersion heat dissipation device according to an embodiment of this application;

[0025] Figure 2 A partial structural schematic diagram of a fully immersion heat dissipation device according to another embodiment of this application;

[0026] Figure 3 A partial structural schematic diagram of a fully immersion heat dissipation device according to another embodiment of this application;

[0027] Figure 4 A partial structural schematic diagram of a fully immersion heat dissipation device according to another embodiment of this application;

[0028] Figure 5 A schematic diagram of a nozzle structure according to an embodiment provided in this application.

[0029] Reference numerals: 100, power element; 110, heating surface; 200, main chamber; 300, balance channel section; 400, auxiliary chamber; 410, telescopic cavity; 420, adjusting baffle; 500, condensation assembly; 510, liquid cooling plate; 511, condensation surface; 600, pressure sensor; 700, second liquid pump; 800, injection pipe assembly; 810, main pipe; 820, branch pipe; 830, nozzle; 831, nozzle hole. Detailed Implementation

[0030] Please see Figures 1-5 This application provides a fully immersion heat dissipation device for cooling one or more power components 100. The power components 100 can be various heat-generating components such as PCB boards, chips, IGBT modules, gallium nitride modules, silicon carbide modules, motors, or batteries. The fully immersion heat dissipation device includes a main chamber 200, a balancing channel section 300, a telescopic cavity 410, and a condensation assembly 500. One end of the balancing channel section 300 is connected to the lower end of the main chamber 200, preferably the bottom of the main chamber 200. Alternatively, it can be connected to the middle region of the main chamber 200 in the height direction, as long as it ensures that the liquid working fluid enters the balancing channel section 300 preferentially over the gaseous working fluid. The other end is connected to the telescopic cavity 410. The main chamber 200, the balancing channel section 300, and the telescopic cavity 410 are connected to form a sealed cavity, which is a cavity free of non-condensable gases (mainly air and other impurity gases).

[0031] The sealed cavity contains a liquid working medium. Preferably, the liquid working medium fills the main chamber 200. The power element 100 is embedded in the bottom wall or side wall of the main chamber 200. The heating surface 110 of the power element 100 is exposed inside the main chamber 200 and completely immersed in the liquid working medium of the main chamber 200. The external wiring terminal of the power element 100 is located outside the main chamber 200. Alternatively, the power element 100 is completely immersed inside the main chamber 200. The connecting wire of the power element 100 is sealed through the inner wall of the main chamber 200. Regardless of the installation method, it can be ensured that at least the heating surface 110 of the power element 100 is immersed in the liquid working medium.

[0032] Specifically, when the power element 100 is embedded in the bottom or side wall of the main chamber 200, the heating surface 110 is directly exposed to the liquid working fluid. Efficient heat dissipation is achieved through the phase change absorption of the liquid working fluid. The external wiring terminals are located outside the main chamber 200 to avoid short-circuit risks caused by contact between the liquid working fluid and external circuits. When the power element 100 is completely submerged in the main chamber 200, the connecting wires are led out to the outside through a sealed installation method. This ensures that the non-condensable gas environment of the sealed cavity is not disrupted, while maintaining direct contact between the power element 100 and the liquid working fluid, thus improving heat dissipation efficiency.

[0033] Compared with existing technologies, this application ensures direct contact between the power element 100 and the liquid working fluid through embedding or sealed penetration, while simplifying the sealing structure and avoiding pressure fluctuations due to seal failure. Furthermore, existing technologies do not specify the installation position and sealing method of the power element 100, resulting in insufficient heat dissipation stability. This application, however, ensures stable pressure in the sealed cavity by defining the installation position and sealing process.

[0034] It should be noted that the power component 100 (e.g., PCB board) can be installed and fixed inside the main chamber 200 by being snapped into a slot in the inner wall of the main chamber 200.

[0035] The condensing assembly 500 is provided with a condensing surface 511, which is located at the upper end of the main chamber 200. It should be noted that "upper end" refers to the relatively high point in the vertical direction. Specifically, in one embodiment, the condensing assembly 500 includes a liquid-cooled plate 510, a first liquid pump (not shown), and a condenser (not shown). The liquid-cooled plate 510 is disposed within the main chamber 200 and is connected to the condenser via the first liquid pump. Gaseous working fluid can be adsorbed onto the surface of the liquid-cooled plate 510 and transfer heat to it, thus heating the coolant within the liquid-cooled plate 510. The coolant is then pumped into the condenser by the first liquid pump, releasing heat, and finally returns to the liquid-cooled plate 510. Of course, to further improve heat dissipation efficiency, the condensing assembly 500 may also include a compressor and a throttle valve, using the compressor and throttle valve for direct cooling to lower the coolant temperature. Furthermore, it should be noted that the top surfaces of the condensing assembly 500 and the inner wall of the main chamber 200 are spaced apart, and the distance A between them satisfies 1mm ≤ A ≤ 5mm. In another embodiment, the condensing assembly 500 can also be part of the upper cover of the main chamber 200. Specifically, the condensing assembly 500 is embedded in the upper cover of the main chamber 200, with its condensing surface 511 exposed to the main chamber 200 and in contact with the working fluid. The other end of the condensing assembly 500 is provided with heat dissipation fins and exposed to the atmospheric environment. Regardless of the form, the heat generated during the liquefaction process of the gaseous working fluid can be quickly transferred out of the main chamber 200, facilitating the rapid liquefaction of the gaseous working fluid.

[0036] It should be noted that the coolant can be a variety of refrigerants such as deionized pure water, ethanol, R1233ZD(E) or R1233ZD(Z).

[0037] When the heat generated by the power element 100 is insufficient to vaporize the liquid working fluid, or when the power element 100 is in a stopped state, the liquid working fluid in the sealed cavity is in an unvaporized state, and the telescopic cavity 410 is in a compressed state; that is, the liquid working fluid will not expand the telescopic cavity 410, or at least will not cause the telescopic cavity 410 to be in its most expanded state. When the liquid working fluid in the sealed cavity absorbs the heat generated by the power element 100 and vaporizes into a gaseous working fluid, the gaseous working fluid can force the liquid working fluid in the main chamber 200 into the telescopic cavity 410 through the balance channel 300, causing the telescopic cavity 410 to expand under the filling of the liquid working fluid. When the gaseous working fluid rises and contacts the condensation surface 511, the gaseous working fluid can re-liquefy into a liquid working fluid, and at this time, the liquid working fluid in the telescopic cavity 410 can re-enter the main chamber 200 through the balance channel 300.

[0038] Specifically, the heat generated when the power element 100 operates causes the liquid working fluid to boil and vaporize. The expansion of the gaseous working fluid pushes the liquid working fluid in the main chamber 200 through the balance channel 300 into the telescopic cavity 410. The telescopic cavity 410 undergoes elastic deformation under hydraulic pressure, expanding its volume and preventing a sharp rise in pressure inside the sealed cavity. When the gaseous working fluid rises to the surface of the condenser assembly 500, it exchanges heat with the coolant and re-liquefies. The liquid working fluid then flows back into the main chamber 200 under gravity. When the amount of gaseous working fluid decreases, causing a pressure drop, the liquid working fluid returns to the main chamber 200, maintaining a dynamic pressure balance within the cavity.

[0039] It should be noted that the rapid heat dissipation of the power element 100 mainly utilizes the latent heat of vaporization characteristic of the working fluid. Specifically, latent heat refers to the heat absorbed or released by a substance during a phase change from one phase to another under constant temperature conditions. Therefore, the latent heat of vaporization refers to the heat absorbed by the working fluid at the moment of vaporization phase change. Taking pure water as an example, without phase change, 1 kg of pure water absorbs 420 kJ of heat when it rises from 0℃ to 100℃. However, the temperature difference before and after cooling of the power element 100, such as the chip, is about 5-6℃. Therefore, the heat absorbed by 1 kg of pure water when its temperature rises by 5℃-6℃ is between 21 kJ and 25.2 kJ. Correspondingly, when 1 kg of pure water changes from a liquid state at its boiling point to a gaseous state at its boiling point, it can absorb 2260 kJ of heat. Obviously, the heat absorption capacity of the latter is nearly 100 times that of the former. That is, the phase change of the working fluid in this application can absorb a huge amount of heat. In other words, water absorbs relatively little heat before the phase change, but absorbs a huge amount of heat at the moment of the phase change.

[0040] Compared with existing technologies, this solution actively compensates for volume changes caused by the phase change of the working fluid through the volume adjustment function of the telescopic cavity 410, thus stabilizing the system pressure within the set threshold range. The sealed cavity filled with working fluid eliminates external environmental pressure interference, and the balance channel 300 ensures the directional flow of the liquid working fluid, forming a closed-loop pressure regulation system.

[0041] Through the above technical solution, this application effectively suppresses pressure fluctuations during the working fluid phase change process, keeping the boiling point of the liquid working fluid stable. The heat continuously generated by the power element 100 can be converted into the latent heat of the working fluid phase change in a timely manner, avoiding performance degradation caused by excessively high local temperatures. The elastic deformation characteristics of the telescopic cavity 410 enable adaptive pressure regulation, effectively maintaining the stable operation of the fully immersion heat dissipation device.

[0042] In one embodiment, the telescopic cavity 410 possesses a certain elastic recovery capability. Specifically, the telescopic cavity 410 is a flexible structure with a built-in return spring, facilitating the re-pressurization of the liquid working fluid into the main chamber 200. Furthermore, the spring constant is a fixed value. The flexible structure with a built-in return spring refers to a cavity made of elastic material with an integrated spring. The spring constant is a fixed value, which can be achieved using a helical spring made of metal or polymer material. Pressure changes are absorbed or released through the elastic deformation of the spring. In some specific embodiments, the spring constant can be selected as a fixed value, for example, within the range of 1 N / mm to 5 N / mm.

[0043] However, this is not the only possibility. In other embodiments, the telescopic cavity 410 can also be a structure with its own tension, such as an elastic bag or a corrugated tube. An elastic bag refers to a telescopic, sealed container made of rubber or silicone, and a corrugated tube refers to a metal or plastic tube with a folded structure. Both adapt to changes in cavity volume through the deformation capacity of the material itself. In some specific embodiments, the wall thickness of the elastic bag can be set to, for example, 0.5 mm to 2 mm, and the number of folds in the corrugated tube can be, for example, 2 to 8 layers.

[0044] In another embodiment, the telescopic cavity 410 can also be an inelastic flexible bag. The vertical height of the telescopic cavity 410 is greater than the vertical height of the main chamber 200, and the liquid working fluid inside the telescopic cavity 410 can flow back into the main chamber 200 by gravity. The vertical height being greater than the main chamber 200 means that a height difference exists between the telescopic cavity 410 and the main chamber 200. This can be achieved by installing the telescopic cavity 410 above the main chamber 200, utilizing the gravitational potential energy of the liquid working fluid to drive its flow. In some specific embodiments, for the height difference design, the vertical distance between the bottom of the telescopic cavity 410 and the top of the main chamber 200 can be set, for example, from 50mm to 200mm.

[0045] Specifically, when the liquid working fluid in the sealed cavity is heated and vaporized, the gaseous working fluid pushes the liquid working fluid in the main chamber 200 into the telescopic cavity 410. If the telescopic cavity 410 is a flexible structure with a built-in return spring, the fixed elastic coefficient of the spring can provide a stable restoring force, allowing the cavity to automatically contract after expansion and maintain pressure balance; if it is an elastic bag or bellows, its deformation characteristics can absorb volume changes and avoid sudden pressure changes; if the telescopic cavity 410 is higher vertically, the liquid working fluid will automatically flow back to the main chamber 200 by gravity after the vaporization pressure disappears, without the need for additional power.

[0046] Compared to existing technologies, pressure fluctuations in the cooling system in existing solutions lead to instability in the boiling point of the working fluid. This solution, however, actively regulates the volume change of the liquid working fluid and suppresses pressure fluctuations through the elastic deformation of the telescopic cavity 410 or a gravity reflux mechanism. For example, pressure fluctuations in existing technologies can reach ±2 kPa, while this solution can control the fluctuation range within ±0.5 kPa, reducing the boiling point change of the working fluid from ±2℃ in existing technologies to ±0.5℃.

[0047] Through the above technical solution, this application solves the problem of unstable heat dissipation efficiency caused by internal pressure fluctuations in the cooling system. The fixed elastic coefficient of the return spring or the deformation characteristics of the elastic bag can precisely control the cavity volume compensation capability, ensuring that the working fluid phase change temperature remains stable; the height difference design utilizes gravity to achieve automatic circulation of the liquid working fluid, avoiding backflow delay caused by pressure imbalance, thereby ensuring continuous and efficient heat dissipation.

[0048] In one embodiment, such as Figures 1-4 As shown, the fully immersion heat dissipation device also includes a secondary chamber 400, and a telescopic cavity 410 is installed inside the secondary chamber 400. The secondary chamber 400 is connected to the external space (mainly referring to the atmospheric environment). Furthermore, the secondary chamber 400 is a rigid structure. It should be noted that a rigid structure does not refer to hardness, but rather to the fact that the secondary chamber 400 cannot be compressed or expanded, thereby limiting the maximum expansion space of the telescopic cavity 410.

[0049] Specifically, the rigid structure of the secondary chamber 400 can resist the internal pressure generated by the expansion of the telescopic cavity 410, thus limiting the maximum expansion space of the telescopic cavity 410 and preventing excessive deformation of the telescopic cavity 410 from obstructing the backflow of the liquid working fluid. When the pressure of the gaseous working fluid in the sealed cavity increases, the characteristic of the secondary chamber 400 communicating with the outside can quickly release excess pressure, preventing the pressure from continuing to rise and causing the boiling point of the working fluid to shift. At the same time, the rigid secondary chamber 400 provides fixed support for the telescopic cavity 410, ensuring that its expansion and contraction process always proceeds in the predetermined direction, and avoiding uneven distribution of the liquid working fluid caused by the displacement of the telescopic cavity 410.

[0050] Specifically, in one embodiment, such as Figure 1As shown, the auxiliary chamber 400 and the main chamber 200 can be separately configured. In this case, the balancing channel 300 connects the telescopic cavity 410 of the auxiliary chamber 400 and the main chamber 200 as a pipeline. Obviously, this configuration can improve the assembly flexibility between the main chamber 200 and the auxiliary chamber 400.

[0051] In another embodiment, such as Figures 2-4 As shown, the secondary chamber 400 and the main chamber 200 can also be integrated, that is, a single box is divided into the main chamber 200 and the secondary chamber 400 by a partition. In this case, the balancing channel 300 serves as a through hole in the partition, connecting the telescopic cavity 410 and the main chamber 200. Obviously, this arrangement greatly improves the integration of the fully immersive heat dissipation device.

[0052] In one embodiment, such as Figures 1-2 As shown, the main chamber 200 and the auxiliary chamber 400 are distributed along the same horizontal plane, that is, the auxiliary chamber 400 is distributed on one side of the main chamber 200 along the horizontal direction. In this case, the telescopic cavity 410 can be distributed above, below, or in the middle of the auxiliary chamber 400 along the vertical direction. The distribution along the same horizontal plane means that the main chamber 200 and the auxiliary chamber 400 are at the same height in the horizontal direction. This can be achieved by fixing them with rigid connectors or support frames. This layout can simplify the flow path of the liquid working medium inside the sealed cavity and reduce energy loss during pressure transmission.

[0053] In another embodiment, such as Figures 3-4 As shown, the main chamber 200 and the auxiliary chamber 400 are positioned at different heights. Preferably, the main chamber 200 and the auxiliary chamber 400 are distributed along the same vertical direction, that is, the auxiliary chamber 400 is distributed on one side of the main chamber 200 along the vertical direction. In this case, the telescopic cavity 410 can be distributed above, below, or in the middle of the auxiliary chamber 400 along the vertical direction. Of course, in other embodiments, the main chamber 200 and the auxiliary chamber 400 can also be arranged obliquely along the vertical direction, for example, the auxiliary chamber 400 is located diagonally above the main chamber 200, etc., which will not be listed here. The distribution along the same vertical direction means that the main chamber 200 and the auxiliary chamber 400 are arranged vertically, which can be achieved by vertical supports or layered structures. This layout can utilize gravity to promote the natural flow of the liquid working medium between the main chamber 200 and the telescopic cavity 410, reducing pressure fluctuations caused by obstructed backflow of the liquid working medium.

[0054] Compared with the prior art, this application can select the layout of the main chamber 200 and the auxiliary chamber 400 according to the actual installation space requirements. In the horizontal distribution scenario, it simplifies the system structure and improves the pressure response speed. In the vertical distribution scenario, it utilizes gravity to optimize the circulation efficiency of the liquid working fluid, thereby maintaining the dynamic balance of pressure in the sealed cavity under various application environments and ensuring the stable heat dissipation performance of the power element 100.

[0055] It should be noted that when the auxiliary chamber 400 is located above the main chamber 200, the balance channel 300 needs to extend downward from the telescopic cavity 410 and connect to the bottom area of ​​the main chamber 200 to prevent the gaseous working fluid from entering the telescopic cavity 410 through the balance channel 300.

[0056] Additionally, it should be noted that when the secondary chamber 400 is located below the main chamber 200, and the telescopic cavity 410 is located below the secondary chamber 400, the balancing channel 300 needs to extend downwards from the bottom of the main chamber 200 and connect to the telescopic cavity 410. Since the telescopic cavity 410 is located at the lower end or bottom of the secondary chamber 400, the balancing channel 300 needs to extend downwards from the bottom of the main chamber 200 and connect to the bottom of the telescopic cavity 410. This allows the telescopic cavity 410 to freely expand and contract within the secondary chamber 400. If the balancing channel 300 extends downwards from the bottom of the main chamber 200 and connects to the top of the telescopic cavity 410, it will restrict the expansion and contraction of the telescopic cavity 410. Alternatively, the balancing channel 300 needs to be made into a flexible structure.

[0057] In one embodiment, such as Figure 4 As shown, the sub-chamber 400 is provided with an adjusting baffle 420. The adjusting baffle 420 is movably disposed relative to the inner wall of the sub-chamber 400. Furthermore, the adjusting baffle 420 can be movably adjusted in the direction of approaching or moving away from the telescopic cavity 410 to increase or decrease the maximum expansion space of the telescopic cavity 410 within the sub-chamber 400. In other words, the adjusting baffle 420 is used to adjust the maximum expansion volume of the telescopic cavity 410 within the sub-chamber 400. Thus, the boiling point of the liquid working fluid can be adjusted according to the different operating temperature ranges of the power element 100.

[0058] Specifically, when the operating temperature range of the power element 100 is below 20°C, the maximum expansion space of the telescopic cavity 410 within the secondary chamber 400 can be appropriately increased. Since the total amount of liquid working fluid remains constant, this design reduces the maximum pressure within the entire sealed cavity, thereby lowering the boiling point of the liquid working fluid within the sealed cavity, allowing it to begin boiling at around 20°C. Conversely, when the operating temperature range of the power element 100 is below 25°C, the maximum expansion space of the telescopic cavity 410 within the secondary chamber 400 can be appropriately reduced. Since the total amount of liquid working fluid remains constant, this design increases the maximum pressure within the entire sealed cavity, thereby increasing the boiling point of the liquid working fluid within the sealed cavity, allowing it to begin boiling only at around 25°C. In summary, this design allows the fully immersion heat dissipation device to be adapted to various power elements 100 operating in different temperature ranges, greatly improving the versatility and convenience of the fully immersion heat dissipation device.

[0059] It should be noted that the working fluid is a thermally conductive but non-electrically conductive insulating liquid. Specifically, the working fluid can be various novel refrigerants such as R1233ZD(E) or R1233ZD(Z). R1233ZD(E) and R1233ZD(Z) are two isomers of 1-chloro-3,3,3-trifluoropropene, differing mainly in the cis / trans (Z / E) configuration of the double bond in their molecular structures. Specifically, R1233ZD(E) is the trans isomer, with a more stable molecular structure. R1233ZD(Z) is the cis isomer, with slightly higher molecular polarity. Specifically, the boiling point of R1233ZD(E) is approximately 18.3℃, and the boiling point of R1233ZD(Z) is approximately 38℃.

[0060] Specifically, in one embodiment, the adjusting partition 420 can be a movable plate structure separately disposed within the sub-chamber 400. Specifically, the adjusting partition 420 is provided with a flange (not shown), the flange is provided with a fixing hole (not shown), and the side wall of the sub-chamber 400 is provided with a linearly arranged adjusting groove (not shown) (along the direction toward or away from the telescopic cavity 410). Fasteners (not shown) can be sequentially inserted into the fixing hole and the adjusting groove to fix the adjusting partition 420 at any position in the adjusting groove, thereby realizing the adjustment of the maximum expansion space of the telescopic cavity 410 within the sub-chamber 400.

[0061] In another embodiment, the adjusting baffle 420 may be the side wall of the sub-chamber 400 away from the telescopic cavity 410. That is, the side wall of the sub-chamber 400 away from the telescopic cavity 410 is movably configured to form the adjusting baffle 420 relative to the main body of the sub-chamber 400.

[0062] Furthermore, in one embodiment, as Figure 4As shown, the fully immersion cooling device also includes a power element (not shown), a pressure sensor 600, and a controller (not shown). The pressure sensor 600 is located inside the telescopic cavity 410, or it can be located in other positions within the sealed cavity, such as the balance channel 300 or the main chamber 200. The connecting wire of the pressure sensor 600 is sealed through the inner wall of the sealed cavity and connected to the controller. The power element (which can be a motor or cylinder) is located on the side of the adjusting baffle 420 away from the telescopic cavity 410. The power element and the pressure sensor 600 are electrically connected to the controller. The controller can control the power element to drive the adjusting baffle 420 to move towards or away from the telescopic cavity 410 based on the pressure value of the working fluid in the sealed cavity measured by the pressure sensor 600, thereby adjusting the pressure of the working fluid in the sealed cavity and stabilizing the working fluid pressure. This prevents the working fluid pressure from fluctuating with changes in the volume of the gaseous working fluid, i.e., controlling the boiling point of the working fluid to be stable.

[0063] Specifically, when the power element 100 heats up, causing the liquid working fluid to vaporize, the pressure inside the sealed cavity rises, triggering the pressure sensor 600 to generate a detection signal. Upon receiving this signal, the controller uses a power element to push the adjusting baffle 420 away from the telescopic cavity 410, thereby increasing the volume within the secondary chamber 400 available for the expansion of the telescopic cavity 410. At this time, the gaseous working fluid pushes the liquid working fluid into the expanded telescopic cavity 410, effectively reducing the pressure inside the sealed cavity. When the gaseous working fluid condenses and liquefies, causing a pressure drop, the controller reverses the flow, driving the adjusting baffle 420 to compress the expansion space, causing the liquid working fluid to flow back to the main chamber 200 to maintain pressure balance.

[0064] Compared with existing technologies, this solution utilizes a closed-loop control mechanism of real-time monitoring by the pressure sensor 600 and active adjustment by the power element. This mechanism dynamically compensates for pressure fluctuations during the working fluid phase change process, overcoming the shortcomings of traditional solutions such as lag and insufficient accuracy in pressure regulation. Furthermore, through the above technical solution, this application ensures that the cooling working fluid is always maintained within the saturation pressure range corresponding to its phase change temperature. This guarantees that the heat generated by the power element 100 can be continuously dissipated through stable latent heat of phase change, avoiding a decrease in heat dissipation efficiency or runaway heat dissipation temperature of the power element 100 due to pressure fluctuations.

[0065] To effectively address the issues of high heat generation from the power element 100 and the limited cooling capacity of existing single-phase or two-phase immersion cooling systems, we employ a dual-flow enhancement approach (natural convection generated by the heating and cooling effect + forced convection from the jet tube assembly 800). This significantly improves the cooling effect of local hot spots (heating surface 110 of the power element 100). If only natural convection is used, the heat transfer coefficient of the heating surface 110 of the power element 100 is only between 0.6 W / (cm²×K) and 1.3 W / (cm²×K), with a critical heat flux density of approximately 12 W / cm². However, by surface-treating the heating surface 110 of the power element 100 and adding fins, the heat transfer coefficient can be increased by 3 to 5 times, reaching 2 W / (cm²×K) to 4 W / (cm²×K), with the critical heat flux density falling within the range of 20 W / cm² to 50 W / cm². Whether it's natural convection or surface treatment and finning of the heating surface 110 of the power element 100, the heat transfer coefficient is still far from our required 300W / (cm²×K). If our target chip (heat flux density of 2500W / cm²) is immersed in the working fluid, the heat dissipation requirements cannot be met.

[0066] Therefore, in one embodiment, as Figures 1-4 As shown, the fully immersion cooling device also includes a second liquid pump 700 and a jet pipe assembly 800. Both the second liquid pump 700 and the jet pipe assembly 800 are disposed within the main chamber 200. Furthermore, the power cable of the second liquid pump 700 is sealed and passes through the inner wall of the main chamber 200 to connect to an external power source. The second liquid pump 700 can drive the jet pipe assembly 800 to spray liquid working fluid toward the heating surface 110 of the power element 100, so that the liquid working fluid forms a liquid flow on the heating surface 110 of the power element 100.

[0067] It should be noted that if the liquid working fluid in the entire main chamber 200 is disturbed over a large area by the second liquid pump 700, its heat dissipation enhancement effect on the power element 100 is relatively limited. However, this application uses the second liquid pump 700 to drive the spray pipe assembly 800 to spray liquid working fluid toward the heating surface 110 of the power element 100, which can greatly increase the heat transfer coefficient, which can reach 300W / (cm²×K) after optimization.

[0068] Specifically, when the power element 100 generates heat, and when the phase change of the working fluid reaches a certain level (this is important; if the jetting starts too early, it will delay the initiation of the phase change. The heating surface 110 must be much higher than its boiling point to generate phase change cooling; before this, it will be single-phase liquid cooling without phase change, and the heat transfer coefficient will be smaller than that of phase change), the second liquid pump 700 starts and draws the liquid working fluid from the main chamber 200. The liquid working fluid is then sprayed onto the surface of the heating surface 110 at a specific flow rate through the injection pipe assembly 800. After impacting the heating surface 110, the liquid working fluid forms a flowing liquid film covering the entire heating surface 110. During the flow, the liquid working fluid absorbs heat and undergoes phase change vaporization. At the same time, the flowing liquid film continuously carries away the bubbles accumulated near the heating surface 110, preventing the formation of localized overheating areas.

[0069] Compared with existing technologies, this solution not only enhances the convective heat transfer efficiency by forming a forced liquid flow through active injection, but also breaks the gas film layer through fluid shear force, so that the liquid working fluid always maintains full contact with the heating surface 110.

[0070] Furthermore, in one embodiment, as Figures 1-4 As shown, there are multiple power elements 100, which are spaced apart within the main chamber 200. The injection pipe assembly 800 includes a main pipe 810, branch pipes 820, and nozzles 830. One end of the main pipe 810 is connected to the second liquid pump 700, and the other end is connected to each branch pipe 820. The nozzles 830 are located at the end of the corresponding branch pipe 820 away from the main pipe 810. Each power element 100 has at least one corresponding nozzle 830, so that the liquid working fluid is sequentially sprayed through the main pipe 810, branch pipes 820, and nozzles 830 onto the heating surface 110 of the corresponding power element 100.

[0071] Specifically, multiple power components 100 are arranged at intervals within the main chamber 200. After the second liquid pump 700 is started, it drives the liquid working fluid into the main pipe 810. The main pipe 810 distributes the working fluid to various branch pipes 820. The nozzle 830 at the end of each branch pipe 820 directly sprays the working fluid onto the heating surface 110 of the corresponding power component 100. Since each power component 100 is equipped with at least one independent nozzle 830, the coverage area of ​​the working fluid spray corresponds to the spatial distribution of the power components 100, thereby ensuring that all heating areas can receive directional cooling. When some power components 100 have a high heat load, the corresponding nozzle 830 can achieve localized enhanced heat dissipation by increasing the spray flow rate.

[0072] Compared with the prior art, this application realizes directional jet cooling of multiple power components 100, avoiding local overheating caused by differences in heat load. At the same time, it maintains the dynamic balance of working fluid pressure in the sealed cavity through independent liquid supply path, so that the phase change heat dissipation process can continue under stable pressure environment.

[0073] Furthermore, in one embodiment, as Figure 5 As shown, the nozzle 830 is provided with a plurality of arrayed nozzles 831. The spray direction of the nozzles 831 is perpendicular to the heating surface 110 of the power element 100, or the spray direction of the nozzles 831 is inclined relative to the heating surface 110 of the power element 100.

[0074] Specifically, when the second liquid pump 700 drives the liquid working medium into the injection pipe assembly 800, the liquid working medium is diverted through the main pipe 810 to each branch pipe 820, and finally ejected from the array of nozzles 831 in the nozzle 830. When the nozzles 831 are vertically arranged, the liquid working medium directly impacts the heating surface 110 of the power element 100, forming a high-velocity liquid film coverage area; when the nozzles 831 are inclined, the liquid working medium flows tangentially along the heating surface 110, flushing away bubbles attached to the heating surface 110 and accelerating their removal. The array of nozzles 831 can cover different positions of the heating surface 110, avoiding local overheating due to injection blind spots.

[0075] Compared with the prior art, this application solves the problem of reduced heat dissipation efficiency of high-density power components 100 due to uneven spray coverage. It achieves uniform distribution of liquid working fluid through array-type nozzles 831 and adjustable spray direction, ensuring that heat can be carried away by liquid flow in each area of ​​the heating surface 110, while accelerating bubble detachment to maintain a stable phase change heat dissipation environment.

[0076] When the power element 100 is a chip, a flow rate of 10L / min-20L / min provided by the jet tube assembly 800 is sufficient. This is because the chip occupies very little space, and with multiple nozzles 830, the jet velocity of the nozzles 830 can quickly exceed 1m / s-2m / s. Furthermore, it can also cool other surfaces of the heat dissipation substrate of the chip package, such as the four sidewalls, enabling them to effectively participate in heat exchange. This is also a key point of the immersion phase change cooling of this application.

[0077] It should be noted that the second liquid pump 700 can be installed in the main chamber 200 or the auxiliary chamber 400. When the second liquid pump 700 is installed in the auxiliary chamber 400, the auxiliary chamber 400 can be divided into a space for accommodating the telescopic cavity 410 and a space for accommodating the second liquid pump 700. The two spaces of the auxiliary chamber 400 are separated, but the space of the auxiliary chamber 400 that accommodates the second liquid pump 700 is connected to the main chamber 200.

[0078] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

[0080] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0081] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0082] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0083] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0084] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0085] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A fully immersion heat dissipation device, characterized in that, For dissipating heat from one or more power components (100), the fully immersion heat dissipation device includes a main chamber (200), a balancing channel (300), a telescopic cavity (410), and a condensation assembly (500). The balancing channel (300) connects the main chamber (200) and the telescopic cavity (410), defining the main chamber (200), the balancing channel (300), and the telescopic cavity (410) as a sealed cavity free of non-condensable gases. The sealed cavity is filled with liquid working fluid, and at least the heating surface (110) of the power element (100) is immersed in the liquid working fluid. The condensation assembly (500) is provided with a condensation surface (511), which is located at the upper end of the main chamber (200). When the liquid working fluid in the sealed cavity vaporizes, the gaseous working fluid can push the liquid working fluid in the main chamber (200) into the telescopic cavity (410) through the balance channel (300) and cause the telescopic cavity (410) to expand. When the gaseous working fluid rises and contacts the condensation surface (511), the gaseous working fluid can liquefy into liquid working fluid. The liquid working fluid in the telescopic cavity (410) can enter the main chamber (200) through the balance channel (300).

2. The fully immersion heat dissipation device according to claim 1, characterized in that, It also includes a sub-chamber (400), the telescopic cavity (410) is installed inside the sub-chamber (400), the sub-chamber (400) is connected to the external space, and the sub-chamber (400) is a rigid structure.

3. The fully immersion heat dissipation device according to claim 2, characterized in that, The sub-chamber (400) is provided with an adjusting baffle (420), which can be adjusted to move towards or away from the telescopic cavity (410) to increase or decrease the maximum expansion space of the telescopic cavity (410) within the sub-chamber (400).

4. The fully immersion heat dissipation device according to claim 3, characterized in that, It also includes a power element, a pressure sensor (600) and a controller. The pressure sensor (600) is disposed in the sealed cavity. The power element is disposed on the side of the adjusting partition (420) away from the telescopic cavity (410). The controller can control the power element to drive the adjusting partition (420) to move toward or away from the telescopic cavity (410) according to the pressure value of the working medium in the sealed cavity measured by the pressure sensor (600), so as to adjust the pressure of the working medium in the sealed cavity.

5. The fully immersion heat dissipation device according to claim 2, characterized in that, The main chamber (200) and the auxiliary chamber (400) are distributed along the same horizontal plane, or the main chamber (200) and the auxiliary chamber (400) are distributed along the same vertical direction.

6. The fully immersion heat dissipation device according to claim 1, characterized in that, It also includes a second liquid pump (700) and a jet pipe assembly (800), both of which are disposed inside the main chamber (200). The second liquid pump (700) can drive the jet pipe assembly (800) to spray liquid working fluid toward the heating surface (110) of the power element (100), so that the liquid working fluid forms a liquid flow on the heating surface (110) of the power element (100).

7. The fully immersion heat dissipation device according to claim 6, characterized in that, The number of power elements (100) is multiple, and the multiple power elements (100) are spaced apart in the main chamber (200). The injection pipe assembly (800) includes a main pipe (810), a branch pipe (820) and a nozzle (830). One end of the main pipe (810) is connected to the second liquid pump (700), and the other end is connected to each of the branch pipes (820). The nozzle (830) is located at the end of the corresponding branch pipe (820) away from the main pipe (810). Each power element (100) has at least one corresponding nozzle (830) so that the liquid working fluid can be sprayed onto the heating surface (110) of the corresponding power element (100) through the main pipe (810), the branch pipe (820) and the nozzle (830) in sequence.

8. The fully immersion heat dissipation device according to claim 7, characterized in that, The nozzle (830) is provided with a plurality of arrayed nozzles (831). The spray direction of the nozzles (831) is perpendicular to the heating surface (110) of the power element (100), or the spray direction of the nozzles (831) is inclined relative to the heating surface (110) of the power element (100).

9. The fully immersion heat dissipation device according to claim 1, characterized in that, The telescopic cavity (410) is a flexible structure with a built-in return spring, and the elastic coefficient of the return spring is a constant value; Alternatively, the telescopic cavity (410) may be an elastic bag or a corrugated tube; Alternatively, the vertical height of the telescopic cavity (410) is greater than the vertical height of the main chamber (200), and the liquid working fluid in the telescopic cavity (410) can flow back into the main chamber (200) by gravity.

10. The fully immersion heat dissipation device according to claim 1, characterized in that, The power element (100) is embedded in the bottom wall or side wall of the main chamber (200), the heating surface (110) of the power element (100) is exposed in the main chamber (200) and completely immersed in the liquid working fluid of the main chamber (200), and the external wiring terminal of the power element (100) is located outside the main chamber (200); Alternatively, the power element (100) is completely submerged in the main chamber (200), and the connecting wires of the power element (100) are sealed through the inner wall of the main chamber (200).

11. The fully immersion heat dissipation device according to claim 1, characterized in that, The distance A between the top surface of the condenser assembly (500) and the inner wall of the main chamber (200) satisfies 1mm≤A≤5mm.

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