Thermal management device

Abstract

The present application relates to a thermal management device. The thermal management device includes a plurality of heat pipe heat exchangers nested with each other. Each heat pipe heat exchanger includes an evaporation section and a condensation section. The installation height of the condensation section is greater than that of the evaporation section. The condensation section of the inner heat pipe heat exchanger is embedded in the evaporation section of the outer heat pipe heat exchanger and can directly contact the liquid working medium in the outer evaporation section. A power element is arranged in the evaporation section of the innermost heat pipe heat exchanger and can directly contact the liquid working medium in the innermost evaporation section. Moreover, the latent heat of vaporization of the liquid working medium in the inner heat pipe heat exchanger is greater than that of the liquid working medium in the outer heat pipe heat exchanger. The thermal management device provided by the present application solves the problem that the working medium in the immersion phase change technology is prone to exceed the critical heat flux density, resulting in a decrease in the heat transfer efficiency of the working medium, and further causing overheating or even damage of the equipment.

Description

Technical Field

[0001] This application relates to the technical field of heat pipes, and particularly to a thermal management device. Background Art

[0002] As the volume of power components becomes smaller and the power density becomes higher, common heat dissipation techniques can no longer meet the heat dissipation requirements of power components.

[0003] Taking the immersion phase change technology as an example, it mainly uses the latent heat of vaporization of the working fluid to directly cool the power component, and its temperature uniformity and heat dissipation capacity are significantly improved compared with other heat dissipation methods. However, due to the existence of the critical heat flux point of nucleate boiling heat transfer, the heat dissipation capacity of the immersion phase change technology decreases instead of increasing.

[0004] It should be noted that the critical heat flux point of nucleate boiling heat transfer refers to the critical heat flux (CHF) in the boiling curve, which is the key turning point from nucleate boiling to film boiling. Specifically, after exceeding the critical heat flux, the bubble generation speed is too fast, and the bubbles merge and cover the heating surface to form a steam film (turning into film boiling). At this time, due to the poor thermal conductivity of the steam film and the fact that it will prevent the liquid from contacting the heating surface, the heat transfer coefficient of the working fluid drops sharply, and the surface temperature of the power component rises sharply, which may even cause the equipment to burn out. Summary of the Invention

[0005] Based on this, it is necessary to provide a thermal management device to solve the problem that the working fluid in the immersion phase change technology is likely to exceed the critical heat flux, resulting in a decrease in the heat transfer efficiency of the working fluid, and further causing overheating or even damage to the equipment.

[0006] The thermal management device provided by this application includes a plurality of heat pipe heat exchangers nested with each other. Each heat pipe heat exchanger includes an evaporation section and a condensation section. The installation height of the condensation section is greater than that of the evaporation section. The condensation section of the inner heat pipe heat exchanger is embedded in the evaporation section of the outer heat pipe heat exchanger and can directly contact the liquid working fluid in the outer evaporation section. The power component is arranged in the evaporation section of the innermost heat pipe heat exchanger and can directly contact the liquid working fluid in the innermost evaporation section; moreover, the latent heat of vaporization of the liquid working fluid in the inner heat pipe heat exchanger is greater than that of the liquid working fluid in the outer heat pipe heat exchanger.

[0007] In one embodiment, the number of heat pipe heat exchangers is two, which are respectively defined as the first heat pipe and the second heat pipe. The first heat pipe is provided with a first working fluid, and the second heat pipe is provided with a second working fluid. The latent heat of vaporization of the first working fluid is greater than that of the second working fluid; the first heat pipe includes a first evaporation section and a first condensation section, and the second heat pipe includes a second evaporation section and a second condensation section. The power element is disposed in the first evaporation section and can directly contact the liquid first working fluid, and the first condensation section is inserted into the second evaporation section and can directly contact the liquid second working fluid.

[0008] In one embodiment, the power element is at least partially immersed in the liquid first working fluid;

[0009] And / or, the first condensation section is at least partially immersed in the liquid second working fluid.

[0010] In one embodiment, the first heat pipe further includes a first eddy current pump disposed in the first evaporation section to enable the first working fluid in the first evaporation section to impinge-flow toward the surface of the power element;

[0011] Alternatively, the first heat pipe further includes a first stirrer disposed in the first evaporation section to enable the first working fluid in the first evaporation section to flow around the surface of the power element and form a vortex.

[0012] In one embodiment, the second heat pipe further includes a second eddy current pump disposed in the second evaporation section to enable the second working fluid in the second evaporation section to impinge-flow toward the surface of the first condensation section;

[0013] Alternatively, the second heat pipe further includes a second stirrer disposed in the second evaporation section to enable the second working fluid in the second evaporation section to flow around the surface of the first condensation section and form a vortex.

[0014] In one embodiment, the first heat pipe further includes a first spray pipe group and a first liquid pump. The first spray pipe group is disposed on the outer peripheral side of the power element, and the first liquid pump is immersed in the first working fluid and communicates with the first spray pipe group to enable the first working fluid to be sprayed onto the outer peripheral side of the power element through the first spray pipe group;

[0015] And / or, the second heat pipe further includes a second spray pipe group and a second liquid pump. The second spray pipe group is disposed on the outer peripheral side of the first condensation section, and the second liquid pump is immersed in the second working fluid and communicates with the second spray pipe group to enable the second working fluid to be sprayed onto the outer peripheral side of the first condensation section through the second spray pipe group.

[0016] In one embodiment, the first spray pipe group is in a net shape and covers the outer peripheral side of the power element. The first spray pipe group is provided with a plurality of first nozzles distributed at intervals, and the first spray pipe group can spray the first working fluid onto each heating surface of the power element through the plurality of first nozzles;

[0017] And / or, the second spray pipe group is in a net shape and covers the outer peripheral side of the first condensation section. The second spray pipe group is provided with a plurality of second nozzles distributed at intervals, and the second spray pipe group can spray the second working medium onto each heat exchange surface of the first condensation section through the plurality of second nozzles.

[0018] In one embodiment, the condensation section includes condensation flat tubes, inner condensation fins and outer condensation fins. The number of condensation flat tubes is multiple, and each condensation flat tube is respectively communicated with the evaporation section. The inner condensation fins are arranged in the corresponding condensation flat tubes, and adjacent condensation flat tubes are arranged at intervals to form a condensation gap. The outer condensation fins are arranged in the corresponding condensation gaps.

[0019] In one embodiment, in the condensation section of the same heat pipe heat exchanger, the sum of the surface areas of all the inner condensation fins is greater than the sum of the surface areas of all the outer condensation fins, or the sum of the surface areas of all the inner condensation fins is less than the sum of the surface areas of all the outer condensation fins.

[0020] In one embodiment, the condensation section further includes an upper end plate, and the upper end plate covers the upper end surfaces of all the condensation flat tubes; the upper end surface of the outer condensation fin and the upper end plate are arranged at intervals to form a first exhaust passage, so that the gas generated by the gasification of the liquid working medium around the outer condensation fin can diffuse and escape through the first exhaust passage to both ends in the length direction of the condensation gap.

[0021] In one embodiment, along one end in the length direction of the condensation gap to the other end in the length direction of the condensation gap, the distance between the upper end surface of the outer condensation fin and the upper end plate remains unchanged.

[0022] Or, along one end in the length direction of the condensation gap to the other end in the length direction of the condensation gap, the distance between the upper end surface of the outer condensation fin and the upper end plate shows an increasing or decreasing trend, and the change trends of the distances between the upper end surfaces of adjacent outer condensation fins and the upper end plate are opposite.

[0023] In one embodiment, the outer condensation fins in each condensation gap are divided into a first fin and a second fin. The first fin and the upper end plate are arranged at intervals to form a first branch passage, and the second fin and the upper end plate are arranged at intervals to form a second branch passage. The first branch passage and the second branch passage are communicated to form a first exhaust passage. The first fin and the second fin are arranged at intervals along the length direction of the condensation gap to form a second exhaust passage, and the second exhaust passage is communicated with the connection part of the first branch passage and the second branch passage.

[0024] In one embodiment, along one end of the first branch passage close to the second branch passage to the other end of the first branch passage far from the second branch passage, the distance between the upper end surface of the first fin and the upper end plate remains unchanged;

[0025] Alternatively, along the direction from the end of the first channel close to the second channel to the end of the first channel far from the second channel, the distance between the upper end surface of the first fin and the upper end plate shows an increasing trend;

[0026] And / or, along the direction from the end of the second channel close to the first channel to the end of the second channel far from the first channel, the distance between the upper end surface of the second fin and the upper end plate remains unchanged;

[0027] Alternatively, along the direction from the end of the second channel close to the first channel to the end of the second channel far from the first channel, the distance between the upper end surface of the second fin and the upper end plate shows an increasing trend.

[0028] Compared with the prior art, for the thermal management device provided by the present application, the condensation section of the inner-layer heat pipe heat exchanger is in direct contact with the liquid working medium of the outer-layer evaporation section, forming a step-by-step heat dissipation path. After the heat is transferred from the power element to the working medium of the innermost evaporation section, the working medium vaporizes and rises to the inner-layer condensation section, and the heat released by condensation is secondarily absorbed by the working medium of the outer-layer evaporation section, forming a heat gradient transfer. This design reduces the single-stage heat flux density through the staged heat dissipation of multiple layers of heat pipes, avoiding local overheating.

[0029] Since the inner-layer working medium has a higher latent heat of vaporization, it means that less steam is generated when it absorbs the same amount of heat, thereby reducing the probability of bubble coalescence to form a steam film, or delaying the occurrence of bubble coalescence to form a steam film covering the heating surface of the power element. Correspondingly, the outer-layer working medium has a lower latent heat of vaporization and can quickly vaporize to efficiently transfer the remaining heat. The synergistic effect of the two evenly disperses the heat, avoiding film boiling.

[0030] In summary, through the sealed nested design (the condensation section of the inner-layer heat pipe heat exchanger is embedded in the outer-layer evaporation section) and the configuration of the latent heat of vaporization gradient of the working medium (the latent heat of vaporization of the inner-layer working medium is greater than that of the outer layer), the heat dissipation efficiency is significantly improved, and the arrival of the critical heat flux density (CHF) is avoided or delayed. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 It is a schematic structural diagram of a thermal management device according to an embodiment provided by the present application;

[0033] Figure 2 It is a cross-sectional view of a thermal management device according to an embodiment provided by the present application;

[0034] Figure 3 Cross-sectional view of the thermal management device according to another embodiment provided by the present application;

[0035] Figure 4 Schematic structural view of the condensation section according to an embodiment provided by the present application;

[0036] Figure 5 Partial structural side view of the condensation section according to an embodiment provided by the present application;

[0037] Figure 6 Partial structural side view of the condensation section according to another embodiment provided by the present application;

[0038] Figure 7 Schematic partial structural view of the condensation section according to still another embodiment provided by the present application;

[0039] Figure 8 Partial structural side view of the condensation section according to yet another embodiment provided by the present application.

[0040] Reference numerals: 100, first heat pipe; 110, first evaporation section; 120, first condensation section; 130, first spray pipe group; 131, first nozzle; 140, first liquid pump; 200, second heat pipe; 210, second evaporation section; 220, second condensation section; 230, second spray pipe group; 231, second nozzle; 240, second liquid pump; 300, condensation flat tube; 310, condensation gap; 400, internal condensation fin; 500, external condensation fin; 510, first fin; 520, second fin; 530, second exhaust duct; 600, upper end plate; 610, first exhaust duct; 611, first branch duct; 612, second branch duct; 620, plate body; 630, plate strip; 700, power element. Detailed implementation manners

[0041] As the volume of the power element becomes smaller and smaller and the power density becomes higher and higher, the common heat dissipation technical means can no longer meet the heat dissipation requirements of the power element.

[0042] Taking the immersion phase change technology as an example, it mainly uses the latent heat of vaporization of the working medium to directly cool the power element, and its temperature uniformity and heat dissipation capacity are significantly improved compared with other heat dissipation methods. However, due to the existence of the nucleate boiling heat transfer inflection point, the heat dissipation capacity of the immersion phase change technology decreases instead of increasing.

[0043] It should be noted that the inflection point of nucleate boiling heat transfer refers to the critical heat flux (CHF) in the boiling curve, which is the key turning point from nucleate boiling to film boiling. Specifically, after exceeding the critical heat flux, the bubble generation rate is too fast, and the bubbles merge and cover the heating surface to form a steam film (turning into film boiling). At this time, due to the poor thermal conductivity of the steam film and the obstruction of the contact between the liquid and the heating surface, the heat transfer coefficient of the working fluid drops sharply, and the surface temperature of the power element rises sharply, which may even cause the equipment to burn out.

[0044] Therefore, in order to solve the problem that the working fluid in the immersion phase change technology is likely to exceed the critical heat flux, resulting in a decrease in the heat transfer efficiency of the working fluid, and further causing overheating or even damage to the equipment, the present application provides a thermal management device.

[0045] Please refer to Figures 1 - 8 , the thermal management device includes a plurality of heat pipe heat exchangers nested with each other. Each heat pipe heat exchanger includes an evaporation section and a condensation section, and the installation height of the condensation section is greater than the installation height of the evaporation section.

[0046] The design that the condensation section is higher than the evaporation section can utilize gravity to drive the liquid working fluid to flow back, ensure continuous liquid supply in the evaporation section, and maintain the stability of nucleate boiling.

[0047] The condensation section of the inner-layer heat pipe heat exchanger is embedded in the evaporation section of the outer-layer heat pipe heat exchanger and can directly contact the liquid working fluid in the outer-layer evaporation section. The power element 700 is arranged in the evaporation section of the innermost heat pipe heat exchanger and can directly contact the liquid working fluid in the innermost evaporation section.

[0048] In this way, the condensation section of the inner-layer heat pipe heat exchanger directly contacts the liquid working fluid in the outer-layer evaporation section, forming a step-by-step heat dissipation path. After the heat is transferred from the power element 700 to the working fluid in the innermost evaporation section, the working fluid vaporizes and rises to the inner-layer condensation section. The heat released by condensation is secondarily absorbed by the working fluid in the outer-layer evaporation section, forming a heat gradient transfer. This design reduces the single-stage heat flux density through the staged heat dissipation of multiple layers of heat pipes and avoids local overheating.

[0049] Moreover, the latent heat of vaporization of the liquid working fluid in the inner-layer heat pipe heat exchanger is greater than the latent heat of vaporization of the liquid working fluid in the outer-layer heat pipe heat exchanger.

[0050] Since the latent heat of vaporization of the inner-layer working fluid is higher, it means that less steam is generated when it absorbs the same amount of heat, thereby reducing the probability of bubble coalescence to form a steam film, or delaying the occurrence of the situation where bubbles coalesce to form a steam film and cover the heating surface of the power element 700. Correspondingly, the latent heat of vaporization of the outer-layer working fluid is lower, and it can vaporize quickly to efficiently transfer the remaining heat. The synergistic effect of the two evenly disperses the heat and avoids the occurrence of film boiling.

[0051] In summary, the sealed nested design (the condensing section of the inner heat pipe heat exchanger is embedded in the outer evaporating section) and the working fluid vaporization latent heat gradient configuration (the inner working fluid vaporization latent heat is greater than the outer working fluid), significantly improves the heat dissipation efficiency and avoids or delays the arrival of the critical heat flux density (CHF).

[0052] Specifically, the working fluid includes but is not limited to R134a (latent heat of vaporization is 217 kJ / kg, and its component is tetrafluoroethane), R471A (latent heat of vaporization is 230~250 kJ / kg, and it is mainly composed of R1234yf, R134a and R1234ze(E)), R1234yf (latent heat of vaporization is 145.37 kJ / kg, and its component is tetrafluoropropylene), R1233zd(E) (latent heat of vaporization is 185.3 kJ / kg, and its component is trans-1-chloro-3,3,3-trifluoropropylene), R1336mzz(Z) (latent heat of vaporization is 170 kJ / kg g, composed of hexafluoro-2-butene), R1234ze(E) (latent heat of vaporization value of 160 kJ / kg, composed of trans-1,3,3,3-tetrafluoropropene), R290 (latent heat of vaporization value of 427 kJ / kg, composed of propane), RE170 (latent heat of vaporization value of 481.5 kJ / kg, composed of ethylene), R601a (latent heat of vaporization value of 367 kJ / kg, composed of n-butane), R600 (latent heat of vaporization value of ~366.5 kJ / kg, composed of isobutane) and R600a (latent heat of vaporization value of 366.5 kJ / kg, mainly composed of isobutane)

[0053] In one embodiment, if Figures 1 - 3 As shown, the number of heat pipe heat exchangers is two, which are defined as a first heat pipe 100 and a second heat pipe 200, respectively. A first working medium is arranged in the first heat pipe 100, and a second working medium is arranged in the second heat pipe 200. The latent heat of vaporization of the first working medium is greater than the latent heat of vaporization of the second working medium. The first heat pipe 100 includes a first evaporation section 110 and a first condensation section 120, and the second heat pipe 200 includes a second evaporation section 210 and a second condensation section 220. The power element 700 is arranged in the first evaporation section 110 and can directly contact the liquid first working medium, and the first condensation section 120 is inserted in the second evaporation section 210 and can directly contact the liquid second working medium.

[0054] In this configuration, the first working fluid (high latent heat of vaporization) directly cools the power element 700, absorbs a large amount of heat and then vaporizes, and the first condensation section 120 is inserted into the second evaporation section 210 to transfer the heat to the second working fluid (low latent heat of vaporization). The second working fluid vaporizes quickly and dissipates the heat to the external environment through its condensation section. This division of labor allows the high heat area (power element 700) to be processed by the high latent heat working fluid first, reducing the bubble generation rate, while the low latent heat working fluid is responsible for quickly exporting the remaining heat.

[0055] Moreover, by only using two - layer nesting, while ensuring the heat dissipation efficiency, the device complexity is simplified, which is suitable for scenarios with limited space.

[0056] However, it is not limited to this. In other embodiments, a third heat pipe can be additionally provided outside the condensation section of the second heat pipe 200. The third heat pipe uses a third working fluid with a latent heat of vaporization smaller than that of the second working fluid. The evaporation section of the third heat pipe is sleeved on the condensation section of the second heat pipe 200 to form a three - stage heat dissipation chain, further dispersing the heat flux density.

[0057] Furthermore, in one embodiment, as Figure 2 shown, the power element 700 is at least partially immersed in the liquid first working fluid, that is to say, the power element 700 is partially immersed in the liquid first working fluid, or the power element 700 is completely immersed in the liquid first working fluid.

[0058] With such a setting, the contact area between the power element 700 and the first working fluid is increased, avoiding local dry burning of the power element 700.

[0059] Even further, in one embodiment, the first heat pipe 100 further includes a first eddy pump (not shown in the figure). The first eddy pump is arranged in the first evaporation section 110 so that the first working fluid in the first evaporation section 110 can flow towards the surface of the power element 700 in an impact manner.

[0060] The first eddy pump drives the first working fluid to impact the surface of the power element 700, destroys the boundary layer, strengthens the convective heat transfer, and prevents bubbles from aggregating on the heating surface. That is to say, with such a setting, the generation of the steam film can be fundamentally solved, avoiding a sudden drop in the heat transfer efficiency.

[0061] In another embodiment, the first heat pipe 100 further includes a first stirrer (not shown in the figure). The first stirrer is arranged in the first evaporation section 110 so that the first working fluid in the first evaporation section 110 can flow around the surface of the power element 700 and form a vortex.

[0062] The first stirrer makes the first working fluid form a vortex around the power element 700, prolongs the residence time of the first working fluid, and improves the phase - change efficiency.

[0063] In summary, both the first eddy pump and the first stirrer control and delay the occurrence of CHF by actively driving the flow of the first working fluid.

[0064] Moreover, in other embodiments, impinging flow and vortex flow can be respectively set in different regions on the outer peripheral side of the power element 700. For example, the first eddy pump is responsible for generating impinging flow in the central high - temperature area on the surface layer of the power element 700, and the first stirrer is responsible for generating vortex flow in the edge area of the first evaporation section 110, thereby achieving zoned enhanced heat transfer.

[0065] Further, in one embodiment, as Figure 2 shown, the first condensation section 120 is at least partially immersed in the liquid second working fluid.

[0066] With such a setting, by immersing the first condensation section 120 in the second working fluid, the heat transfer efficiency of the first heat pipe 100 and the second heat pipe 200 can be improved through direct gas-to-liquid heat exchange.

[0067] Furthermore, in one embodiment, the second heat pipe 200 further includes a second eddy pump (not shown in the figure), and the second eddy pump is arranged in the second evaporation section 210 so that the second working fluid in the second evaporation section 210 can flow towards the surface of the first condensation section 120 in an impact manner.

[0068] In this way, driving the second working fluid to impact the surface of the first condensation section 120 accelerates the transfer of heat from the first condensation section 120 to the second working fluid, and avoids secondary overheating of the first condensation section 120 caused by heat accumulation.

[0069] In another embodiment, the second heat pipe 200 further includes a second stirrer (not shown in the figure), and the second stirrer is arranged in the second evaporation section 210 so that the second working fluid in the second evaporation section 210 can flow around the surface of the first condensation section 120 and form a vortex.

[0070] With such a setting, a vortex surrounding the first condensation section 120 is formed in the second evaporation section 210, increasing the contact time between the second working fluid and the first condensation section 120 and improving the heat absorption efficiency of the second working fluid.

[0071] In summary, both the second eddy pump and the second stirrer actively drive the flow of the second working fluid.

[0072] Moreover, in other embodiments, an impact flow and a vortex flow can be respectively arranged in different regions on the outer peripheral side of the first condensation section 120. For example, the second eddy pump is responsible for generating an impact flow in the central high-temperature area on the surface layer of the first condensation section 120, and the second stirrer is responsible for generating a vortex flow in the edge area of the second evaporation section 210, so as to achieve zonal enhanced heat transfer.

[0073] In one embodiment, as Figure 3 shown, the first heat pipe 100 further includes a first spray pipe group 130 and a first liquid pump 140. The first spray pipe group 130 is arranged on the outer peripheral side of the power element 700, and the first liquid pump 140 is immersed in the first working fluid and communicates with the first spray pipe group 130 so that the first working fluid can be sprayed on the outer peripheral side of the power element 700 through the first spray pipe group 130.

[0074] With such a setting, the coverage of the first working fluid on the surface of the power component 700 is enhanced by active spraying. Moreover, since the sprayed first working fluid is continuously flowing, the bubbles attached to the surface of the power component 700 will be washed away in time. That is to say, a continuous steam film cannot be formed on the surface of the power component 700, thus avoiding a sudden drop in the heat transfer efficiency.

[0075] Further, in one embodiment, as Figure 3 shown, the first spray pipe group 130 is in a net shape and covers the outer peripheral side of the power component 700. The first spray pipe group 130 is provided with a plurality of first nozzles 131 distributed at intervals, and the first spray pipe group 130 can spray the first working fluid onto each heat generating surface of the power component 700 through the plurality of first nozzles 131.

[0076] With such a setting, on the one hand, the net-shaped first spray pipe group 130 covers the entire circumference of the power component 700, eliminating the spraying dead angle. On the other hand, through the design of the dense first nozzles 131, the entire area of the heat generating surface of the power component 700 is covered, avoiding local heat flux concentration.

[0077] In one embodiment, as Figure 3 shown, the second heat pipe 200 further includes a second spray pipe group 230 and a second liquid pump 240. The second spray pipe group 230 is arranged on the outer peripheral side of the first condensation section 120, and the second liquid pump 240 is immersed in the second working fluid and communicates with the second spray pipe group 230, so that the second working fluid can be sprayed onto the outer peripheral side of the first condensation section 120 through the second spray pipe group 230.

[0078] With such a setting, the coverage of the second working fluid on the surface of the first condensation section 120 is enhanced by active spraying. Moreover, since the sprayed second working fluid is continuously flowing, the bubbles attached to the surface of the first condensation section 120 will be washed away in time. That is to say, a continuous steam film cannot be formed on the surface of the first condensation section 120, thus avoiding a sudden drop in the heat transfer efficiency.

[0079] Further, in one embodiment, as Figure 3 shown, the second spray pipe group 230 is in a net shape and covers the outer peripheral side of the first condensation section 120. The second spray pipe group 230 is provided with a plurality of second nozzles 231 distributed at intervals, and the second spray pipe group 230 can spray the second working fluid onto each heat exchange surface of the first condensation section 120 through the plurality of second nozzles 231.

[0080] With such a setting, on the one hand, the net-shaped second spray pipe group 230 covers the entire circumference of the first condensation section 120, eliminating the spraying dead angle. On the other hand, through the design of the dense second nozzles 231, the entire area of the heat exchange surface of the first condensation section 120 is covered, avoiding local heat flux concentration.

[0081] In other embodiments, a micro atomizer may also be integrated in the first nozzle 131 or the second nozzle 231 to atomize the first working fluid or the second working fluid into micron-sized droplets for ejection, thereby increasing the gas-liquid contact area and enhancing the phase change efficiency.

[0082] In one embodiment, as Figures 2 - 4 shown, the condensation section includes condensation flat tubes 300, inner condensation fins 400, and outer condensation fins 500. The number of condensation flat tubes 300 is multiple, and each condensation flat tube 300 is respectively connected to the evaporation section. The inner condensation fins 400 are disposed in the corresponding condensation flat tubes 300. Adjacent condensation flat tubes 300 are spaced apart to form a condensation gap 310, and the outer condensation fins 500 are disposed in the corresponding condensation gap 310.

[0083] With such an arrangement, multiple condensation flat tubes 300 are arranged in parallel, which can increase the heat dissipation area of the condensation section. At the same time, the flat cross-section of the condensation is conducive to the rapid diffusion of steam. The inner condensation fins 400 are disposed in the condensation flat tubes 300 to increase the heat transfer area inside the condensation flat tubes 300. Correspondingly, the outer condensation fins 500 are disposed in the condensation gap 310, which can enhance the external heat dissipation.

[0084] However, it is not limited thereto. In other embodiments, the condensation flat tubes 300 may be replaced with corrugated tubes to enhance the heat transfer inside the corrugated tubes by utilizing the turbulent effect of the corrugated structure. At the same time, the outer condensation fins 500 or the inner condensation fins 400 are made of porous materials to increase the surface area.

[0085] Furthermore, in one embodiment, in the condensation section of the same heat pipe heat exchanger, the sum of the surface areas of all the inner condensation fins 400 is greater than the sum of the surface areas of all the outer condensation fins 500.

[0086] It can be understood that the heat transfer in the condensation flat tubes 300 is the liquefaction heat release of the gaseous first working fluid, and the heat transfer in the condensation gap 310 is the heat absorption of the liquid second working fluid. Obviously, the heat transfer efficiency of the liquid second working fluid is greater than that of the gaseous first working fluid. Therefore, by setting the sum of the surface areas of all the inner condensation fins 400 to be greater than the sum of the surface areas of all the outer condensation fins 500, the heat transfer efficiency on both sides of the condensation flat tubes 300 can be effectively ensured to be balanced.

[0087] In another embodiment, the sum of the surface areas of all the inner condensation fins 400 is less than the sum of the surface areas of all the outer condensation fins 500.

[0088] At this time, the second condensation section 220 of the second heat pipe exchanges heat with air. The specific heat capacity of air is often less than that of the second working fluid. Therefore, the sum of the surface areas of all the outer condensation fins 500 is larger, which is beneficial to balancing the heat transfer balance on both sides of the second condensation section 220.

[0089] Further, in an embodiment, in the condensation section of the same heat pipe heat exchanger, the sum of the surface areas A of all the inner condensation fins 400 and the sum of the surface areas B of all the outer condensation fins 500 satisfy 1 < A / B ≤ 1.3.

[0090] With such a setting, a dynamic balance can be achieved between the liquefaction heat release of the gaseous first working fluid and the heat absorption of the liquid second working fluid.

[0091] In an embodiment, the surface roughness Q of the inner condensation fins 400 satisfies 0.1 μm ≤ Q ≤ 3 μm.

[0092] With such a setting, a moderately rough surface can promote droplet nucleation and aggregation and dripping, thereby accelerating the condensation process. However, too high a roughness will increase the flow resistance of the first working fluid or the second working fluid. Therefore, this range balances the nucleation efficiency and the flow resistance.

[0093] In an embodiment, the surface roughness P of the outer condensation fins 500 satisfies 0.1 μm ≤ P ≤ 3 μm.

[0094] With such a setting, a moderately rough surface can promote droplet nucleation and aggregation and dripping, thereby accelerating the condensation process. However, too high a roughness will increase the flow resistance of the first working fluid or the second working fluid. Therefore, this range balances the nucleation efficiency and the flow resistance.

[0095] In an embodiment, as Figures 2 - 8 shown, the condensation section further includes an upper end plate 600, and the upper end plate 600 covers the upper end surfaces of all the condensation flat tubes 300.

[0096] It should be noted that a balance cavity is provided between the upper end plate 600 and the condensation flat tubes 300 so that the gaseous working fluid can be evenly distributed through the balance cavity. Further, as Figures 5 - 8 shown, a first exhaust passage 610 is formed by spacing the upper end surface of the outer condensation fin 500 from the upper end plate 600, so that the gas generated by the vaporization of the liquid working fluid around the outer condensation fin 500 can diffuse and escape through the first exhaust passage 610 to both ends in the length direction of the condensation gap 310.

[0097] It should be noted that the height direction of the condensation gap 310 is the direction from the evaporation section to the condensation section, the width direction of the condensation gap 310 is the direction in which a plurality of condensation flat tubes 300 are arranged, and the length direction of the condensation gap 310 is the horizontal extension direction of the condensation flat tubes 300.

[0098] With such a setting, the vaporized working fluid is allowed to escape along both ends of the condensation gap 310, preventing the gas from staying in the condensation gap 310 and affecting the heat exchange of the working fluid.

[0099] Specifically, in an embodiment, as Figures 5 - 8As shown in the figure, the upper end plate 600 includes a plate body 620 and slats 630. The plate body 620 is disposed on the upper end surfaces of all the flat condensation tubes 300 to seal the flat condensation tubes 300. The slats 630 are arranged in one-to-one correspondence with the condensation gaps 310. One end of each slat 630 is connected to the plate body 620, and the other end extends towards the condensation gap 310 and is spaced from the outer condensation fins 500 to form a first exhaust passage 610.

[0100] By forming a customized first exhaust passage 610 with a gap between the slats 630 and the outer condensation fins 500, it ensures uniform gas diffusion and avoids local blockage.

[0101] It should be noted that there is also a gap between the lower end surface of the outer condensation fins 500 and the bottom seal, so as to facilitate the rapid reflux of the working fluid after condensation.

[0102] Furthermore, in one embodiment, as Figure 5 shown, along one end of the length direction of the condensation gap 310 to the other end of the length direction of the condensation gap 310, the distance between the upper end surface of the outer condensation fins 500 and the upper end plate 600 remains unchanged.

[0103] It should be noted that the first exhaust passage 610 extends obliquely upwards, and the orientations of adjacent first exhaust passages 610 are opposite, one extending towards the upper right and the other extending towards the upper left. Moreover, the channel direction of the outer condensation fins 500 is consistent with the orientation of the first exhaust passage 610.

[0104] With such a setting, it is applicable to the scenario of heat uniformity and is beneficial to the uniform discharge of gas.

[0105] In another embodiment, as Figure 6 shown, along one end of the length direction of the condensation gap 310 to the other end of the length direction of the condensation gap 310, the distance between the upper end surface of the outer condensation fins 500 and the upper end plate 600 shows an increasing or decreasing trend.

[0106] With such a setting, it can guide the gas to be concentrated and discharged towards the low-pressure area, relieve the gas accumulation pressure, and reduce the flow resistance of the gas.

[0107] Furthermore, the changing trends of the distances between the upper end surfaces of adjacent outer condensation fins 500 and the upper end plate 600 are opposite.

[0108] With such a setting, the distribution of the amount of gaseous working fluid escaping from both sides of the condensation section is made more uniform.

[0109] However, it is not limited to this. In other embodiments, a plurality of variable-diameter sections can also be arranged along the length direction of the condensation gap 310 to form a Venturi effect to accelerate the discharge of gas.

[0110] In one embodiment, as Figures 7 - 8As shown, the external condensation fins 500 within each condensation gap 310 are divided into a first fin 510 and a second fin 520. A first channel 611 is formed by the spaced arrangement between the first fin 510 and the upper end plate 600, and a second channel 612 is formed by the spaced arrangement between the second fin 520 and the upper end plate 600. The first channel 611 and the second channel 612 communicate to form a first exhaust channel 610. The first fin 510 and the second fin 520 are spaced along the length direction of the condensation gap 310 to form a second exhaust channel 530, and the second exhaust channel 530 communicates with the connection point of the first channel 611 and the second channel 612.

[0111] In this way, the first channel 611 and the second channel 612 communicate, allowing the gas to be discharged in a split manner, reducing the turbulence within the first exhaust channel 610. Moreover, the second exhaust channel 530 further disperses the air flow, avoiding the interference of backflow.

[0112] Furthermore, in one embodiment, a flow guiding fin can also be provided between the first channel 611 and the second channel 612 to force the air flow to turn, enhancing the contact between the gas and the external condensation fins 500.

[0113] Furthermore, in one embodiment, as Figure 7 shown, along the end of the first channel 611 close to the second channel 612 to the end of the first channel 611 far from the second channel 612, the distance between the upper end surface of the first fin 510 and the upper end plate 600 remains unchanged.

[0114] Specifically, the first channel 611 and the second channel 612 extend obliquely upward in opposite directions, enabling the bubbles to escape upward and outward from the first exhaust channel 610 under the action of gravity. Moreover, the extension direction of the internal channel of the first fin 510 is consistent with the extension direction of the first channel 611, and the extension direction of the internal channel of the second fin 520 is consistent with the extension direction of the second channel 612.

[0115] With such a setting, it is applicable to the scenario of heat soaking, which is beneficial to the uniform discharge of gas.

[0116] In another embodiment, as Figure 8 shown, along the end of the first channel 611 close to the second channel 612 to the end of the first channel 611 far from the second channel 612, the distance between the upper end surface of the first fin 510 and the upper end plate 600 shows an increasing trend.

[0117] With such a setting, the gas can be guided to be concentrated and discharged to the low-pressure area, relieving the gas accumulation pressure and reducing the flow resistance of the gas.

[0118] In one embodiment, as Figure 7As shown, along the direction from the end of the second channel 612 close to the first channel 611 to the end of the second channel 612 far from the first channel 611, the distance between the upper end surface of the second fin 520 and the upper end plate 600 remains unchanged.

[0119] With such a setting, it is applicable to the soaking scenario and is beneficial to the uniform discharge of gas.

[0120] In another embodiment, as Figure 8 shown, along the direction from the end of the second channel 612 close to the first channel 611 to the end of the second channel 612 far from the first channel 611, the distance between the upper end surface of the second fin 520 and the upper end plate 600 shows an increasing trend.

[0121] With such a setting, it can guide the gas to be concentratedly discharged to the low-pressure area, relieve the gas accumulation pressure, and reduce the flow resistance of the gas.

[0122] In one embodiment, the maximum liquid level of the liquid working medium in the evaporation section is lower than the lower end surface of the condensation section.

[0123] Through liquid level control, the liquid level is prevented from being too high, ensuring that the working medium in the evaporation section only flows back through capillary force or gravity, avoiding the steam from carrying liquid droplets into the condensation section, and maintaining the stability of the two-phase flow.

[0124] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope described in this specification.

[0125] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

[0126] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present application.

[0127] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0128] In this application, unless otherwise clearly stipulated and defined, terms such as "mounted", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0129] In this application, unless otherwise clearly stipulated and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0130] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0131] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific implementations and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

Claims

1. A thermal management device, characterized in that: A heat pipe heat exchanger comprising a plurality of partially nested arrangements, each of the heat pipe heat exchangers comprising an evaporation section and a condensation section, the condensation section being arranged at a height greater than the evaporation section, the condensation section of the inner heat pipe heat exchanger being arranged in the evaporation section of the outer heat pipe heat exchanger and being able to directly contact the liquid working medium in the outer evaporation section, and the power element (700) being arranged in the evaporation section of the innermost heat pipe heat exchanger and being able to directly contact the liquid working medium in the innermost evaporation section; Furthermore, the latent heat of vaporization of the liquid working medium in the inner heat pipe heat exchanger is greater than the latent heat of vaporization of the liquid working medium in the outer heat pipe heat exchanger.

2. The thermal management device according to claim 1, characterized in that: The number of the heat pipe heat exchangers is two, which are defined as a first heat pipe (100) and a second heat pipe (200), the first heat pipe (100) being provided with a first working fluid, the second heat pipe (200) being provided with a second working fluid, and the latent heat of vaporization of the first working fluid being greater than the latent heat of vaporization of the second working fluid; The first heat pipe (100) comprises a first evaporation section (110) and a first condensation section (120); the second heat pipe (200) comprises a second evaporation section (210) and a second condensation section (220); the power element (700) is arranged in the first evaporation section (110) and is capable of directly contacting a liquid first working medium; and the first condensation section (120) is inserted in the second evaporation section (210) and is capable of directly contacting a liquid second working medium.

3. The thermal management device according to claim 2, characterized in that: The power element (700) is at least partially immersed in the liquid first working medium; And / or, the first condensation section (120) is at least partially immersed in the liquid second working medium.

4. The thermal management device according to claim 3, characterized in that: The first heat pipe (100) further comprises a first vortex pump, the first vortex pump being arranged in the first evaporation section (110) so as to enable the first working fluid in the first evaporation section (110) to flow toward the surface of the power element (700) in an impact manner; Alternatively, the first heat pipe (100) further comprises a first stirrer, the first stirrer being arranged in the first evaporation section (110) so as to enable the first working fluid in the first evaporation section (110) to flow around the surface of the power element (700) and form a vortex.

5. The thermal management device according to claim 3, characterized in that: The second heat pipe (200) further comprises a second vortex pump, the second vortex pump being arranged in the second evaporation section (210) so as to enable the second working fluid in the second evaporation section (210) to flow toward the surface of the first condensation section (120); Alternatively, the second heat pipe (200) further comprises a second stirrer, which is arranged in the second evaporation section (210) so that the second working fluid in the second evaporation section (210) can flow around the surface of the first condensation section (120) and form a vortex.

6. The thermal management device according to claim 2, characterized in that: The first heat pipe (100) further comprises a first spray pipe group (130) and a first liquid pump (140); the first spray pipe group (130) is arranged on the outer peripheral side of the power element (700); the first liquid pump (140) is immersed in the first working medium and is connected to the first spray pipe group (130), so that the first working medium can be sprayed on the outer peripheral side of the power element (700) through the first spray pipe group (130); And / or, the second heat pipe (200) further comprises a second spray pipe group (230) and a second liquid pump (240), wherein the second spray pipe group (230) is arranged on the outer peripheral side of the first condensation section (120), and the second liquid pump (240) is immersed in the second working fluid and connected to the second spray pipe group (230), so that the second working fluid can be sprayed on the outer peripheral side of the first condensation section (120) through the second spray pipe group (230).

7. The thermal management device according to claim 6, characterized in that: The first spray pipe group (130) is in a mesh shape and is arranged on the outer peripheral side of the power element (700). The first spray pipe group (130) is provided with a plurality of first nozzles (131) distributed at intervals. The first spray pipe group (130) can spray the first working medium toward each heating surface of the power element (700) through the plurality of first nozzles (131); And / or, the second spray pipe group (230) is mesh-shaped and is arranged on the outer peripheral side of the first condensation section (120), and the second spray pipe group (230) is provided with a plurality of second nozzles (231) distributed at intervals, and the second spray pipe group (230) can spray the second working fluid toward each heat exchange surface of the first condensation section (120) through the plurality of second nozzles (231).

8. The thermal management device according to claim 1, characterized in that: The condensation section includes a condensation flat tube (300), an inner condensation fin (400) and an outer condensation fin (500), the number of the condensation flat tube (300) is multiple, each of the condensation flat tubes (300) is connected to the evaporation section, the inner condensation fin (400) is arranged in the corresponding condensation flat tube (300), the adjacent condensation flat tubes (300) are arranged at intervals to form a condensation gap (310), and the outer condensation fin (500) is arranged in the corresponding condensation gap (310).

9. The thermal management device according to claim 8, characterized in that: In the condensing section of the same heat pipe heat exchanger, the sum of the surface areas of all the inner condensing fins (400) is greater than the sum of the surface areas of all the outer condensing fins (500), or the sum of the surface areas of all the inner condensing fins (400) is less than the sum of the surface areas of all the outer condensing fins (500).

10. The thermal management device according to claim 8, characterized in that: The condensation section further comprises an upper end plate (600), wherein the upper end plate (600) is arranged to cover the upper end surfaces of all the condensation flat tubes (300); The upper end surface of the external condensation fin (500) and the upper end plate (600) are spaced apart to form a first exhaust channel (610), so that the gas generated by the vaporization of the liquid working medium around the external condensation fin (500) can diffuse and escape to both ends of the condensation gap (310) in the length direction through the first exhaust channel (610).

11. The thermal management device according to claim 10, characterized in that: Along the distance from one end of the condensation gap (310) in the length direction to the other end of the condensation gap (310) in the length direction, the distance between the upper end surface of the external condensation fin (500) and the upper end plate (600) remains unchanged; Alternatively, along the distance from one end of the condensation gap (310) in the length direction to the other end of the condensation gap (310) in the length direction, the distance between the upper end surface of the external condensation fin (500) and the upper end plate (600) tends to increase or decrease, and the distance between the upper end surface of adjacent external condensation fins (500) and the upper end plate (600) has an opposite trend of change.

12. The thermal management device according to claim 10, characterized in that: The external condensation fin (500) in each of the condensation gaps (310) is divided into a first fin (510) and a second fin (520); the first fin (510) and the upper end plate (600) are spaced apart to form a first branch channel (611); the second fin (520) and the upper end plate (600) are spaced apart to form a second branch channel (612); the first branch channel (611) and the second branch channel (612) are connected to form the first exhaust channel (610); the first fin (510) and the second fin (520) are spaced apart along the length direction of the condensation gap (310) to form a second exhaust channel (530); the second exhaust channel (530) is connected to the connecting point between the first branch channel (611) and the second branch channel (612).

13. The thermal management device according to claim 12, characterized in that: Along the distance from one end of the first branch channel (611) close to the second branch channel (612) to one end of the first branch channel (611) far from the second branch channel (612), the distance between the upper end surface of the first fin (510) and the upper end plate (600) remains unchanged; Alternatively, along the direction from one end of the first branch channel (611) close to the second branch channel (612) to one end of the first branch channel (611) far from the second branch channel (612), the distance between the upper end surface of the first fin (510) and the upper end plate (600) tends to increase; and / or, along the distance from one end of the second branch channel (612) close to the first branch channel (611) to one end of the second branch channel (612) far from the first branch channel (611), the distance between the upper end surface of the second fin (520) and the upper end plate (600) remains unchanged; Alternatively, the distance between the upper end surface of the second fin (520) and the upper end plate (600) tends to increase from one end of the second branch channel (612) closer to the first branch channel (611) to one end of the second branch channel (612) farther from the first branch channel (611).

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