Three-dimensional vapor cavity heat dissipation device

Abstract

The application relates to the technical field of electronic heat dissipation, and particularly provides a three-dimensional vapor cavity heat dissipation device, aiming at solving the problems of low natural convection heat dissipation efficiency and poor heat dissipation effect in the prior art. In the application, pseudo-boiling of a working medium in the evaporation cavity is caused, the heat absorption capacity of the working medium is increased, the heat transfer rate of the working medium is improved, heat is transferred to the evaporation fins, the working medium in the evaporation fins is heated to cause nucleate boiling to form a vapor-liquid bubble-shaped mixed flow, the bubbles rise to the condensation fins under the action of buoyancy, partial condensation is completed, the remaining steam is condensed in the condensation cavity and returns to the evaporation fins to be heated and evaporated, and heat dissipation is completed. The application provides the three-dimensional vapor cavity heat dissipation device with high heat transfer, small temperature difference and high heat dissipation efficiency, and can effectively solve the problems of low natural convection heat dissipation efficiency and poor heat dissipation effect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electronic heat dissipation, and particularly relates to a three-dimensional vapor cavity heat dissipation device. BACKGROUND

[0002] With the rapid development of the electronic technology field, the heat production of electronic equipment is higher and higher, and the heat dissipation problem is more and more serious, especially for the electronic equipment cooling using natural convection heat dissipation. Natural convection heat dissipation is a phenomenon of heat transfer caused by the fluid flow around the heat dissipation surface driven by the temperature difference between the heat dissipation surface and the environment without external force driving such as a fan. The natural convection heat dissipation technology mainly improves the overall temperature uniformity of the heat dissipation device and increases the heat dissipation area to improve the natural convection heat dissipation efficiency.

[0003] However, due to the limitation of the distribution space and weight of the current electronic equipment heat dissipation device, the heat dissipation area cannot be expanded in a large amount; in addition, the temperature distribution of the natural convection heat dissipation device in the prior art is uneven, resulting in poor heat dissipation effect. SUMMARY

[0004] The present application provides a three-dimensional vapor cavity heat dissipation device, which aims to solve the problem of low natural convection heat dissipation efficiency and poor heat dissipation effect in the prior art.

[0005] In order to solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0006] The present application provides a three-dimensional vapor cavity heat dissipation device, which includes an evaporation cavity, at least two evaporation fins, a condensation cavity and at least two condensation fins; the evaporation cavity and the evaporation fins are filled with working medium; the evaporation fins are provided with evaporation channels; the condensation fins are provided with condensation channels;

[0007] The evaporation fins are arranged on the evaporation cavity, and the condensation fins are arranged on the condensation cavity; the evaporation channel is connected with the evaporation cavity at the inlet end, the outlet end of the evaporation channel is connected with the inlet end of the condensation channel, and the outlet end of the condensation channel is connected with the condensation cavity.

[0008] Further scheme: a plurality of cylindrical ribs are arranged in the evaporation cavity, each cylindrical rib is arranged on the bottom surface of the evaporation cavity and protrudes upward, and the space in the evaporation cavity except the space occupied by the cylindrical ribs is a porous structure.

[0009] Based on the above scheme, the plurality of cylindrical ribs arranged in the evaporation cavity increase the heating area of the evaporation cavity, so that the working medium in the evaporation cavity is quickly heated to form a pseudo-boiling state.

[0010] Further scheme: the porous structure is a surface extended skeleton, a foam metal, a sintered metal powder or a sintered metal wire mesh; the space formed by the porous structure is smaller than the working medium vaporization space in the evaporation cavity; the diameter of the vaporization space is 0.05mm-2mm.

[0011] Based on the above scheme, the space formed by the porous structure is smaller than the working medium vaporization space in the evaporation cavity, so that the working medium in the evaporation cavity forms a pseudo-boiling state after being heated, thereby improving the heat absorption capacity of the working medium and further improving the heat transfer speed of the working medium.

[0012] Further scheme: the condensation cavity is provided with a plurality of cuboid-shaped convex edges, each of the cuboid-shaped convex edges is uniformly arranged on the bottom surface of the condensation cavity and protrudes upward; the bottom surface of the condensation cavity, except for the bottom surface area occupied by the cuboid-shaped convex edges, is a biomimetic lotus leaf surface microstructure.

[0013] Based on the above scheme, the condensation cavity is provided with a plurality of cuboid-shaped convex edges to increase the heat dissipation area of the condensation cavity, so that the steam in the condensation cavity is quickly condensed into liquid; the biomimetic lotus leaf surface microstructure makes the condensed liquid not adhere to the inner wall of the condensation cavity but naturally fall off.

[0014] Further scheme: a channel is arranged between two adjacent evaporation fins and between two adjacent condensation fins, the width of the channel is 1mm-200mm; the width of the channel between two adjacent evaporation fins is equal to the width of the channel between two adjacent condensation fins.

[0015] Further scheme: the thickness of the evaporation fin and the condensation fin is 0.5mm-50mm; the thickness of the evaporation fin is equal to the thickness of the condensation fin.

[0016] Based on the above scheme, the width of the channel between two adjacent evaporation fins is equal to the width of the channel between two adjacent condensation fins, and the thickness of the evaporation fin is equal to the thickness of the condensation fin, which avoids the diffusion of steam when flowing through the evaporation fin and the condensation fin.

[0017] Further scheme: a separation rib is uniformly arranged in the evaporation fin to form a plurality of evaporation channels.

[0018] Further scheme: the hydraulic diameter of the evaporation channel is smaller than the critical size; the critical size is 0.1mm-20mm.

[0019] Based on the above scheme, the hydraulic diameter of the evaporation channel is smaller than the critical size, so that the working medium in the evaporation channel is heated to form a vapor-liquid bubble-like mixed flow, and then the gas bubbles rise to the condensation fin under the action of buoyancy.

[0020] Further scheme: the condensing channel comprises sawtooth-shaped liquid channels and vapor channels arranged on the inner wall of the condensing fins; the space remaining in the condensing fins except the liquid channels is the vapor channel.

[0021] Based on the above scheme, the liquid condensed in the condensing fins after part of the vapor state working medium is condensed flows back to the evaporation fins through the liquid channels; the liquid channels and the vapor channels make the vapor state working medium and the liquid state working medium flow separately, reduce the vapor-liquid friction, and then make the uncondensed vapor state working medium flow upward into the condensing cavity for condensation.

[0022] Further scheme: the evaporation cavity, the evaporation fins, the condensing cavity and the condensing fins are all made of light metal with high thermal conductivity.

[0023] The beneficial effects of the present application are:

[0024] In the present application, the working medium in the evaporation cavity undergoes pseudo-boiling, which increases the heat absorption capacity of the working medium and improves the heat transfer rate of the working medium; the heat is transferred to the evaporation fins, so that the working medium in the evaporation fins is heated to form a vapor-liquid bubble-shaped mixed flow; the bubbles rise to the condensing fins through the evaporation channels under the action of buoyancy, complete partial condensation, the remaining vapor is condensed in the condensing cavity, and flows back to the evaporation fins through the condensing channels to be heated and evaporated, completing heat dissipation. In addition, by combining pseudo-boiling in the evaporation cavity and nucleate boiling in the evaporation fins, on the one hand, the problem of too high local temperature in the evaporation cavity and the evaporation fins caused by too high superheat degree when only nucleate boiling occurs is avoided; the temperature distribution of the three-dimensional vapor cavity heat dissipation device of the present application is more uniform, thereby improving the heat dissipation efficiency; on the other hand, the charge amount of the working medium is reduced, so that the heat dissipation device is more portable under the condition of ensuring smaller temperature difference.

[0025] In the present application, the working medium in the evaporation fins is heated to form a vapor-liquid bubble-shaped mixed flow, and the bubble transportation in the evaporation fins shortens the heat transfer path, so that the phase change circulation path of the working medium in the entire heat dissipation device is shortened, and the heat transfer and heat dissipation efficiency is increased. In addition, the phase change spaces inside the vapor cavity, the vapor fins, the condensing cavity and the condensing fins are interconnected, so that the working medium has higher freedom degree of movement, and the situation of too high local temperature or too high pressure in the device is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0027] Figure 1 is a structural schematic diagram of a three-dimensional steam cavity heat dissipation device of the present application;

[0028] Figure 2 is an exploded structural schematic diagram of a three-dimensional steam cavity heat dissipation device of the present application;

[0029] Figure 3 is a sectional view of an evaporation cavity in the present application;

[0030] Figure 4 is a sectional view of a condensation cavity in the present application;

[0031] Figure 5 is a sectional view of an evaporation fin in the present application;

[0032] Figure 6 is a sectional view of a condensation fin in the present application.

[0033] Explanation of the reference numerals in the drawings:

[0034] 1-evaporation cavity; 2-evaporation fin; 3-condensation cavity; 4-condensation fin; 11-cylindrical rib; 12-porous structure; 21-separation rib; 22-evaporation channel; 31-cuboid-shaped rib; 32-bionic lotus leaf surface microstructure; 41-liquid channel; 42-vapor channel. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings of the embodiments of the present application. It should be understood that the specific embodiments described here are only used to explain the present application, and should not be regarded as a limitation to the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0036] As shown in Figures 1-2 , the present embodiment provides a three-dimensional steam cavity heat dissipation device, which comprises: an evaporation cavity 1, at least two evaporation fins 2, a condensation cavity 3 and at least two condensation fins 4; the evaporation cavity 1 and the evaporation fins 2 are both filled with a working medium; the evaporation fins 2 are provided with evaporation channels 22; the condensation fins 4 are provided with condensation channels;

[0037] The evaporation fin 2 is arranged on the evaporation cavity 1, and the condensation fin 4 is arranged on the condensation cavity 3; the steam inlet end of the evaporation channel 22 is connected with the evaporation cavity 1, the steam outlet end of the evaporation channel 22 is connected with the steam inlet end of the condensation channel, and the steam outlet end of the condensation channel is connected with the condensation cavity 3.

[0038] Specifically, the phase change space inside the evaporation cavity 1, the evaporation fin 2, the condensation cavity 3 and the condensation fin 4 are connected with each other.

[0039] Specifically, the evaporation cavity 1, the evaporation fin 2, the condensation cavity 3 and the condensation fin 4 are connected with each other.

[0040] As shown in the figure, the evaporation cavity 1 is provided with a plurality of cylindrical ribs 11, each of which is arranged on the bottom surface of the evaporation cavity 1 and protrudes upward; the space in the evaporation cavity 1 except the space occupied by the cylindrical ribs 11 is a porous structure 12. Figure 3 Specifically, the cylindrical ribs 11 are at least two, and the actual number can be arranged according to the size of the bottom surface of the evaporation cavity 1.

[0041] The porous structure 12 is a surface extension skeleton, a foamed metal, a sintered metal powder or a sintered metal wire mesh; the space formed by the porous structure 12 is smaller than the working medium vaporization space in the evaporation cavity 1; the diameter of the vaporization space is 0.05mm-2mm.

[0042] Specifically, the space formed by the porous structure 12 is smaller than the working medium vaporization space in the evaporation cavity 1, so that the working medium in the evaporation cavity 1 forms a pseudo-boiling state after being heated, and the working medium in the pseudo-boiling state has an unstable thermodynamic state; at this time, the specific heat of the working medium is much higher than that of the working medium in the equilibrium thermodynamic state, and the pseudo-boiling state greatly enhances the heat absorption capacity of the working medium.

[0043] Specifically, the working medium pseudo-boiling process is as follows:

[0044] First, the working medium has the conditions of normal nuclear boiling, but does not produce internal vaporization and form bubbles in the heat transfer process;

[0045] Second, when the working medium in the pseudo-boiling state enters a space larger than the required vaporization space, the working medium inside will immediately vaporize to form bubbles or evaporate.

[0046] Specifically, the space formed by the porous structure 12 is measured by the equivalent diameter of the pore channel; the calculation formula of the equivalent diameter of the pore is as follows:

[0047]

[0048] ​

[0049] The working medium vaporization space is the minimum liquid scale required for vaporization and bubble formation inside the working medium; the diameter of the vaporization space changes in the range of 0.05mm-2mm according to the working medium.

[0050] As shown in Figure 4 The condensation cavity 3 is provided with a plurality of cuboid protrusions 31, each of which is uniformly arranged on the bottom surface of the condensation cavity 3 and protrudes upward; the bottom surface of the condensation cavity 3, except for the area occupied by the cuboid protrusions 31, is a biomimetic lotus leaf surface microstructure 32.

[0051] Specifically, the number of cuboid protrusions 31 can be set according to the size of the bottom surface of the condensation cavity 3, for example, 11, 13, 15 or 17 can be set.

[0052] The biomimetic lotus leaf surface microstructure 32 is a structure that imitates the surface of a lotus leaf, and is provided with countless wax papillary structures of micro-nano scale, so that the contact area between the liquid condensed in the condensation cavity 3 and the inner wall of the condensation cavity 3 is very limited, thereby preventing the liquid from adhering to the inner wall of the condensation cavity 3.

[0053] Channels are provided between adjacent two evaporation fins 2 and between adjacent two condensation fins 4, and the width of the channels is 1mm-200mm; the width of the channels between adjacent two evaporation fins 2 is equal to that between adjacent two condensation fins 4.

[0054] The thickness of the evaporation fins 2 and the condensation fins 4 is 0.5mm-50mm; the thickness of the evaporation fins 2 and the condensation fins 4 is the same.

[0055] Specifically, the width of the channels between adjacent two evaporation fins 2 or condensation fins 4, the number of evaporation fins 2 and condensation fins 4, and the thickness of evaporation fins 2 and condensation fins 4 are set according to the size of the bottom surface of the evaporation cavity 1 and the condensation cavity 3; for example, the width of the channels between adjacent two evaporation fins 2 or condensation fins 4 can be set to 1mm, 20mm, 50mm, 100mm, 150mm or 200mm; the number of evaporation fins 2 and condensation fins 4 can be set to 14, 16 or 18 respectively; the thickness of evaporation fins 2 and condensation fins 4 can be set to 0.5mm, 2mm, 10mm, 20mm, 30mm, 40mm or 50mm.

[0056] As shown in Figure 5 The evaporation fins 2 are uniformly provided with partition ribs 21 inside, forming a plurality of evaporation channels 22.

[0057] The hydraulic diameter of the evaporation channel 22 is less than a critical size; the critical size is 0.1mm-20mm.

[0058] Specifically, the hydraulic diameter of the evaporation channel 22 is less than the critical size, so that the working medium in the evaporation channel 22 is heated to form a vapor-liquid bubble-like mixed flow; the calculation formula of the hydraulic diameter of the evaporation channel 22 is:

[0059]

[0060] The critical size is the maximum hydraulic diameter of the working medium heated to form a vapor-liquid bubble-like mixed flow in the evaporation channel 22; the critical size changes in the range of 0.1mm-20mm according to different working media.

[0061] Specifically, the separation ribs 21 can be arranged according to the size of the evaporation fins 2, for example, 9 separation ribs 21 are arranged to form 10 evaporation channels 22, 15 separation ribs 21 are arranged to form 16 evaporation channels 22, or 19 separation ribs 21 are arranged to form 20 evaporation channels 22.

[0062] As shown in Figure 6 The condensation channel includes a sawtooth-shaped liquid channel 41 and a steam channel 42 arranged on the inner wall of the condensation fin 4; the space remaining in the condensation fin 4 except the liquid channel 41 is the steam channel 42.

[0063] The evaporation cavity 1, the evaporation fin 2, the condensation cavity 3 and the condensation fin 4 are all made of light metal with high thermal conductivity, for example: aluminum alloy.

[0064] Next, the application will be further described in combination with working principle:

[0065] The bottom surface of the evaporation cavity 1 contacts the heat source, and after the working medium in the evaporation cavity 1 absorbs heat, due to the limitation of the vaporization space, the internal working medium forms a pseudo-boiling state for heat transfer. Under the action of internal working medium flow and heat conduction, heat is quickly transmitted upward to the working medium in the evaporation fin 2. At this time, the working medium in the evaporation fin 2 is heated to form a vapor-liquid bubble-like mixed flow, and the gas bubbles rise to the condensation fin 4 under the action of buoyancy, complete partial condensation, and the remaining steam rises to the condensation cavity 3 through the steam channel 42, collects and mixes, and automatically completes pressure distribution, avoiding the occurrence of local temperature and pressure being too high. After the steam in the condensation cavity 3 completes condensation, the liquid working medium is automatically returned to the evaporation fin 2 through the liquid channel 41 of the condensation fin 4 to continue receiving the heat transmitted in the evaporation cavity 1, forming a vapor-liquid bubble-like mixed flow.

[0066] The present application is not limited to the above-mentioned optional embodiments, and each scheme can be combined arbitrarily without mutual contradiction; anyone can derive other various forms of products under the inspiration of the present application, but regardless of any change in shape or structure, any technical scheme falling within the scope defined by the claims of the present application falls within the protection scope of the present application.

Claims

1. A three-dimensional vapor chamber heat dissipation device, characterized in that, The application relates to a heat pipe, which comprises the following parts: an evaporation cavity, at least two evaporation fins, a condensation cavity and at least two condensation fins; the evaporation cavity and the evaporation fins are filled with a working medium; the evaporation fins are provided with evaporation channels; the condensation fins are provided with condensation channels; the evaporation fins are arranged on the evaporation cavity, the condensation fins are arranged on the condensation cavity; the steam inlet end of the evaporation channel is connected with the evaporation cavity, the steam outlet end of the evaporation channel is connected with the steam inlet end of the condensation channel, and the steam outlet end of the condensation channel is connected with the condensation cavity; the working medium undergoes pseudo-boiling in the evaporation cavity and nuclear boiling in the evaporation fins; the evaporation cavity is provided with a plurality of cylindrical convex edges, each of which is arranged on the bottom surface of the evaporation cavity and protrudes upwards; the space in the evaporation cavity, except the space occupied by the cylindrical convex edges, is a porous structure; the porous structure is a surface extension framework, a foamed metal, sintered metal powder or sintered metal wire mesh; the space formed by the porous structure is smaller than the working medium vaporization space in the evaporation cavity; the diameter of the vaporization space is 0.05mm-2mm; the condensation cavity is provided with a plurality of cuboid convex edges, each of which is arranged on the bottom surface of the condensation cavity and protrudes upwards; the bottom surface of the condensation cavity, except the bottom surface area occupied by the cuboid convex edges, is a biomimetic lotus leaf surface microstructure; the evaporation fins are uniformly provided with partition ribs, forming a plurality of evaporation channels; the hydraulic diameter of the evaporation channels is smaller than the critical size; the critical size is 0.1mm-20mm; the condensation channel comprises sawtooth-shaped liquid channels and steam channels arranged on the inner wall of the condensation fins; the space in the condensation fins, except the liquid channels, is a steam channel; channels are arranged between two adjacent evaporation fins and two adjacent condensation fins, and the width of the channels is 1mm-200mm; the width of the channels between two adjacent evaporation fins is equal to the width of the channels between two adjacent condensation fins; the thickness of the evaporation fins and the condensation fins is 0.5mm-50mm; the thickness of the evaporation fins is equal to the thickness of the condensation fins; the evaporation cavity, the evaporation fins, the condensation cavity and the condensation fins are made of light metal with high thermal conductivity. ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The three-dimensional vapor cavity heat dissipating device according to claim 1, wherein: ​ 3. The three-dimensional vapor cavity heat dissipating device according to claim 2, wherein: ​ 4. The three-dimensional vapor cavity heat dissipating device according to claim 1, wherein: ​

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