Micropore and microchannel composite self-circulation dual-channel cold plate

Abstract

The invention discloses a micropore and microchannel composite self-circulation dual-channel cold plate, and belongs to the technical field of heat dissipation of electronic equipment. The device comprises a shell, an inlet multi-stage channel, an outlet multi-stage channel, a liquid separation cavity, a liquid collection cavity, a micro-channel area, a porous area and a steam cavity. Fluid is uniformly distributed in the inlet multi-stage channel and enters the micro-channel area through the liquid separation cavity, the fluid in the micro-channel area is heated and evaporated and enters the outlet multi-stage channel under the action of capillary force, part of the fluid enters the porous area under the driving of the capillary force, and the fluid in the porous area is heated and evaporated to form a vapor-liquid meniscus. The surface tension of the vapor-liquid meniscus drives the fluid into the vapor chamber. In the process, the porous area provides a large capillary force for fluid flowing, the micro-channel area provides a large flow rate, the fluid driving force is improved, meanwhile, the flow resistance can be reduced, and cooling of high-power-consumption devices can be achieved without external input power.

Description

Technical Field

[0001] The invention belongs to the technical field of heat dissipation of electronic equipment. Background Art

[0002] The capillary pump two-phase cooling loop is a highly efficient phase change heat transfer device that uses the internal capillary force of the device as the fluid driving force and does not require external input driving power. However, the capillary structure inside the traditional capillary pump two-phase cooling loop has a contradiction between increasing the capillary force and reducing the flow resistance. The heat dissipation limit of the capillary pump makes it difficult to meet the heat dissipation requirements of high-power devices. Microchannel cold plates are considered to be one of the effective ways to solve the heat dissipation of high-power devices due to their large specific surface area and high fluid heat transfer coefficient. However, the flow resistance inside the microchannel cold plate is large, which limits the application of capillary pump two-phase cooling loops with microchannel cold plates.

[0003] Invention patent CN201710288107.4 discloses a staggered microchannel condenser for capillary pump rings. The steam and cooling water channels inside the device are staggered, and the two transfer heat through the side wall surface, which effectively increases the heat exchange area and improves the condensation efficiency of the condenser. This invention cannot solve the contradiction between the capillary force of the capillary structure and the flow resistance, and it is difficult to meet the heat dissipation requirements of high-power devices. Utility model patent CN202220585748.2 discloses a composite microchannel heat dissipation device. This device causes changes in the flow state of the fluid in the flow channel through its complex internal structure, increases fluid disturbance, and improves heat exchange efficiency. The heat dissipation area of ​​this invention is limited and cannot meet the heat dissipation requirements of high-power devices. Invention patent CN202110937700.3 discloses an impact flow double-layer guide microchannel heat sink suitable for high heat flux density devices. The device reduces the pressure drop loss by shortening the coolant's travel in the channel. The guide structure in the middle cut-off area can significantly mix the upper and lower coolants, greatly improving the cooling performance of the upper coolant and thus improving the heat transfer efficiency. The invention requires external input power drive and is not suitable for capillary pump two-phase cooling circuits. Summary of the invention

[0004] In order to solve the problem that the heat dissipation limit of the two-phase cooling loop of the capillary pump makes it difficult to meet the heat dissipation requirements of high-power devices, the present invention proposes a self-circulating dual-channel cold plate with micropores and microchannels. By combining microchannels and porous structures, it can provide both large capillary force and high flow rate, reduce flow resistance and improve the heat dissipation limit of the capillary pump, thereby meeting the heat dissipation requirements of high-power devices.

[0005] In order to achieve the above technical objectives, the present invention is implemented by the following technical solutions:

[0006] A self-circulating double-channel cold plate of micropore and microchannel composite comprises a shell 1, an inlet multi-stage channel 2, an outlet multi-stage channel 3, a liquid separation chamber 4, a liquid collection chamber 5, a microchannel area 6, a porous area 7, and a steam chamber 8; the inlet multi-stage channel 2 is composed of multiple stages of channels with different hydraulic diameters; the outlet multi-stage channel 3 is composed of multiple stages of channels with different hydraulic diameters; the liquid separation chamber 4 is connected with the inlet multi-stage channel 2 and the microchannel area 6; the liquid collection chamber 5 is connected with the outlet multi-stage channel 3 and the porous area 7; the microchannel area 6 is composed of multiple microchannels; the porous area 7 is located on the upper part of the microchannel area 6; the steam chamber 8 is located on the upper part of the porous area 7.

[0007] Furthermore, the upper channel in the inlet multi-level channel 2 is divided into two lower channels, and the radius of the lower channel is determined by the upper channel, r i 3 =2r i+1 3 , where r i is the radius of the previous channel, r i+1 is the radius of the next level channel.

[0008] Furthermore, the two upper-level channels in the outlet multi-level channel 3 converge into the lower-level channel, and the radius of the lower-level channel is determined by the upper-level channel. i 3 =t i+1 3 , where t i is the radius of the previous channel, t i+1 is the radius of the next level channel.

[0009] Furthermore, the liquid separation chamber 4 before the entrance of the microchannel zone 6 has a width the same as that of the microchannel zone 6 and a thickness the same as that of the microchannel zone 6 .

[0010] Furthermore, the porous region 7 is formed of a wire mesh or a sintered capillary core, and the bottom of the porous region 7 is in contact with the top of the microchannel region 6 .

[0011] Furthermore, the fluid inside the microchannel area 6 and the porous area 7 is a low surface tension fluid.

[0012] Compared with the prior art, the present invention has the following significant advantages:

[0013] (1) The self-circulating dual-channel cold plate of the present invention, which is a composite of micropores and microchannels, increases the capillary driving force and fluid flow rate, reduces the flow resistance, and improves the heat dissipation limit of the cold plate without the need for external input power by combining the microchannel cold plate and the capillary wick.

[0014] (2) The inlet and outlet channels of the self-circulating dual-channel cold plate of the present invention, which is a composite of micropores and microchannels, adopt a fractal structure to evenly distribute the flow to each microchannel, thereby increasing the average heat transfer coefficient and improving the temperature uniformity of the cold plate.

[0015] (3) The self-circulating dual-channel cold plate of the present invention, which is a composite of micropores and microchannels, can also provide high capillary force when used for low surface tension fluids such as fluorocarbon compounds, thereby expanding the application scenarios.

[0016] The present invention is further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention.

[0018] Figure 2 It is a transverse cross-sectional view of an embodiment of the present invention.

[0019] Figure 3 It is a longitudinal sectional view of an embodiment of the present invention.

[0020] Figure 4 It is a cross-sectional view of the microchannel area of ​​an embodiment of the present invention.

[0021] Figure 5 4 is a cross-sectional view of a porous area according to an embodiment of the present invention.

[0022] Among them, 1. Shell; 2. Inlet multi-stage channel; 3. Outlet multi-stage channel; 4. Liquid separation chamber; 5. Liquid collection chamber; 6. Microchannel area; 7. Porous area; 8. Steam chamber. DETAILED DESCRIPTION

[0023] In order to illustrate the technical solution and technical purpose of the present invention, the present invention is further introduced below in conjunction with the accompanying drawings and specific embodiments.

[0024] Combination Figures 1 to 5 The embodiment of the present invention includes a shell 1, an inlet multi-stage channel 2, an outlet multi-stage channel 3, a liquid separation chamber 4, a liquid collection chamber 5, a microchannel area 6, a porous area 7, and a steam chamber 8; the inlet multi-stage channel 2 is composed of multiple levels of channels with different hydraulic diameters; the outlet multi-stage channel 3 is composed of multiple levels of channels with different hydraulic diameters; the liquid separation chamber 4 is connected with the inlet multi-stage channel 2 and the microchannel area 6; the liquid collection chamber 5 is connected with the outlet multi-stage channel 3 and the porous area 7; the microchannel area 6 and the porous area 7 are composed of multiple microporous structures and are located on the upper part of the microchannel area 6; the steam chamber 8 is located on the upper part of the porous area 7.

[0025] Preferably, the upper channel in the inlet multi-level channel 2 is divided into two lower channels, and the radius of the lower channel is determined by the upper channel, r i 3 =2ri+1 3 , where r i is the radius of the previous channel, r i+1 is the radius of the next level channel.

[0026] Preferably, two upper-level channels in the outlet multi-level channel 3 converge into a lower-level channel, and the radius of the lower-level channel is determined by the upper-level channel. i 3 =t i+1 3 , where t i is the radius of the previous channel, t i+1 is the radius of the next level channel.

[0027] Preferably, the liquid separation chamber 4 is before the entrance of the microchannel zone 6 , and has a width the same as that of the microchannel zone 6 , and a thickness the same as that of the microchannel zone 6 .

[0028] Preferably, the porous region 7 is formed of a wire mesh or a sintered capillary wick, and the bottom of the porous region 7 is in contact with the top of the microchannel region 6 .

[0029] Preferably, the fluid inside the microchannel area 6 and the porous area 7 is a low surface tension fluid such as a fluorocarbon compound.

[0030] In some embodiments, the interface of the microchannel region 6 is trapezoidal.

[0031] In some embodiments, the inlet multi-stage channel 2 has a channel cross-section that tapers along the flow direction.

[0032] In some embodiments, the outlet multi-stage channel 3 has a gradually expanding channel cross-section along the flow direction.

[0033] The cold plate has a length of 20-100mm, a width of 20-100mm, a thickness of 4-15mm, a thickness of 1-4mm in the microchannel zone, a thickness of 1-10mm in the porous zone, a first-stage channel width of 5-10mm in the inlet multi-stage channel, a last-stage channel width of 5-10mm in the outlet multi-stage channel, a channel width of 1-100μm in the microchannel zone, a channel spacing of 1-100μm, a pore size of 1-100μm in the porous zone, and a pore spacing of 1-100μm.

Claims

1. A self-circulating dual-channel cold plate with micropores and microchannels, characterized in that: The invention comprises a shell (1), an inlet multi-stage channel (2), an outlet multi-stage channel (3), a liquid separation chamber (4), a liquid collection chamber (5), a microchannel area (6), a porous area (7), and a steam chamber (8); the inlet multi-stage channel (2) is composed of multiple stages of channels with different hydraulic diameters; the outlet multi-stage channel (3) is composed of multiple stages of channels with different hydraulic diameters; the liquid separation chamber (4) is connected to the inlet multi-stage channel (2) and the microchannel area (6); the liquid collection chamber (5) is connected to the outlet multi-stage channel (3) and the porous area (7); the microchannel area (6) is composed of multiple microchannels; the porous area (7) is located on the upper part of the microchannel area (6); and the steam chamber (8) is located on the upper part of the porous area (7).

2. The self-circulating dual-channel cold plate with micropores and microchannels according to claim 1 is characterized by: The upper channel in the inlet multi-level channel (2) is divided into two lower channels, and the radius of the lower channel is determined by the upper channel: r i 3 ＝2r i+1 3 ； where r i is the radius of the previous channel, r i+1 is the radius of the next level channel.

3. The self-circulating dual-channel cold plate with micropores and microchannels according to claim 1 is characterized in that: In the outlet multi-level channel (3), two upper-level channels converge into a lower-level channel, and the radius of the lower-level channel is determined by the upper-level channel: 2t i 3 =t i+1 3 ; where t i is the radius of the previous channel, t i+1 is the radius of the next level channel.

4. The self-circulating dual-channel cold plate with micropores and microchannels according to claim 1, characterized in that: The liquid separation chamber (4) is located before the entrance of the microchannel zone (6), has a width that is the same as the width of the microchannel zone (6), and has a thickness that is the same as the thickness of the microchannel zone (6).

5. The self-circulating dual-channel cold plate with micropores and microchannels according to claim 1, characterized in that: The porous region (7) is formed of a wire mesh or a sintered capillary core, and the bottom of the porous region (7) is in contact with the top of the microchannel region (6).

6. The self-circulating dual-channel cold plate with micropores and microchannels according to claim 1, characterized in that: The fluid inside the microchannel area (6) and the porous area (7) is a low surface tension fluid.

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