Passive heat dissipation evaporator and passive heat dissipation system

Abstract

The present invention relates to a passive heat dissipation evaporator and a passive heat dissipation system, comprising a plate body made of a heat-conducting material, wherein a steam backflow prevention channel, an evaporation channel and an outlet channel are sequentially arranged inside the plate body along the flow direction of a cooling medium, wherein the evaporation channel comprises a plurality of micron-level capillary channels, wherein one end of the micron-level capillary channel is connected to a confluence cavity, the confluence cavity is connected to the steam backflow prevention channel, and the other end of the micron-level capillary channel is connected to the outlet channel. The evaporator adopting the present invention has a good heat dissipation effect and is suitable for use in a narrow space.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic component heat dissipation, and in particular to a passive heat dissipation evaporator and a passive heat dissipation system. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the rapid development of microelectronics technology, the high heat flux density generated by electronic devices during operation has become a key factor affecting the reliability and service life of the equipment. How to efficiently dissipate the extremely high heat generated per unit area has become one of the key issues restricting the development of microelectronic devices.

[0004] According to whether there is an external circulation power device, the current heat dissipation technology can be divided into two categories: active and passive. Pump-driven microfluidic heat dissipation technology is one of the important research directions of active heat dissipation technology for current electronic equipment. It has the advantages of small heat exchange unit size, high heat exchange efficiency, and can be directly integrated on the chip. In addition, efficient active heat dissipation technologies include jet impact cooling, spray cooling, etc. Current active heat dissipation technologies all have common disadvantages such as high energy consumption, complex system structure and poor operation stability.

[0005] At present, loop heat pipe technology is one of the most ideal technologies for passive thermal management of electronic devices. However, the inventors found that due to the shortcomings of low permeability, loose contact between the capillary wick and the evaporator, and low boiling limit, the heat dissipation capacity of the loop heat pipe is still significantly lower than that of the active heat dissipation technology. In addition, the capillary wick is usually thicker, which is not conducive to layout in a small space. These problems limit the application of loop heat pipes in the heat dissipation of microelectronic devices.

[0006] Moreover, the inventors also found that capillary pressure and permeability are the key parameters of heat exchange equipment driven by capillary force, which determine the capillary limit and heat transfer limit under high heat flux density or anti-gravity conditions. In passive heat dissipation technology, it is usually achieved by reducing the pore size of the capillary core, which greatly reduces the permeability of the capillary core and thus reduces the heat dissipation performance. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a passive heat dissipation evaporator which has good heat dissipation performance and is easy to be arranged in a narrow space.

[0008] To achieve the above purpose, the present invention adopts the following technical solutions

[0009] In the first aspect, an embodiment of the present invention provides a passive heat dissipation evaporator, comprising a plate body made of a heat-conducting material, wherein a steam backflow prevention channel, an evaporation channel and an outlet channel are sequentially arranged inside the plate body along the flow direction of the cooling medium, the evaporation channel comprising a plurality of layers of micron-level capillary channels, one end of the micron-level capillary channel is connected to a confluence cavity, the confluence cavity is connected to the steam backflow prevention channel, and the other end of the micron-level capillary channel is connected to the outlet channel.

[0010] Optionally, the steam anti-backflow flow channel includes multiple layers of arc flow channels, in which, in the arc flow channels of two adjacent layers, along the flow direction of the cooling medium, both ends of the first arc flow channel located in the previous layer are connected to a second arc flow channel, and multiple second arc flow channels constitute the arc flow channel of the next layer, and the arc flow channel of the last layer is connected to the confluence chamber.

[0011] Optionally, along the flow direction of the cooling medium, the bottom surface of the arc-shaped flow channel located at the front is connected to a first inlet flow channel perpendicular to the plate body, the first inlet flow channel is connected to a second inlet flow channel, and the second inlet flow channel extends to the outside of the plate body.

[0012] Optionally, the outlet flow channel adopts a tapered cavity structure, and the end with a large area is connected to a plurality of micron-scale capillary flow channels.

[0013] Optionally, the end of the tapered cavity with a smaller structural area is connected to one end of the discharge flow channel, and the other end of the discharge flow channel extends to the outside of the plate body.

[0014] Optionally, the micrometer-scale capillary channel has a square cross-section with a side length of 50 micrometers to 100 micrometers.

[0015] Optionally, the plate body includes a first plate portion and a second plate portion, the bottom surface of the first plate portion is provided with a steam backflow prevention channel, an evaporation channel and an outlet channel, and the second plate portion is attached to the bottom surface of the first plate portion and fixed to the first plate portion by a fixing member.

[0016] In the second aspect, an embodiment of the present invention provides a passive heat dissipation system, comprising the passive heat dissipation evaporator described in the first aspect, the inlet of the steam anti-backflow flow channel of the passive heat dissipation evaporator is connected to the outlet of the compensation chamber through a liquid phase pipeline, the outlet of the outlet flow channel of the passive heat dissipation evaporator is connected to the inlet of the condenser through a gas phase pipeline, and the outlet of the condenser is connected to the inlet of the compensation chamber through a pipeline.

[0017] Optionally, a pipeline between the outlet of the condenser and the inlet of the compensation chamber is connected with a cooling medium filling mechanism.

[0018] Optionally, the installation height of the compensation chamber is higher than that of the passive heat dissipation evaporator, and the installation height of the condenser is higher than that of the compensation chamber;

[0019] Furthermore, the condenser adopts a vertically arranged spiral tube condenser.

[0020] Beneficial effects of the present invention:

[0021] 1. The passive heat dissipation evaporator of the present invention is provided with a plurality of micron-level capillary channels inside the plate body. The micron-level capillary channels are integrated on a flat plate to replace the capillary core, which can provide extremely high capillary pressure and permeability to overcome density difference and gravity, avoid the conflict between capillary pressure and permeability, improve the boiling limit and critical heat flux density of the evaporator, and improve the circulation flow rate of the cooling medium. Moreover, the plate body is a flat plate structure and can be directly integrated on an electronic device or chip, with close contact and a large heat exchange area, thereby improving the heat dissipation capacity. Moreover, since the capillary channels are at the micron level, the thickness of the plate body can be made into the millimeter level, which is convenient for integrated installation with the equipment. The plate body is small in size and is conducive to arrangement in a small space.

[0022] 2. The passive heat dissipation evaporator of the present invention has a steam backflow prevention flow channel, which is a multi-layer arc flow channel, which will prevent the cooling medium from flowing back after evaporation and boiling. Combined with the tapered cavity structure of the outlet flow channel, it ensures that the gas of the cooling medium can flow out of the plate smoothly after evaporation.

[0023] 3. In the passive heat dissipation system of the present invention, the installation height of the compensation chamber is higher than the passive heat dissipation evaporator, and the installation height of the condenser is higher than the compensation chamber. Therefore, the circulation of the cooling medium in the whole system is through capillary force and gravity circulation, which avoids the external driving device and can provide stable and efficient heat dissipation capabilities. The heat can also be transported over long distances, from the surface of the electronic components inside the equipment to the outside of the equipment, thereby ensuring the operation of the electronic equipment.

[0024] 4. The passive heat dissipation system of the present invention has a compensation chamber for collecting the condensed working fluid refluxed from the condenser, thereby increasing the cooling working fluid capacity of the entire system, ensuring the cooling working fluid replenishment of the evaporator, and increasing the boiling limit and heat dissipation limit of the evaporator.

[0025] 5. The passive heat dissipation system of the present invention adopts a vertically arranged spiral tube condenser, which reduces the loss along the system flow channel while ensuring the condensation effect, and ensures the circulation effect of the working medium. The condenser is placed vertically and connected to the compensation chamber, which accelerates the reflux of the working medium after condensation, increases the flow rate of the working medium in the system, and improves the heat dissipation effect of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings in the specification, which constitute a part of the present application, are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute a limitation on the present application.

[0027] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0028] Figure 2 This is a schematic diagram of the overall structure of the first plate portion of Example 1 of the present invention;

[0029] Figure 3 This is a bottom view of the first plate portion of Example 1 of the present invention;

[0030] Figure 4 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention;

[0031] Figure 5 This is a front view of the compensation chamber of Example 2 of the present invention;

[0032] Figure 6 This is a side view of the compensation chamber of Example 2 of the present invention;

[0033] Figure 7 This is a schematic diagram of the structure of a condenser according to Embodiment 2 of the present invention;

[0034] Among them, 1. the first plate portion, 2. the second plate portion, 3. the cooling medium inlet pipe, 4. the cooling medium outlet pipe, 5. the fixing bolt, 6. the arc flow channel, 7. the confluence cavity, 8. the first inlet flow channel, 9. the micron-level capillary channel, 10. the outlet flow channel, 11. the first flow channel portion, 12. the liquid phase pipeline, 13. the compensation chamber, 14. the condenser, 14-1. the outer shell, 14-2. the spiral tube, 14-3. the cooling water inlet pipe, 14-4. the cooling water outlet pipe, 14-5. the steam inlet pipe, 14-6. the liquid outlet pipe, 15. the flow meter, 16. the filling equipment, 17. the pressure gauge. DETAILED DESCRIPTION

[0035] Example 1

[0036] This embodiment provides a passive heat dissipation evaporator, such as Figure 1-3 As shown, it includes a plate body, which is made of heat-conducting material. The plate body in this embodiment is made of copper material, which improves the thermal conductivity of the entire evaporator. In addition, it adopts a flat plate structure, which is convenient for direct installation on the surface of electronic components or chips.

[0037] The plate body is assembled by a first plate portion 1 and a second plate portion 2. The lower surface of the first plate portion is attached to the upper surface of the second plate portion. The first plate portion and the second plate portion are connected as a whole by a plurality of fixing bolts 5 to form the entire plate body.

[0038] When the first plate portion 1 and the second plate portion 2 are connected, sealant is applied between the first plate portion 1 and the second plate portion 2 to prevent leakage of the cooling medium.

[0039] A flow channel for the flow of cooling medium is provided on the lower surface of the first plate portion 1. Along the flow direction of the cooling medium, the flow channel includes a steam backflow prevention flow channel, an evaporation flow channel and an outlet flow channel which are arranged in sequence.

[0040] The evaporation channel is used for heat exchange between the cooling medium and the electronic components, and evaporates and boils after absorbing the heat generated by the electronic components. The steam backflow prevention channel is used to prevent the backflow of steam generated after the cooling medium evaporates and boils. The outlet channel is used for the generated steam to flow out of the plate.

[0041] In this embodiment, the steam backflow prevention channel includes a multi-layer arcuate channel 6 distributed along the flow direction of the cooling medium. The arcuate channel is a semicircular channel that bends toward the cooling medium inlet direction.

[0042] In two adjacent layers of arcuate flow channels 6, both ends of the first arcuate flow channel in the previous layer are connected to a second arcuate flow channel and to the middle of the second arcuate flow channel, and all the second arcuate flow channels together constitute the arcuate flow channel of the next layer.

[0043] In this embodiment, there are four layers of arcuate flow channels 6 , wherein the frontmost layer has one arcuate flow channel 6 , the corresponding second layer has two arcuate flow channels 6 , the third layer has four arcuate flow channels 6 , and the fourth layer has eight arcuate flow channels 6 .

[0044] The overall width of the first layer of arcuate flow channel 6 is 4000 microns, the width of a single arcuate flow channel of the second layer of arcuate flow channel 6 is 2000 microns, the width of a single arcuate flow channel of the third layer of arcuate flow channel 6 is 1000 microns, and the width of a single arcuate flow channel of the fourth layer of arcuate flow channel 6 is 500 microns.

[0045] The cross-sectional shape of the arc-shaped flow channel 6 is a rectangle.

[0046] The last layer of arcuate flow channel 6 , that is, the fourth layer of arcuate flow channel, is connected to the confluence cavity 7 opened on the bottom surface of the first plate portion, so that the cooling medium converges in the confluence cavity 7 .

[0047] A first inlet flow channel 8 is provided on the bottom surface of the frontmost arc-shaped flow channel, and the axis of the first inlet flow channel 8 is perpendicular to the plate body. A second inlet flow channel is provided on the inlet end surface of the first plate portion, and a cooling medium inlet pipe 3 is provided at the second inlet flow channel. The second inlet flow channel is perpendicular to and connected with the first inlet flow channel. The cooling medium can flow into the steam reflux prevention flow channel through the second inlet flow channel and the first inlet flow channel 8.

[0048] With this arrangement, there is a certain height difference between the inflow end of the cooling medium and the anti-steam backflow flow channel, which facilitates the cooling medium to flow by its own gravity.

[0049] One end of the evaporation flow channel is communicated with the confluence cavity.

[0050] The evaporation flow channel is composed of a multi-layer micron-scale capillary channel 9 opened on the first plate portion. One end of the micron-scale capillary channel 9 extends to the confluence cavity 7 and is connected to the confluence cavity 7 , and the other end extends to the outlet flow channel 10 and is connected to the outlet flow channel 10 .

[0051] In this embodiment, three layers of micron-scale capillary channels 9 are arranged along a direction perpendicular to the plate body, each layer has 160 micron-scale capillary channels 9, the distance between adjacent micron-scale capillary channels 9 is 300 microns, the spacing between micron-scale capillary channels 9 between adjacent layers is 1000 microns, the cross-section of the micron-scale capillary channels 9 is square, and the side length is 50-100 microns. The cross-section side length of the micron-scale capillary channels in this embodiment is 50 microns.

[0052] By using micron-scale capillary channels as evaporation channels instead of capillary cores, extremely high capillary pressure and permeability can be provided to overcome density differences and gravity, avoid the conflict between capillary pressure and permeability, increase the boiling limit and critical heat flux density of the evaporator, increase the circulation flow of the cooling medium, and thus improve the heat dissipation effect of the entire evaporator.

[0053] At the same time, the capillary channel is at the micron level, so that the thickness of the plate can be made at the millimeter level, reducing the size of the entire evaporator and making it suitable for use in small spaces.

[0054] The outlet channel 10 is a tapered cavity structure, with a larger end connected to the evaporation channel and a smaller end connected to the discharge channel, for discharging the cooling medium to the outside of the plate body.

[0055] The discharge flow channel includes a first flow channel portion 11 and a second flow channel portion. The first flow channel portion 11 is vertically arranged with the plate body and is opened on the bottom surface of the outlet flow channel. The second flow channel portion is perpendicular to the first flow channel portion 11, one end of the second flow channel portion is connected with the first flow channel portion 11, and the other end extends to the side of the outlet end of the first plate portion 1. A cooling medium outflow pipe 4 is provided at the second flow channel portion, and the cooling medium in the outlet flow channel can flow out to the outside of the plate body through the discharge flow channel.

[0056] The tapered cavity structure of the outlet flow channel cooperates with the anti-steam backflow flow channel to ensure that the gas after evaporation of the cooling medium is smoothly discharged from the plate body and flows into the circulation pipeline.

[0057] The evaporator of this embodiment adopts a structure in which micron-level capillary channels are integrated in a plate body, occupies a small volume, and is suitable for use in a narrow space.

[0058] Example 2

[0059] This embodiment provides a passive heat dissipation system. Figure 4 As shown, the passive heat dissipation evaporator described in Example 1 is provided.

[0060] Specifically, the second inlet flow channel of the passive heat dissipation evaporator is connected to the outlet of the compensation chamber 13 through the liquid phase pipeline 12, the inlet of the compensation chamber 13 is connected to the outlet of the condenser 14 through a pipeline, and the inlet of the condenser 14 is connected to the second flow channel of the passive heat dissipation evaporator through a gas phase pipeline.

[0061] The installation height of the compensation chamber 13 is higher than the installation height of the passive heat dissipation evaporator, and the installation height of the condenser 14 is higher than the installation height of the compensation chamber 13 .

[0062] In this embodiment, Figure 5-Figure 6 As shown, the compensation chamber 13 can adopt the compensation chamber structure in the existing loop heat pipe. Its specific structure will not be described in detail here. It can prevent heat leakage, prevent the cooling medium from flowing back, prevent drying out, and increase the storage capacity of the cooling medium. When the system is running stably, it is used to store the excess condensed medium generated in the condenser 14. While ensuring the cooling medium capacity in the system, it ensures the cooling medium supply to the evaporator, improves the boiling limit and heat dissipation limit of the evaporator, and prevents the evaporator from drying out.

[0063] The condenser 14 adopts a vertically arranged spiral tube condenser, which reduces the loss along the system channel while ensuring the condensation effect, and ensures the circulation effect of the working medium. The condenser 14 is placed vertically and connected to the compensation chamber 13, which accelerates the reflux of the working medium after condensation, increases the flow rate of the working medium in the system, and improves the heat dissipation effect of the entire system.

[0064] like Figure 7 As shown, the condenser includes a shell 14-1, a vertically arranged spiral tube 14-2 is arranged inside the shell 14-1, one end of the spiral tube. The bottom end of the spiral tube 14-2 is provided with a cooling water inlet pipe 14-3 for passing cooling water, the top end of the spiral tube is provided with a cooling water outlet pipe 14-4, the top end of the shell 14-1 is provided with a steam inlet pipe 14-5, and the steam inlet pipe is connected to the gas phase pipeline. The bottom end of the shell is provided with a liquid outlet pipe 14-6 for discharging the condensed cooling medium.

[0065] A flow meter 15 is installed in the liquid phase pipeline between the compensation chamber 13 and the passive heat dissipation evaporator for detecting the flow rate of the cooling medium in real time.

[0066] The pipeline between the inlet of the compensation chamber 13 and the outlet of the condenser 14 is connected with a coolant filling mechanism for filling the coolant into the entire system, including a filling device 16. The filling device 16 is connected to the pipeline between the outlet of the condenser 14 and the inlet of the compensation chamber 13 through a filling pipeline. The filling device 16 can use existing equipment, and its specific structure will not be described in detail here.

[0067] The pipeline between the inlet of the compensation chamber 13 and the outlet of the condenser 14 is also connected with a pressure gauge 17 for detecting the pressure of the cooling medium.

[0068] In the system of this embodiment, since the height of the compensation chamber 13 is higher than the height of the passive heat dissipation evaporator, and the height of the condenser 14 is higher than the height of the compensation chamber 13, it plays an auxiliary role in the circulation of the cooling medium. Therefore, the circulation of the working medium in the entire system is carried out through capillary force and gravity, avoiding the external driving device while providing stable and efficient heat dissipation capabilities, and can transport heat over long distances, from the surface of electronic devices inside the device to the outside of the device, thereby ensuring the operation of the electronic equipment.

[0069] The working method of the system in this embodiment is:

[0070] The passive heat dissipation evaporator is fixed to the heating part of the electronic components. First, the entire system is evacuated, and the cooling medium is injected into the system through the cooling medium filling mechanism. The cooling medium flows from the compensation chamber 13 into the passive heat dissipation evaporator under the action of capillary force. When the external heat source (electronic components) heats the passive heat dissipation evaporator, the cooling medium absorbs heat and evaporates, and becomes gaseous and is transported to the condenser through the gas phase pipeline. In the condenser, the high-temperature gas is condensed and liquefied and flows back to the compensation chamber 13, thereby achieving efficient cooling of the electronic components in the process.

[0071] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A passive heat dissipation evaporator, characterized in that: It comprises a plate body made of a heat-conducting material, wherein a steam backflow prevention channel, an evaporation channel and an outlet channel are sequentially arranged in the plate body along the flow direction of the cooling medium, wherein the evaporation channel comprises a multi-layer micron-level capillary channel, wherein one end of the micron-level capillary channel is connected to a confluence cavity, the confluence cavity is connected to the steam backflow prevention channel, and the other end of the micron-level capillary channel is connected to the outlet channel; The steam anti-backflow flow channel includes multiple layers of arc flow channels. In the arc flow channels of two adjacent layers, along the flow direction of the cooling medium, both ends of the first arc flow channel located in the previous layer are connected to a second arc flow channel, and multiple second arc flow channels constitute the arc flow channel of the next layer, and the arc flow channel of the last layer is connected to the confluence cavity.

2. A passive heat dissipation evaporator as claimed in claim 1, characterized in that: Along the flow direction of the cooling medium, the bottom surface of the arc-shaped flow channel located at the front is connected with the first inlet flow channel perpendicular to the plate body, the first inlet flow channel is connected with the second inlet flow channel, and the second inlet flow channel extends to the outside of the plate body.

3. A passive heat dissipation evaporator as claimed in claim 1, characterized in that The outlet flow channel adopts a tapered cavity structure, and the end with a large area is connected to a plurality of micron-level capillary flow channels.

4. A passive heat dissipation evaporator as claimed in claim 3, characterized in that: The end of the tapered cavity with a smaller structural area is communicated with one end of the discharge flow channel, and the other end of the discharge flow channel extends to the outside of the plate body.

5. A passive heat dissipation evaporator as claimed in claim 1, characterized in that: The micron-scale capillary flow channel has a square cross section with a side length of 50 microns to 100 microns.

6. A passive heat dissipation evaporator as claimed in claim 1, characterized in that: The plate body includes a first plate portion and a second plate portion. The bottom surface of the first plate portion is provided with a steam backflow prevention channel, an evaporation channel and an outlet channel. The second plate portion is attached to the bottom surface of the first plate portion and is fixed to the first plate portion through a fixing member.

7. A passive heat dissipation system, characterized in that: It comprises the passive heat dissipation evaporator as described in any one of claims 1 to 6, wherein the inlet of the steam anti-backflow flow channel of the passive heat dissipation evaporator is connected to the outlet of the compensation chamber through a liquid phase pipeline, the outlet of the outlet flow channel of the passive heat dissipation evaporator is connected to the inlet of the condenser through a gas phase pipeline, and the outlet of the condenser is connected to the inlet of the compensation chamber through a pipeline.

8. A passive heat dissipation system as claimed in claim 7, characterized in that: The pipeline between the outlet of the condenser and the inlet of the compensation chamber is connected with a cooling medium filling mechanism.

9. A passive heat dissipation system as claimed in claim 7, characterized in that: The installation height of the compensation chamber is higher than that of the passive heat dissipation evaporator, and the installation height of the condenser is higher than that of the compensation chamber.

10. A passive heat dissipation system as claimed in claim 7, characterized in that: The condenser adopts a vertically arranged spiral tube condenser.

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