Loop heat pipe heat dissipation device

Abstract

The invention relates to the field of chip heat dissipation, in particular to a loop heat pipe heat dissipation device which is characterized in that an evaporator is composed of an evaporation end cover, an evaporation bottom face and a sintered porous capillary core, the sintered porous capillary core divides an inner cavity of the evaporator into an upper liquid storage cavity and a lower evaporation area, and a micron-sized micro-channel structure is arranged on the inner surface of the evaporation bottom face; and the sintered porous capillary core is welded on the evaporation bottom surface. According to the invention, through the synergistic effect of the micro-channel structure in the evaporator and the sintered porous capillary core and the cooperation of the double-sided fine capillary condensation structure on the condenser, the phase change heat transfer process is enhanced, so that the heat dissipation performance of extremely low thermal resistance, ultrahigh heat flux and large total heat transfer capacity is realized, and the heat dissipation capability is greatly improved compared with that of an existing liquid cooling technology; according to the utility model, the harsh heat dissipation requirement of the high-performance chip can be met, and the condensate formed by steam condensation in the steam pipeline can be automatically discharged through the arrangement of the liquid discharge structure in the steam pipeline.

Description

Technical Field

[0001] This invention relates to the field of chip heat dissipation technology, and in particular to a loop heat pipe heat dissipation device. Background Technology

[0002] With chip manufacturing processes approaching physical limits and data center computing power demands surging, liquid cooling technology has become a key solution to overcome heat dissipation bottlenecks. As a highly efficient passive two-phase heat dissipation technology, loop heat pipes have shown significant potential in the field of server heat dissipation, especially suitable for scenarios with both high power density and high power consumption.

[0003] Loop heat pipe technology, as a highly efficient passive two-phase heat transfer method, was initially mainly used in the aerospace field, focusing on long-distance heat transfer. Its requirements for heat flux density were relatively low, and the system thermal resistance was relatively high. However, in civilian high-performance chip cooling applications, a comprehensive requirement of high heat flux density, high heat transfer capacity, and low thermal resistance must be achieved within a limited volume. Existing loop heat pipe structures and performance are no longer sufficient to meet practical needs.

[0004] Furthermore, due to the complex airflow organization and variable ambient temperature within the server chassis, even with existing loop heat pipes providing insulation for the steam pipes, it is still difficult to completely prevent localized condensation of the working fluid within the steam pipes. This prematurely condensed steam forms condensate in the steam pipes, causing blockage of the gas-liquid two-phase flow. This significantly increases steam flow resistance and disrupts the system's normal pressure balance. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a loop heat pipe heat dissipation device.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A loop heat pipe heat dissipation device includes an evaporator, which is composed of an evaporation end cap, an evaporation bottom surface and a sintered porous capillary core. The sintered porous capillary core divides the inner cavity of the evaporator into an upper liquid storage chamber and a lower evaporation area. The inner surface of the evaporation bottom surface is provided with a micron-level microchannel structure, and the sintered porous capillary core is welded to the evaporation bottom surface. The condenser consists of a condensing end cap and a condensing bottom surface, and both the inner surface of the condensing end cap and the inner surface of the condensing bottom surface are provided with condensing capillary structures. The loop heat pipe includes a liquid pipe and a vapor pipe, which are respectively connected between the evaporator end cap and the condenser end cap, and the liquid pipe is installed at a higher height than the vapor pipe. The internal working fluid is pure water.

[0007] Furthermore, in a preferred structure, the pore diameter of the sintered porous capillary core is 0.1 μm-10 μm.

[0008] Furthermore, in a preferred configuration, the condensation capillary structure on the condensation end cap and the condensation bottom surface is one or a combination of a microgroove structure, a microcolumn structure, or a porous structure.

[0009] Furthermore, in a preferred configuration, the interface of the liquid pipeline on the evaporator side is located on the side wall of the liquid storage chamber, and the interface on the condenser side is located at the apex corner of the condenser.

[0010] In addition, in the preferred structure, there is one or more liquid pipelines and steam pipelines, the liquid pipeline is provided with a filling port, the cross-sectional area of ​​the steam pipeline is larger than that of the liquid pipeline, and the condenser is made of oxygen-free copper with a thickness of 1mm.

[0011] In addition, in a preferred configuration, the liquid pipeline is provided with a butterfly-shaped channel.

[0012] The beneficial effects of this invention are as follows: through the synergistic effect of the microchannel structure in the evaporator and the sintered porous capillary core, combined with the double-sided micro-capillary condensation structure on the condenser, the phase change heat transfer process is enhanced to achieve heat dissipation performance with extremely low thermal resistance, ultra-high heat flux density and large total heat transfer. Its heat dissipation capacity is greatly improved compared with the existing liquid cooling technology, which can meet the demanding heat dissipation requirements of high-performance chips. Furthermore, through the setting of the drain structure in the steam pipeline, the condensate formed by the condensation of steam in the steam pipeline can be automatically discharged. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the evaporator structure proposed in this invention; Figure 2 This is a schematic diagram of the condenser proposed in this invention; Figure 3 This is a schematic diagram illustrating the working principle of the loop heat pipe proposed in this invention. Figure 4 This is a schematic diagram of the single-steam loop heat pipe heat dissipation device proposed in this invention; Figure 5 This is a schematic diagram of the dual-vapor loop heat pipe heat dissipation device proposed in this invention; Figure 6 These are various morphologies of the condensation capillary structure proposed in this invention; Figure 7 This is a schematic diagram of the internal structure of the liquid pipeline proposed in this invention.

[0014] In the diagram: 1 Evaporator, 11 Evaporation end cap, 12 Evaporation bottom surface, 13 Liquid storage chamber, 2 Sintered porous capillary wick, 3 Condenser, 31 Condensation end cap, 32 Condensation bottom surface, 33 Condensation capillary structure, 331 Microgroove structure, 332 Microcolumn structure, 333 Porous structure, 4 Liquid pipeline, 41 Butterfly channel, 5 Steam pipeline, 6 Liquid filling port. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0016] Reference Figure 1-6 A high-performance loop heat pipe cooling device for chip heat dissipation includes an evaporator 1, which consists of an evaporation end cap 11, an evaporation bottom surface 12, and a sintered porous capillary wick 2. The sintered porous capillary wick 2 divides the inner cavity of the evaporator 1 into an upper liquid storage chamber 13 and a lower evaporation region. The inner surface of the evaporation bottom surface 12 is provided with a micron-level microchannel structure, and the sintered porous capillary wick 2 is welded to the evaporation bottom surface 12. A condenser 3 consists of a condensation end cap 31 and a condensation bottom surface 32, and both the inner surfaces of the condensation end cap 31 and the condensation bottom surface 32 are provided with condensation capillary structures 33. The loop heat pipe includes a liquid pipe 4 and a vapor pipe 5, which are respectively connected between the evaporation end cap 11 and the condensation end cap 31. The installation height of the liquid pipe 4 is higher than that of the vapor pipe 5, and the internal working fluid is pure water.

[0017] The sintered porous capillary core 2 has a pore diameter of 0.1μm-10μm. The pore diameter of the sintered porous capillary core 2 is on the micrometer scale, and the pore size is adjusted according to the requirements of capillary force. In addition, the thermal conductivity of the capillary core is required to be as low as possible.

[0018] The condensation capillary structure 33 on the condensation end cap 31 and the condensation bottom surface 32 is one or more combinations of microgroove structure 331, micropillar structure 332, or porous structure 333. The porous structure 333 (such as metal powder sintering or foam metal) is preferably a combination of microgroove structure 331 and micropillar structure 332.

[0019] The interface of the liquid pipeline 4 on the evaporator 1 side is located on the side wall of the liquid storage chamber 13, and the interface on the condenser 3 side is located at the top corner of the condenser 3. The steam pipeline 5 is connected to the side walls of the evaporator 1 and the condenser 3 respectively.

[0020] The liquid pipeline 4 and the steam pipeline 5 are both one or more, and the liquid pipeline 5 is equipped with a filling port 6.

[0021] Among them, the cross-sectional area of ​​steam pipe 5 is larger than that of liquid pipe 4.

[0022] The condenser 3 is made entirely of oxygen-free copper with a thickness of 1mm. The upper and lower condensation surfaces feature capillary and microchannel structures, with the microchannel size recommended to be no more than 200 micrometers. This is complemented by the airflow design within the cavity.

[0023] The internal working fluid is pure water. Pure water possesses the highest quality factor (M=σ*hfg*ρl / μl) within the operating temperature range of the loop heat pipe, providing the best performance level. The pure water working fluid and oxygen-free copper exhibit good compatibility, supporting reliable and stable operation of the loop heat pipe within the product's lifespan requirements. The total thermal resistance of the loop heat pipe is no higher than 0.005K / W, the maximum heat flux density of evaporator 1 is no less than 200W / cm², and the maximum total heat transfer is no less than 1500W.

[0024] See Figure 7 A butterfly-shaped channel 41 is provided inside the liquid pipeline 4. In this way, the steam that leaks heat from the evaporator 1 to the liquid storage chamber 13 can no longer obstruct the liquid backflow, thus increasing the liquid-gas separation efficiency.

[0025] In this embodiment, see Figure 1 The evaporator 1 consists of an evaporation end cap 11, an evaporation bottom surface 12, and a sintered porous capillary wick 2. The inner wall of the evaporation bottom surface 12 is machined with a microchannel structure. The bottom surface of the sintered porous capillary wick 2 is welded to the inner surface of the evaporation bottom surface 12. The evaporation end cap 11 and the evaporation bottom surface 12 together form an evaporation cavity. The space between the evaporation end cap 11 and the sintered porous capillary wick 2 is a liquid storage cavity 13, used to store the refluxed liquid working fluid. The side wall of the evaporation end cap 11 has a steam pipe interface for connecting one end of a steam pipe 5; the upper part of the evaporation end cap 11 has a protruding structure, and the side wall of the protruding structure has a liquid pipe interface for connecting one end of a liquid pipe 4.

[0026] See Figure 2 The condenser 3 consists of a condensing end cap 31, a condensing bottom surface 32, and a condensing capillary structure 33. Both the inner walls of the condensing end cap 31 and the condensing bottom surface 32 are machined with capillary structures and microchannels. The side wall of the condensing end cap 31 has a steam pipe interface and a liquid pipe interface, used to connect the other end of the steam pipe 5 and the other end of the liquid pipe 4, respectively.

[0027] See Figure 3 The bottom surface of evaporator 1 is tightly attached to the high heat flux chip. When the chip is working, the heat generated is transferred to the inner surface of the evaporation bottom surface 12, and the temperature of the inner surface rises, causing the working fluid in the microchannels of the evaporation bottom surface 12 to evaporate into steam. The generated steam flows through the steam pipe 5 into the condenser 2. It condenses inside the condenser 3. The condensed liquid working fluid then flows back to the liquid storage chamber 13 of evaporator 1 along the liquid pipe 4 under the action of the thermal pressure difference between evaporator 1 and condenser 3. The liquid working fluid in the liquid storage chamber 13 is then transported to the evaporation bottom surface 12 by the capillary suction of the sintered porous liquid wick 2. This cycle repeats, spontaneously forming a gas-liquid two-phase cycle, achieving efficient heat transfer.

[0028] See Figure 4The evaporator 1 and condenser 3 are connected by a steam pipe 5 and a liquid pipe 4. The liquid pipe 4 is higher than the steam pipe 5, with one end connected to the liquid storage chamber 13 of the evaporator 1, and the connection port located on the side wall of the liquid storage chamber 13. The other end is connected to the condenser 3, and the connection port is located at the apex of the condenser 3. The steam pipe 5 is connected to the side walls of both the evaporator 1 and the condenser 3.

[0029] See Figure 5 The evaporator 1 and condenser 3 are connected by two steam pipes 5 and one liquid pipe 4. The liquid pipe 4 is higher than the steam pipe 5, with one end connected to the liquid storage chamber 13 of the evaporator 1, and the connection port located on the side wall of the liquid storage chamber 13. The other end is connected to the condenser 3, and the connection port is located at the apex of the condenser 3. The steam pipes 5 are connected to the side walls of both the evaporator 1 and the condenser 3.

[0030] See Figure 6 The condensation capillary structure can be a microgroove structure 331, a micropillar structure 332, or a porous structure 333 (such as metal powder sintering or foam metal), preferably a combination of microgroove structure 331 and micropillar structure 332.

[0031] See Figure 7 A butterfly-shaped channel 41 is provided inside the liquid pipeline 4. In this way, the steam that leaks heat from the evaporator 1 to the liquid storage chamber 13 can no longer obstruct the liquid backflow, thus increasing the liquid-gas separation efficiency.

[0032] Referring to Table 1 below, with an evaporation area of ​​7.68 cm² 2 Under these conditions, the single-steam loop heat pipe can still operate normally under a heating condition of Q=1550W, and its heat flux density reaches q=201.8W / cm³. 2 At this point, the evaporator bottom surface temperature T1 is 61℃, the condenser temperature T3 is 53℃, and the thermal resistance R1 of the loop heat pipe is only 0.0053K / W. The heat dissipation capacity of this embodiment is significantly higher than the limit of existing liquid cooling plate technology (approximately 100W / cm²). 2 The heat transfer effect is significantly improved.

[0033] Table 1

[0034] Referring to Table 2 below, with an evaporation area of ​​only 7.68 cm² 2 Under these conditions, the dual-steam loop heat pipe can still operate normally under extreme heating conditions of Q=1550W, and its heat flux density reaches q=201.8W / cm³. 2 At this point, the evaporator bottom surface temperature T1 is only 59°C, the condenser temperature T3 is only 53°C, and the thermal resistance R1 of the loop heat pipe is only 0.0038 K / W. The heat dissipation capacity of this embodiment far exceeds that of existing liquid cooling plate technology (approaching 100 W / cm²).2 ).

[0035] Table 2

[0036] In this invention, the phase change heat transfer process is enhanced by the synergistic effect of the microchannel structure in the evaporator 1 and the sintered porous capillary core 2, combined with the double-sided micro-capillary condensation structure 33 on the condenser 3, so as to achieve heat dissipation performance with extremely low thermal resistance, ultra-high heat flux density and large total heat transfer. Its heat dissipation capacity is greatly improved compared with the existing liquid cooling technology, which can meet the demanding heat dissipation requirements of high-performance chips. Furthermore, the condensate formed by the condensation of steam in the steam pipe 5 can be automatically discharged through the setting of the drainage structure in the steam pipe 5.

[0037] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A loop heat pipe heat dissipation device, characterized in that, include: Evaporator (1), the evaporator (1) is composed of evaporation end cap (11), evaporation bottom surface (12) and sintered porous capillary core (2). The sintered porous capillary core (2) divides the inner cavity of the evaporator (1) into an upper liquid storage chamber (13) and a lower evaporation area. The inner surface of the evaporation bottom surface (12) is provided with a micron-level microchannel structure, and the sintered porous capillary core (2) is welded to the evaporation bottom surface (12). The condenser (3) is composed of a condensing end cap (31) and a condensing bottom surface (32), and both the inner surface of the condensing end cap (31) and the inner surface of the condensing bottom surface (32) are provided with condensing capillary structures (33). The loop heat pipe includes a liquid pipe (4) and a steam pipe (5), which are respectively connected between the evaporator end cap (11) and the condenser end cap (31), and the installation height of the liquid pipe (4) is higher than that of the steam pipe (5). The internal working fluid is pure water.

2. The loop heat pipe heat dissipation device according to claim 1, characterized in that, The pore diameter of the sintered porous capillary core (2) is 0.1μm-10μm.

3. The loop heat pipe heat dissipation device according to claim 1, characterized in that, The condensation capillary structure (33) on the condensation end cap (31) and the condensation bottom surface (32) is one or more combinations of microgroove structure (331), microcolumn structure (332) or porous structure (333).

4. The loop heat pipe heat dissipation device according to claim 1, characterized in that, The interface of the liquid pipeline (4) on the evaporator (1) side is located on the side wall of the liquid storage chamber (13), and the interface on the condenser (3) side is located at the top corner of the condenser (3).

5. The loop heat pipe heat dissipation device according to claim 1, characterized in that, The number of liquid pipelines (4) and steam pipelines (5) is one or more. The liquid pipeline (5) is provided with a filling port (6). The cross-sectional area of ​​the steam pipeline (5) is larger than that of the liquid pipeline (4). The condenser (3) is made of oxygen-free copper with a thickness of 1 mm.

6. A loop heat pipe heat dissipation device according to claim 5, characterized in that, The liquid pipeline (4) is provided with a butterfly channel (41).

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