Server liquid cooling micro-channel heat dissipation device

Abstract

The invention particularly relates to a liquid cooling micro-channel heat dissipation device for a server. According to the liquid cooling micro-channel heat dissipation device for the server, a flexible cover plate is arranged at the top of a micro-channel heat dissipation device, and a piezoelectric transducer is arranged above the flexible cover plate; the condenser is connected to an inlet of the micro-channel radiator through the driving pump, an outlet of the micro-channel radiator is connected back to an inlet of the condenser, and cyclic utilization of cooling liquid in the micro-channel radiator and the condenser is achieved under the action of the driving pump. During working, the piezoelectric transducer is connected with a power supply to trigger vibration, and then the flexible cover plate is triggered to vibrate, so that disturbance of fluid in the micro-channel radiator is caused, a speed boundary layer and a temperature boundary layer of cooling liquid are damaged, and heat exchange of the fluid is enhanced. According to the liquid cooling micro-channel heat dissipation device for the server, the local flow channel layout design and the vibration working principle of the piezoelectric transducer are combined, the flow heat transfer efficiency is enhanced through high-frequency vibration, the fluid flow resistance is reduced, and the heating requirement of an extremely-high-power chip can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid cooling and heat dissipation of electronic devices, and in particular to a liquid cooling microchannel heat dissipation device for a server. Background Art

[0002] Microchannel cooling technology, a key solution for thermal management in high-power-density electronic devices, typically consists of a network of micron-scale (10-500μm) fluid channels. Existing technologies primarily create regularly arranged parallel channels on the surface of substrates (such as silicon, metal, or ceramics) through etching, micro-nanofabrication, or additive manufacturing processes, achieving heat transfer through forced convection.

[0003] A typical implementation plan includes the following technical aspects:

[0004] 1) Channel topology optimization design based on fluid-structure interaction simulation;

[0005] 2) Fabricating the channel structure using photolithography-electrochemical etching or laser micromachining technology;

[0006] 3) Forming a closed circulation system through sealed packaging;

[0007] 4) Combined with pump-driven working fluid (such as water, fluorinated liquid) to achieve forced convection heat exchange.

[0008] By increasing the surface area to volume ratio and reducing the thickness of the thermal boundary layer, the technology can achieve a theoretical heat transfer coefficient of 5-10 times that of traditional radiators.

[0009] However, existing technologies still have several limitations in practical applications:

[0010] First, the narrow channel in the single-phase flow scheme leads to a significant increase in flow resistance, forcing the system to use high-power micropumps, resulting in a decrease in overall energy efficiency.

[0011] Secondly, the traditional parallel straight channel structure is prone to uneven flow distribution, leading to the formation of local hot spots (temperature differences exceeding 15°C), affecting device reliability;

[0012] Furthermore, the single-phase cold plate microchannel heat dissipation capacity is limited and still cannot meet the heating requirements of extremely high-power chips;

[0013] In addition, the poor bubble overflow capability of the two-phase cold plate microchannel during operation leads to increased flow resistance, modal boiling, and evaporation-drying phenomena.

[0014] These problems all limit the further improvement of the performance of the microchannel radiator. In order to solve the above problems, the present invention proposes a server liquid cooling microchannel radiator. Summary of the Invention

[0015] In order to overcome the defects of the prior art, the present invention provides a simple and efficient server liquid cooling microchannel heat dissipation device.

[0016] The present invention is achieved through the following technical solutions:

[0017] A server liquid-cooled microchannel heat sink, comprising a condenser, a drive pump, a control unit, a temperature sensor, a piezoelectric transducer, and a microchannel heat sink;

[0018] The driving pump and the piezoelectric transducer are respectively connected to a control unit;

[0019] The microchannel radiator is provided with a substrate at the bottom and a flexible cover at the top, and the piezoelectric transducer is arranged above the flexible cover; the chip is placed on the substrate, and an interface material is provided between the chip and the microchannel radiator;

[0020] The condenser is connected to the inlet of the microchannel radiator through a driving pump, and the outlet of the microchannel radiator is connected back to the inlet of the condenser, so that the coolant is circulated in the microchannel radiator and the condenser under the action of the driving pump;

[0021] During operation, the piezoelectric transducer is powered on to induce vibration, which in turn induces vibration of the flexible cover plate, thereby causing disturbances in the fluid inside the microchannel radiator, destroying the velocity boundary layer and temperature boundary layer of the coolant fluid and enhancing fluid heat exchange.

[0022] The piezoelectric transducer is placed in the middle part above the flexible cover plate, the two are in close contact, and are fixed through reserved bolt holes arranged at the four corners of the microchannel radiator body.

[0023] The middle part above the flexible cover is considered to be a local hot spot. If the local hot spot changes, the position of the piezoelectric transducer can be adjusted in time.

[0024] The flexible cover plate is made of, but not limited to, polytetrafluoroethylene, polyimide and carbon fiber reinforced polymer materials;

[0025] Other parts of the microchannel heat sink are made of metal materials, including but not limited to copper, aluminum, titanium and stainless steel.

[0026] A temperature sensor is provided at the outlet of the microchannel radiator, and the temperature sensor is connected to a control unit;

[0027] The temperature sensor measures the coolant temperature at the microchannel radiator outlet and transmits it to the control unit. The control unit then controls the input voltage to the piezoelectric transducer based on the coolant temperature, thereby controlling the piezoelectric transducer's vibration frequency and amplitude. This provides real-time regulation based on the heat generation power of the electronic device. This not only saves power but also prevents the piezoelectric transducer from operating at full capacity, which could shorten its lifespan.

[0028] The control unit compares the received coolant temperature information with a custom threshold:

[0029] If the coolant temperature at the outlet of the microchannel radiator reaches or exceeds the custom threshold, the input voltage of the piezoelectric transducer is increased, thereby increasing the vibration frequency and amplitude of the piezoelectric transducer until the input voltage of the piezoelectric transducer reaches the custom threshold or the coolant temperature at the outlet of the microchannel radiator is lower than the custom threshold;

[0030] If the coolant temperature at the outlet of the microchannel radiator is lower than the custom threshold, the input voltage of the piezoelectric transducer is reduced, thereby reducing the vibration frequency and amplitude of the piezoelectric transducer until the input voltage of the piezoelectric transducer reaches the custom threshold or the coolant temperature at the outlet of the microchannel radiator is no longer lower than the custom threshold.

[0031] When the coolant uses a phase change working fluid, the fluid in the microchannel radiator will boil and produce bubbles. However, due to the high-frequency vibration of the piezoelectric transducer, its boiling process will always maintain a foam flow state, preventing the aggregation of bubbles and thus maintaining a boiling heat transfer state with extremely high heat exchange efficiency.

[0032] Whether it is a single-phase heat transfer process or a two-phase heat transfer process, this device will greatly improve the heat transfer efficiency of the microchannel radiator.

[0033] Under the flexible cover, the flow channel of the microchannel radiator is specially designed and divided into non-local hot spot areas and local hot spot areas to enhance the heat transfer effect of the local characteristic areas and the temperature uniformity of the entire radiator;

[0034] For the non-local hot spot region, a straight microchannel structure with a channel width of 400 μm was used;

[0035] For local hotspot areas, a pin-fin microchannel structure is used, with a pin-fin diameter of 1 mm and a spacing of 1.5 mm.

[0036] The hot spot area is the middle area below the flexible cover plate, and its size is 10mm×10mm.

[0037] The beneficial effects of the present invention are: the server liquid-cooled microchannel heat dissipation device, combined with the local flow channel layout design and the vibration working principle of the piezoelectric transducer, enhances the flow heat transfer efficiency through high-frequency vibration, reduces the fluid flow resistance, and can meet the heating requirements of extremely high-power chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 This is a schematic diagram of the liquid-cooled microchannel heat dissipation device for a server according to the present invention.

[0040] Figure 2 This is a schematic diagram of the installation structure of the piezoelectric transducer and the microchannel radiator of the present invention.

[0041] Figure 3 This is a schematic diagram of the internal flow channel structure of the microchannel radiator of the present invention. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0043] A server liquid-cooled microchannel heat sink, comprising a condenser, a drive pump, a control unit, a temperature sensor, a piezoelectric transducer, and a microchannel heat sink;

[0044] The driving pump and the piezoelectric transducer are respectively connected to a control unit;

[0045] The microchannel radiator is provided with a substrate at the bottom and a flexible cover at the top, and the piezoelectric transducer is arranged above the flexible cover; the chip is placed on the substrate, and an interface material is provided between the chip and the microchannel radiator;

[0046] The condenser is connected to the inlet of the microchannel radiator through a driving pump, and the outlet of the microchannel radiator is connected back to the inlet of the condenser, so that the coolant is circulated in the microchannel radiator and the condenser under the action of the driving pump;

[0047] During operation, the piezoelectric transducer is powered on to induce vibration, which in turn induces vibration of the flexible cover plate, thereby causing disturbances in the fluid inside the microchannel radiator, destroying the velocity boundary layer and temperature boundary layer of the coolant fluid and enhancing fluid heat exchange.

[0048] The piezoelectric transducer is placed in the middle part above the flexible cover plate, the two are in close contact, and are fixed through reserved bolt holes arranged at the four corners of the microchannel radiator body.

[0049] The middle part above the flexible cover is considered to be a local hot spot. If the local hot spot changes, the position of the piezoelectric transducer can be adjusted in time.

[0050] The flexible cover plate is made of, but not limited to, polytetrafluoroethylene, polyimide and carbon fiber reinforced polymer materials;

[0051] Other parts of the microchannel heat sink are made of metal materials, including but not limited to copper, aluminum, titanium and stainless steel.

[0052] A temperature sensor is provided at the outlet of the microchannel radiator, and the temperature sensor is connected to a control unit;

[0053] The temperature sensor measures the coolant temperature at the microchannel radiator outlet and transmits it to the control unit. The control unit then controls the input voltage to the piezoelectric transducer based on the coolant temperature, thereby controlling the piezoelectric transducer's vibration frequency and amplitude. This provides real-time regulation based on the heat generation power of the electronic device. This not only saves power but also prevents the piezoelectric transducer from operating at full capacity, which could shorten its lifespan.

[0054] The control unit compares the received coolant temperature information with a custom threshold:

[0055] If the coolant temperature at the outlet of the microchannel radiator reaches or exceeds the custom threshold, the input voltage of the piezoelectric transducer is increased, thereby increasing the vibration frequency and amplitude of the piezoelectric transducer until the input voltage of the piezoelectric transducer reaches the custom threshold or the coolant temperature at the outlet of the microchannel radiator is lower than the custom threshold;

[0056] If the coolant temperature at the outlet of the microchannel radiator is lower than the custom threshold, the input voltage of the piezoelectric transducer is reduced, thereby reducing the vibration frequency and amplitude of the piezoelectric transducer until the input voltage of the piezoelectric transducer reaches the custom threshold or the coolant temperature at the outlet of the microchannel radiator is no longer lower than the custom threshold.

[0057] When the coolant uses a phase change working fluid, the fluid in the microchannel radiator will boil and produce bubbles. However, due to the high-frequency vibration of the piezoelectric transducer, its boiling process will always maintain a foam flow state, preventing the aggregation of bubbles and thus maintaining a boiling heat transfer state with extremely high heat exchange efficiency.

[0058] Whether it is a single-phase heat transfer process or a two-phase heat transfer process, this device will greatly improve the heat transfer efficiency of the microchannel radiator.

[0059] Under the flexible cover, the flow channel of the microchannel radiator is specially designed and divided into non-local hot spot areas and local hot spot areas to enhance the heat transfer effect of the local characteristic areas and the temperature uniformity of the entire radiator;

[0060] For the non-local hot spot region, a straight microchannel structure with a channel width of 400 μm was used;

[0061] For local hotspot areas, a pin-fin microchannel structure is used, with a pin-fin diameter of 1 mm and a spacing of 1.5 mm.

[0062] The hot spot area is the middle area below the flexible cover plate, and its size is 10mm×10mm.

[0063] Compared with existing technologies, this server liquid-cooled microchannel heat sink achieves efficient enhancement of the heat dissipation performance of the microchannel radiator through a multi-physics field and multidisciplinary design concept that combines piezoelectric transducer technology and flexible materials, solving problems such as high local hotspot temperature, weak heat dissipation capacity, and poor steam overflow capacity in existing microchannel heat sinks of electronic devices.

[0064] First, for the single-phase heat transfer process, the velocity boundary layer and the temperature boundary layer are destroyed, and the flow heat transfer efficiency is enhanced.

[0065] Secondly, for the two-phase heat transfer process, high-frequency vibration is used to hinder the aggregation and adhesion of bubbles, so that the boiling heat transfer process always maintains the flow pattern of foam flow. This is a heat transfer mode with extremely high heat transfer efficiency, which further enhances the heat transfer efficiency of the microchannel; and since there is no formation and blockage of large bubbles, the fluid flow resistance is greatly reduced.

[0066] Finally, by combining the local flow channel layout design with the vibration working principle of the piezoelectric transducer, the heat transfer efficiency of the local hotspot was enhanced and the temperature of the local hotspot was reduced.

[0067] The embodiment described above is only one specific implementation of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A server liquid cooling microchannel heat dissipation device, characterized by: Includes condenser, drive pump, control unit, temperature sensor, piezoelectric transducer and microchannel radiator; The driving pump and the piezoelectric transducer are respectively connected to a control unit; The microchannel radiator is provided with a substrate at the bottom and a flexible cover at the top, and the piezoelectric transducer is arranged above the flexible cover; the chip is placed on the substrate, and an interface material is provided between the chip and the microchannel radiator; The condenser is connected to the inlet of the microchannel radiator through a driving pump, and the outlet of the microchannel radiator is connected back to the inlet of the condenser, so that the coolant is circulated in the microchannel radiator and the condenser under the action of the driving pump; During operation, the piezoelectric transducer is powered on to induce vibration, which in turn induces vibration of the flexible cover plate, thereby causing disturbances in the fluid inside the microchannel radiator, destroying the velocity boundary layer and temperature boundary layer of the coolant fluid and enhancing fluid heat exchange.

2. The server liquid-cooled microchannel heat sink according to claim 1, characterized in that: The piezoelectric transducer is placed in the middle part above the flexible cover plate, the two are in close contact, and are fixed through reserved bolt holes arranged at the four corners of the microchannel radiator body.

3. The server liquid-cooled microchannel heat sink according to claim 1, characterized in that: The flexible cover plate is made of, but not limited to, polytetrafluoroethylene, polyimide and carbon fiber reinforced polymer materials; Other parts of the microchannel heat sink are made of metal materials, including but not limited to copper, aluminum, titanium and stainless steel.

4. The server liquid-cooled microchannel heat sink according to claim 1, characterized in that: A temperature sensor is provided at the outlet of the microchannel radiator, and the temperature sensor is connected to a control unit; The temperature sensor is responsible for collecting the coolant temperature at the outlet of the microchannel radiator and sending it to the control unit; the control unit controls the input voltage of the piezoelectric transducer according to the coolant temperature at the outlet of the microchannel radiator, thereby controlling the vibration frequency and amplitude of the piezoelectric transducer, and performing real-time regulation according to the heating power of the electronic device.

5. The server liquid-cooled microchannel heat sink according to claim 4, characterized in that: The control unit compares the received coolant temperature information with a custom threshold: If the coolant temperature at the outlet of the microchannel radiator reaches or exceeds the custom threshold, the input voltage of the piezoelectric transducer is increased, thereby increasing the vibration frequency and amplitude of the piezoelectric transducer until the input voltage of the piezoelectric transducer reaches the custom threshold or the coolant temperature at the outlet of the microchannel radiator is lower than the custom threshold; If the coolant temperature at the outlet of the microchannel radiator is lower than the custom threshold, the input voltage of the piezoelectric transducer is reduced, thereby reducing the vibration frequency and amplitude of the piezoelectric transducer until the input voltage of the piezoelectric transducer reaches the custom threshold or the coolant temperature at the outlet of the microchannel radiator is no longer lower than the custom threshold.

6. The server liquid-cooled microchannel heat sink according to claim 1, characterized in that: When the coolant uses a phase change working fluid, the fluid in the microchannel radiator will boil and produce bubbles. However, due to the high-frequency vibration of the piezoelectric transducer, its boiling process will always maintain a foam flow state, preventing the aggregation of bubbles and thus maintaining a boiling heat transfer state with extremely high heat exchange efficiency.

7. The server liquid-cooled microchannel heat sink according to claim 1, characterized in that: Under the flexible cover, the flow channel of the microchannel radiator is divided into a non-local hot spot area and a local hot spot area to enhance the heat transfer effect of the local characteristic area and the temperature uniformity of the entire radiator; For the non-local hot spot region, a straight microchannel structure with a channel width of 400 μm was used; For local hotspot areas, a pin-fin microchannel structure is used, with a pin-fin diameter of 1 mm and a spacing of 1.5 mm.

8. The server liquid-cooled microchannel heat sink according to claim 7, characterized in that: The hot spot area is the middle area below the flexible cover plate, and its size is 10mm×10mm.

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