WO2020258379A1

WO2020258379A1 - High-power chip closed liquid metal two-loop cooling system

Info

Publication number: WO2020258379A1
Application number: PCT/CN2019/095383
Authority: WO
Inventors: 刘慧�; 宋雯煜; 康刘胜; 李麒麟; 史金星
Original assignee: 东北大学
Priority date: 2019-06-26
Filing date: 2019-07-10
Publication date: 2020-12-30
Also published as: CN110299336A

Abstract

A high-power chip closed liquid metal two-loop cooling system, relating to the technical field of electronic device heat dissipation, and comprising a primary loop pipe (1), a primary coolant, a secondary cooling pipe (3), a secondary coolant, an adaptive induction electromagnetic pump (5), a direct current motor (6), a stirring rod group (7), and a liquid supplementation cover (2). Liquid metal with a high thermal conduction coefficient and high dynamic viscosity is used to transfer out the heat of the chip, and the high specific heat and high thermal conductivity of the secondary coolant are used to lower the temperature of the primary coolant, whilst the stirring in the secondary cooling pipe (3) can promptly transfer out the heat of the coolant, thereby implementing closed secondary high-efficiency cooling. As a novel high-efficiency reliable cooling system, the present invention can be widely used in chip cooling systems of home appliances and inverters, has a small volume and low noise, and the cooling capacity can be actively adjusted. The cooling effect of the present system is better than the water cooling systems currently used for chip heat dissipation, and meets the heat dissipation requirements of high-power electronic devices.

Description

High-power chip closed type liquid metal secondary circuit cooling system

Technical field

The invention belongs to the technical field of heat dissipation of electronic devices, and particularly relates to a high-power chip closed type liquid metal secondary circuit cooling system.

Background technique

With the accelerating process of contemporary scientific and technological innovation, the currently available cooling technology and corresponding heat dissipation system have become increasingly unable to meet the development needs of high-capacity, high-power, and small-volume electronic devices. Electronic devices are in high heat flux and overheating conditions. There is no good cooling, and this thermal barrier problem has even restricted the further development of high-power microelectronics. At present, the main cooling methods for high-power electronic devices are ordinary convection heat exchange and jet heat exchange with water as the coolant. However, water-cooled heat transfer needs to face phase change boiling, overheating and dry burning, limited heat transfer capacity, and the need to further improve the surface heat transfer coefficient through a complicated channel structure, and at the same time, there are problems such as increased resistance and reduced heat transfer capacity due to backflow. However, simply using the primary coolant as the coolant will also face the problems of high price, high thermal conductivity and high viscosity coefficient, which cannot be matched with other cooling systems.

Therefore, for the high-power electronic chip cooling technology, the team is committed to developing a primary coolant cooling system that can meet high heat flux cooling, is economical, safe and reliable, and has a simple industrialization process.

Summary of the invention

technical problem

The solution to the problem

Technical solutions

In view of the aforementioned shortcomings of the current cooling system, the purpose of the present invention is to provide a high-power chip closed liquid metal secondary circuit cooling system to alleviate the current lack of cooling capacity for high-power chips under high heat flux conditions. Utilize the high thermal conductivity of the primary coolant to transfer heat to the secondary coolant with a lower temperature. At the same time, the agitation of the secondary circuit improves its heat exchange intensity with the external environment. When the load power changes, it can pass Change the electromagnetic pump and motor voltage to adjust the primary coolant flow rate and the rotational speed of the radiant stirring rod group, change the flow pattern, and achieve adjustable closed cooling, enhanced heat exchange capacity, and no pollution. In order to maintain its working stability, the secondary coolant can be supplemented regularly, with low price and good stability.

In order to achieve the above objectives, the present invention adopts the following technical solutions:

A high-power chip closed type liquid metal secondary circuit cooling system, including a primary circuit tube, a primary coolant, a secondary cooling tube, a secondary coolant, an adaptive induction electromagnetic pump, a DC motor, a stirring rod group, and a liquid supplement cover, The primary circuit tube is filled with primary coolant, the outer wall of the primary circuit tube is sleeved with an adaptive induction electromagnetic pump through a fixed sleeve, the primary circuit tube is sealed with the secondary cooling tube, and the secondary cooling tube is filled with secondary coolant. A stirring rod group is installed at the end of the inner cavity of the secondary cooling tube to rotate, a DC motor is installed at the outer end of the secondary cooling tube, and the output shaft of the DC motor is fixedly installed with the stirring rod group, and the convex port of the secondary cooling tube is connected with the liquid supplement cover .

The stirring rod set consists of a base plate and a stirring rod. The base plate is fixedly installed with the inner wall of the ring through a number of connecting arms. The cross section of the ring is rectangular. The holes enclosed by the adjacent connecting arms, the ring and the base plate are fan-shaped holes. A stirring rod is arranged at the connection between the connecting arm and the ring, and adjacent stirring rods are arranged symmetrically with respect to the connecting arm, a semicircular protrusion is arranged at the center of the substrate, and a blind is provided on the semicircular protrusion. hole.

The adaptive induction electromagnetic pump is composed of a plurality of magnetic pole cores and a plurality of three-phase winding coils. The plurality of magnetic pole cores are evenly arranged along the circumferential direction into an elliptical structure with an inner hole along the axial direction of the plurality of magnetic pole cores. Several three-phase winding coils are arranged circularly in the three-phase sequence.

The primary cooling liquid is a low melting point metal liquid or a low melting point alloy solution, and the melting point is at or below room temperature.

The outer circular surface of the convex port is provided with external threads, and the convex port is connected with the liquid supplement cover through the threads.

The adaptive induction electromagnetic pump is a three-phase induction electromagnetic pump.

The liquid supplement cover is made of anti-oxidation and corrosion-resistant materials.

The fixed sleeve is composed of an upper sleeve body and a lower sleeve body, the upper sleeve body and the lower sleeve body are connected by a bayonet, the upper sleeve body and the lower sleeve body have the same structure, and the inner cavity of the upper sleeve body and the lower sleeve body is provided with a triangular plate , Both ends of the upper sleeve body and the lower sleeve body are symmetrically provided with horizontal plates, and the fixed sleeve is made of magnetic material.

The beneficial effects of the invention

Beneficial effect

The beneficial effects of the present invention are:

1. The liquid metal secondary circuit cooling system of the present invention makes up for the difficult heat exchange problem of the liquid metal single working medium cooling, and at the same time, the closed form also improves the stability of the system. The scope of application covers ordinary household appliances, industrial inverters and A charging pile with higher power still has the advantages of small size and convenient installation.

2. The adaptive induction electromagnetic pump used in the present invention can complete the regulation of the liquid metal flow rate under non-contact conditions. The cross-sectional shape matches the cross-sectional shape of the liquid metal pipe. At the same time, the electromagnetic pump has low noise and is easy to follow. Advantages of load regulation.

3. The secondary cooling liquid used in the present invention can change the physical properties of the cooling liquid according to different materials of accessories, power system changes and different working conditions to achieve different effects. Under the premise of high specific heat capacity, this cooling system has greater Use space.

4. The stirring rod group used in the present invention has a stable structure and good replaceability. According to different heat flow requirements, by changing the shape, number and rotation of the blades, it can more effectively assist the swirling heat dissipation of the secondary coolant.

5. The secondary loop nesting pipe of the present invention has a compact structure, high efficiency, few accessories, and a variable placement method, making it easier to function when the equipment space is insufficient.

6. The partial nesting of the primary loop pipe and the secondary cooling pipe not only ensures the heat conduction between the primary coolant and the device, but also ensures the timely output of the heat of the primary coolant, and ensures the stability of the cooling system. At the same time, the second nest can also increase the air-cooling mode by changing the tube length and tube shape.

Brief description of the drawings

Description of the drawings

Figure 1 is a front view of a high-power chip closed liquid metal secondary circuit cooling system;

Figure 2 is a B-B sectional view of a high-power chip closed liquid metal secondary circuit cooling system;

Figure 3 is a C-C cross-sectional view of a high-power chip closed liquid metal secondary circuit cooling system;

Figure 4 is a schematic diagram of the matching structure of the adaptive induction electromagnetic pump and the fixed sleeve of the high-power chip closed liquid metal secondary circuit cooling system;

Figure 5 is a three-dimensional schematic diagram of the stirring rod group of the high-power chip closed liquid metal secondary circuit cooling system;

Figure 6 is a schematic diagram of an adaptive induction electromagnetic pump for a high-power chip-enclosed liquid metal secondary circuit cooling system;

Figure 7 is a schematic diagram of the upper sleeve structure of a high-power chip closed liquid metal secondary circuit cooling system;

Figure 8 is a schematic diagram of the L-shaped buckle and L-shaped hole structure of the high-power chip closed liquid metal secondary circuit cooling system;

Figure 9 is a schematic diagram of the operation of the liquid metal closed secondary circuit cooling system;

1-primary circuit pipe, 2-refill cover, 3-secondary cooling pipe, 4-convex, 5-adaptive induction electromagnetic pump, 501-magnetic pole core, 502-three-phase winding coil, 6-DC motor, 7-Stirring rod set, 701-base plate, 702-connecting arm, 703-stirring rod, 704-sector hole, 8-fixed sleeve, 801-upper sleeve, 802-lower sleeve, 803-horizontal plate, 804-triangular plate , 805-L-shaped buckle, 806-L-shaped hole.

Invention embodiment

Embodiments of the invention

The present invention will be further described in detail below with reference to the drawings and embodiments.

As shown in Figure 1 to Figure 4 and Figure 9, a high-power chip closed liquid metal secondary circuit cooling system includes a primary circuit tube made of a metal material with high thermal conductivity and electrical conductivity. The secondary cooling pipe 2, the secondary cooling liquid, the adaptive induction electromagnetic pump 5, the direct current motor 6, the stirring rod group 7, and the liquid supplement cover 2 made of thermally conductive material. The primary circuit pipe 1 is filled with primary cooling liquid, The outer wall of a horizontal pipe of the primary loop pipe 1 is fitted with an adaptive induction electromagnetic pump 5 through a fixed sleeve 8, and the adaptive induction electromagnetic pump 5 is surrounded by a fixed sleeve 8, located in the inner cavity of the fixed sleeve 8, and the other end of the primary loop tube 1 is horizontal The section part is connected to the chip, and the outer wall of the primary circuit tube 1 is coated with thermal grease at the contact point of the chip to achieve good thermal conductivity. The section of the primary circuit tube 1 is elliptical to increase the contact area with the chip. At the same time, the primary circuit tube 1 It has the characteristics of long straightness, which ensures sufficient cooling length and flow stability. The primary loop pipe 1 and the front end of the secondary cooling pipe 2 are connected in a sealed manner, and the secondary cooling pipe 2 is filled with secondary coolant. The specific heat capacity of the secondary coolant is 1600-5000J/(kg.K), the thermal conductivity is 0.16-1W/(m·K), the conductivity is less than 0.005S/m, the dynamic viscosity is less than 10 ^-5 Pa·s, the secondary The working temperature range of the cooling liquid is wider than the working temperature range of the chip to be cooled, and the thermal stability is good. It follows the movement of the stirring rod group 7 to form a swirling motion. The secondary cooling liquid is water, dimethylsilane or both For mixed liquid, the inner cavity of the secondary cooling pipe 2 is equipped with a stirring rod group 7 at the end of the rotation, and the end of the secondary cooling pipe 2 is equipped with a DC motor 6 through the tail end hole and shaft seal to prevent the secondary cooling pipe 2 from being used. Liquid leakage, and the output shaft of the DC motor 6 is fixedly installed with the stirring rod group 7. The convex port 4 of the secondary cooling pipe 2 is connected with the liquid supplement cover 2, and the secondary cooling liquid can be periodically supplemented through the convex port 4 to ensure the cooling effect. The high-power chips of this system include computer chips, home appliances chips, and industrial product chips.

As shown in FIG. 5, the stirring rod set 7 consists of a base plate 701 and a stirring rod 703. The base plate 701 is fixedly installed with the inner wall of the ring through a number of connecting arms 702. The cross section of the ring is rectangular, and the adjacent connecting

arms

702 and 703 The hole surrounded by the ring and the base plate 701 is a fan-shaped hole 704. The fan-shaped hole 704 prevents the movement of the liquid from being hindered, and at the same time can strengthen the base plate 701 and reduce its deformation. A stirring rod 703 is arranged at the connection between the connecting arm 702 and the ring, and the same The adjacent stirring rod 703 is arranged symmetrically with respect to the connecting arm 702, a semicircular protrusion is provided at the center of the base plate 701, and a blind hole is opened on the semicircular protrusion. The blind hole is used to communicate with the output of the DC motor 6. The shafts are connected. The stirring rod group 7 is made of high-pressure, deformation-resistant, and corrosion-resistant materials, and has a radial shape. All the stirring rods 703 move together as a whole. Driven by the DC motor 6, the stirring rod group 7 overcomes the secondary cooling liquid. The gravity and viscous force move around the axis to drive the liquid to flow and enhance heat exchange. The material of the stirring rod group 7, the structure of the substrate 701, and the blade type can be adjusted in number and shape according to the power change of the cooled object to adapt to different Working conditions.

As shown in FIG. 6, the adaptive induction electromagnetic pump 5 is a three-phase induction electromagnetic pump, which is composed of a plurality of magnetic pole cores 501 and a plurality of three-phase winding coils 502, and the plurality of magnetic pole cores 501 are uniform along the circumferential direction. It is arranged in a structure with an elliptical inner hole, and a plurality of three-phase winding coils 502 are cyclically arranged in a three-phase sequence along the axial direction of the plurality of magnetic pole cores 501. When the three-phase winding coil 502 is energized with alternating current, a sinusoidal alternating current that changes with time is generated, and then a sinusoidal traveling magnetic field is formed. This magnetic field cuts the closed ring liquid metal to induce current inside the liquid metal. The current also changes with the traveling magnetic field at the same time, and the magnetic induction intensity is the largest on the surface of the liquid metal to drive the flow of the liquid metal. Through the adjustment of the power supply voltage, the sinusoidal alternating current is changed, and the Lorentz force received by the liquid metal is adjusted to control the flow rate of the liquid metal; the magnetic pole core 501 is evenly distributed on the tube wall of the primary loop tube 1, by influencing the liquid metal The magnetic field distribution changes the force of the liquid metal.

The primary cooling liquid is a low melting point metal liquid or a low melting point alloy solution, and the melting point is at or below room temperature, the thermal conductivity is 15-45 W/(m·K), and the dynamic viscosity is 0.0017-0.003 Pa·s, which has excellent The low melting point alloy solution is gallium, gallium indium alloy, gallium indium tin alloy, and sodium potassium alloy or a combination of several of them.

The outer circular surface of the convex port 4 is provided with an external thread, and the convex port 4 is connected to the liquid supplement cap 2 through the thread.

The liquid supplement cover 2 is made of oxidation-resistant and corrosion-resistant materials, and a rubber sealing ring is installed at the contact point between the inner end surface of the liquid supplement cover 2 and the end surface of the convex port 4 to prevent the secondary coolant from leaking through the convex port 4.

As shown in Figures 7 and 8, the fixing sleeve 8 is composed of an upper sleeve body 801 and a lower sleeve body 802. The inner walls of the upper sleeve body 801 symmetrically arranged in the direction of extension are provided with L-shaped buckles 805, and the lower sleeve body L-shaped holes 806 are provided on the two end surfaces of the 802 in the direction of extension. The upper sleeve body 801 and the lower sleeve body 802 are fixedly connected through the L-shaped buckle 805 and the L-shaped hole 806. The upper sleeve body 801 and the lower sleeve body The horizontal plate of 802 is provided with a triangular plate 804 along the length direction. The triangular plate 804 is installed in the gap of the magnetic pole core 501 adjacently arranged on the adaptive induction electromagnetic pump 5 to tighten the adaptive induction electromagnetic pump 5, and the upper casing 801 The two ends of the lower sleeve body 802 are symmetrically provided with a horizontal plate 803 along the length direction. The horizontal plate 803 on the upper sleeve body 801 and the horizontal plate 803 on the lower sleeve body 802 arranged at one end cooperate with the clamping-adaptive induction electromagnetic The magnetic pole core 501 and the fixed sleeve 8 of the pump 5 are made of magnetic material to isolate the adaptive induction electromagnetic pump 5 from causing magnetic interference to other equipment.

The working principle of the present invention is:

Firstly, the surface of the primary loop tube 1 of the device of the present invention where the adaptive induction electromagnetic pump 5 is not installed is attached to the chip. When the electronic device is working, the adaptive induction electromagnetic pump 5 and the DC motor 6 start to operate at the same time. The primary coolant is driven by the adaptive induction electromagnetic pump 5 in the direction of the chip in the primary loop tube 1. In order to maintain the stability of flow and heat absorption, the primary coolant flow is always in a low-speed state, when the primary coolant flows through When the primary loop pipe 1 part of the secondary cooling pipe 2 is located, the DC motor 6 works to drive the stirring rod group 7 to rotate, and the stirring rod group 7 makes the secondary coolant flow around the axis at a uniform speed, and the heat carried by the primary coolant passes through The convective heat transfer is transferred to the tube wall of the primary loop tube 1, and the heat of the primary loop tube 1 is taken away by the convection of the secondary coolant. Because the secondary coolant has a higher specific heat capacity and a lower temperature change rate, the heat is transferred to The outside world is easier and there is a longer buffer time. The heat generated by the chip is exported. The primary coolant in the primary circuit pipe 1 is cooled by entering the secondary cooling pipe 2, and then returned by the driving force provided by the adaptive induction electromagnetic pump 5. The inlet of the adaptive induction electromagnetic pump 5 completes a heat dissipation cycle. After the secondary coolant in the secondary cooling pipe 2 absorbs the heat transferred by the primary coolant, it conducts heat to the outside through the swirling effect of the secondary coolant to maintain the temperature stability , To further reduce the temperature when the equipment is under low load or shutdown, to realize the closed temperature control function of the secondary circuit.

Claims

A high-power chip closed type liquid metal secondary circuit cooling system, which is characterized in that it comprises a primary circuit tube, a primary coolant, a secondary cooling tube, a secondary coolant, an adaptive induction electromagnetic pump, a DC motor, and a stirring rod group , Liquid supplement cover, the primary circuit tube is filled with primary coolant, the outer wall of the primary circuit tube is fitted with an adaptive induction electromagnetic pump through a fixed sleeve, the primary circuit tube is sealed with the secondary cooling tube, and the secondary cooling tube is filled with secondary Coolant, a stirring rod group is installed at the end of the inner cavity of the secondary cooling tube to rotate, a DC motor is installed at the outer end of the secondary cooling tube, and the output shaft of the DC motor is fixedly installed with the stirring rod group, the convex port of the secondary cooling tube Connect with the refill cap.
The high-power chip closed type liquid metal secondary circuit cooling system according to claim 1, wherein the stirring rod group includes a substrate and a stirring rod, and the substrate is fixedly installed with the inner wall of the ring through a plurality of connecting arms , The cross section of the circular ring is rectangular, the holes enclosed by the adjacent connecting arms, the circular ring and the base plate are fan-shaped holes, and the stirring rod is arranged at the connection of the connecting arm and the circular ring, and the adjacent stirring rods are arranged symmetrically with respect to the connecting arm, A semicircular protrusion is provided at the center of the substrate, and a blind hole is opened on the semicircular protrusion.
The high-power chip closed liquid metal secondary circuit cooling system according to claim 1, wherein the adaptive induction electromagnetic pump is composed of a plurality of magnetic pole cores and a plurality of three-phase winding coils, and the plurality of magnetic poles The iron core is uniformly arranged in the circumferential direction into a structure with an elliptical inner hole, and a number of three-phase winding coils are cyclically arranged in a three-phase sequence along the axial direction of the several magnetic pole iron cores.
The high-power chip closed liquid metal secondary circuit cooling system according to claim 1, wherein the primary cooling liquid is a low melting point metal liquid or a low melting point alloy solution, and the melting point is at or below room temperature.
The high-power chip closed-type liquid metal secondary circuit cooling system according to claim 1, wherein the outer circular surface of the convex port is provided with an external thread, and the convex port is connected to the liquid supplement cover through the thread.
The high-power chip enclosed liquid metal secondary circuit cooling system according to claim 1, wherein the adaptive induction electromagnetic pump is a three-phase induction electromagnetic pump.
The high-power chip enclosed liquid metal secondary circuit cooling system according to claim 1, wherein the liquid supplement cover is made of anti-oxidation and corrosion-resistant materials.
The high-power chip closed liquid metal secondary circuit cooling system according to claim 1, wherein the fixed sleeve is composed of an upper sleeve body and a lower sleeve body, and the upper sleeve body and the lower sleeve body are connected by a bayonet , The upper sleeve body and the lower sleeve body have the same structure, the upper sleeve body and the lower sleeve body are provided with triangular plates in the middle of the inner cavity, the upper sleeve body and the lower sleeve body are symmetrically provided with horizontal plates at both ends, and the fixed sleeve is made of magnetic material .