Immersed cooling battery pack for enhancing heat transfer by piezoelectric driving

Abstract

An immersed cooling battery pack for enhancing heat exchange by piezoelectric driving comprises a cooling box body, a piezoelectric element and a voltage-stabilized alternating current power supply, and a battery element and the piezoelectric element are both arranged in the cooling box body and immersed by cooling liquid; and the voltage-stabilized alternating current power supply is connected with the piezoelectric element to supply power to the piezoelectric element, so that the piezoelectric element vibrates or deforms, the cooling liquid is disturbed, and the heat exchange effect of the cooling liquid is enhanced. According to the invention, enhanced heat exchange of immersed cooling is realized, the highest temperature of the heating element can be effectively reduced, the temperature uniformity of immersed cooling is further improved, and the requirement of heat management of the heating element is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery thermal management, relates to immersion cooling, and in particular to an immersion cooling battery pack that utilizes piezoelectric drive to enhance heat exchange. Background Art

[0002] Thermal management is essential to ensure the safe and efficient operation of electronic devices and heat-generating components such as batteries. With the continuous development of technology, the integration of electronic devices and batteries continues to increase, and the accompanying thermal management challenges are becoming increasingly severe. The equipment will generate a lot of heat during daily operation. If the heat is not dissipated in a timely and effective manner, it will cause the temperature to rise, thereby affecting the performance of the equipment, shortening its life, and even causing safety problems. Therefore, an efficient thermal management system has become the key to ensuring the stable operation of the battery system.

[0003] Among the many methods of thermal management, immersion cooling stands out for its excellent heat dissipation performance. By fully or partially immersing the heat-generating components in the coolant, immersion cooling can minimize the thermal resistance between the components and the cooling medium and achieve rapid heat transfer. In the immersion cooling system, the application of enhanced heat exchange technology further improves the heat dissipation efficiency, but its enhanced heat exchange means are still relatively limited, mainly relying on the optimization of coolant performance, the improvement of cooling structure and the application of surface engineering technology. These traditional means have gradually approached their performance limits and are difficult to meet the growing demand for high efficiency and energy saving. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, an object of the present invention is to provide an immersion-cooled battery pack that utilizes piezoelectric drive to enhance heat exchange, so as to solve the problem of insufficient heat exchange in the existing immersion cooling system.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] An immersion cooling battery pack utilizing piezoelectric drive to enhance heat exchange comprises a cooling box, a piezoelectric element and a voltage-stabilized AC power supply, wherein the battery element and the piezoelectric element are both arranged in the cooling box and immersed in a coolant;

[0007] The voltage-stabilized AC power source is connected to the piezoelectric element to supply power thereto, causing the piezoelectric element to vibrate or deform, thereby disturbing the coolant and enhancing the heat exchange effect of the coolant.

[0008] In one embodiment, the battery element is fixed in the box and generates heat during operation, which requires cooling fluid to cool it down so that it can operate within a normal temperature range.

[0009] In one embodiment, the coolant is an oil coolant or a fluorocarbon coolant.

[0010] In one embodiment, the piezoelectric element is a piezoelectric ceramic or a piezoelectric fiber.

[0011] In one embodiment, the piezoelectric element is in the shape of a long straight or curved sheet or strip, which is installed in a cooling box with space left around it for vibration or deformation.

[0012] In one embodiment, the battery elements are grouped, and the piezoelectric elements are evenly arranged in the gaps between each battery element group and in the gaps between the battery element groups and the inner wall of the cooling box. Adjacent battery elements in the same group are connected by thermally conductive gaskets.

[0013] In one embodiment, a plurality of temperature sensors are arranged in the cooling box. When the temperature in the cooling box is lower than the optimum working temperature T1 of the battery elements, the voltage-stabilized AC power supplies connected to all the piezoelectric elements operate at a uniform voltage, so that the piezoelectric elements form a regular disturbance action together. When the local temperature in the cooling box is higher than the optimum working temperature T1 of the battery elements, the voltage-stabilized AC power supply connected to the piezoelectric element close to the local high temperature individually controls the vibration amplitude or deformation degree of the piezoelectric element to increase.

[0014] In one embodiment, a thermosensitive material is added to the interior of the piezoelectric element, and the thermosensitive metal is made into a flexible structure with mechanical adaptability and added to the interior of the piezoelectric element to take into account the function of temperature measurement and detect the temperature of the coolant in the cooling box.

[0015] In one embodiment, the output voltage range of the stabilized AC power supply is 10-200V. When the temperature of the piezoelectric element is greater than the optimal operating temperature T1 of the battery element, the output voltage of the stabilized AC power supply is increased to V1=100V-150V; when the temperature of the piezoelectric element is greater than the normal operating temperature T2 of the battery element, the output voltage of the stabilized AC power supply is increased to V2=150V-200V.

[0016] In one embodiment, the immersion cooling battery pack further includes a control center, which controls the output voltage of a regulated AC power supply connected to the piezoelectric element through the control center, and the number of the regulated AC power supplies is multiple, each connected to a different piezoelectric element.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. Piezoelectric elements have sensitive electromechanical conversion characteristics. Through piezoelectric drive and adjusting the input voltage, the vibration state of the heat exchange surface can be accurately controlled to intelligently enhance the heat exchange between the coolant and the battery element surface.

[0019] 2. The system can be intelligently adjusted according to the actual temperature requirements of the battery components, achieving more precise temperature control.

[0020] 3. The piezoelectric drive system is small in size and light in weight, and can be easily integrated into the existing immersion cooling system, reducing system complexity and improving overall performance.

[0021] 4. Piezoelectric drive systems usually have high energy conversion efficiency and relatively simple drive circuits. In the process of enhanced heat exchange, piezoelectric drive can reduce energy consumption and improve the energy efficiency of the overall system.

[0022] 5. Piezoelectric elements have fast dynamic response characteristics, which can achieve rapid vibration and adjustment of the heat exchange surface in a short time. This helps to achieve rapid heat dissipation under transient high temperature conditions and protect the equipment from damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the system structure in Example 1 of the present invention.

[0024] Figure 2 It is a schematic diagram of the system structure in Example 2 of the present invention.

[0025] Figure 3 It is a schematic diagram of temperature feedback control of the piezoelectric element of the present invention.

[0026] Figure 4 It is a schematic diagram of the piezoelectric driving principle used in the present invention.

[0027] Among them, 1-cooling box, 2-piezoelectric element, 3-heating element, 4-thermal conductive pad, 5-control center, 6-stabilized AC power supply, 7-electrode, 8-electric dipole in initial state, 9-internal polarized electric dipole. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below with reference to the accompanying drawings and examples.

[0029] The present invention discloses an immersion cooling battery pack that utilizes piezoelectric drive to enhance heat exchange, and utilizes the mechanical vibration generated by the piezoelectric element to disturb the coolant of the immersion cooling, thereby achieving efficient and balanced temperature management. Figure 1 and Figure 2As shown, the present invention includes a cooling box 1, a piezoelectric element 2 and a voltage-stabilized AC power supply 6. The battery element 3 and the piezoelectric element 2 are both arranged in the cooling box 1, and the cooling box 1 is filled with a coolant, which completely wraps and immerses the battery element 3 and the piezoelectric element 2 to be cooled, and is used to cool the battery element 3 and uniform the temperature in the box; in addition to being a battery, the battery element 3 can also be a heating element of an electronic device such as a server computer host, which will generate heat during operation and have a temperature control requirement, and requires a coolant to cool it down, so that it can work in a normal temperature range (20°C-40°C). The piezoelectric element 2 is powered by a voltage-stabilized AC power supply 6, has an electric field deformation characteristic, and converts electrical energy into mechanical energy through the piezoelectric driving principle, so that the piezoelectric element 2 vibrates or deforms, thereby disturbing the coolant and promoting enhanced heat exchange between the coolant and the battery element 3. The present invention realizes enhanced heat exchange of immersion cooling, can effectively reduce the maximum temperature of the heating element, and further improves the temperature uniformity of immersion cooling, meeting the requirements of thermal management of the heating element.

[0030] In a further embodiment of the present invention, the battery elements 3 are fixed in the cooling box 1, preferably connected to the bottom of the box, and can be grouped according to needs and actual conditions. The piezoelectric elements 2 are evenly arranged in the gaps between each battery element group and in the gaps between the battery element groups and the inner walls of the cooling box 1. Adjacent battery elements 3 in the same group are connected with thermally conductive gaskets 4 to even out the heat.

[0031] In a further embodiment of the present invention, the coolant is a liquid with good electrical insulation and stability and can dissipate heat efficiently. The high-quality coolant also has rust and corrosion resistance to protect the metal parts in the electronic device from corrosion. This protection will not affect the normal operation of the battery element 3 and can extend the service life of the equipment, reducing the need for maintenance and replacement of parts. For example, organic compounds such as oil coolants and fluorocarbon coolants, commonly used ones are polyolefins, natural gas synthetic oils, fluoropolyethers, etc., and the battery element 3 and the piezoelectric element 2 need to be completely wrapped in the cooling box 1.

[0032] In a further embodiment of the present invention, the piezoelectric element 2 has the characteristics of generating current and pressure changes under the stimulation of pressure or current, such as piezoelectric ceramics, piezoelectric fibers, etc., and its shape is a long straight or curved sheet, strip, etc. Through the external voltage-stabilized AC power supply 6 connected to the wire, under the action of the external electric field, the electric dipole inside the piezoelectric element 2 is affected by the electric field force, and the orientation changes, resulting in changes in the internal charge distribution, causing changes in the stress distribution inside the element, thereby generating deformation or displacement. This phenomenon is called the piezoelectric drive principle. Under the action of the alternating electric field, the piezoelectric element 2 will generate mechanical vibrations with the same frequency as the electric field, so it can disturb the coolant, so that the coolant and the heating element can fully exchange heat. Therefore, after the piezoelectric element 2 is installed in the cooling box 1, the necessary space for its vibration or deformation should generally be left around it.

[0033] In a further embodiment of the present invention, a plurality of temperature sensors are arranged in the cooling box 1. When the temperature in the cooling box 1 is lower than the optimum working temperature T1 of the battery element 3, the voltage-stabilized AC power supply 6 connected to all the piezoelectric elements 2 operates at a uniform voltage, so that each piezoelectric element 2 forms a regular disturbance action together; when the local temperature in the cooling box 1 is higher than the optimum working temperature T1 of the battery element 3, the voltage-stabilized AC power supply 6 connected to the piezoelectric element 2 close to the local high temperature individually controls the vibration amplitude or deformation degree of the piezoelectric element 2 to increase, thereby ensuring that the local high temperature of the heating element is improved.

[0034] In a further embodiment of the present invention, the piezoelectric element 2 is mainly arranged between the gaps of the battery element 3 and between the battery element 3 and the box body, and there are no special requirements for its position, form and shape. Similarly, the piezoelectric element 2 can be directly fixed in the cooling box body 1 instead of being embedded in the box body 1.

[0035] In a further embodiment of the present invention, a thermosensitive material, such as metal platinum, is added to the inside of the piezoelectric element 2. After the thermosensitive metal is made into a flexible structure with stronger mechanical adaptability and added to the piezoelectric element 2, it can also function as a temperature sensor to detect the temperature of the coolant in the cooling box 1.

[0036] In a further embodiment of the present invention, Figure 3 As shown, it also includes a control center 5 for processing temperature feedback, and the control center 5 controls the output voltage of the stabilized AC power supply 6 connected to the piezoelectric element 2, so as to achieve the purpose of controlling the vibration amplitude or deformation degree of the piezoelectric element 2. In this embodiment, the number of stabilized AC power supplies 6 can be multiple, each connected to different piezoelectric elements 2.

[0037] In a further embodiment of the present invention, the output voltage range of the stabilized AC power supply 6 is 10-200V, and the piezoelectric element 2 is connected by wires. The temperature is monitored during the process. When the temperature of the piezoelectric element 2 is greater than the optimal working temperature T1 of the battery element 3 (typically 20°C-30°C), the output voltage of the stabilized AC power supply 6 is increased to V1=100V-150V; when the temperature of the piezoelectric element 2 is greater than the normal working temperature T2 of the battery element 3 (typically 30°C-40°C), the output voltage of the stabilized AC power supply 6 is increased to V2=150V-200V. By adjusting the voltage, the vibration amplitude or deformation amplitude of the piezoelectric element is controlled, that is, the piezoelectric driving principle, and this principle can be used to enhance the heat exchange efficiency between the coolant and the heating element.

[0038] The specific principle of the present invention is:

[0039] Piezoelectric element 2 has sensitive electromechanical conversion characteristics. The piezoelectric drive of piezoelectric element 2 is used to enhance heat exchange, and the vibration state of the heat exchange surface can be accurately controlled, thereby enhancing the convective heat exchange between the coolant and the battery surface. This dynamic control mechanism not only improves the heat exchange efficiency, but also enables the system to be intelligently adjusted according to the actual temperature requirements of the battery, achieving more accurate temperature control, and bringing a new solution to the immersion cooling system. Piezoelectric drive means that piezoelectric elements such as quartz, lithium niobate, piezoelectric ceramics, piezoelectric fibers, etc. have the characteristic of deforming under the action of an electric field. Reference Figure 4 As shown, the piezoelectric element 2 is connected to the voltage-stabilized AC power supply 6 via an electric wire. When there is no electric field, the electric dipole 8 between the electrodes 7 is in the initial state; when the electric field energy acts on the crystal structure, the positive and negative ions in the unit cell are relatively displaced, resulting in macroscopic polarization, and the internally polarized electric dipole 9 has undergone a significant change compared with the initial electric dipole 8, resulting in mechanical stress in the material, thereby inducing deformation, which is usually manifested in the form of vibration, bending, etc. The vibration generated by the piezoelectric drive of the piezoelectric element 2 is used to form a turbulent flow in the coolant, which can accurately control the vibration state of the heat exchange surface and enhance the convective heat exchange between the coolant and the surface of the heating element. Adding a thermosensitive material to the piezoelectric element 2 can also intelligently respond to the actual temperature of the battery element 3, so that the system can intelligently adjust the vibration frequency, amplitude or deformation degree according to the actual temperature requirements of the heating element, achieve more accurate temperature control, and significantly improve the system efficiency and flexibility. In addition, the piezoelectric drive system is small in size and light in weight, and is easy to integrate into the existing immersion cooling system, reducing the complexity of the system and improving the overall performance.

[0040] Two specific embodiments of the present invention are as follows.

[0041] Example 1

[0042] like Figure 1 and Figure 3As shown, an immersion cooling battery pack using piezoelectric drive to enhance heat exchange is shown. The cooling box 1 is filled with coolant, and piezoelectric elements 2 and battery elements 3 are arranged in the box. The coolant fully soaks and wraps the battery element 3 and the piezoelectric element 2 to achieve a balanced temperature distribution and effectively cool the battery element 3. The battery element 3 generates heat during operation, so temperature control is required.

[0043] Two or more battery elements 3 form a cluster, thirteen battery elements 3 in this example, and the battery elements 3 are not in direct contact with each other but are connected to a 10 mm thick thermal conductive gasket 4, in order to make the element temperature uniform. The cooling box 1 contains at least two clusters of heating element groups, four clusters in this example, with a spacing of 20 mm between each cluster.

[0044] In this example, the piezoelectric element 2 has a size of 100mm*50mm*2mm, is evenly embedded in the cover of the cooling box 1, and extends into the middle of the gap of the battery element group. Eight piezoelectric elements 2 are arranged in each gap, and a total of 40 piezoelectric elements are arranged in five gaps. The piezoelectric element 2 is focused on disturbing and dissipating heat in the middle and upper part of the battery element 3 where the heat is most concentrated. The arrangement in this example can ensure that the coolant around each battery element 3 can be disturbed, thereby obtaining a higher enhanced heat transfer efficiency.

[0045] The positive and negative electrodes of the voltage-stabilized AC power supply 6 are connected to two different sides of the piezoelectric element 2 by wires, so that the piezoelectric element vibrates under the action of voltage. The piezoelectric element 2 has the ability to convert electrical energy into mechanical energy. This conversion process can disturb the coolant. At the same time, according to the monitored temperature, the resistance of the piezoelectric element 2 changes accordingly, and the signal is transmitted to the control center 5. The control center then converts the command into an electrical signal and transmits it to the voltage-stabilized AC power supply 6. The voltage on both sides of the piezoelectric element 2 changes, so that it adjusts its vibration frequency and amplitude accordingly, thereby enhancing the heat exchange efficiency between the coolant and the battery element 3.

[0046] Example 2

[0047] like Figure 2 and Figure 3 As shown, an immersion cooling battery pack using piezoelectric drive to enhance heat exchange is shown. The cooling box 1 is filled with coolant, and piezoelectric elements 2 and battery elements 3 are arranged in the box. The coolant fully soaks and wraps the battery element 3 and the piezoelectric element 2 to achieve a balanced temperature distribution and effectively cool the battery element 3. The battery element 3 generates heat during operation, so temperature control is required.

[0048] Two or more battery elements 3 form a cluster, thirteen battery elements 3 in this example, and the battery elements 3 are not in direct contact with each other but are connected to a 10 mm thick thermal conductive gasket 4, in order to make the element temperature uniform. The cooling box 1 contains at least two clusters of heating element groups, four clusters in this example, with a spacing of 20 mm between each cluster.

[0049] In this example, the piezoelectric element 2 has a size of 500mm*50mm*2mm, and is evenly embedded in the sides of the cooling box 1 at both ends, and extends into the middle of the gap of the battery element group. There are 4 symmetrical piezoelectric elements 2 arranged on the left and right sides of each gap, and a total of 20 piezoelectric elements are arranged in five gaps. The piezoelectric elements 2 in this example are evenly distributed in the upper and lower parts of the battery element 3, and because the piezoelectric element 2 in this example is longer, the swing amplitude at the end is larger, which is conducive to heat dissipation in the middle part of the element where the heat is concentrated.

[0050] The positive and negative electrodes of the voltage-stabilized AC power supply 6 are connected to two different sides of the piezoelectric element 2 by wires, so that the piezoelectric element vibrates under the action of voltage. The piezoelectric element 2 has the ability to convert electrical energy into mechanical energy. This conversion process can disturb the coolant. At the same time, according to the monitored temperature, the resistance of the piezoelectric element 2 changes accordingly, and the signal is transmitted to the control center 5. The control center then converts the command into an electrical signal and transmits it to the voltage-stabilized AC power supply 6. The voltage on both sides of the piezoelectric element 2 changes, so that it adjusts its vibration frequency and amplitude accordingly, thereby enhancing the heat exchange efficiency between the coolant and the battery element 3.

[0051] In summary, the present invention is an immersion-cooled battery pack that utilizes piezoelectric drive to enhance heat exchange, and uses the piezoelectric effect of piezoelectric elements to open up a new technical path for immersion cooling systems. Through the sensitive electromechanical conversion performance of the piezoelectric element, the vibration state of the heat exchange surface can be precisely controlled, thereby promoting the convective heat transfer efficiency between the coolant and the battery surface. This dynamic adjustment mechanism not only greatly improves the heat exchange effect, but also gives the system the ability to make intelligent adjustments based on the real-time temperature requirements of the battery, ensuring the accuracy of temperature control. In addition, thanks to the compact size and lightweight design of the piezoelectric drive system, this method is easy to integrate with the existing immersion cooling system, effectively simplifying the system structure and further improving the overall performance.

Claims

1. An immersion cooling battery pack utilizing piezoelectric drive to enhance heat exchange, characterized in that: It comprises a cooling box (1), a piezoelectric element (2) and a voltage-stabilized AC power supply (6), wherein the battery element (3) and the piezoelectric element (2) are both arranged in the cooling box (1) and immersed in a cooling liquid; The voltage-stabilized AC power source (6) is connected to the piezoelectric element (2) to supply power thereto, causing the piezoelectric element (2) to vibrate or deform, thereby disturbing the coolant and enhancing the heat exchange effect of the coolant.

2. The immersion cooling battery pack using piezoelectric drive to enhance heat exchange according to claim 1, characterized in that: The battery element (3) is fixed in the box and generates heat when working, requiring cooling liquid to cool it down so that it can work within a normal temperature range.

3. The immersion cooling battery pack using piezoelectric drive to enhance heat exchange according to claim 1, characterized in that: The coolant is an oil coolant or a fluorocarbon coolant.

4. The immersion cooling battery pack using piezoelectric drive to enhance heat exchange according to claim 1, characterized in that: The piezoelectric element (2) is piezoelectric ceramic or piezoelectric fiber.

5. The immersion cooling battery pack using piezoelectric drive to enhance heat exchange according to claim 1 or 4, characterized in that: The piezoelectric element (2) is in the shape of a long straight or curved sheet or strip and is installed in the cooling box (1), with space left around it for vibration or deformation.

6. The immersion cooling battery pack using piezoelectric drive to enhance heat exchange according to claim 1, characterized in that: The battery elements (3) are grouped, and the piezoelectric elements (2) are evenly arranged in the gap between each battery element group and in the gap between the battery element group and the inner wall of the cooling box (1). Adjacent battery elements (3) in the same group are connected by thermally conductive pads (4).

7. The immersion cooling battery pack using piezoelectric drive to enhance heat exchange according to claim 1, characterized in that: A plurality of temperature sensors are arranged in the cooling box (1). When the temperature in the cooling box (1) is lower than the optimum working temperature T1 of the battery element (3), the voltage-stabilized AC power supply (6) connected to all the piezoelectric elements (2) operates at a uniform voltage, so that all the piezoelectric elements (2) form a regular disturbance action together. When the local temperature in the cooling box (1) is higher than the optimum working temperature T1 of the battery element (3), the voltage-stabilized AC power supply (6) connected to the piezoelectric element (2) close to the local high temperature controls the vibration amplitude or deformation degree of the piezoelectric element (2) to increase individually.

8. The immersion cooling battery pack using piezoelectric drive to enhance heat exchange according to claim 1, characterized in that: The piezoelectric element (2) has a thermosensitive material added therein, and the thermosensitive metal is made into a flexible structure with mechanical adaptability and added to the piezoelectric element (2) to have a temperature measurement function, thereby detecting the temperature of the coolant in the cooling box (1).

9. The immersion cooling battery pack using piezoelectric drive to enhance heat exchange according to claim 1, characterized in that: The output voltage range of the stabilized AC power supply (6) is 10-200V. When the temperature of the piezoelectric element (2) is greater than the optimal working temperature T1 of the battery element (3), the output voltage of the stabilized AC power supply (6) is increased to V1=100V-150V; when the temperature of the piezoelectric element (2) is greater than the normal working temperature T2 of the battery element (3), the output voltage of the stabilized AC power supply (6) is increased to V2=150V-200V.

10. The immersion cooling battery pack using piezoelectric drive to enhance heat exchange according to claim 7, 8 or 9, characterized in that: The immersion cooling battery pack also includes a control center (5), which controls the output voltage of a voltage-stabilized AC power source (6) connected to the piezoelectric element (2) through the control center (5), wherein the voltage-stabilized AC power source (6) is multiple in number and is respectively connected to different piezoelectric elements (2).

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