A liquid cooling system based on phase change material circulation heat exchange

Abstract

The invention discloses a liquid cooling system based on phase change material circulation heat exchange, including a liquid cooling plate, a circulation heat exchange module and a driving plate; the liquid cooling plate is arranged horizontally, and is provided with an input main pipe, an output main pipe, and N heat pipes; each heat pipe is provided with M circulation heat exchange units; the circulation heat exchange units all include an outer shell, an inner shell, a solid phase change material, a pressure plate and a pressure rod; the center of the inner shell of the M circulation heat exchange units on the heat pipe divides the heat pipe into equal M+1 sections, and the cross-sectional area of ​​the inner shell of the M circulation heat exchange units increases according to a preset gradient along the flow direction of the cooling medium in the heat pipe; the driving plate is connected to the external pressure system, and is used to press the solid phase change material in the inner shell of each circulation heat exchange unit on the end surface of the liquid cooling plate. The invention has good refrigeration effect, high heat dissipation efficiency, low temperature difference, is suitable for heat dissipation of electrical components with high power and high charging cycle, and can improve the working performance and stability of electrical components.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation of electronic equipment, and in particular to a liquid cooling system based on cyclic heat exchange of phase change materials. Background Art

[0002] With the rapid development of industry, the integration of electronic chips in military and civilian fields such as aerospace, electronic information, etc. has been continuously improved, and their functions and complexity have grown at an alarming rate. As power increases and volume decreases, the heat flux density of electronic equipment during operation increases. At the same time, some highly integrated and high-powered power batteries also have heat concentration problems. The cooling technology of electronic components and power batteries will become a key technology that needs to be solved in the future development of electronic technology. If excessive heat dissipation cannot be dissipated to the surrounding environment in time, the junction temperature of the device will rise rapidly or even burn out. This has become one of the main factors affecting the reliability and performance of electronic devices and equipment, and directly affects the service life of equipment and instruments. Traditional air-cooled heat dissipation technology can no longer meet the gradually developing high heat dissipation needs. Liquid cooling technology is currently the most effective way to solve the heat dissipation problem of electronic equipment and power batteries.

[0003] With the rapid development of industry, the problem of heat concentration in a large number of components cannot be solved, such as power batteries and chips. In order to solve this problem, most scholars put forward views based on microchannel heat dissipation technology. Microchannel heat dissipation technology was first proposed by Tuckerman and Pease in 1981. Microchannel heat dissipation technology can be roughly divided into air cooling, liquid cooling and phase change material cooling according to the different cooling media. However, in some high-integrated circuits and high-power power batteries, air cooling cannot meet their heat dissipation requirements, so liquid cooling has become the mainstream heat dissipation method for chips and automotive power batteries. Controlling stable and appropriate temperature plays a decisive role in improving the performance of chips and power batteries.

[0004] The current liquid cooling plate is basically formed by opening a water channel on the substrate, and the water channel is an integral design, that is, the entire water channel has only one liquid inlet and one liquid outlet. The liquid needs to flow through the entire circuit to go out. Basically, there are problems such as unclear heat dissipation effect and increasing temperature along the outlet direction. The use of phase change materials has the advantages of temperature stability and high storage density during the solid-liquid phase change process. It can effectively improve the heat dissipation performance of the liquid cooling plate, but the traditional method of using phase change materials to cool power batteries often leads to a contradiction between the amount of phase change materials used and the weight of the battery pack because the temperature control effect of the phase change materials will decrease with the increase of discharge time. The present invention uses a piston to compress the phase change material in the solid phase state to form a cycle to dissipate heat for electronic equipment and power batteries, which better solves the problem of temperature control time of the phase change material. The present invention arranges the phase change material in equal gradients on the liquid cooling plate flow channel, and at the same time solves the problem of temperature unevenness that is common in liquid cooling. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a liquid cooling system based on phase change material circulation heat exchange in view of the defects involved in the background technology.

[0006] The present invention adopts the following technical solutions to solve the above technical problems:

[0007] A liquid cooling system based on phase change material circulation heat exchange, comprising a liquid cooling plate, a circulation heat exchange module and a driving plate;

[0008] The liquid cooling plate is arranged horizontally, and is provided with an input main pipe, an output main pipe, and N heat dissipation pipes, wherein N is a natural number greater than or equal to 1, wherein the input main pipe and the output main pipe are arranged in parallel; one end of the input main pipe is closed, and the other end extends from the side wall of the liquid cooling plate, and is used to connect the cooling medium; one end of the output main pipe is closed, and the other end extends from the side wall of the liquid cooling plate, and is used to output the cooling medium; the N heat dissipation pipes are arranged in parallel between the input main pipe and the output main pipe, and one end of each is connected to the input main pipe, and the other end is connected to the output main pipe;

[0009] The circulating heat exchange module comprises N*M circulating heat exchange units, where M is a natural number greater than or equal to 1, wherein each heat dissipation pipe is provided with M circulating heat exchange units;

[0010] The circulating heat exchange units all include an outer shell, an inner shell, a solid phase change material, a pressure plate and a pressure rod;

[0011] The outer shell and the inner shell are both hollow cylinders with openings at both ends, are both arranged vertically, and the lower ends are both sealed and fixedly connected to the upper end surface of the liquid cooling plate; the outer shell is sleeved outside the inner shell, the height of the outer shell is greater than that of the inner shell, a first cavity is formed between the outer shell, the liquid cooling plate, and the inner shell, and a second cavity is formed between the inner shell and the liquid cooling plate; the radius of the outer shell cross section is a times the radius of the inner shell cross section, and a is a preset threshold value greater than 1;

[0012] The inner shell is provided with a plurality of through holes at its bottom for connecting the first cavity and the second cavity;

[0013] The solid phase change material is filled in the second cavity;

[0014] The lower end of the pressure rod is vertically fixedly connected to the upper end surface of the pressure plate, and the upper end of the pressure rod is vertically fixedly connected to the lower end surface of the driving plate;

[0015] The centers of the inner shells of the M circulating heat exchange units on the heat dissipation pipe divide the heat dissipation pipe into M+1 equal sections, and the cross-sectional areas of the inner shells of the M circulating heat exchange units increase according to a preset gradient along the flow direction of the cooling medium in the heat dissipation pipe;

[0016] The driving plate is connected to the external pressure system, and is used to press the solid phase change material in the inner shell of each circulating heat exchange unit onto the upper surface of the liquid cooling plate to ensure that the solid phase change material in the inner shell of each circulating heat exchange unit is always in contact with the upper surface of the liquid cooling plate.

[0017] As a further optimization solution of the liquid cooling system based on phase change material circulation heat exchange of the present invention, the liquid cooling plate is made of aluminum alloy.

[0018] As a further optimization solution of the liquid cooling system based on phase change material circulation heat exchange of the present invention, the outer shell and the inner shell are made of any one of aluminum, aluminum alloy or stainless steel.

[0019] As a further optimization scheme of the liquid cooling system based on phase change material circulation heat exchange of the present invention, the solid phase change material is a composite of organic and inorganic substances, and its phase change stability is 40-50°C, wherein the organic substance is a saturated fatty acid or a straight-chain alkane, and the inorganic substance is expanded graphite.

[0020] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0021] 1. The composite phase change material of the present invention has a high thermal conductivity and a strong heat storage capacity, so that the liquid cooling system has a high heat storage and heat dissipation rate;

[0022] 2. Since the present invention proposes solid-liquid-solid phase recycling of phase change materials, the phase change material near the heat source of the device can always remain in a solid state, the temperature control time of the battery is long and the uniformity is better;

[0023] 3. Parallel liquid cooling channels are used for heat transfer of the liquid cooling plate, with high heat transfer coefficient and faster heat transfer rate;

[0024] 4. The phase change material circulation heat exchange device is arranged in equal gradient, which improves the temperature uniformity;

[0025] 5. The phase change material circulation heat exchange device of the liquid cooling system of the present invention can be disassembled and assembled, so that the whole device is modularized, which is convenient for maintenance and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a liquid cooling system based on phase change material circulation heat exchange.

[0027] Figure 2 This is a phase change material circulation heat exchange device of the present invention.

[0028] Figure 3 It is a structural schematic diagram of the circulating heat exchange unit in the present invention.

[0029] In the figure, 1-liquid cooling plate, 2-driving plate, 3-circulating heat exchange unit, 4-input main pipe, 5-output main pipe, 6-heat dissipation pipe, 7-outer shell, 8-inner shell. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings:

[0031] The present invention can be implemented in many different forms and should not be considered to be limited to the embodiments described herein. On the contrary, these embodiments are provided to make this disclosure thorough and complete, and will fully express the scope of the present invention to those skilled in the art. In the accompanying drawings, components are enlarged for clarity.

[0032] like Figure 1 As shown, the present invention discloses a liquid cooling system based on phase change material circulation heat exchange, including a liquid cooling plate, a circulation heat exchange module and a driving plate;

[0033] like Figure 2As shown, the liquid cooling plate is arranged horizontally, and is provided with an input main pipe, an output main pipe, and N heat dissipation pipes, wherein N is a natural number greater than or equal to 1, wherein the input main pipe and the output main pipe are arranged in parallel; one end of the input main pipe is closed, and the other end extends from the side wall of the liquid cooling plate, and is used to connect the cooling medium; one end of the output main pipe is closed, and the other end extends from the side wall of the liquid cooling plate, and is used to output the cooling medium; the N heat dissipation pipes are arranged in parallel between the input main pipe and the output main pipe, and one end of each is connected to the input main pipe, and the other end is connected to the output main pipe;

[0034] The circulating heat exchange module comprises N*M circulating heat exchange units, where M is a natural number greater than or equal to 1, wherein each heat dissipation pipe is provided with M circulating heat exchange units;

[0035] like Figure 3 As shown, the circulating heat exchange unit comprises an outer shell, an inner shell, a solid phase change material, a pressure plate and a pressure rod;

[0036] The outer shell and the inner shell are both hollow cylinders with openings at both ends, are both arranged vertically, and the lower ends are both sealed and fixedly connected to the upper end surface of the liquid cooling plate; the outer shell is sleeved outside the inner shell, the height of the outer shell is greater than that of the inner shell, a first cavity is formed between the outer shell, the liquid cooling plate, and the inner shell, and a second cavity is formed between the inner shell and the liquid cooling plate; the radius of the outer shell cross section is a times the radius of the inner shell cross section, and a is a preset threshold value greater than 1;

[0037] The inner shell is provided with a plurality of through holes at its bottom for connecting the first cavity and the second cavity;

[0038] The solid phase change material is filled in the second cavity;

[0039] The lower end of the pressure rod is vertically fixedly connected to the upper end surface of the pressure plate, and the upper end of the pressure rod is vertically fixedly connected to the lower end surface of the driving plate;

[0040] The center of the inner shells of the M circulating heat exchange units on the heat pipe divides the heat pipe into M+1 equal sections, and the cross-sectional area of ​​the inner shells of the M circulating heat exchange units increases according to a preset gradient along the flow direction of the cooling medium in the heat pipe, such as Figure 2 As shown;

[0041] The driving plate is connected to the external pressure system, and is used to press the solid phase change material in the inner shell of each circulating heat exchange unit onto the upper surface of the liquid cooling plate to ensure that the solid phase change material in the inner shell of each circulating heat exchange unit is always in contact with the upper surface of the liquid cooling plate.

[0042] The liquid cooling plate is made of aluminum alloy. The outer shell and inner shell are made of any one of aluminum, aluminum alloy or stainless steel.

[0043] The solid phase change material is a composite of organic and inorganic substances, and its phase change stability is 40-50° C., wherein the organic substance is a saturated fatty acid or a straight-chain alkane, and the inorganic substance is expanded graphite.

[0044] The working process of each circulating heat exchange unit is as follows:

[0045] The bottom of the solid phase change material in contact with the upper end surface of the liquid cooling plate begins to melt after being heated, and after being converted into liquid phase, it flows from the second cavity to the first cavity through the through hole at the bottom of the inner shell. While the solid phase change material is melting, the solid phase change material is always in contact with the upper end of the liquid cooling plate during the entire working process under the action of the external pressure system. At the end of the initial work, that is, when the discharge is finished, the liquid phase of the phase change material has filled the first cavity and flows back to the second cavity from the upper end of the first cavity. At this time, the pressure rod and the pressure plate are slowly retracted so that the liquid phase attached to them falls into the second cavity due to gravity. The liquid phase change material in the first and second cavities will gradually cool and solidify due to the decrease in temperature, and will eventually be completely converted into a solid phase. At this time, the height of the upper end surface of the solid phase will be lower than the height of the upper end surface of the solid phase change material during the first work. When working again, the battery module continues to transfer heat to the bottom of the solid phase change material, and the bottom of the solid phase change material in the first and second cavities melts at the same time and converts into liquid phase; at this time, the external pressure system applies pressure to the solid phase change material in the second cavity again, so that the liquid phase in the second cavity flows to the first cavity and squeezes the liquid phase at the lower end of the first cavity. As the pressure of the liquid phase in the first cavity continues to increase, it will push the solid phase change material remaining in the first cavity due to the previous cycle upward, and fall into the second cavity at the top and then be covered by the remaining liquid phase, and finally enter the cycle at the end of the second work, and repeat this process to complete the phase change material circulation heat exchange module.

[0046] As the cooling medium gradually heats up along the flow direction, the cross-sectional area of ​​the inner shell of the circulating heat exchange unit on each heat dissipation tube also increases in a gradient to enhance heat exchange.

[0047] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0048] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A liquid cooling system based on phase change material circulation heat exchange, characterized in that: It includes a liquid cooling plate, a circulating heat exchange module and a driving plate; The liquid cooling plate is arranged horizontally, and is provided with an input main pipe, an output main pipe, and N heat dissipation pipes, wherein N is a natural number greater than or equal to 1, wherein the input main pipe and the output main pipe are arranged in parallel; one end of the input main pipe is closed, and the other end extends from the side wall of the liquid cooling plate, and is used to connect the cooling medium; one end of the output main pipe is closed, and the other end extends from the side wall of the liquid cooling plate, and is used to output the cooling medium; the N heat dissipation pipes are arranged in parallel between the input main pipe and the output main pipe, and one end of each is connected to the input main pipe, and the other end is connected to the output main pipe; The circulating heat exchange module comprises N*M circulating heat exchange units, where M is a natural number greater than or equal to 1, wherein each heat dissipation pipe is provided with M circulating heat exchange units; The circulating heat exchange units all include an outer shell, an inner shell, a solid phase change material, a pressure plate and a pressure rod; The outer shell and the inner shell are both hollow cylinders with openings at both ends, are both arranged vertically, and the lower ends are both sealed and fixedly connected to the upper end surface of the liquid cooling plate; the outer shell is sleeved outside the inner shell, the height of the outer shell is greater than that of the inner shell, a first cavity is formed between the outer shell, the liquid cooling plate, and the inner shell, and a second cavity is formed between the inner shell and the liquid cooling plate; the radius of the outer shell cross section is a times the radius of the inner shell cross section, and a is a preset threshold value greater than 1; The inner shell is provided with a plurality of through holes at its bottom for connecting the first cavity and the second cavity; The solid phase change material is filled in the second cavity; The lower end of the pressure rod is vertically fixedly connected to the upper end surface of the pressure plate, and the upper end of the pressure rod is vertically fixedly connected to the lower end surface of the driving plate; The centers of the inner shells of the M circulating heat exchange units on the heat dissipation pipe divide the heat dissipation pipe into M+1 equal sections, and the cross-sectional areas of the inner shells of the M circulating heat exchange units increase according to a preset gradient along the flow direction of the cooling medium in the heat dissipation pipe; The driving plate is connected to the external pressure system, and is used to press the solid phase change material in the inner shell of each circulating heat exchange unit onto the upper surface of the liquid cooling plate to ensure that the solid phase change material in the inner shell of each circulating heat exchange unit is always in contact with the upper surface of the liquid cooling plate.

2. The liquid cooling system based on phase change material circulation heat exchange according to claim 1 is characterized in that: The liquid cooling plate is made of aluminum alloy.

3. The liquid cooling system based on phase change material circulation heat exchange according to claim 1 is characterized in that: The outer shell and the inner shell are made of any one of aluminum, aluminum alloy or stainless steel.

4. The liquid cooling system based on phase change material circulation heat exchange according to claim 1 is characterized in that: The solid phase change material is a composite of organic and inorganic substances, and its phase change stability is 40-50° C., wherein the organic substance is a saturated fatty acid or a straight-chain alkane, and the inorganic substance is expanded graphite.

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