Topological optimization multi-level liquid cooling structure and manufacturing method

Abstract

The invention discloses a topological optimization multi-level liquid cooling structure and a manufacturing method, and relates to the technical field of heat dissipation and thermal management, the topological optimization multi-level liquid cooling structure comprises a liquid cooling plate, and a multi-level flow channel network composed of a first macroscopic main flow channel, a second macroscopic main flow channel and micro flow channels is arranged in a cavity of the liquid cooling plate; a liquid inlet and a liquid outlet are formed in the symmetrical positions of the two ends of the upper surface of the liquid cooling plate in the length direction; the liquid inlet is communicated with the first macroscopic main runner; the liquid outlet is communicated with the second macroscopic main runner; the liquid inlet is used for allowing cooling liquid jet flow to enter the multi-level flow channel network; the first macroscopic main flow channel and the second macroscopic main flow channel are communicated with the micro-channel and are lower than the micro-channel; a to-be-cooled heat source abuts against the upper surface of the liquid cooling plate through the heat conduction slide glass. And the horizontal position of the micro-channel in the cavity corresponds to a heat source to be cooled. The heat dissipation requirement under the working condition of high heat flux can be met, the cooling efficiency is high, and the temperature equalization performance is excellent.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation and thermal management technology, specifically to a topology-optimized multi-level liquid cooling structure and its manufacturing method. Background Technology

[0002] With the widespread application of high heat flux density devices such as electronic equipment, engines, and high-power batteries, the importance of thermal management technology is becoming increasingly prominent. In related technologies, most heat dissipation channels adopt single-layer or regularly shaped cooling channels, which limit their cooling efficiency and make it difficult to address the problem of localized heat accumulation caused by complex heat source distribution under high heat flux density conditions.

[0003] In recent years, with the rise of additive manufacturing technology, the fabrication of complex geometries has become possible. However, in related technologies, the fabrication methods for flow channel structures lack deep integration with additive manufacturing technology, making it difficult to simultaneously meet the geometric constraints of complex equipment while also considering cooling efficiency and manufacturing feasibility. For example, although jet cooling technology has good local cooling performance, it still cannot effectively solve the problem of heat accumulation.

[0004] Therefore, there is an urgent need for a cooling structure and manufacturing method that can balance cooling efficiency and temperature uniformity under high heat flux density conditions. Summary of the Invention

[0005] In view of this, the present invention provides a topology-optimized multi-level liquid cooling structure and manufacturing method to solve the technical problems in related technologies.

[0006] In a first aspect, the present invention provides a topology-optimized multi-level liquid cooling structure, comprising: a liquid cooling plate; the liquid cooling plate has a cavity inside, and the cavity has a multi-level flow channel network composed of a first macroscopic main flow channel, a second macroscopic main flow channel and microflow channels;

[0007] The upper surface of the liquid cooling plate is provided with an inlet and an outlet at symmetrical positions at both ends along the length direction; the inlet is connected to the first macroscopic main channel; the outlet is connected to the second macroscopic main channel; the inlet is used to allow the cooling liquid jet to enter the multi-level flow channel network;

[0008] The heights of the first and second macro-channels are both less than the height of the microchannels, and both the first and second macro-channels are connected to the microchannels.

[0009] The heat source to be cooled is in contact with the upper surface of the liquid cooling plate through a heat-conducting carrier; the horizontal position of the microchannel in the cavity corresponds to the heat source to be cooled.

[0010] Secondly, the present invention provides a method for manufacturing a topology-optimized multi-level liquid cooling structure, comprising:

[0011] S1. Determine the heat dissipation requirements, the shape and size of the liquid cooling plate based on the structure, size and heat flux density distribution of the application equipment that generates the heat source; the heat dissipation requirements include: heat dissipation power and the type of microchannel;

[0012] S2. Based on the heat flux density distribution, heat dissipation requirements, and the shape and size of the liquid cooling plate, determine the number of layers of the flow channel network, the arrangement and size of the first macroscopic main flow channel and the second macroscopic main flow channel, and the reserved space for the microflow channels.

[0013] S3. Based on the structure, size, and heat flux density distribution of the application equipment that generates the heat source, as well as the shape and size of the liquid cooling plate, determine the location of the inlet and outlet, the type and flow rate of the cooling liquid, and the material parameters of the cooling liquid and the flow channel network; the material parameters include: permeability, thermal conductivity, density, and specific heat.

[0014] S4. Based on the material parameters of the cooling liquid and the flow channel network, establish an interpolation format for the material parameters, and based on the interpolation format, establish a topology optimization model for the microchannel; the topology optimization model takes the design variable field as input and the field response of the design variable field as output; the output format of the field response is a two-dimensional density distribution map;

[0015] S5. Establish an objective function with the goal of minimizing the average temperature of the target area covered by the heat source to be cooled; the objective function simultaneously satisfies a first constraint and a second constraint; the first constraint is used to limit the volume of the cooling liquid in the microchannel; the second constraint is used to limit the size of the microchannel.

[0016] S6. Calculate the field response of the design variable field using the finite element analysis method, and calculate the sensitivity information of the objective function using the sensitivity analysis method;

[0017] S7. Based on the sensitivity information, the design variable field is updated and iterated using the moving asymptote method; when the sensitivity information meets the desired threshold, the field response of the current design variable field is output.

[0018] S8. Extract the contour curve of the two-dimensional density distribution map corresponding to the field response of the current design variable field to obtain the two-dimensional model of the microchannel, and stretch the two-dimensional model of the microchannel along the height direction of the liquid cooling plate to obtain the plate-shaped three-dimensional model of the microchannel.

[0019] S9. Embed the plate-shaped three-dimensional model into the corresponding reserved space, and connect the three-dimensional plate-shaped model with the first macroscopic flow channel and the second macroscopic flow channel through the vertical channel to obtain the three-dimensional model corresponding to the topology-optimized multi-level liquid cooling structure.

[0020] S10. Based on the three-dimensional model corresponding to the topology-optimized multi-level liquid-cooled structure, laser powder bed melting technology is used for integrated manufacturing to obtain the final topology-optimized multi-level liquid-cooled structure entity.

[0021] The topology-optimized microchannel structure of this invention significantly reduces the average temperature and maximum temperature difference in the heat source region, improves temperature distribution uniformity, and, by combining with the macroscopic main channel, optimizes the flow path of the cooling liquid, thereby effectively reducing pressure drop. Furthermore, by integrating the locally enhanced heat transfer characteristics of jet cooling technology with the global flow optimization capability of the topology-optimized microchannel, a multi-level liquid cooling channel structure adapted to array-type heat source distribution is formed. This solves the problems of low cooling efficiency and poor temperature uniformity in high heat flux density equipment in related technologies, thus achieving efficient heat dissipation and optimized fluid flow performance. Under the same flow rate conditions, the topology-optimized multi-level liquid cooling structure of this invention exhibits superior thermal management capabilities, particularly in enhancing local cooling and improving the overall system heat dissipation efficiency, meeting the complex cooling requirements of high heat flux density and multiple heat sources.

[0022] Furthermore, this invention fully integrates the process characteristics of additive manufacturing technology (laser powder bed melting), and achieves integrated forming of complex flow channel networks by optimizing the geometric constraints of microchannels (minimum channel size constraints), ensuring manufacturing precision and the connectivity of the internal flow channel network. It is not only suitable for applications requiring efficient heat dissipation, such as high-performance electronic devices and battery modules, but also has strong design flexibility, and can be adapted to diverse heat dissipation needs by adjusting the topology optimization target or vertical channels. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a topology-optimized multi-level liquid cooling structure according to an embodiment of the present invention;

[0025] Figure 2 This is another schematic diagram of the topology-optimized multi-level liquid cooling structure according to an embodiment of the present invention;

[0026] Figure 3 This is a left view of a topology-optimized multi-level liquid cooling structure according to an embodiment of the present invention;

[0027] Figure 4This is a front view of a topology-optimized multi-level liquid cooling structure according to an embodiment of the present invention;

[0028] Figure 5 This is a top view of a topology-optimized multi-level liquid cooling structure according to an embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the flow path of the cooling liquid in the flow channel network formed by the first type of microchannel structure according to an embodiment of the present invention.

[0030] Figure 7 This is a two-dimensional density distribution diagram of the first type of microchannel structure in this embodiment of the invention;

[0031] Figure 8 This is a two-dimensional density distribution diagram of the second type of microchannel structure in this embodiment of the invention;

[0032] Figure 9 This is a schematic diagram of the flow path of the cooling liquid in the channel network formed by the second type of microchannel structure according to an embodiment of the present invention.

[0033] Figure 10 This is a two-dimensional density distribution diagram of the third type of microchannel structure in this embodiment of the invention;

[0034] Figure 11 This is a schematic diagram of the flow path of the cooling liquid in the flow channel network formed by the third type of microchannel structure according to an embodiment of the present invention.

[0035] Figure 12 This is a two-dimensional density distribution diagram of the first type of microchannel structure in different sizes according to the embodiments of the present invention;

[0036] Figure 13 This is a CFD simulation result diagram of the flow channel network formed by the first type of microchannel structure in the embodiment of the present invention;

[0037] Figure 14 This is a CFD simulation result diagram of the flow channel network formed by the second type of microchannel structure in this embodiment of the invention.

[0038] Figure 15 This is a CFD simulation result diagram of the flow channel network formed by the third type of microchannel structure in this embodiment of the invention.

[0039] Figure label:

[0040] 1. Liquid cooling plate; 2. Cavity; 3. First macroscopic main channel; 4. Second macroscopic main channel; 5. Microchannel; 51. First liquid inlet; 52. First branch section; 53. First confluence section; 54. Second branch section; 55. First liquid outlet; 56. Second liquid inlet; 57. Third branch section; 58. Second liquid outlet; 59. Third liquid inlet; 510. Second confluence section; 511. Fourth branch section; 512. Fifth branch section; 513. Third liquid outlet; 514. Fourth liquid outlet; 6. Liquid inlet; 7. Liquid outlet; 8. Heat source to be cooled; 9. Thermally conductive carrier; 10. Vertical channel. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the purpose of simplifying the description of this invention and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] like Figure 1 and Figure 2As shown, the topology-optimized multi-level liquid cooling structure includes: a liquid cooling plate 1; the liquid cooling plate 1 has a cavity 2 inside, and the cavity 2 has a multi-level flow channel network composed of a first macroscopic main flow channel 3, a second macroscopic main flow channel 4 and a microflow channel 5;

[0046] The upper surface of the liquid cooling plate 1 is provided with an inlet 6 and an outlet 7 at symmetrical positions at both ends in the length direction; the inlet 6 is connected to the first macroscopic main channel 3; the outlet 7 is connected to the second macroscopic main channel 4; the inlet 6 is used to allow the cooling liquid jet to enter the multi-level flow channel network.

[0047] The heights of both the first macroscopic main channel 3 and the second macroscopic main channel 4 are less than the height of the microchannel 5, and both the first macroscopic main channel 3 and the second macroscopic main channel 4 are connected to the microchannel 5. Figure 3 and Figure 4 As shown;

[0048] like Figure 2 As shown, the heat source 8 to be cooled abuts against the upper surface of the liquid cooling plate 1 through the thermally conductive carrier 9; the horizontal position of the microchannel 5 within the cavity 2 corresponds to that of the heat source 8 to be cooled, as shown in the figure. Figure 5 As shown.

[0049] Specifically, the inlet 6 is located at one end of the liquid cooling plate 1 along its length and is used to introduce cooling liquid. First, the cooling liquid jets into the inlet 6 at a certain velocity and flows into the first macroscopic main channel 3, achieving initial fluid distribution. Subsequently, the cooling liquid flows through the microchannels 5 generated by the topology optimization algorithm and exchanges heat with the corresponding heat sources 8. Finally, it converges in the second macroscopic main channel 4 and is discharged from the liquid cooling plate 1 through the outlet 7. The flow path of the cooling liquid is as follows: Figure 6 As shown.

[0050] Preferably, the velocity of the cooling liquid jet entering the liquid cooling plate 1 is 1 m / s.

[0051] Preferably, the inlet 6 and the outlet 6 are circular in shape.

[0052] The outlet 7 is located at the other end of the liquid cooling plate 1 along its length and is symmetrically arranged with the inlet 6. This ensures that the cooling liquid entering the inlet 6 can flow evenly in the multi-level flow channel network and be efficiently discharged through the outlet 7, thereby allowing the flow path of the cooling liquid to run through the entire topology-optimized multi-level liquid cooling structure.

[0053] Secondly, the microchannel 5 is formed through a topology optimization algorithm, which can improve heat exchange efficiency and reduce fluid pressure drop.

[0054] In this embodiment of the invention, the cooling liquid is injected at high speed into the inlet via a jet, and then enters a multi-level flow channel network formed by the first and second macroscopic main channels and microchannels for layer-by-layer heat exchange. The locally enhanced cooling effect of the jet significantly improves the heat dissipation efficiency of the heat source to be cooled. The multi-level flow channel network reduces the average temperature and maximum temperature difference of the heat source, improving temperature distribution uniformity. Simultaneously, the flow path of the cooling liquid within the multi-level flow channel network effectively reduces pressure drop, meeting the complex cooling requirements of high heat flux density and multiple heat sources.

[0055] In one optional embodiment, the liquid cooling plate 1, the first macroscopic main flow channel 3, the second macroscopic main flow channel 4, the microflow channel 5, the liquid inlet 6, and the liquid outlet 7 are all made of high thermal conductivity aluminum alloy material (AlSi10Mg) and are integrally formed, such as... Figure 2 As shown.

[0056] Preferably, in this embodiment of the invention, the liquid cooling plate 1, the first macroscopic main channel 3, the second macroscopic main channel 4, the microchannel 5, the liquid inlet 6 and the liquid outlet 7 can be printed in an integrated manner using laser powder bed fusion (LPBF) technology.

[0057] In one alternative implementation, such as Figure 1-4 , Figure 7 As shown, the microchannel 5 is a plate-shaped structure that is wide at both ends and narrow in the middle; the microchannel 5 includes: a first inlet end 51, a first diversion section 52, a first confluence section 53, a second diversion section 54 and a first outlet end 55;

[0058] One end of the first liquid inlet 51 is connected to the first macroscopic main channel 3 through the vertical channel 10; one end of the first liquid outlet 55 is connected to the second macroscopic main channel 4 through the vertical channel 10.

[0059] Both the first diversion section 52 and the second diversion section 54 are plate-like structures with an elliptical outer contour and hollow interior, and both ends of the liquid cooling plate 1 extend with multiple branch channels; the other end of the first liquid inlet 51 is connected to the multiple branch channels at one end of the first diversion section 52; the other end of the first liquid outlet 55 is connected to the multiple branch channels at one end of the second diversion section 54; the first confluence section 53 is connected to the multiple branch channels at the other end of the first diversion section 52 and the other end of the second diversion section 54.

[0060] The microchannel structure described above is the first microchannel structure according to the embodiments of the present invention, and is applicable to the case of dual heat sources.

[0061] In one alternative implementation, such as Figure 5 As shown, both the microchannels 5 and the heat sources 8 to be cooled include multiple components; the number of microchannels 5 is equal to the number of heat sources 8 to be cooled. The heat sources 8 to be cooled are arranged in an array. The first diversion part 52 and the second diversion part 54 of each microchannel 5 correspond to one heat source 8 to be cooled in the horizontal position of the cavity 2.

[0062] In one alternative implementation, such as Figure 8 As shown, the microchannel 5 has a plate-like structure; the microchannel 5 includes a second inlet end 56, a third diversion section 57, and a second outlet end 58;

[0063] One end of the second liquid inlet 56 is connected to the first macroscopic main channel 3 through the vertical channel 10; one end of the second liquid outlet 58 is connected to the second macroscopic main channel 4 through the vertical channel 10.

[0064] The third diversion section 57 is a plate-like structure with an elliptical outer contour and hollow interior, and multiple branch channels extend from both ends along the width direction of the liquid cooling plate 1; the other end of the second liquid inlet 56 is connected to the multiple branch channels at one end of the third diversion section 57; the other end of the second liquid outlet 58 is connected to the multiple branch channels at one end of the third diversion section 57.

[0065] The microchannel structure described above is the second type of microchannel structure (single inlet, single outlet) designed for a single heat source in this embodiment of the invention, suitable for efficient heat dissipation in areas with concentrated local heat sources. See also Figure 9 By leveraging the distribution characteristics of a single heat source and adjusting the positions of the inlet and outlet as well as the topology of the microchannels, local heat dissipation performance can be maximized. It should be noted that for the second microchannel structure, the number and size of the corresponding first and second macroscopic main channels will be adaptively adjusted.

[0066] Cooling liquid enters the liquid-cooled plate 1 through a high-speed jet at a single inlet 6, flows through a topology-optimized single-heat-source channel network, and is discharged from a single outlet 7. The optimized channel structure creates a highly efficient local heat transfer effect in the concentrated heat source area, while achieving an optimal balance between the channel network length and the fluid pressure drop.

[0067] The geometry of the cooling channels is controlled based on Equation 10 to ensure that the minimum channel size meets the process requirements of additive manufacturing. The channel paths are precisely adjusted using topology optimization to maximize coverage of the heat source area. The flow path of the cooling liquid is as follows: Figure 9 As shown.

[0068] In one alternative implementation, such as Figure 10 As shown, the microchannel 5 has a plate-like structure; the microchannel 5 includes a third inlet end 59, a second confluence section 510, a fourth diversion section 511, a fifth diversion section 512, a third outlet end 513, and a fourth outlet end 514.

[0069] One end of the third liquid inlet 59 is connected to the first macroscopic main channel 3 through the vertical channel 10; one end of the third liquid outlet 513 and the fourth liquid outlet 514 are both connected to the second macroscopic main channel 4 through the vertical channel 10.

[0070] Both the fourth diversion section 511 and the fifth diversion section 512 are plate-like structures with a semi-elliptical outer contour and hollow interior, and both ends of the liquid cooling plate 1 extend with multiple branch channels; the other end of the third liquid outlet 513 is connected to the multiple branch channels at one end of the fourth diversion section 511; the other end of the fourth liquid outlet 514 is connected to the multiple branch channels at one end of the fifth diversion section 512.

[0071] A second confluence section 510 is formed between the fourth diversion section 511 and the fifth diversion section 512; the second confluence section 510 is two leaf-shaped plate-like structures connected at the root, and the second confluence section 510 is connected to the other end of the third liquid inlet end 59, the other end of the multi-branch channel of the fourth diversion section 511, and the other end of the multi-branch channel of the fifth diversion section 512.

[0072] In one optional embodiment, both the microchannels 5 and the heat sources 8 to be cooled include multiple microchannels 5; the number of microchannels 5 is equal to the number of heat sources 8 to be cooled; the heat sources 8 to be cooled are arranged in an array, and the horizontal position of each microchannel 5 in the cavity 2 corresponds to one heat source 8 to be cooled.

[0073] The microchannel structure described above is the third type of microchannel structure (single inlet, double outlet) in this embodiment of the invention. It is suitable for complex heat source distribution scenarios. By combining with the first macroscopic main channel and the second macroscopic main channel, it can significantly improve the uniformity and heat dissipation efficiency of the cooling liquid.

[0074] The single-inlet, dual-outlet microchannel structure addresses uneven heat source distribution by providing a single inlet at one end of the liquid cooling plate 1. This guides the cooling liquid into the jet region, where it flows through the topology-optimized microchannel structure and finally exits through two symmetrically arranged outlets. The flow path of the cooling liquid is as follows: Figure 11 As shown.

[0075] The jet region and the microchannel structure are combined to form a multi-stage heat exchange channel. The jet enhancement effect of the cooling liquid and the heat exchange effect of the topology-optimized microchannel work together to effectively improve the heat dissipation performance in complex heat source distribution scenarios.

[0076] Preferably, the diameter of the vertical channel is 1 mm.

[0077] This invention also provides a method for manufacturing a topology-optimized multi-level liquid-cooled structure, comprising the following steps:

[0078] S1. Determine the heat dissipation requirements, the shape and size of the liquid cooling plate based on the structure, size and heat flux density distribution of the application equipment that generates the heat source; the heat dissipation requirements include: heat dissipation power and the shape of the microchannel.

[0079] Specifically, heat-generating applications are devices with high heat density flux, such as electronic equipment, engines, and high-power battery modules. Of course, this also applies to ordinary heat-generating applications. Because the types of applications differ, their structures, dimensions, and heat flux distributions also vary. Therefore, the heat dissipation requirements, as well as the shape and size of the liquid cooling plate, need to be tailored to the specific application.

[0080] The heat dissipation requirements include both heat dissipation power and the type of microchannel. First, different application devices exhibit significant differences in heat flux density. For example, high-power electronic devices (such as CPUs and GPUs) may have high heat flux density, while low-power devices (such as sensors and low-power chips) have low heat flux density. This invention can assess the heat flux density distribution of application devices to determine their required heat dissipation power. Second, different application devices have different heat source distributions, and therefore require different types of microchannels. For example, for array-distributed heat sources, any type of microchannel can be used; for irregularly distributed heat sources, both the second and third types of microchannels can be used.

[0081] The shape and size of the liquid cooling plate must match the structure and size of the application equipment. At the same time, the shape and size of the liquid cooling plate directly limit the layout space of the multi-level flow channel network. It is necessary to fully consider the length, width, and height of the liquid cooling plate, as well as the arrangement of the first macroscopic main flow channel, the second macroscopic main flow channel, and the microflow channels inside, to ensure that the flow channel network can be reasonably arranged in a limited space, without interfering with other components, and effectively covering the areas that need heat dissipation.

[0082] For example, the heat sources to be cooled are in the form of a uniformly distributed array, with each unit heat source measuring 6mm × 6mm and having a heat flux density of 2 × 10⁻⁶. 9 W / m 3 ,like Figure 5 As shown, the overall dimensions of the liquid cooler are 150mm × 70mm × 8mm.

[0083] S2. Based on the heat flux density distribution, heat dissipation requirements, and the shape and size of the liquid cooling plate, determine the number of layers in the flow channel network, the arrangement and size of the first macroscopic main flow channel and the second macroscopic main flow channel, and the reserved space for the microflow channels.

[0084] Specifically, based on the heat flux density distribution and the type of microchannels, the number and arrangement of microchannels can be determined; based on the shape and size of the liquid cooling plate and the heat dissipation power, the number of layers in the channel network can be determined; finally, based on the number and arrangement of microchannels and the number of layers in the channel network, the arrangement between the microchannels and the first and second macroscopic main channels, as well as the dimensions of the first and second macroscopic main channels, can be further determined. Based on this, reserved space is provided for the microchannels to facilitate subsequent integration with the topology-optimized microchannels.

[0085] S3. Based on the structure, size, and heat flux density distribution of the application equipment that generates the heat source, as well as the shape and size of the liquid cooling plate, determine the location of the inlet and outlet, the type and flow rate of the cooling liquid, and the material parameters of the cooling liquid and the flow channel network; the material parameters include: permeability, thermal conductivity, density, and specific heat.

[0086] The location of the inlet and outlet has a significant impact on the flow and heat dissipation performance of the cooling liquid within the channel network. The locations of the inlet and outlet must be rationally selected based on heat dissipation requirements, heat flux density distribution, and the layout of the channel network to ensure effective circulation of the cooling liquid within the network and adequate coverage of the areas requiring heat dissipation. Simultaneously, the space constraints of the application equipment and the liquid cooling plate must also be met.

[0087] For example, the inlet and outlet are located at opposite ends of the liquid cooling plate along its length, respectively, and heat exchange is achieved through the inflow and outflow of cooling liquid. Both the inlet and outlet are circular with a diameter of 15 mm.

[0088] In addition, the type of cooling liquid can be deionized water, ethylene glycol, etc.

[0089] It should be noted that, depending on the type of material, cooling liquid and flow channel network can be referred to as fluid and solid, respectively.

[0090] S4. Based on the material parameters of the cooling liquid and the flow channel network, establish the interpolation format of the material parameters, and based on the interpolation format, establish the topology optimization model of the microchannel; the topology optimization model takes the design variable field as input and the field response of the design variable field as output; the output format of the field response is a two-dimensional density distribution map.

[0091] Specifically, in order to realize the dynamic evolution of the microchannels during the topology optimization process, the target region is discretized using four-node elements, and each element is assigned a relative density variable. and The target area is the area covered by the heat source to be cooled. The subscript i represents the element number of a finite number of elements, N eLet be the total number of units within the target area. For unit i, when... When, it indicates that unit i is a fluid; when When the value is 1, it indicates that unit i is a solid.

[0092] Based on the material parameterization of the cooling liquid (i.e., fluid) and the channel network (i.e., solid) described above, the solid isotropic material with penalization (SIMP) strategy is used to parameterize the permeability κ, thermal conductivity k, density ρ, and specific heat c of element i. p Establish the following interpolation format:

[0093]

[0094] in, Let κ be the relative density variable of unit i. s κ represents the permeability of the solid phase. f p represents the permeability of the fluid phase. k As the first penalty factor, and p k =3; k s k is the thermal conductivity of the solid phase. f ρ is the thermal conductivity of the fluid phase; ρf is the density of the solid phase; ρs is the density of the fluid phase; c f ρ is the specific heat of the solid phase. s Specific heat of the fluid phase; p ρ As the second penalty factor; p cp The third penalty factor; p ρ =p cp =1.

[0095] Based on the above interpolation format, a topology optimization model for the microchannel is established, and its expression is:

[0096]

[0097] Where γ is the design variable field, γ={γ1,γ2,...,γN} e}, γ i ∈[0,1](i=1,2,...N e ), N e γ represents the total number of finite element elements within the target region; i Used to characterize whether unit i is a fluid or a solid; when γ i =1, indicating that unit i is a fluid; when γ i When = 0, it indicates that unit i is a solid; φ is the objective function; h j Let M represent the j-th constraint function; M is the total number of constraint functions; K pK is the stiffness matrix of the fluid pressure field; p is the pressure field vector; t C is the thermal stiffness matrix; C(p) is the convection coupling term matrix related to the pressure field; t is the temperature vector; f p The output of the discrete equation for the pressure field; f t This is the output of the discrete equation for the temperature field coupled with heat conduction and convection.

[0098] It should be noted that the input to the topology optimization model is the design variable field γ, and the output is the field response of the design variable field. The field response includes the field response f of the pressure field. p and the field response f of the temperature field t Furthermore, the field response f of the pressure field. p and the field response f of the temperature field t The output format is a two-dimensional density distribution map, such as... Figure 7 , Figure 8 and Figure 10 As shown.

[0099] S5. Establish an objective function with the goal of minimizing the average temperature of the target area covered by the heat source to be cooled. The objective function simultaneously satisfies the first constraint and the second constraint. The first constraint is used to limit the volume of the cooling liquid in the microchannel. The second constraint is used to limit the size of the microchannel.

[0100] The objective function φ is expressed as follows:

[0101]

[0102] Among them, Ω * For the target area (i.e., the area covered by the heat source to be cooled), A Ω* N1 is the area of ​​the target region; T is the temperature field in K; L1 is the indicator vector, which is 1 for nodes within the target region and 0 for nodes outside the target region; t is the temperature vector.

[0103] First constraint:

[0104] The constraint function h1 that limits the volume of fluid within the microchannel can be expressed as:

[0105]

[0106] Among them, V f This represents the upper limit of the fluid's volume fraction. Let N be the relative density variable of unit i. e This represents the total number of finite element elements within the target area.

[0107] Second constraint:

[0108] When the fluid's structural features are too fine, dimensional errors caused by machining are difficult to control effectively. To eliminate excessively fine cooling channels in the optimization design, a minimum size constraint is used to control the channel size. That is, the minimum size feature of the fluid is constrained during the optimization process. The expression for the minimum size constraint is:

[0109]

[0110] in,

[0111]

[0112] For a given minimum size b, select an appropriate η d The specific selection method is as follows:

[0113]

[0114] in, For density filtering field, I f Here, r is the indicator function, r is the number of cells that the density filtering radius can accommodate during the iteration process, and h is the number of cells that can be accommodated. e For the unit size, η d ε is a parameter used to control the size of the flow channel. g To control the minimum value of the constraint strength; r min The density filtration radius.

[0115] Microchannels constrained by minimum size, such as Figure 12 As shown, its geometry and size are more regular, ensuring uniform distribution of cooling liquid in the flow channel network and efficient heat exchange performance.

[0116] It should be noted that the dimensions of the three microchannel structures designed in the embodiments of the present invention can be strictly controlled. The above only shows the first microchannel structure as an example, and the other two will not be described in detail here.

[0117] For example, when the minimum size b of the microchannel is equal to the density filter radius r min When they are equal, η d =0.75. Although the Heaviside projection (projection function) makes it difficult to precisely control the geometry of the flow channels in topology optimization, an explicit geometry control strategy can further ensure the independence of the optimization design from the mesh. The sensitivity of the objective function and constraint functions to the design variable field is calculated using the adjoint method, and the optimization problem is solved using the Method of Moving Asymptotes (MMA).

[0118] S6. Calculate the field response of the design variable field using the finite element analysis method, and calculate the sensitivity information of the objective function using the sensitivity analysis method.

[0119] Among these methods, Matlab software can be used to write code to solve the topology optimization model and obtain the field response of the design variable field.

[0120] S7. Based on the sensitivity information, the design variable field is updated and iterated using the moving asymptote method; when the sensitivity information meets the desired threshold, the field response of the current design variable field is output.

[0121] S8. Extract the contour curve of the two-dimensional density distribution map corresponding to the field response of the current design variable field to obtain the two-dimensional model of the microchannel, and stretch the two-dimensional model of the microchannel along the height direction of the liquid cooling plate to obtain the plate-shaped three-dimensional model of the microchannel.

[0122] S9. Embed the plate-shaped 3D model into the corresponding reserved space, and connect the 3D plate-shaped model with the first macroscopic flow channel and the second macroscopic flow channel through the vertical channel to obtain the 3D model corresponding to the topology-optimized multi-level liquid cooling structure.

[0123] Specifically, when embedding the three-dimensional plate model into the corresponding reserved space, it is necessary to combine the layout of the first and second macroscopic main channels and the actual spatial constraints to arrange the array distribution of microchannels and vertical channels, so as to match them with the area corresponding to the heat source, thereby obtaining a multi-level channel network to obtain the configuration of a topology-optimized multi-level liquid cooling structure, ensuring the connectivity of each channel network with the adjacent layer.

[0124] S10. Based on the three-dimensional model corresponding to the topology-optimized multi-level liquid-cooled structure, laser powder bed melting technology is used for integrated manufacturing to obtain the final topology-optimized multi-level liquid-cooled structure entity.

[0125] Specifically, the liquid cooling plate in this embodiment of the invention is printed in one piece using Laser Powder Bed Fusion (LPBF) technology. This manufacturing process has high precision, high degree of freedom and good material density, which can fully meet the manufacturing requirements of complex cooling channel structures.

[0126] Preferably, the following main process parameters are used during the printing process: laser power of 350W, layer thickness of 50μm, and scanning speed of 1200mm / s, to ensure high precision and high quality of the printed products.

[0127] Preferably, after printing, the surface of the internal flow channel network of the liquid cooling plate is optimized through post-processing to control the surface roughness to within 10 μm, thereby improving the heat exchange efficiency of the cooling liquid within the flow channels. The liquid cooling plate of this invention is suitable for array-type heat source devices with high heat flux density, and exhibits excellent heat dissipation performance, especially in applications such as phased array antennas and high-power electronic chips.

[0128] In an optional implementation, step S7 further includes:

[0129] During the update iteration of the design variable field, density filtering is used to transform the design variable field into a filtered density field, and a projection function is used to transform the filtered density field into a physical density field.

[0130] The physical density field is used as input to the topology optimization model for updating and iteration.

[0131] To avoid grid dependency and checkerboard problems in the topology optimization process, density filtering is used to transform the design variable field into a filtered density field.

[0132]

[0133] in,

[0134]

[0135] in, r is the filter density field of element i; min Represents the density filtering radius, ||γ i -γ e || represents the centroid distance between element i and element e; γ i The design variable field for unit i.

[0136] Furthermore, to eliminate grayscale cells in the topology optimization results, a smooth Heaviside projection function is used to transform the filtered density field into the physical density field:

[0137]

[0138] in, Let be the physical density field of element i, β represent the steepness of the projection, and η be the threshold of the projection.

[0139] Preferably, to quickly obtain a clearer microchannel topology, β = 16 and η = 0.5.

[0140] The embodiments of the present invention further optimize the microchannel structure by employing density filtering and projection functions to obtain a clear microchannel profile.

[0141] To verify the technical effect of the present invention, Fluent CFD simulation software was used to perform conjugate heat transfer simulation analysis on the first type of microchannel, the different sizes corresponding to the first type of microchannel, the second type of microchannel, and the third type of microchannel forming a topology-optimized multi-level liquid cooling structure, to obtain the global temperature field, pressure field, and velocity field, so as to prove the heat dissipation capability of the optimized liquid cooling structure.

[0142] For the first type of microchannel-formed topology-optimized multi-level liquid cooling structure:

[0143] Simulation results are as follows Figure 13 As shown, when the heat source power density reaches 400 W / cm² 2 Under these conditions, the average temperature of the heat source region is 86.62℃, and the highest temperature is 93.6℃. The temperature field exhibits high uniformity with no obvious local overheating. The pressure and velocity field distributions indicate that the coolant flows stably and at a uniform velocity within the microchannel region. This effectively improves the heat transfer efficiency of the coolant within the channel network, ensuring excellent temperature uniformity and low pressure drop performance under high power density heat source conditions. This result verifies that the topology-optimized multi-level liquid cooling structure can meet requirements exceeding 400 W / cm². 2 The heat dissipation performance requirements.

[0144] The embodiments of the present invention flexibly control the microchannel size through minimum size constraints, thereby improving heat dissipation performance and structural manufacturability, demonstrating its wide applicability and superiority in complex cooling structure design.

[0145] For the second type of microchannel formation, a topology-optimized multi-level liquid cooling structure is required:

[0146] Simulation results are as follows Figure 14 As shown, CFD simulations demonstrate that the single-inlet, single-outlet microchannel structure can significantly reduce the maximum temperature on the heat source surface, even when the heat source power density reaches 400 W / cm². 2 Under these conditions, the average temperature of the heat source region is 80.7℃, and the highest temperature is 85.8℃. Its heat dissipation performance in the local area is superior to that of the first microchannel structure. Furthermore, the temperature and pressure fields are uniformly distributed, avoiding problems such as localized overheating and uneven flow.

[0147] It should be noted that the second type of microfluidic structure can be further extended to heat dissipation scenarios for small electronic devices and components with localized high heat flux density, such as high-power laser diodes and single-chip heat dissipation modules. Compared to the first type of microfluidic structure, it has more significant advantages in local optimization and targeted applications.

[0148] For the topology-optimized multi-level liquid cooling structure formed by the third type of microchannel:

[0149] Simulation results are as follows Figure 15 As shown, CFD simulations demonstrate that the single-inlet, dual-outlet microchannel structure can achieve efficient heat dissipation in scenarios with complex heat source distribution, reaching a heat source power density of 400 W / cm². 2Under these conditions, the average temperature in the heat source region is 81.1℃, and the highest temperature is 86.2℃. The flow velocity of the cooling liquid is uniform in the microchannel and jet regions, avoiding local flow dead zones and overheating problems. The pressure and velocity field distributions show that the microchannel structure can significantly improve the overall heat transfer performance.

[0150] Compared to the second type of microchannel structure, the third type of microchannel structure is suitable for heat dissipation needs with a wider heat source area or lower power consumption.

[0151] It should be noted that the single-inlet dual-outlet microfluidic structure can be widely used to meet the heat dissipation needs of complex heat source devices such as high-power multi-chip modules and phased array radar components. Compared with the second type of single-inlet single-outlet microfluidic structure, it is more flexible, can be optimized for more complex heat source layouts, and has lower voltage drop and lower power consumption, making it suitable for heat dissipation needs with wider heat source areas or greater temperature gradients.

[0152] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A topology-optimized multi-level liquid cooling structure, characterized in that, include: Liquid cooling plate (1); The interior of the liquid cooling plate (1) is provided with a cavity (2), and the cavity (2) is provided with a multi-level flow channel network consisting of a first macro-mainstream channel (3), a second macro-mainstream channel (4) and a micro-channel (5); The upper surface of the liquid cooling plate (1) is provided with an inlet (6) and an outlet (7) at symmetrical positions at both ends in the length direction; the inlet (6) is connected to the first macroscopic main channel (3); the outlet (7) is connected to the second macroscopic main channel (4); the inlet (6) is used to allow the cooling liquid jet to enter the multi-level flow channel network; The heights of the first macro-mainstream channel (3) and the second macro-mainstream channel (4) are both less than the height of the microchannel (5), and the first macro-mainstream channel (3) and the second macro-mainstream channel (4) are both connected to the microchannel (5); The heat source (8) to be cooled is in contact with the upper surface of the liquid cooling plate (1) through the heat-conducting carrier (9); the horizontal position of the microchannel (5) in the cavity (2) corresponds to the heat source (8) to be cooled.

2. The topology-optimized multi-level liquid cooling structure according to claim 1, characterized in that, The microchannel (5) is a plate-like structure that is wide at both ends and narrow in the middle; the microchannel (5) includes: a first inlet end (51), a first diversion section (52), a first confluence section (53), a second diversion section (54) and a first outlet end (55); One end of the first liquid inlet (51) is connected to the first macroscopic main channel (3) through a vertical channel (10); one end of the first liquid outlet (55) is connected to the second macroscopic main channel (4) through a vertical channel (10); Both the first diversion section (52) and the second diversion section (54) are plate-shaped structures with an elliptical outer contour and hollow interior, and both ends of the liquid cooling plate (1) extend with multiple branch channels; the other end of the first liquid inlet end (51) is connected to the multiple branch channels at one end of the first diversion section (52); the other end of the first liquid outlet end (55) is connected to the multiple branch channels at one end of the second diversion section (54); the first confluence section (53) is connected to the multiple branch channels at the other end of the first diversion section (52) and the other end of the second diversion section (54).

3. The topology-optimized multi-level liquid cooling structure according to claim 2, characterized in that, Both the microchannels (5) and the heat sources to be cooled (8) comprise multiple components; the number of microchannels (5) is equal to the number of heat sources to be cooled (8). The heat sources to be cooled (8) are arranged in an array. The first branch section (52) and the second branch section (54) of each microchannel (5) correspond to a heat source to be cooled (8) at their respective horizontal positions within the cavity (2).

4. The topology-optimized multi-level liquid cooling structure according to claim 1, characterized in that, The microchannel (5) has a plate-like structure; the microchannel (5) includes a second inlet end (56), a third diversion section (57), and a second outlet end (58); One end of the second liquid inlet (56) is connected to the first macroscopic main channel (3) through a vertical channel (10); one end of the second liquid outlet (58) is connected to the second macroscopic main channel (4) through a vertical channel (10); The third diversion section (57) is a plate-like structure with an elliptical outer contour and hollow interior, and has multiple branch channels extending from both ends along the width direction of the liquid cooling plate (1); the other end of the second liquid inlet (56) is connected to the multiple branch channels at one end of the third diversion section (57); the other end of the second liquid outlet (58) is connected to the multiple branch channels at one end of the third diversion section (57).

5. The topology-optimized multi-level liquid cooling structure according to claim 1, characterized in that, The microchannel (5) has a plate-like structure; the microchannel (5) includes a third inlet end (59), a second confluence section (510), a fourth diversion section (511), a fifth diversion section (512), a third outlet end (513), and a fourth outlet end (514); One end of the third liquid inlet (59) is connected to the first macroscopic main channel (3) through a vertical channel (10); one end of the third liquid outlet (513) and the fourth liquid outlet (514) are both connected to the second macroscopic main channel (4) through a vertical channel (10); The fourth diversion section (511) and the fifth diversion section (512) are both plate-shaped structures with a semi-elliptical outer contour and hollow interior, and both ends of the liquid cooling plate (1) extend with multiple branch channels; the other end of the third liquid outlet (513) is connected to the multiple branch channels at one end of the fourth diversion section (511); the other end of the fourth liquid outlet (514) is connected to the multiple branch channels at one end of the fifth diversion section (512); A second confluence section (510) is formed between the fourth diversion section (511) and the fifth diversion section (512); the second confluence section (510) is a plate-like structure with two leaf-like shapes connected at the root, and the second confluence section (510) is connected to the other end of the third liquid inlet (59), the multi-branch channel at the other end of the fourth diversion section (511), and the multi-branch channel at the other end of the fifth diversion section (512).

6. The topology-optimized multi-level liquid cooling structure according to claim 4 or 5, characterized in that, Both the microchannels (5) and the heat sources to be cooled (8) include multiple microchannels (5); the number of microchannels (5) is equal to the number of heat sources to be cooled (8); the heat sources to be cooled (8) are arranged in an array, and the horizontal position of each microchannel (5) in the cavity (2) corresponds to one heat source to be cooled (8).

7. The topology-optimized multi-level liquid cooling structure according to claim 1, characterized in that, The liquid cooling plate (1), the first macroscopic main channel (3), the second macroscopic main channel (4), the microchannel (5), the liquid inlet (6) and the liquid outlet (7) are all made of aluminum alloy and are integrally formed.

8. A method for manufacturing a topology-optimized multi-level liquid-cooled structure, characterized in that, include: S1. Determine the heat dissipation requirements, the shape and size of the liquid cooling plate based on the structure, size and heat flux density distribution of the application equipment that generates the heat source; the heat dissipation requirements include: heat dissipation power and the type of microchannel; S2. Based on the heat flux density distribution, heat dissipation requirements, and the shape and size of the liquid cooling plate, determine the number of layers of the flow channel network, the arrangement and size of the first macroscopic main flow channel and the second macroscopic main flow channel, and the reserved space for the microflow channels. S3. Based on the structure, size, and heat flux density distribution of the application equipment that generates the heat source, as well as the shape and size of the liquid cooling plate, determine the location of the inlet and outlet, the type and flow rate of the cooling liquid, and the material parameters of the cooling liquid and the flow channel network; the material parameters include: permeability, thermal conductivity, density, and specific heat. S4. Based on the material parameters of the cooling liquid and the flow channel network, establish an interpolation format for the material parameters, and based on the interpolation format, establish a topology optimization model for the microchannel; the topology optimization model takes the design variable field as input and the field response of the design variable field as output; the output format of the field response is a two-dimensional density distribution map; S5. Establish an objective function with the goal of minimizing the average temperature of the target area covered by the heat source to be cooled; the objective function simultaneously satisfies a first constraint and a second constraint; the first constraint is used to limit the volume of the cooling liquid in the microchannel; the second constraint is used to limit the size of the microchannel. S6. Calculate the field response of the design variable field using the finite element analysis method, and calculate the sensitivity information of the objective function using the sensitivity analysis method; S7. Based on the sensitivity information, the design variable field is updated and iterated using the moving asymptote method; when the sensitivity information meets the desired threshold, the field response of the current design variable field is output. S8. Extract the contour curve of the two-dimensional density distribution map corresponding to the field response of the current design variable field to obtain the two-dimensional model of the microchannel, and stretch the two-dimensional model of the microchannel along the height direction of the liquid cooling plate to obtain the plate-shaped three-dimensional model of the microchannel. S9. Embed the plate-shaped three-dimensional model into the corresponding reserved space, and connect the three-dimensional plate-shaped model with the first macroscopic flow channel and the second macroscopic flow channel through the vertical channel to obtain the three-dimensional model corresponding to the topology-optimized multi-level liquid cooling structure. S10. Based on the three-dimensional model corresponding to the topology-optimized multi-level liquid-cooled structure, laser powder bed melting technology is used for integrated manufacturing to obtain the final topology-optimized multi-level liquid-cooled structure entity.

9. The manufacturing method according to claim 8, characterized in that, The S7 also includes: During the update iteration of the design variable field, density filtering is used to transform the design variable field into a filtered density field, and a projection function is used to transform the filtered density field into a physical density field. The physical density field is used as input to the topology optimization model for updating and iteration.

10. The manufacturing method according to claim 9, characterized in that, The interpolation format for the material parameters is as follows: in, Let κ be the relative density variable of unit i. s κ represents the permeability of the solid phase. f p represents the permeability of the fluid phase. k As the first penalty factor, and p k =3; k s k is the thermal conductivity of the solid phase. f ρ is the thermal conductivity of the fluid phase; ρf is the density of the solid phase; ρs is the density of the fluid phase; c f ρ is the specific heat of the solid phase. s Specific heat of the fluid phase; p ρ As the second penalty factor; p cp The third penalty factor; p ρ =p cp =1; The topology optimization model for the microchannel is as follows: find:γ min:φ s.t.h j ≤0,j=1,2,...M K p p=f p (K t +C(p))t=f t 0≤γ i ≤1,i=1,2,...N e Where γ is the design variable field, γ i ∈[0,1](i=1,2,...N e ), N e γ represents the total number of finite element elements within the target region; i Used to characterize whether unit i is a fluid or a solid; when γ i =1, indicating that unit i is a fluid; when γ i When = 0, it indicates that unit i is a solid; φ is the objective function; h j Let M represent the j-th constraint function; M is the total number of constraint functions; K p K is the stiffness matrix of the fluid pressure field; p is the pressure field vector; t C is the thermal stiffness matrix; C(p) is the convection coupling term matrix related to the pressure field; t is the temperature vector; f p The output of the discrete equation for the pressure field; f t This is the output of the discrete equation for the temperature field coupled with heat conduction and convection; The objective function is: Among them, Ω * For the target area, N1 is the area of ​​the target region; N1 is the total number of nodes in the target region; T is the temperature field in K; L1 is the indicator vector, which is 1 for nodes in the target region and 0 for nodes not in the target region; t is the temperature vector. The first constraint is: Among them, V f This represents the upper limit of the fluid's volume fraction. Let N be the relative density variable of unit i. e This represents the total number of finite element elements within the target area; The second constraint is: in, in, For density filtering field, I f Here, r is the indicator function, r is the number of cells that the density filtering radius can accommodate during the iteration process, and h is the number of cells that can be accommodated. e For the unit size, η d ε is a parameter used to control the size of the flow channel. g To control the minimum value of the constraint strength; r min denoted as density filtration radius; b is the minimum size of the microchannel. The expression for density filtering is: in, r is the filter density field of element i; min Represents the density filtering radius, ||γ i -γ e || represents the centroid distance between element i and element e; γ i The design variable field for unit i; The expression for the projection function is: in, Let be the physical density field of element i, β represent the steepness of the projection, and η be the threshold of the projection.

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