A phase change cold plate and electronic equipment

Abstract

This utility model discloses a phase change cold plate and an electronic device. The cold plate includes a cavity, a bubble adjustment structure, a microchannel structure, a liquid inlet, and a liquid outlet. The bubble adjustment structure and the microchannel structure are disposed within the cavity, and the liquid inlet and the liquid outlet are connected to the cavity. Along the direction of gravity, the cavity includes a top wall and a bottom wall disposed opposite each other. The microchannel structure and the bubble adjustment structure are disposed on the bottom wall, and a first gap exists between them and the top wall. The microchannel structure includes a refrigerant inlet and a refrigerant outlet, and the bubble adjustment structure is located between the refrigerant inlet and the refrigerant outlet. Using the phase change cold plate provided by this utility model, the bubble adjustment structure can be used to divide some of the bubbles generated by refrigerant vaporization into multiple independent small bubbles, thereby reducing the risk of bubbles clogging the microchannel structure and reducing the heat dissipation efficiency of the cold plate. The other part of the bubbles generated by refrigerant vaporization flows to the liquid outlet through the first gap, thereby reducing the risk of bubbles forming a vapor film on the bottom wall, which could lead to the burnout of the heating element.

Description

Technical Field

[0001] This utility model relates to the field of liquid cooling technology, and in particular to a phase change cold plate and electronic equipment. Background Technology

[0002] With the rapid development of science and technology, the power density of electronic devices such as CPUs and GPUs is constantly increasing, and the heat generated by these devices is also constantly increasing. In current technologies, air cooling or single-phase liquid cooling is mainly used to meet the heat dissipation requirements of CPUs, GPUs, and other electronic devices. However, when the heat flux density of these devices is high, for example, greater than 100 W / cm³, the heat flux density becomes insufficient. 2 At that time, existing technologies will find it difficult to meet the heat dissipation requirements of electronic devices.

[0003] Therefore, how to improve the heat dissipation efficiency of electronic devices has become a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] This invention provides a phase change cooling plate and an electronic device to improve the heat dissipation efficiency of electronic devices.

[0005] In a first aspect, this utility model provides a phase change cooling plate, including a cavity, a bubble regulating structure, a microchannel structure, a liquid inlet, and a liquid outlet. The bubble regulating structure and the microchannel structure are disposed within the cavity, and the liquid inlet and the liquid outlet are connected to the cavity. Along the direction of gravity, the cavity includes a top wall and a bottom wall disposed opposite each other. The microchannel structure and the bubble regulating structure are disposed on the bottom wall, and a first gap exists between them and the top wall. A portion of the bubbles formed by the vaporization of the refrigerant flows to the liquid outlet through the first gap. The microchannel structure includes a refrigerant inlet and a refrigerant outlet, and the bubble regulating structure is located between the refrigerant inlet and the refrigerant outlet. At least a portion of the refrigerant flows sequentially through the refrigerant inlet, the bubble regulating structure, and the refrigerant outlet to the liquid outlet. The bubble regulating structure is used to divide a portion of the bubbles.

[0006] The phase change cold plate provided by this invention utilizes a microchannel structure and a bubble regulating structure within the cavity. The bubble regulating structure is located between the refrigerant inlet and outlet of the microchannel structure, and there is a gap between both structures and the top wall of the cavity. During the boiling process where the liquid refrigerant absorbs heat from the heating element, the bubble regulating structure can divide some of the bubbles generated during boiling into multiple independent small bubbles. The remaining bubbles flow through the first gap to the outlet. It is understood that some of the small bubbles separated by the bubble regulating structure can also flow through the first gap to the outlet. This effectively reduces the risk of reduced heat transfer efficiency due to bubble aggregation and blockage of the microchannel structure during the vaporization of the liquid refrigerant. It also effectively reduces the risk of the heating element burning out due to the formation of a vapor film by bubbles on the bottom wall.

[0007] In one possible implementation of this utility model, the phase change cold plate includes multiple bubble adjustment structures. Along the direction from the refrigerant inlet to the refrigerant outlet, the multiple bubble adjustment structures are spaced apart to break the microchannel structure into independent segments, thereby reducing the risk of large bubbles being generated in the channel due to the excessive length of the microchannel structure, which could lead to blockage of the microchannel structure.

[0008] In one possible implementation of this invention, the height of the first gap between the microchannel structure on the side closer to the outlet than the inlet and the top wall is 'a'; the height of the first gap between the microchannel structure on the side closer to the inlet than the outlet and the top wall is 'b', and a > b. This effectively reduces the flow resistance on the side closer to the top wall, thereby effectively promoting the rapid discharge of bubbles, delaying the vapor film covering the bottom wall, and reducing the risk of reduced heat dissipation efficiency due to the accumulation of a large number of bubbles.

[0009] In one possible implementation of this invention, the phase change cold plate includes multiple bubble regulating structures spaced apart along the direction from the refrigerant inlet to the refrigerant outlet. The height of the first gap between the bubble regulating structure on the side near the outlet and the top wall is m. The height of the first gap between the bubble regulating structure on the side near the inlet and the top wall is n, where a > m > n > b. This is to reduce the flow resistance near the top wall, thereby effectively promoting rapid bubble discharge, delaying vapor film coverage of the bottom wall, and reducing the risk of reduced heat dissipation efficiency due to the accumulation of a large number of bubbles.

[0010] In one possible implementation of this invention, the microchannel structure includes at least two sets of microchannels, with the bubble adjustment structure located between two adjacent sets of microchannels. This is to improve the ease of installation of the bubble adjustment structure.

[0011] In one possible implementation of this utility model, the bubble regulating structure includes a plurality of first through holes, and the refrigerant inlet is connected to the refrigerant outlet through the first through holes, so as to simplify the bubble regulating structure while separating large bubbles into multiple independent small bubbles.

[0012] In one possible implementation of this invention, the phase change cold plate further includes a throttling structure located between the liquid inlet and the refrigerant inlet. This throttling structure alters the flow rate of the refrigerant, causing localized acceleration and pressure drop in the liquid refrigerant, thereby allowing it to reach saturation earlier and improving the heat exchange efficiency of the cold plate.

[0013] In one possible implementation of this utility model, the throttling structure includes a first plate structure, one end of which is connected to the top wall, and the other end of which has a second gap with the bottom wall. The refrigerant enters the refrigerant inlet through the second gap, so as to effectively suppress the backflow of bubbles under low mass flow conditions while meeting the requirement of the liquid refrigerant reaching saturation in advance, and simplify the throttling structure.

[0014] In one possible implementation of this utility model, the microchannel structure includes multiple second plate structures disposed on the bottom wall, and there is a third gap between two adjacent second plate structures. The third gap is used to form a refrigerant channel for refrigerant flow, so as to simplify the microchannel structure while meeting the refrigerant flow requirements.

[0015] In one possible implementation of this invention, the throttling structure includes a first plate structure located between and connected to the top and bottom walls. The first plate structure has multiple second through holes, each corresponding to a refrigerant inlet in one of the multiple refrigerant channels. After the liquid refrigerant passes through the cavity via the second through holes, the flow rate of the liquid refrigerant increases, thereby achieving the requirement of the liquid refrigerant reaching saturation earlier while simplifying the throttling structure.

[0016] In one possible implementation of this invention, the projection of the second through-hole toward the refrigerant inlet falls into the refrigerant inlet of the refrigerant channel. This is to reduce the impact of liquid refrigerant entering the microchannel structure through the second through-hole on the sidewall at the refrigerant inlet, which would increase resistance, reduce the liquid flow rate, and thus affect the heat exchange efficiency of the cold plate.

[0017] In one possible implementation of this invention, the cavity includes a first cavity, through which a liquid inlet communicates with a refrigerant inlet. The first cavity includes a first end and a second end, with the first end facing away from the refrigerant inlet relative to the second end, and the width of the first end being smaller than the width of the second end. The projection of the liquid inlet into the first cavity is located between the first end and the second end to reduce the lateral pressure gradient, thereby effectively reducing the risk of uneven flow distribution in the parallel refrigerant channels.

[0018] In one possible implementation of this invention, the cavity further includes a second cavity, through which the refrigerant outlet is connected to the liquid outlet. The second cavity includes a third end and a fourth end, with the fourth end facing away from the refrigerant outlet relative to the third end, and the width of the fourth end being smaller than the width of the third end, so as to continuously increase the refrigerant flow rate, thereby effectively promoting the bubble breaking efficiency and preventing refrigerant backflow.

[0019] In one possible implementation of this invention, the diameter of the inlet is smaller than the diameter of the outlet. This is to effectively compensate for the pressure rise at the outlet section caused by refrigerant vaporization and volume expansion, thereby increasing the discharge speed of the vaporized refrigerant and reducing the risk of heating element burnout caused by continuous merging of bubbles covering the bottom wall.

[0020] Secondly, this invention provides an electronic device, including a heating element and a phase change cooling plate (as described in the first aspect). The heating element is mounted on the phase change cooling plate and abuts against the outer wall of the bottom wall of the cavity. This is to improve the heat dissipation efficiency of the electronic device. Attached Figure Description

[0021] Figure 1 A schematic diagram of a phase change cold plate provided by this utility model;

[0022] Figure 2 for Figure 1 Exploded view of the provided phase change cold plate;

[0023] Figure 3 for Figure 1 A cross-sectional view of the phase change cold plate along the X direction;

[0024] Figure 4 for Figure 3 A schematic diagram of the first gap of the provided phase change cold plate;

[0025] Figure 5 for Figure 2 A magnified view of part A of the provided phase change cold plate;

[0026] Figure 6 for Figure 2 A schematic diagram of a bubble adjustment structure for a phase change cold plate is provided.

[0027] Figure 7 for Figure 1 A cross-sectional view of the phase change cold plate along the Y direction;

[0028] Figure 8 for Figure 7 A magnified view of part B of the provided phase change cold plate;

[0029] Figure 9 for Figure 2 A partial schematic diagram of the provided phase change cold plate.

[0030] Reference numerals: 1-Outer shell; 11-Top plate; 12-Bottom plate; 13-Cavity; 2-Liquid inlet; 3-Liquid outlet; 4-Bubble regulating structure; 41-First through hole; 5-Microchannel structure; 51-Refrigerant inlet; 52-Refrigerant outlet; 53-Second plate structure; 6-First gap; 7-Throttling structure; 71-First plate structure; 72-Second gap; 73-Second through hole; 8-First cavity; 81-First end; 82-Second end; 9-Second cavity; 91-Third end; 92-Fourth end. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted. The terms expressing position and direction described in the embodiments of this utility model are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the protection scope of this utility model. The accompanying drawings of the embodiments of this utility model are only for illustrating relative positional relationships and do not represent actual proportions.

[0032] It should be noted that specific details are set forth in the following description to facilitate understanding of this utility model. However, this utility model can be implemented in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0033] With the rapid development of science and technology, the power density of electronic devices such as Central Processing Units (CPUs), Dual Inline Memory Modules (DIMMs), and Graphics Processing Units (GPUs) is constantly increasing, and the heat generated by these devices is also constantly increasing. Understandably, the heat generated by electronic devices leads to a continuous rise in their operating temperature, which directly determines the lifespan and stability of the electronic devices. In other words, if the generated heat cannot be dissipated in a timely manner, the actual operating temperature will far exceed the normal operating temperature, affecting the device's operating status and ultimately leading to equipment failure.

[0034] However, in existing technologies, air cooling or single-phase liquid cooling is mainly used to meet the heat dissipation requirements of electronic devices such as CPUs and GPUs. However, when the heat flux density of electronic devices such as CPUs and GPUs is high, for example, greater than 100W / cm³, the heat flux density becomes insufficient. 2At that time, existing technologies will find it difficult to meet the heat dissipation requirements of electronic devices.

[0035] In view of this, the phase change cold plate and electronic device provided by this utility model have a microchannel structure and a bubble regulating structure arranged in the cavity of the phase change cold plate. The liquid refrigerant flows from the refrigerant inlet of the microchannel structure to the refrigerant outlet through the bubble regulating structure. During this process, when the temperature of the heating surface of the heating element exceeds the saturation temperature of the liquid refrigerant, the liquid refrigerant in the cavity boils, and bubbles are formed in the cavity. The generation, growth, and detachment of the bubbles will violently disturb the liquid refrigerant, thereby effectively improving the heat exchange efficiency of the cold plate. To make the purpose, technical solution, and advantages of this utility model clearer, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] It should be noted that this utility model is described using a server as an example; exemplary heat-generating components may include hard drives, CPUs, storage modules, GPUs, and power supplies. (See reference) Figure 1 , Figure 1 This is a schematic diagram of a phase change cooling plate provided by this utility model. The phase change cooling plate includes a shell 1, a liquid inlet 2, and a liquid outlet 3. The shell 1 can, exemplarily, be composed of a top plate 11 and a bottom plate 12, with the direction from the top plate 11 to the bottom plate 12 being the negative direction of the Z-axis. Additionally, as... Figure 2 As shown, Figure 2 For display Figure 1 An exploded view of the provided phase change cooling plate is shown. The outer shell 1 contains a cavity 13, with an inlet 2 and an outlet 3 both located on the top plate 11 and communicating with the cavity 13. The phase change cooling plate also includes a bubble adjustment structure 4 and a microchannel structure 5, both of which are disposed within the cavity 13.

[0037] When specifically setting up cavity 13, such as Figure 3 As shown, Figure 3 For display Figure 1 A cross-sectional view of the phase change cold plate along the X direction is provided. Along the direction of gravity, the cavity 13 includes a top wall (the inner wall of the top plate 11 facing the cavity 13 in the negative direction of the Z-axis) and a bottom wall (the inner wall of the bottom plate 12 facing the cavity 13 in the positive direction of the Z-axis) disposed opposite each other. The microchannel structure 5 and the bubble adjustment structure 4 are disposed on the bottom wall, and a first gap 6 exists between the side of the microchannel structure 5 away from the bottom wall and the side of the bubble adjustment structure 4 away from the bottom wall and the top wall.

[0038] Please refer to the above. Figure 2 and Figure 3In the specific configuration of the microchannel structure 5, the microchannel structure 5 includes a refrigerant inlet 51 and a refrigerant outlet 52, with the bubble regulating structure 4 located between the refrigerant inlet 51 and the refrigerant outlet 52. The refrigerant flows from the liquid inlet 2 through the cavity 13 to the liquid outlet 3, and at least a portion of the refrigerant entering the cavity 13 from the liquid inlet 2 flows sequentially through the refrigerant inlet 51, the bubble regulating structure 4, and the refrigerant outlet 52 to the liquid outlet 3, for the purpose of dissipating heat from the heating element.

[0039] It should be noted that the heating element of the server is located on the outside of the cavity 13. It can be installed on the bottom plate 12, and the heating element is opposite to the top plate 11 relative to the bottom plate 12. That is, the heating element is installed on the outer wall of the bottom wall of the cavity 13. Preferably, the heating surface of the heating element can be made to abut against the outer wall of the bottom wall to improve heat transfer efficiency. In this way, as the liquid refrigerant flows from the refrigerant inlet 51 of the microchannel structure 5 to the outlet 3 through the bubble regulating structure 4, the liquid refrigerant absorbs the heat from the heating element and boils (vaporizes). When some of the bubbles generated by boiling pass through the bubble regulating structure 4, the bubble regulating structure 4 can divide the bubbles into multiple independent small bubbles, thereby reducing the risk of heat transfer efficiency reduction due to bubble blockage of the microchannel structure 5.

[0040] It is worth mentioning that the bubble regulating structure 4 can also provide a large number of nucleation sites for the liquid refrigerant to promote bubble nucleation.

[0041] In addition, another part of the bubbles generated by boiling can flow to the liquid outlet 3 through the first gap 6 mentioned above, so as to effectively reduce the risk of bubbles forming a vapor film on the bottom wall during the vaporization of liquid refrigerant, which could lead to the burnout of the heating element.

[0042] It is understandable that the outer shell 1 is equipped with a cooling module and a circulation path. After vaporization, the refrigerant liquefies after reaching the cooling module through the liquid outlet 3 and the circulation path. The liquefied refrigerant then continues to flow into the liquid inlet 2 of the phase change cold plate for the next round of heat exchange.

[0043] In addition, the server provided by this utility model also includes a circulation pump, which is disposed outside the cavity 13 of the phase change cold plate and connected to the external circulation path to provide forced driving force, establish and maintain the directional circulation flow of the refrigerant, thereby effectively improving the reliability of server heat dissipation.

[0044] The phase change cold plate provided by this invention utilizes a microchannel structure 5 and a bubble regulating structure 4 within the cavity 13. The bubble regulating structure 4 is located between the refrigerant inlet 51 and refrigerant outlet 52 of the microchannel structure 5, and there is a gap between both structures and the top wall of the cavity 13. During the boiling process where the liquid refrigerant absorbs heat from the heating element, the bubble regulating structure 4 can divide some of the bubbles generated by boiling into multiple independent small bubbles. The remaining bubbles flow through the first gap 6 to the liquid outlet 3. This effectively reduces the risk of reduced heat transfer efficiency due to bubble aggregation and blockage of the microchannel structure 5 during the vaporization of the liquid refrigerant. It also effectively reduces the risk of the heating element burning out due to the formation of a vapor film on the bottom wall caused by bubbles.

[0045] It is worth mentioning that, in an optional implementation, such as Figure 3 As shown, the phase change cold plate includes multiple bubble adjustment structures 4, which are spaced apart along the direction from the refrigerant inlet 51 to the refrigerant outlet 52. It can be understood that since the overall length of the microchannel structure 5 can be set to a fixed value based on the area of ​​the heating surface of the heating element, by spaced multiple bubble adjustment structures 4 between the refrigerant inlet 51 and the refrigerant outlet 52 of the microchannel structure 5, the microchannel structure 5 can be broken into independent segments. This reduces the risk of large bubbles forming within the channel due to excessive length, which could lead to blockage of the microchannel structure 5.

[0046] Furthermore, as the refrigerant flows from inlet 2 to outlet 3, some bubbles rise in the opposite direction of gravity (moving towards the top wall), and the liquid refrigerant continuously absorbs heat. Therefore, the amount of bubbles accumulating near outlet 3 will be greater than the amount accumulating near inlet 2. Thus, in a specific embodiment, such as... Figure 4 As shown, Figure 4 For display Figure 3 A schematic diagram of the first gap in the microchannel structure 5. The height of the first gap 6 between the microchannel structure 5 and the top wall on the side of the microchannel structure 5 near the outlet 3 relative to the inlet 2 can be set to 'a', and the height of the first gap 6 between the microchannel structure 5 and the top wall on the side of the microchannel structure 5 near the inlet 2 relative to the outlet 3 can be set to 'b', where a and b satisfy: a > b. This effectively reduces the flow resistance on the side near the top wall, allowing a large number of bubbles that accumulate near the outlet 3 to flow smoothly to the outlet 3 through the first gap 6, thereby effectively delaying the vapor film from covering the bottom wall and reducing the risk of reduced heat dissipation efficiency due to the accumulation of a large number of bubbles.

[0047] It is worth mentioning that, please refer to the following: Figure 2 and Figure 4When the phase change cooling plate includes multiple bubble regulating structures 4, and these structures are spaced apart along the direction from the refrigerant inlet 51 to the refrigerant outlet 52, the height of the first gap 6 between the bubble regulating structure 4 on the side near the outlet 3 relative to the inlet 2 and the top wall can be set to m, and the height of the first gap 6 between the bubble regulating structure 4 on the side near the inlet 2 relative to the outlet 3 and the top wall can be set to n, where a, m, n, and b satisfy: a > m > n > b. Thus, even if the amount of bubbles continuously increases along the direction from the refrigerant inlet 51 to the refrigerant outlet 52, the increased bubbles can quickly flow to the outlet 3 through the gaps because the gaps between the microchannel structure 5 and the bubble regulating structures 4 and the top wall also continuously increase. This effectively delays the vapor film covering the bottom wall and effectively reduces the risk of reduced heat dissipation efficiency due to the accumulation of a large number of bubbles.

[0048] Meanwhile, the remaining bubbles can also be separated into smaller bubbles by multiple bubble adjustment structures 4 in sequence, in order to further reduce the risk of large bubbles being generated inside the microchannel structure 5 due to its excessive length, which could lead to blockage of the microchannel structure 5 and improve heat dissipation efficiency.

[0049] It is worth mentioning that, since the amount of bubbles generated is directly affected by the heat output of the heating element, when setting multiple bubble adjustment structures 4, the spacing between the multiple bubble adjustment structures 4 can be adjusted according to the heat output of the heating element. For example, the spacing between two adjacent bubble adjustment structures 4 can be shortened at locations with relatively high heat output to further reduce the risk of blockage of the microchannel structure 5 due to excessive bubble generation and excessive length of the microchannel structure 5.

[0050] In the specific configuration of the microchannel structure 5, in one optional implementation, such as Figure 5 As shown, Figure 5 For display Figure 2 A partially enlarged view of point A of the provided phase change cold plate. The microchannel structure 5 includes at least two sets of microchannels. Specifically, the microchannel includes multiple second plate structures 53, which are disposed on the bottom wall. The surfaces of two adjacent second plate structures 53 are arranged opposite each other, and a third gap exists between two adjacent second plate structures 53. The third gap is used to form a refrigerant channel. This simplifies the microchannel structure while meeting the refrigerant flow requirements. It can be understood that the refrigerant channel is open in the negative direction of gravity, allowing some bubbles to float to the first gap 6 in the negative direction of gravity. Furthermore, both ends of the refrigerant channel in the horizontal direction are also open; one end in the horizontal direction forms a refrigerant inlet 51, and the other end forms a refrigerant outlet 52. The bubble regulating structure 4 is located between two adjacent sets of microchannels, that is, between the refrigerant outlet 52 of the previous set of microchannels and the refrigerant inlet 51 of the next set of microchannels.

[0051] It is understandable that the height of the first gap 6 between the microchannel on the side of the inlet 2 closer to the outlet 3 and the top wall can be set to a, and the height of the first gap 6 between the microchannel on the side of the outlet 3 closer to the inlet 2 and the top wall can be set to b, and a > b.

[0052] It should be noted that this utility model does not limit the connection method between the bubble regulating structure 4 and the microchannel. For example, the bubble regulating structure 4 can abut against the side wall of the plate structure and be fixedly connected to the bottom wall of the cavity 13, such as by welding. Furthermore, since the bubble regulating structure 4 is located between two adjacent sets of microchannels, compared to setting the bubble regulating structure 4 in the refrigerant channel, it can effectively improve the processing and installation convenience of the bubble regulating structure 4.

[0053] In the specific configuration of the bubble adjustment structure 4, in one optional implementation, refer to... Figure 2 and Figure 6 , Figure 6 A schematic diagram illustrating the bubble adjustment structure 4. The bubble adjustment structure 4 includes multiple first through holes 41. A refrigerant inlet 51 communicates with a refrigerant outlet 52 via the first through holes 41, thereby simplifying the bubble adjustment structure 4 while separating large bubbles into multiple independent small bubbles. It is worth noting that the axis of the first through holes 41 can be arranged in different directions. For example, the axis of some of the first through holes 41 can be arranged along... Figure 6 As shown in the diagram, the axis of a portion of the first through-hole 41 is along the Y-axis, and the angle between the axis of a portion of the first through-hole 41 and the Y-axis and Z-axis is 45°. Adjacent first through-holes 41 are interconnected to form a tortuous channel structure. This tortuous channel structure promotes bubble breakage and turbulence of the refrigerant. Furthermore, as the refrigerant passes through the tortuous channel structure, it can be re-optimized and distributed to the next set of parallel refrigerant channels, thus achieving refrigerant rectification. Additionally, the outer contour of the bubble regulating structure 4 can be cubic to improve the ease of installation.

[0054] In addition, such as Figure 6 As shown, part of the first through hole 41 is connected to the first gap 6, so part of the small bubbles obtained by the bubble adjustment structure 4 can also flow to the liquid outlet through the first gap 6, thereby further improving the heat exchange efficiency of the cold plate.

[0055] It is worth mentioning that the porosity of the bubble conditioning structure 4 between two adjacent sets of microchannels is, for example, 0.5-0.99, and the pore density is 5-120 PPI. Furthermore, when the cold plate is equipped with multiple spaced bubble conditioning structures 4, their porosity and pore density can be adjusted according to the amount of bubbles at the current location and the heat generation of the heating element. For example, the porosity of the bubble conditioning structure 4 on the side relative to the inlet 2 and closer to the outlet 3 can be set to be greater than 80% to promote bubble detachment. For locations with high heat generation, the porosity of the bubble conditioning structure 4 can be reduced to less than 80% to promote bubble nucleation. The width of the bubble conditioning structure 4 is less than or equal to the length of the microchannel, which helps reduce the flow resistance of the refrigerant.

[0056] When the temperature of the heating surface of the heating element exceeds the saturation temperature of the liquid refrigerant, bubbles will form on the bottom wall of the cavity 13, the side walls of the microchannel, and the bubble adjustment structure 4. The generation, growth, and detachment of bubbles will violently disturb the liquid refrigerant, which is beneficial to enhancing the heat transfer effect. Therefore, in a specific embodiment, the phase change cold plate also includes a throttling structure 7, which is located between the liquid inlet 2 and the refrigerant inlet 51. The throttling structure 7 is used to change the flow rate of the liquid refrigerant to reduce the liquid flow area of ​​the liquid refrigerant, so as to locally accelerate the liquid refrigerant and generate a pressure drop, thereby causing the liquid refrigerant to reach the saturation state earlier (lowering the saturation temperature of the liquid refrigerant), promoting the transformation of single-phase liquid cooling into a more efficient phase change heat transfer, that is, accelerating the boiling (vaporization) rate of the liquid refrigerant in the cavity 13 (shortening the conversion cycle of the liquid refrigerant to the vaporization state), thereby improving the heat exchange efficiency of the cold plate.

[0057] When specifically setting the throttling structure 7, options include, for example: Figure 3 As shown, the throttling structure 7 includes a first plate structure 71. One end of the first plate structure 71 is connected to the top wall, and the other end has a second gap 72 between it and the bottom wall. Liquid refrigerant, after passing through the inlet 2, first enters the cavity 13, and then enters the refrigerant inlet 51 of the microchannel structure 5 through the second gap 72. Since the first plate structure 71 is located in the cavity 13, the size of the second gap 72 is much smaller than the space of the cavity 13. For example, the height of the second gap 72 can be set (along the...). Figure 3 The dimension in the Z-axis direction is less than 1 / 3 of the height of the cavity 13. Therefore, after the liquid refrigerant passes through the second gap 72 from the cavity 13, the liquid refrigerant is locally accelerated and a pressure drop is generated. This effectively suppresses the backflow of bubbles under low mass flow conditions and simplifies the throttling structure 7, while meeting the requirement of the liquid refrigerant reaching saturation in advance.

[0058] In one alternative implementation, such as Figure 7 As shown, Figure 7 For Figure 1A cross-sectional view of the phase change cold plate along the Y direction is provided. The first plate structure 71 of the throttling structure 7 can also be located between the top wall and the bottom wall, and connected to both the top and bottom walls. Figure 8 For display Figure 7 The provided enlarged view shows a portion of the phase change cold plate at point B. The first plate structure 71 is also provided with multiple second through holes 73, each corresponding to a refrigerant inlet 51 in one of the multiple refrigerant channels. It is understandable that, since the aperture of the second through holes 73 is much smaller than the space of the cavity 13, the flow rate of the liquid refrigerant will increase after passing through the second through holes 73 from the cavity 13. This simplifies the throttling structure 7 while simultaneously achieving the requirement of the liquid refrigerant reaching saturation earlier.

[0059] In addition, the first plate structure 71 can be welded to the cover plate and the bottom plate 12 as an integral structure, so that while achieving the above functions, the first plate structure 71 can also be used as a reinforcing rib to enhance the pressure-bearing performance of the cold plate.

[0060] It is worth mentioning that the projection of the second through hole 73 toward the refrigerant inlet 51 can be completely placed into the refrigerant inlet 51. This can reduce the impact of liquid refrigerant entering the microchannel structure 5 through the second through hole 73 on the side wall of the refrigerant inlet 51, which would lead to increased resistance, reduced liquid flow rate, and affected the heat exchange efficiency of the cold plate.

[0061] It should be noted that this utility model does not limit the materials of the bottom plate 12, top plate 11, first plate structure 71 and bubble adjustment structure 4. For example, copper material can be selected to improve thermal conductivity.

[0062] In one specific implementation, see also: Figure 2 , Figure 3 and Figure 9 , Figure 9 For display Figure 2 A partial schematic diagram of the provided phase change cold plate. The cavity 13 of the phase change cold plate includes a first cavity 8, through which the liquid inlet 2 communicates with the refrigerant inlet 51. The first cavity 8 includes a first end 81 and a second end 82, extending along... Figure 1 In the X-axis direction shown, the first end 81 is opposite to the refrigerant inlet 51 relative to the second end 82, and the width of the first end 81 (along the X-axis direction) is as follows: Figure 2 The dimension along the Y-axis (as shown) is smaller than the width of the second end 82. Based on the continuity equation and Bernoulli effect, after the liquid refrigerant flows into the cavity 13 through the inlet 2, the liquid refrigerant flowing into the first cavity 8 through the inlet 2 first reaches between the first end 81 and the second end 82. Then, the liquid refrigerant flowing towards the first end 81 accelerates smoothly, effectively reducing the lateral (e.g., Figure 2The pressure gradient (shown in the X-axis direction) is increased, and the static pressure at the inlet of each refrigerant channel is improved to reduce the pressure distribution difference at the inlet of each refrigerant channel, thereby effectively reducing the risk of uneven flow distribution of refrigerant channels connected in parallel.

[0063] It is worth mentioning that the cavity 13 also includes a second cavity 9, through which the refrigerant outlet 52 of the microchannel structure 5 is connected to the liquid outlet 3. It can be understood that after the liquid refrigerant inlet 2 flows into the cavity 13, it flows sequentially through the first cavity 8, the refrigerant inlet 51, the refrigerant outlet 52, and the second cavity 9 to the liquid outlet 3.

[0064] In the specific configuration of the second cavity 9, the second cavity 9 includes a third end 91 and a fourth end 92. The fourth end 92 is located away from the refrigerant outlet 52 relative to the third end 91, and the width of the fourth end 92 (along as shown) Figure 2 The dimension shown in the Y-axis direction is smaller than the width of the third end 91. During the process of refrigerant flowing from refrigerant outlet 52 to the second chamber 9, since the width of the fourth end 92 is smaller than the width of the third end 91, the refrigerant flow rate will continuously increase, which is beneficial to promoting the efficiency of bubble breaking and preventing refrigerant backflow.

[0065] In one specific implementation, such as Figure 2 As shown, the diameter of the liquid inlet 2 can be set smaller than the diameter of the liquid outlet 3 to effectively compensate for the pressure rise at the liquid outlet 3 caused by the vaporization and volume expansion of the refrigerant, thereby increasing the discharge speed of the vaporized refrigerant and reducing the risk of the heating element burning out due to the continuous merging of bubbles covering the bottom wall.

[0066] In summary, the phase change cold plate provided by this invention, by setting a microchannel structure 5 and a bubble regulating structure 4 within the cavity 13, with the bubble regulating structure 4 located between the refrigerant inlet 51 and refrigerant outlet 52 of the microchannel structure 5, and with a gap between both and the top wall of the cavity 13, allows the bubble regulating structure 4 to divide some of the bubbles generated during the boiling process of the liquid refrigerant absorbing heat from the heating element into multiple independent small bubbles. The remaining bubbles flow through the first gap 6 to the liquid outlet 3. This effectively reduces the risk of reduced heat transfer efficiency due to bubble aggregation and blockage of the microchannel structure 5 during the vaporization of the liquid refrigerant. It also effectively reduces the risk of the heating element burning out due to the formation of a vapor film by bubbles on the bottom wall.

[0067] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A phase change cold plate, characterized in that, The system includes a cavity, a bubble regulating structure, a microchannel structure, an inlet, and an outlet. The bubble regulating structure and the microchannel structure are disposed within the cavity. The inlet and the outlet communicate with the cavity. Along the direction of gravity, the cavity includes a top wall and a bottom wall arranged opposite to each other. The microchannel structure and the bubble adjustment structure are disposed on the bottom wall and there is a first gap between them and the top wall. Part of the bubbles formed by the vaporization of the refrigerant flow to the liquid outlet through the first gap. The microchannel structure includes a refrigerant inlet and a refrigerant outlet, and the bubble regulating structure is located between the refrigerant inlet and the refrigerant outlet. At least a portion of the refrigerant flows sequentially through the refrigerant inlet, the bubble regulating structure, and the refrigerant outlet to the liquid outlet. The bubble regulating structure is used to divide a portion of the bubbles.

2. The phase change cold plate according to claim 1, characterized in that, The phase change cold plate includes a plurality of bubble adjustment structures, which are spaced apart along the direction from the refrigerant inlet to the refrigerant outlet.

3. The phase change cold plate according to claim 1, characterized in that, The height of the first gap between the microchannel structure and the top wall on the side of the liquid outlet closer to the liquid outlet is a; the height of the first gap between the microchannel structure and the top wall on the side of the liquid outlet closer to the liquid outlet is b, and a > b.

4. The phase change cold plate according to claim 3, characterized in that, The phase change cold plate includes a plurality of bubble adjustment structures, which are spaced apart along the direction from the refrigerant inlet to the refrigerant outlet. The height of the first gap between the bubble regulating structure and the top wall on the side of the liquid inlet closer to the liquid outlet is m; The height of the first gap between the bubble adjustment structure and the top wall on the side of the outlet closer to the inlet is n, and a > m > n > b.

5. The phase change cold plate according to claim 1, characterized in that, The microchannel structure includes at least two sets of microchannels, and the bubble adjustment structure is located between two adjacent sets of microchannels.

6. The phase change cold plate according to claim 1, characterized in that, The bubble regulating structure includes a plurality of first through holes, and the refrigerant inlet is connected to the refrigerant outlet through the first through holes.

7. The phase change cold plate according to claim 1, characterized in that, The phase change cold plate also includes a throttling structure located between the liquid inlet and the refrigerant inlet, which is used to change the flow rate of the refrigerant.

8. The phase change cold plate according to claim 7, characterized in that, The throttling structure includes a first plate structure, one end of which is connected to the top wall, and the other end of which has a second gap with the bottom wall, through which the refrigerant enters the refrigerant inlet.

9. The phase change cold plate according to claim 7, characterized in that, The microchannel structure includes multiple second plate structures disposed on the bottom wall, and there is a third gap between two adjacent second plate structures, the third gap being used to form a refrigerant channel for refrigerant flow.

10. The phase change cold plate according to claim 9, characterized in that, The throttling structure includes a first plate structure, which is located between the top wall and the bottom wall and is connected to the top wall and the bottom wall; the first plate structure is provided with a plurality of second through holes, which correspond one-to-one with the refrigerant inlets of the plurality of refrigerant channels.

11. The phase change cold plate according to claim 10, characterized in that, The projection of the second through hole toward the refrigerant inlet of the refrigerant channel falls into the refrigerant inlet.

12. The phase change cold plate according to claim 1, characterized in that, The cavity includes a first cavity, and the liquid inlet is connected to the refrigerant inlet through the first cavity; The first cavity includes a first end and a second end, the first end being opposite to the refrigerant inlet relative to the second end, and the width of the first end being smaller than the width of the second end; the projection of the liquid inlet into the first cavity is located between the first end and the second end.

13. The phase change cold plate according to claim 1 or 12, characterized in that, The cavity further includes a second cavity, through which the refrigerant outlet is connected to the liquid outlet; The second cavity includes a third end and a fourth end, the fourth end being opposite to the refrigerant outlet relative to the third end, and the width of the fourth end being smaller than the width of the third end.

14. The phase change cold plate according to claim 1, characterized in that, The diameter of the inlet is smaller than the diameter of the outlet.

15. An electronic device, characterized in that, It includes a heating element and a phase change cold plate as described in any one of claims 1-14, wherein the heating element is mounted on the phase change cold plate and abuts against the outer side wall of the bottom wall of the cavity.

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