Phase change cold plate and liquid cooling device
By setting up upper and lower cooling channels in the cold plate, the problem of poor heat dissipation at the cold plate inlet is solved, the uniformity of chip surface temperature and heat dissipation efficiency are improved, and local overheating of the chip and increased system complexity are avoided.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN ENVICOOL TECH
- Filing Date
- 2025-08-01
- Publication Date
- 2026-07-21
Smart Images
Figure CN224538587U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of liquid cooling technology, and in particular to a phase change cold plate and a liquid cooling device including the phase change cold plate. Background Technology
[0002] A pump-driven two-phase cold plate liquid cooling system typically includes a pump, a cold plate, a condenser, and a liquid storage tank. During cooling, the cold plate can be attached to the chip. The liquid refrigerant evaporates in the cold plate and absorbs the heat generated by the chip during operation, becoming a gas-liquid two-phase state. The gas-liquid two-phase refrigerant condenses into a liquid state in the condenser and releases the heat. The liquid refrigerant then flows sequentially through the liquid storage tank, the mechanical pump, and the cold plate to complete a refrigeration cycle.
[0003] To reduce cavitation in mechanical pumps and improve their reliability, the refrigerant at the condenser outlet is usually in a subcooled state, ensuring that the inlet of the mechanical pump is a subcooled liquid at a temperature 5K or higher below the evaporation temperature (K is an international unit of temperature, also known as Kelvin).
[0004] However, after the subcooled refrigerant enters the cold plate, it needs to undergo sensible heat exchange first, increasing its temperature to absorb heat from the chip. Only when the refrigerant temperature rises to its evaporation temperature can it undergo latent heat exchange, evaporating and absorbing heat. Since the sensible heat exchange efficiency of the refrigerant is far lower than its latent heat exchange efficiency, the heat dissipation effect at the inlet section of the cold plate channel is poor. Consequently, the chip temperature at the inlet section of the cold plate will be relatively high, and there is even a risk of it burning out. Utility Model Content
[0005] In order to overcome the problems existing in the prior art, the main objective of this application is to provide a phase change cold plate and liquid cooling device that can improve the uniformity of chip surface temperature.
[0006] To achieve the above objectives, this application specifically adopts the following technical solution:
[0007] This application provides a phase change cold plate, which has an upper surface, a lower surface, a first cooling channel and a second cooling channel. The first cooling channel is located inside the phase change cold plate on the side closer to the upper surface, and the second cooling channel is located inside the phase change cold plate on the side closer to the lower surface.
[0008] The first cooling channel has an inlet at one end, the second cooling channel has an outlet at one end, and the other end of the second cooling channel is connected to the other end of the first cooling channel, so that the refrigerant can flow into the first cooling channel through the inlet, and flow through the first cooling channel and the second cooling channel in sequence before flowing out through the outlet.
[0009] In some embodiments, the other end of the first cooling channel is provided with a first connecting end, the other end of the second cooling channel is provided with a second connecting end, the second connecting end is connected to the first connecting end, and both the first connecting end and the second connecting end are located at one end of the phase change cold plate, and both the liquid inlet and the liquid outlet are located at the other end of the phase change cold plate.
[0010] In some embodiments, along the thickness extension direction of the phase change cold plate, the projections of the first cooling channel and the second cooling channel at least partially overlap.
[0011] In some embodiments, along the thickness extension direction of the phase change cold plate, the projections of the first cooling channel and the second cooling channel completely overlap.
[0012] In some embodiments, the first cooling channel includes a plurality of first flow channels, which are spaced apart along the width extension direction of the phase change cold plate and the length of the plurality of first flow channels extends along the length extension direction of the phase change cold plate, and the plurality of first flow channels are interconnected.
[0013] The second cooling channel includes a plurality of second flow channels, which are spaced apart along the width extension direction of the phase change cold plate, and the length of the plurality of second flow channels extends along the length extension direction of the phase change cold plate, and the plurality of second flow channels are interconnected.
[0014] In some embodiments, both the first cooling channel and the second cooling channel are S-shaped.
[0015] In some embodiments, the diameter of the first cooling channel and the diameter of the second cooling channel are the same.
[0016] Accordingly, this application also provides a liquid cooling device, which includes a condenser, a liquid storage tank, a mechanical pump, and a phase change cold plate as described in any of the above embodiments. The output end of the condenser is connected to the input end of the liquid storage tank, the output end of the liquid storage tank is connected to the input end of the phase change cold plate via the mechanical pump, and the output end of the phase change cold plate is connected to the input end of the condenser.
[0017] In some embodiments, the liquid cooling device further includes a flow meter disposed on the connecting pipeline between the mechanical pump and the phase change cold plate.
[0018] In some embodiments, the liquid cooling device further includes a first pressure sensor and a first temperature sensor, the first pressure sensor and the first temperature sensor being respectively disposed at the input end of the phase change cold plate.
[0019] The phase change cold plate of this application has an upper surface, a lower surface, a first cooling channel, and a second cooling channel. The first cooling channel is located inside the phase change cold plate near the upper surface, and the second cooling channel is located inside the phase change cold plate near the lower surface. One end of the first cooling channel has a liquid inlet, and one end of the second cooling channel has a liquid outlet. The other end of the second cooling channel is connected to the other end of the first cooling channel. Compared to related technologies, this application allows the chip's heating surface to be in contact with the outer wall of the second cooling channel during cooling and heat dissipation. The subcooled refrigerant flows into the first cooling channel through the liquid inlet and then flows through both the first and second cooling channels before exiting through the liquid outlet. At this time, the subcooled refrigerant in the first cooling channel and the higher-temperature two-phase refrigerant in the second cooling channel indirectly exchange heat. The subcooled refrigerant in the first cooling channel absorbs heat, increasing its temperature and achieving a preheating effect. This ensures that the heat exchange between the refrigerant and the chip in the phase change cold plate is entirely latent heat, resulting in a more uniform temperature on the chip surface and preventing excessively high temperatures in certain areas of the chip. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the liquid cooling device provided in the embodiments of this application.
[0021] Figure 2 This is a schematic diagram of the phase change cold plate provided in an embodiment of this application.
[0022] Figure 3 A perspective view of a phase change cold plate provided in an embodiment of this application.
[0023] Figure 4 A cross-sectional view of the phase change cold plate provided in an embodiment of this application.
[0024] Figure 5 Another cross-sectional view of the phase change cold plate provided in the embodiment of this application.
[0025] Figure 6 for Figure 3 Cross-sectional view at point AA.
[0026] Figure 7 for Figure 3 Cross-sectional view at point BB.
[0027] Attached image labels:
[0028] 1. Phase change cold plate; 10a. Upper surface; 10b. Lower surface; 11. First cooling channel; 111. Liquid inlet; 112. First connecting end; 113. First flow channel; 12. Second cooling channel; 121. Liquid outlet; 122. Second connecting end; 123. Second flow channel; 2. Condenser; 3. Liquid storage tank; 4. Mechanical pump; 5. Flow meter; 61. First pressure sensor; 62. Second pressure sensor; 63. Third pressure sensor; 64. Fourth pressure sensor; 71. First temperature sensor; 72. Second temperature sensor; 73. Third temperature sensor; 74. Fourth temperature sensor; 100. Liquid cooling device; 200. Chip. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0030] In the description of this application, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" refers to two or more; the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0031] In the description of this specification, it should be understood that the directional terms such as "upper" and "lower" used in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should also be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.
[0032] A pump-driven two-phase cold plate liquid cooling system typically includes a pump, cold plate, condenser, and receiver tank. During cooling, the cold plate is attached to the chip. The liquid refrigerant evaporates within the cold plate, absorbing heat generated during chip operation and transforming into a two-phase state. This two-phase refrigerant then condenses back into a liquid state in the condenser, releasing heat. The liquid refrigerant then flows sequentially through the receiver tank, the mechanical pump, and the cold plate, completing one refrigeration cycle. To reduce cavitation in the mechanical pump and improve its reliability, the refrigerant at the condenser outlet is typically in a subcooled state, ensuring that the inlet of the mechanical pump is a subcooled liquid at least 5K below its evaporation temperature.
[0033] However, after the subcooled refrigerant enters the cold plate, it needs to undergo sensible heat exchange, absorbing heat from the chip and raising its temperature. Only when the refrigerant temperature rises to its evaporation temperature can it undergo latent heat exchange, evaporating and absorbing heat. Since the sensible heat exchange efficiency of the refrigerant is much lower than its latent heat exchange efficiency, the heat dissipation effect at the inlet of the cold plate channel is poor, resulting in a relatively high chip temperature at the inlet area, potentially even leading to burnout. To improve the uniformity of the chip surface temperature and prevent localized chip burnout, a preheating method is typically used in the system to preheat the subcooled refrigerant before it enters the cold plate, raising its temperature to near its evaporation temperature (saturation state).
[0034] In related technologies, the following methods can be used to preheat the subcooled refrigerant before it enters the cold plate. One method is to use an electric heating element: an electric heating element can be used to preheat the subcooled refrigerant before it enters the cold plate. However, the use of an electric heating element will increase the total heat in the system, and the heat exchange on the condenser side needs to be increased. Therefore, this method not only requires the condenser to have a higher heat exchange capacity, but also increases the system power consumption. Another method is to use a regenerator: the gas-liquid two-phase refrigerant at the outlet of the cold plate can be indirectly heat-exchanged with the liquid phase refrigerant at the inlet of the cold plate to reduce the subcooling of the refrigerant at the inlet of the cold plate. However, this method requires the design of a regenerator, which not only increases the structural layout of the system, but also increases the complexity of the pipeline structure design.
[0035] Based on the above, the inventors of this application propose a phase change cold plate with self-preheating function (a phase change cold plate refers to a heat dissipation device that uses phase change materials to absorb heat). This phase change cold plate can preheat the subcooled refrigerant before the inlet of the phase change cold plate without the need for additional heat, so that the refrigerant is close to saturation.
[0036] Reference Figure 1 As shown, an embodiment of this application discloses a liquid cooling device 100, which includes a phase change cooling plate 1, a condenser 2, a liquid storage tank 3, a mechanical pump 4, and a flow meter 5. The output end of the phase change cooling plate 1 is connected to the input end of the condenser 2, the output end of the condenser 2 is connected to the input end of the liquid storage tank 3, the output end of the liquid storage tank 3 is connected to the input end of the mechanical pump 4, and the output end of the mechanical pump 4 is connected to the input end of the phase change cooling plate 1 via the flow meter 5.
[0037] During refrigeration, the phase change cold plate 1 can be attached to the chip. At this time, the liquid refrigerant evaporates in the phase change cold plate 1 and absorbs the heat generated by the chip during operation, so as to become a gas-liquid two-phase state. The gas-liquid two-phase refrigerant flows to the condenser 2 and condenses into liquid refrigerant, releasing heat. Then, the liquid refrigerant flows through the liquid storage tank 3, the mechanical pump 4 and the flow meter 5 in sequence before flowing to the phase change cold plate 1 to complete the refrigeration cycle.
[0038] Continue to refer to Figure 1 As shown, the liquid cooling device 100 also includes a first pressure sensor 61, a second pressure sensor 62, a third pressure sensor 63, a fourth pressure sensor 64, a first temperature sensor 71, a second temperature sensor 72, a third temperature sensor 73, and a fourth temperature sensor 74. The first pressure sensor 61 and the first temperature sensor 71 are respectively located at the input end of the flow meter 5. The first pressure sensor 61 is used to detect the pressure in the output pipe of the mechanical pump 4, and the first temperature sensor 71 is used to detect the temperature in the output pipe of the mechanical pump 4. The second pressure sensor 62 and the second temperature sensor 72 are respectively located at the input end of the liquid storage tank 3. The second pressure sensor 62 is used to detect the pressure in the output pipe of the condenser 2, and the second temperature sensor 72 is used to detect the temperature in the output pipe of the condenser 2. The third pressure sensor 63 and the third temperature sensor 73 are respectively located at the input end of the mechanical pump 4. The third pressure sensor 63 is used to detect the pressure in the input pipe of the mechanical pump 4, and the third temperature sensor 73 is used to detect the temperature in the input pipe of the mechanical pump 4. The fourth pressure sensor 64 and the fourth temperature sensor 74 are respectively installed at the input end of the condenser 2. The fourth pressure sensor 64 is used to detect the pressure in the pipeline at the input end of the condenser 2, and the fourth temperature sensor 74 is used to detect the temperature in the pipeline at the input end of the condenser 2.
[0039] Reference Figure 2 and Figure 3 As shown, the phase change cold plate 1 has an upper surface 10a, a lower surface 10b, a first cooling channel 11, and a second cooling channel 12. The upper surface 10a and the lower surface 10b extend along the thickness direction of the phase change cold plate 1. Figure 3 The phase change cold plate 1 is arranged with the first cooling channel 11 located on the side of the phase change cold plate 1 near the upper surface 10a, and the second cooling channel 12 located on the side of the phase change cold plate 1 near the lower surface 10b. That is, the phase change cold plate 1 can be considered as having an upper structure and a lower structure, with the first cooling channel 11 in the upper structure and the second cooling channel 12 in the lower structure, thus creating a similar stacked arrangement. One end of the first cooling channel 11 has a liquid inlet 111, and the other end has a first connecting end 112. One end of the second cooling channel 12 has a liquid outlet 121, and the other end has a second connecting end 122. The second connecting end 122 communicates with the first connecting end 112 and is located at one end of the phase change cold plate 1, while the liquid inlet 111 and the liquid outlet 121 are located at the other end of the phase change cold plate 1.
[0040] The phase change cold plate 1 of this application mainly consists of two layers. The upper layer has a first cooling channel 11 (upper inner flow channel), and the lower layer has a second cooling channel 12 (lower inner flow channel). The first cooling channel 11 and the second cooling channel 12 have a connecting port at their flow ends. The first cooling channel 11 has a liquid inlet 111 on its side, and the second cooling channel 12 has a liquid outlet 121 on its side. During cooling and heat dissipation, the heat-generating surface of the chip can be placed against the outer wall of the second cooling channel 12. The supercooled refrigerant flows into the first cooling channel 11 through the liquid inlet 111 and flows sequentially through the first connecting end 112, the second connecting end 122, and the second cooling channel 12 before flowing out through the liquid outlet 121. At this time, the refrigerant in the subcooled state in the first cooling channel 11 and the refrigerant in the two-phase state with a higher temperature in the second cooling channel 12 exchange heat indirectly. The refrigerant in the subcooled state in the first cooling channel 11 absorbs heat and its temperature rises, achieving a preheating effect. This ensures that the refrigerant in the phase change cold plate 1 exchanges heat with the chip entirely through latent heat, thereby making the temperature on the chip surface more uniform and preventing the temperature in some parts of the chip from becoming too high.
[0041] In this embodiment, along the thickness extension direction of the phase change cold plate 1, the projections of the first cooling channel 11 and the second cooling channel 12 at least partially overlap. Exemplarily, along the thickness extension direction of the phase change cold plate 1, the projection of the first cooling channel 11 may completely fall within the projection of the second cooling channel 12, or the projection of the second cooling channel 12 may also completely fall within the projection of the first cooling channel 11, or the projections of the first cooling channel 11 and the second cooling channel 12 may partially overlap. In one possible embodiment, the diameter of the first cooling channel 11 and the diameter of the second cooling channel 12 are the same, and along the thickness extension direction of the phase change cold plate, the projections of the first cooling channel 11 and the second cooling channel 12 completely overlap.
[0042] Reference Figure 4 and Figure 5 As shown, the first cooling channel 11 includes a plurality of first flow channels 113, which extend along the width direction of the phase change cold plate 1. Figure 3 The multiple first flow channels 113 are spaced apart in the Y direction, and their lengths extend along the length of the phase change cold plate 1. Figure 3 The first flow channels 113 extend in the X direction and are interconnected. The second cooling channel 12 includes multiple second flow channels 123, which are spaced apart along the width extension direction of the phase change cold plate 1 and extend along the length extension direction of the phase change cold plate 1. The multiple second flow channels 123 are interconnected. The distance between two adjacent first flow channels 113 is equal to the distance between two adjacent second flow channels 123.
[0043] In this embodiment, both the first cooling channel 11 and the second cooling channel 12 are curved. For example, the first cooling channel 11 and the second cooling channel 12 can be serpentine, S-shaped, wavy, etc.
[0044] In practical application scenarios, refer to Figure 6 and Figure 7 As shown, the heating surface of the chip 200 can be placed against the outer wall of the second cooling channel 12, and the subcooled refrigerant can flow into the first cooling channel 11 from the inlet 111. The refrigerant then flows sequentially through the first connecting end 112 and the second connecting end 122 before flowing into the second cooling channel 12, and finally exits the phase change cold plate 1 from the outlet 121 of the second cooling channel 12. This allows the heat generated on the surface of the chip 200 to be transferred through thermal conduction to the inner surface of the second cooling channel 12, which is the lower layer of the phase change cold plate 1. The refrigerant undergoes convective heat exchange within the second cooling channel 12, absorbing heat and carrying it away through flow. Simultaneously, the subcooled refrigerant flows into the first cooling channel 11 and indirectly exchanges heat with the higher-temperature two-phase refrigerant in the second cooling channel 12. This causes the subcooled refrigerant in the first cooling channel 11 to absorb heat and increase its temperature, achieving a preheating effect. When the refrigerant flows to the end of the first cooling channel 11, it reaches the saturation temperature after heat exchange and then flows to the second cooling channel 12 of the lower structure of the phase change cold plate 1. At this time, the refrigerant in the second cooling channel 12 undergoes latent heat exchange, absorbing the heat transferred from the chip surface to the inner surface of the second cooling channel 12 of the lower structure of the phase change cold plate through phase change evaporation. In addition, although the refrigerant is in a phase change process in the second cooling channel 12, the saturation pressure decreases due to the influence of flow resistance, which in turn leads to a decrease in saturation temperature. Therefore, in actual operation, the refrigerant is in a cooling process in the second cooling channel 12. In the phase change cold plate of this application, the flow direction of the refrigerant in the first cooling channel 11 is opposite to the flow direction in the second cooling channel 12, making the heat exchange of the refrigerant in the first cooling channel 11 and the second cooling channel 12 a counter-flow design, which makes the heat exchange efficiency higher and the heat exchange more complete.
[0045] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A phase change cold plate, characterized in that, The phase change cold plate has an upper surface, a lower surface, a first cooling channel, and a second cooling channel. The first cooling channel is located inside the phase change cold plate on the side closer to the upper surface, and the second cooling channel is located inside the phase change cold plate on the side closer to the lower surface. The first cooling channel has an inlet at one end, the second cooling channel has an outlet at one end, and the other end of the second cooling channel is connected to the other end of the first cooling channel, so that the refrigerant can flow into the first cooling channel through the inlet, and flow through the first cooling channel and the second cooling channel in sequence before flowing out through the outlet.
2. The phase change cold plate according to claim 1, characterized in that, The first cooling channel has a first connecting end at one end, and the second cooling channel has a second connecting end at the other end. The second connecting end is connected to the first connecting end, and both the first connecting end and the second connecting end are located at one end of the phase change cold plate. The liquid inlet and the liquid outlet are both located at the other end of the phase change cold plate.
3. The phase change cold plate according to claim 2, characterized in that, Along the thickness extension direction of the phase change cold plate, the projections of the first cooling channel and the second cooling channel at least partially overlap.
4. The phase change cold plate according to claim 3, characterized in that, Along the thickness extension direction of the phase change cold plate, the projections of the first cooling channel and the second cooling channel completely overlap.
5. The phase change cold plate according to claim 2, characterized in that, The first cooling channel includes a plurality of first flow channels, which are spaced apart along the width extension direction of the phase change cold plate, and the length of the plurality of first flow channels extends along the length extension direction of the phase change cold plate, and the plurality of first flow channels are interconnected. The second cooling channel includes a plurality of second flow channels, which are spaced apart along the width extension direction of the phase change cold plate, and the length of the plurality of second flow channels extends along the length extension direction of the phase change cold plate, and the plurality of second flow channels are interconnected.
6. The phase change cold plate according to any one of claims 1 to 5, characterized in that, Both the first cooling channel and the second cooling channel are S-shaped.
7. The phase change cold plate according to any one of claims 1 to 5, characterized in that, The diameter of the first cooling channel is the same as the diameter of the second cooling channel.
8. A liquid cooling device, characterized in that, The device includes a condenser, a liquid storage tank, a mechanical pump, and a phase change cold plate as described in any one of claims 1 to 7. The output end of the condenser is connected to the input end of the liquid storage tank, the output end of the liquid storage tank is connected to the input end of the phase change cold plate via the mechanical pump, and the output end of the phase change cold plate is connected to the input end of the condenser.
9. The liquid cooling device according to claim 8, characterized in that, The liquid cooling device also includes a flow meter, which is installed on the connecting pipeline between the mechanical pump and the phase change cold plate.
10. The liquid cooling device according to claim 8, characterized in that, The liquid cooling device further includes a first pressure sensor and a first temperature sensor, which are respectively disposed at the input end of the phase change cold plate.