Rack or system level two-phase cooling system

Abstract

This invention discloses a rack- or system-level two-phase cooling system for circulating a coolant to cool a heat source. It includes a pump, a liquid cooling pipe, a cooling and heat dissipation device, a liquid-gas two-phase pipe, a heat exchanger, and a cooling liquid pipe connected in sequence. The pump delivers the coolant via the liquid cooling pipe to the cooling and heat dissipation device in contact with the heat source, where the coolant cools the heat source. A portion of the coolant evaporates upon heating, forming vapor. The vapor and coolant are then transported via the liquid-gas two-phase pipe to the heat exchanger, where they are cooled and the vapor condenses back into coolant. The condensed coolant is then transported back to the pump via the cooling liquid pipe. By placing the heat exchanger above the pump, the vapor and coolant are naturally separated by gravity and density difference, thereby improving cooling efficiency.

Description

Technical Field

[0001] This invention relates to a water-cooled heat dissipation system for electronic devices, and more particularly to a rack or system-level two-phase cooling system for AI servers. Background Technology

[0002] In electronic devices, such as servers, there are various electronic components inside, such as central processing units (CPUs) and graphics processing units (GPUs). These electronic components generate heat when they are operating, so coolant must be used to cool them to prevent the electronic components from failing due to overheating, which could lead to the entire server becoming unusable.

[0003] With the rapid advancement of AI technology and advanced packaging processes, the wattage of chip heat sources continues to increase. This increase in wattage renders current mainstream single-phase liquid cooling solutions inadequate for future needs. Two-phase evaporative cooling technology, however, can meet these future cooling requirements. It absorbs a significant amount of heat through the latent heat of vaporization (liquid to gas) and solves the problem of high heat flux over a single area. However, the cooling distribution unit (CDU) in a two-phase cooling system must address more complex issues such as pressure control, gas-liquid separation, and vapor reflux management.

[0004] Therefore, how to solve the problems of pressure control, gas-liquid separation and vapor reflux management in two-phase cooling systems is a direction that relevant developers are eager to study and improve. Summary of the Invention

[0005] Therefore, in order to effectively solve the above problems, the purpose of this invention is to provide a rack or system-level two-phase cooling system that allows for natural separation of steam and coolant.

[0006] To achieve the above objectives, the present invention provides a rack- or system-level two-phase cooling system for circulating a coolant to cool at least one heat source, comprising: at least one pump device for increasing the pressure of the coolant to facilitate pressurized delivery of the coolant; at least one liquid cooling pipe connected to the pump device, the pump device delivering the coolant to the liquid cooling pipe; and at least one cooling and heat dissipation device connected to the liquid cooling pipe, the cooling and heat dissipation device contacting the heat source, wherein the coolant in the liquid cooling pipe is delivered to the cooling and heat dissipation device to cool the heat source, wherein a portion of the coolant... The liquid is heated and evaporates to form a vapor; at least one liquid-gas two-phase pipe is connected to the cooling and heat dissipation device, and the coolant and vapor in the cooling and heat dissipation device are transported to the liquid-gas two-phase pipe; at least one heat exchanger is connected to the liquid-gas two-phase pipe, and the coolant and vapor in the liquid-gas two-phase pipe are transported to the heat exchanger for heat exchange, so that the vapor condenses back into the coolant; at least one cooling liquid pipe is connected to the heat exchanger and the pump device, and the cooling liquid in the heat exchanger is transported to the pump device via the cooling liquid pipe, wherein the heat exchanger is located above the pump device.

[0007] The heat exchanger is located above the cooling and heat dissipation device.

[0008] The rack-level two-phase cooling system is mounted on a rack, and the heat exchanger is located at the top of the rack.

[0009] The rack-level two-phase cooling system is mounted on a rack, and the pump unit is located at the bottom of the rack.

[0010] The rack-level two-phase cooling system is mounted on a rack, with the heat exchanger located at the top of the rack, the pump unit located at the bottom of the rack, and the cooling and heat dissipation device located between the heat exchanger and the pump unit.

[0011] The diameter of the liquid-gas two-phase pipe is larger than the diameter of the liquid cooling pipe.

[0012] The cooling and heat dissipation device includes a server's cold plate.

[0013] It also includes at least one liquid storage tank, which connects the heat exchanger and the cooling liquid pipe. The cooling liquid in the heat exchanger is transported to the cooling liquid pipe via the liquid storage tank.

[0014] The liquid storage tank is located above the pump unit and the cooling and heat dissipation device.

[0015] The liquid storage tank is located adjacent to the heat exchanger.

[0016] Therefore, the rack or system-level two-phase cooling system provided by the present invention utilizes the placement of a heat exchanger above the pump device. By placing the heat exchanger above the pump device, steam can quickly flow upward to the heat exchanger for heat exchange, thereby improving cooling efficiency and preventing steam from flowing downward to the pump device, which would cause cavitation and reduced cooling efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the component configuration of the rack or system-level two-phase cooling system of the present invention.

[0018] Explanation of reference numerals in the attached drawings: 1-Rack or system-level two-phase cooling system; 11-Pump unit; 12-Liquid cooling pipe; 13-Cooling and heat dissipation device; 14-Liquid-gas two-phase pipe; 15-Heat exchanger; 16-Cooling liquid pipe; 17-Liquid storage tank; 18-Rack; 181-Top; 182-Bottom. Detailed Implementation

[0019] The above-mentioned objectives of the present invention and its structural and functional characteristics will be described with reference to the preferred embodiments shown in the accompanying drawings.

[0020] like Figure 1 As shown, a rack-mount or system-level two-phase cooling system 1 of the present invention is used to circulate a coolant to cool at least one heat source (not shown). It includes a pump device 11, a liquid cooling pipe 12, a cooling and heat dissipation device 13, a liquid-gas two-phase pipe 14, a heat exchanger 15, and a cooling liquid pipe 16, which are sequentially connected in a coolant circulation configuration. In this embodiment, the heat source is a chip, such as the transistor of a CPU, GPU, TPU, or other heat-generating source. The coolant is a refrigerant, water, or other or chemical liquid. The solid arrows indicate the flow direction of the coolant, while the dashed arrows indicate the flow direction of the coolant after absorbing heat and becoming gas. Therefore, the term "two-phase" in the rack-mount or system-level two-phase cooling system 1 of the present invention refers to both the liquid phase and the gas phase, indicating that during cooling operations, the coolant in the rack-mount or system-level two-phase cooling system 1 simultaneously exists in both liquid and gas phases.

[0021] Pump device 11 is used to increase the pressure of the coolant to facilitate its pressurized delivery. It delivers the coolant via liquid cooling pipe 12 to cooling and heat dissipation device 13, which is in contact with a heat source. Liquid cooling pipe 12 is connected to pump device 11, and pump device 11 delivers coolant to liquid cooling pipe 12. Cooling and heat dissipation device 13 is connected to liquid cooling pipe 12 to receive coolant from liquid cooling pipe 12, and cooling and heat dissipation device 13 is in contact with a heat source. The coolant in liquid cooling pipe 12 is delivered to cooling and heat dissipation device 13 to cool the heat source, and some of the coolant evaporates due to the high temperature of the heat source to form vapor.

[0022] The liquid-gas two-phase pipe 14 is connected to the cooling and heat dissipation device 13. The coolant and vapor in the cooling and heat dissipation device 13 are transported to the liquid-gas two-phase pipe 14 and then to the heat exchanger 15. The heat exchanger 15 is connected to the liquid-gas two-phase pipe 14, and the coolant and vapor in the liquid-gas two-phase pipe 14 are transported to the heat exchanger 15 for heat exchange. The heat exchanger 15 cools the vapor and coolant and condenses the vapor back into coolant. The cooling liquid pipe 16 connects the heat exchanger 15 to the pump device 11. The condensed coolant in the heat exchanger 15 is transported to the pump device 11 via the cooling liquid pipe 16. In this way, the entire liquid-gas two-phase cooling cycle of the coolant in the rack or system-level two-phase cooling system 1 is completed.

[0023] It is worth mentioning that, due to the significant difference in gravity and density between the two phases of steam and coolant, this difference can be used to naturally separate the steam and coolant for pressure control, gas-liquid separation, and steam reflux management, thereby improving cooling efficiency. Therefore, in this embodiment, the heat exchanger 15 is specifically positioned above the pump unit 11 and the cooling and heat dissipation device 13. By positioning the heat exchanger 15 above the pump unit 11 and the cooling and heat dissipation device 13, steam can quickly flow upwards to the heat exchanger 15 for heat exchange, while also preventing steam from flowing downwards to the pump unit 11 and other cooling and heat dissipation devices 13, thus avoiding problems such as cavitation and reduced cooling efficiency.

[0024] It is understandable that the liquid-gas two-phase pipe 14 connects the cooling and heat dissipation device 13 and the heat exchanger 15 to transport the coolant and vapor in the cooling and heat dissipation device 13 to the heat exchanger 15. Therefore, the heat exchanger 15 is also located above the liquid-gas two-phase pipe 14 to facilitate the rapid upward flow of vapor to the heat exchanger 15 for heat exchange. In other words, due to the characteristic that vapor flows upward rapidly, the heat exchanger 15 is positioned higher than all other components in the rack or system-level two-phase cooling system 1. That is, the pump device 11, liquid cooling pipe 12, cooling and heat dissipation device 13, liquid-gas two-phase pipe 14, and cooling liquid pipe 16 are positioned lower than the heat exchanger 15. In other words, the heat exchanger 15 is located at the top. This allows the vapor to quickly separate from the coolant and escape to the heat exchanger 15, facilitating rapid heat exchange of the vapor and effectively preventing the vapor from flowing downward to other components such as the pump device 11, which could lead to cavitation and reduced cooling efficiency.

[0025] In this embodiment, the rack or system-level two-phase cooling system 1 is mounted on a rack (cabinet) 18. A heat exchanger 15 is located at the top 181 of the rack 18, a pump unit 11 is located at the bottom 182 of the rack 18, and a cooling device 13 is located between the heat exchanger 15 and the pump unit 11. The cooling device 13 includes a server's cold plate, but is not limited to this; other cooling components, such as a water-cooled head or a water-cooled plate, can also be used in this invention. Furthermore, it is worth mentioning that the diameter of the liquid-gas two-phase pipe 14 is designed to be larger than the diameter of the liquid cooling pipe 12, to facilitate the simultaneous containment of both vapor and coolant two-phase fluids and to provide sufficient space for the vapor to quickly rise and escape. It is understood that the heat exchanger 15 can also be located above the rack 18, for example, on the ceiling above the rack 18. In other words, not all components in the rack or system-level two-phase cooling system 1 of this invention must be mounted on the rack 18; some components may be located outside the rack 18.

[0026] Furthermore, in this embodiment, the rack-mount or system-level two-phase cooling system 1 further includes at least one liquid storage tank 17, connecting the heat exchanger 15 and the cooling liquid pipe 16. The coolant in the heat exchanger 15 is first transported to the liquid storage tank 17 for storage, and then transported to the cooling liquid pipe 16 via the liquid storage tank 17. It is understood that the liquid storage tank 17 functions similarly to a reservoir providing coolant, maintaining a continuous supply of pressure-stabilized coolant, and also has a degassing function, preventing gas from entering the pump device 11 via the cooling liquid pipe 16. Figure 1 As shown, the liquid storage tank 17, like the heat exchanger 15, is located above the pump unit 11 and the cooling and heat dissipation device 13, and is adjacent to the heat exchanger 15. Therefore, in this embodiment, both the liquid storage tank 17 and the heat exchanger 15 are located at the top of the entire frame 18, so as to facilitate the natural separation of steam and coolant by utilizing the gravity and density difference between them, thereby improving cooling efficiency and avoiding problems such as cavitation and deterioration of cooling efficiency.

[0027] In summary, this invention provides a rack- or system-level two-phase cooling system that utilizes the gravity and density difference between steam and coolant to naturally separate them, thereby improving cooling efficiency. Therefore, this invention specifically positions the heat exchanger above the pump unit. By placing the heat exchanger above the pump unit, steam can quickly flow upwards to the heat exchanger for heat exchange, while also preventing steam from flowing downwards to the pump unit, thus avoiding problems such as cavitation and reduced cooling efficiency.

[0028] The present invention has been described in detail above. However, the above description is only a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent variations and modifications made in accordance with the claims of the present invention should still fall within the scope of the present invention.

Claims

1. A rack- or system-level two-phase cooling system for circulating a coolant to cool at least one heat source, characterized in that, Include: At least one pump device is used to increase the pressure of the coolant in order to pressurize and deliver the coolant. At least one liquid cooling pipe is connected to the pump assembly, which delivers the coolant to the liquid cooling pipe; At least one cooling and heat dissipation device is connected to the liquid cooling pipe. The cooling and heat dissipation device is in contact with the heat source. The coolant in the liquid cooling pipe is delivered to the cooling and heat dissipation device to cool the heat source. A portion of the coolant evaporates upon heating to form a vapor. At least one liquid-gas two-phase pipe is connected to the cooling and heat dissipation device, and the coolant and vapor in the cooling and heat dissipation device are transported to the liquid-gas two-phase pipe. At least one heat exchanger is connected to the liquid-gas two-phase pipe, through which the coolant and the vapor in the liquid-gas two-phase pipe are transported to the heat exchanger for heat exchange, causing the vapor to condense back into the coolant; and At least one cooling liquid pipe connects the heat exchanger and the pump assembly, wherein the coolant in the heat exchanger is delivered to the pump assembly via the cooling liquid pipe, and the heat exchanger is located above the pump assembly.

2. The rack- or system-level two-phase cooling system as described in claim 1, characterized in that, The heat exchanger is located above the cooling and heat dissipation device.

3. The rack- or system-level two-phase cooling system as described in claim 1, characterized in that, The rack-level two-phase cooling system is mounted on a rack, with the heat exchanger located at the top of the rack.

4. The rack- or system-level two-phase cooling system as described in claim 1, characterized in that, The rack-level two-phase cooling system is mounted on a rack, and the pump unit is located at the bottom of the rack.

5. The rack- or system-level two-phase cooling system as described in claim 1, characterized in that, The rack-mounted two-phase cooling system is mounted on a rack, with the heat exchanger located at the top of the rack, the pump unit located at the bottom of the rack, and the cooling and heat dissipation device located between the heat exchanger and the pump unit.

6. The rack- or system-level two-phase cooling system as described in claim 1, characterized in that, The diameter of the liquid-gas two-phase pipe is larger than the diameter of the liquid cooling pipe.

7. The rack- or system-level two-phase cooling system as described in claim 1, characterized in that, The cooling system includes a server's cold plate.

8. The rack- or system-level two-phase cooling system as described in claim 1, characterized in that, It also includes at least one liquid storage tank, which connects the heat exchanger and the cooling liquid pipe, and the cooling liquid in the heat exchanger is transported to the cooling liquid pipe via the liquid storage tank.

9. The rack or system-level two-phase cooling system as described in claim 8, characterized in that, The liquid storage tank is located above the pump unit and the cooling and heat dissipation device.

10. The rack- or system-level two-phase cooling system as described in claim 8, characterized in that, The liquid storage tank is located adjacent to the heat exchanger.

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