Patent ID: 12200904

DETAILED DESCRIPTION

For the completeness of the description of the present disclosure, reference is made to the accompanying drawings and the various embodiments described below. Various features in the drawings are not drawn to scale and are provided for illustration purposes only. To provide full understanding of the present disclosure, various practical details will be explained in the following descriptions. However, a person with an ordinary skill in relevant art should realize that the present disclosure can be implemented without one or more of the practical details. Therefore, the present disclosure is not to be limited by these details.

Reference is made toFIG.1. An immersion cooling system10includes a cooling tank20. The cooling tank20is configured to accommodate a liquid coolant30and one or more electronic devices E immersed in the liquid coolant30. The electronic devices E may include, for example, one or more computer servers or data storage devices. During operation, the electronic devices E produce heat. The liquid coolant30is configured to contact the electronic devices E and absorb heat therefrom, so as to facilitate the cooling of the electronic devices E. The liquid coolant30is a non-conductive liquid, such as a dielectric liquid.

As shown inFIG.1, in some embodiments, the liquid coolant30in the cooling tank20partially vaporizes as a result of absorbing heat from the electronic devices E. The part of the cooling tank20above the liquid coolant30includes a vaporized coolant35that vaporized from the liquid coolant30. The immersion cooling system10further includes a condenser41. The condenser41is disposed in the cooling tank20and is configured to perform a condensing operation. The condensing operation includes condensing at least part of the vaporized coolant35to the liquid coolant30. In the two-phase cooling method described above, the liquid coolant30facilitates the cooling of the electronic devices E by repeating the process of: (i) absorbing heat from the electronic devices E and vaporizing; and (ii) being converted back to the liquid state by the condenser41.

As shown inFIG.1, the immersion cooling system10further includes a filtration system90. The filtration system90is connected to the cooling tank20and is configured to draw the liquid coolant30from the cooling tank20for filtration, so as to remove contaminates from the liquid coolant30(e.g., contaminates that reside in the cooling tank20or the electronic devices E might mix into the liquid coolant30). Removing contaminates from the liquid coolant30can improve the efficiency of the immersion cooling system10.

As shown inFIG.1, the filtration system90includes a pipeline91in fluid communication with the cooling tank20. The pipeline91has an inlet A and an outlet B. The inlet A and the outlet B of the pipeline91are both connected to the cooling tank20, and the positions of the inlet A and the outlet B are below a surface37of the liquid coolant30in the cooling tank20. The inlet A is where the liquid coolant30in the cooling tank20flows into the pipeline91, and the outlet B is where the liquid coolant30flows out of the pipeline91and returns to the cooling tank20.

As shown inFIG.1, the filtration system90further includes a pump92configured to draw the liquid coolant30from the cooling tank20into the pipeline91for filtration. Specifically, the pump92is disposed in the pipeline91and is configured to drive the liquid coolant30to flow through the pipeline91. When driven by the pump92, the liquid coolant30enters the pipeline91from the inlet A and exits the pipeline91from the outlet B.

As shown inFIG.1, the filtration system90further includes a filter93. The filter93is disposed in the pipeline91and is configured to filter the liquid coolant30passing through the pipeline91. The filter93can remove contaminates from the liquid coolant30, such that the efficiency of the immersion cooling system10can be improved. In some embodiments, the filter93is configured to remove at least one of particles, plasticizer or water from the liquid coolant30. In some embodiments, the filter93includes at least one of a filter screen, a semipermeable membrane or an activated carbon. In some embodiments, the filter93is provided with connectors95on its two ends. The filter93is removably connected to the pipeline91via the connectors95to facilitate the replacement of the filter93in the filtration system90. In some embodiments, the connectors95include quick connect fittings.

In two-phase cooling, the liquid coolant30in the cooling tank20is kept at a temperature close to the boiling point. As the liquid coolant30passes through the pipeline91, the liquid coolant30suffers from pressure loss due to the pipeline91itself or the components in the pipeline91. In addition, the liquid coolant30would also experience pressure drop when the liquid coolant30enters the low pressure region of the pump92. These factors may reduce the pressure of the liquid coolant30to below the saturation vapor pressure, leading to the formation of bubbles in the liquid coolant30. When subject to high pressure (e.g., when passing through the pump92), the bubbles in the liquid coolant30may collapse and generate shock waves that can damage system components or cause problems such as vibration or noise.

In view of said issue, as shown inFIG.1, the filtration system90further includes a cooling device94. The cooling device94is connected to the pipeline91and is configured to cool the liquid coolant30passing through the pipeline91. The cooling device94is located between the pump92and the inlet A of the pipeline91, and the pipeline91passes through the cooling device94, such that the liquid coolant30flowing into the pipeline91is cooled by the cooling device94before entering the pump92. By this arrangement, the saturation vapor pressure of the liquid coolant30can be lowered, and the problem of cavitation thus becomes less likely to occur. As a result, the lifespan of the pump92is increased, and the pump92would generate less vibration/noise. In some embodiments, the cooling device94is configured to cool the liquid coolant30to a temperature below a saturation temperature of the liquid coolant30corresponding to a pressure in the pipeline91. In other words, the liquid coolant30is cooled to a temperature below the saturation temperature before entering the pump92. In some embodiments, the cooling device94is connected to an input port C of the pump92.

In some embodiments, the cooling device94includes a liquid-to-liquid heat exchanger or a gas-to-liquid heat exchanger. In some embodiments, the cooling device94is configured to circulate a liquid or a gas to make heat exchange with the liquid coolant30, so as to lower the temperature of the liquid coolant30.

As shown inFIG.1, in some embodiments, the filter93is located between the pump92and the outlet B of the pipeline91. Accordingly, the liquid coolant30flowing into the pipeline91passes through the pump92before entering the filter93, or in other words, the liquid coolant30passes through the filter93after leaving the pump92. In other embodiments, the filter93may alternatively be disposed at the outlet B of the pipeline91.

The filter93also causes pressure loss of the liquid coolant30. By positioning the filter93between the pump92and the outlet B of the pipeline91or positioning the filter93at the outlet B of the pipeline91, the liquid coolant30would be free of the extra pressure loss caused by the filter93, and the likelihood of cavitation occurring in the pump92can be further reduced. Besides, positioning the filter93between the pump92and the outlet B of the pipeline91or positioning the filter93at the outlet B of the pipeline91can also reduce the load of the cooling device94. If the liquid coolant30passes through the filter93before entering the pump92, then the cooling device94would have to cool the liquid coolant30to a lower temperature to prevent cavitation, because of the extra pressure loss caused by the filter93.

As shown inFIG.1, in some embodiments, the filter93is connected to an output port D of the pump92. In some embodiments, the pump92is configured to drive the liquid coolant30to flow through the cooling device94, the pump92and the filter93in order (i.e., in the order of the cooling device94, followed by the pump92, and then followed by the filter93). In other words, on the flow path of the liquid coolant30, the cooling device94is positioned before the pump92, and the pump92is positioned before the filter93.

As shown inFIG.1, in some embodiments, a position of the pump92is below the surface37of the liquid coolant30in the cooling tank20. By virtue of the height difference between the pump92and the surface37of the liquid coolant30, the pressure of the liquid coolant30can be increased and the likelihood of cavitation occurring in the pump92can be further reduced. In some embodiments, the pump92is located below the cooling tank20.

Generally speaking, the gas pressure inside the cooling tank20is positively correlated with the workload of the electronic devices E. Specifically, when the workload of the electronic devices E is increased (e.g., when the amount of computation performed by the electronic devices E is increased), the electronic devices E would generate more heat per unit time. As a result, the liquid coolant30would be vaporized more quickly, and the gas pressure inside the cooling tank20increases accordingly. On the other hand, when the workload of the electronic devices E is reduced, the electronic devices E would generate less heat per unit time. As a result, the liquid coolant30would be vaporized more slowly, and the gas pressure inside the cooling tank20decreases accordingly.

As shown inFIG.1, the immersion cooling system10further includes a housing50. The housing50covers a side of the cooling tank20and thereby forms an enclosure56. The enclosure56has a fixed volume. In the illustrated embodiment, the housing50covers the top side of the cooling tank20. In some embodiments, the housing50may include metal, glass, acrylic, other suitable materials or any combination thereof.

As shown inFIG.1, the immersion cooling system10further includes a valve61. The valve61has two ports, one of which communicates with the enclosure56and the other communicates with the part of the cooling tank20above the liquid coolant30(i.e., the space inside the cooling tank20that is filled with the vaporized coolant35). The valve61is configured to switch between an open state and a closed state. When the valve61is in the open state, the valve61allows the flow of gas between the enclosure56and the cooling tank20. When the valve61is in the closed state, the valve61prohibits the flow of gas between the enclosure56and the cooling tank20.

Continuing from the discussion in the previous paragraph, the valve61is configured to open in response to the gas pressure inside the cooling tank20exceeding an upper limit. The opening of the valve61enables the flow of gas from the cooling tank20to the enclosure56, and the gas pressure inside the cooling tank20is reduced accordingly. As a result, structural damage of the cooling tank20can be prevented, and the liquid coolant30can be kept from having an excessively high boiling point as well, which could lead to poor heat dissipation for the electronic devices E. The gas flowing from the cooling tank20to the enclosure56includes the vaporized coolant35, and may additionally include other gases mixing in the vaporized coolant35, such as air or water vapor.

In the immersion cooling system10of the present disclosure, when the gas pressure inside the cooling tank20is too high, the gas inside the cooling tank20can be discharged to the enclosure56located on a side of the cooling tank20, rather than being discharged directly to the atmosphere. By this arrangement, the vaporized coolant35would not be lost. The vaporized coolant35can be collected by the enclosure56and can be recycled to the cooling tank20for reuse.

As shown inFIG.1, in some embodiments, the immersion cooling system10further includes a recycling system70. The recycling system70includes a condenser72and a recycling pipe74. The condenser72is disposed in the enclosure56and is configured to condense the vaporized coolant35in the enclosure56. The recycling pipe74has two opposite ends, one of which is connected to the enclosure56and the other is connected to the cooling tank20. The recycling pipe74is configured to guide the liquid coolant30condensed by the condenser72to flow into the cooling tank20. In some embodiments, the recycling pipe74includes a check valve77configured to prevent the backflow of the liquid coolant30or the vaporized coolant35from the cooling tank20to the enclosure56.

Reference is made toFIG.2. The immersion cooling system10A of the present embodiment differs from the embodiment shown inFIG.1in that the pipeline91A of the filtration system90A penetrates a wall of the cooling tank20and extends into the cooling tank20, such that the outlet B of the pipeline91A is located within the cooling tank20. Moreover, in the present embodiment, the filter93of the filtration system90A is disposed at the outlet B of the pipeline91A. Hence, the filter93is also located within the cooling tank20and is immersed in the liquid coolant30.

Reference is made toFIG.3. The immersion cooling system10B of the present embodiment differs from the embodiment shown inFIG.1in that the outlet B of the pipeline91B of the filtration system90B is located above the surface37of the liquid coolant30in the cooling tank20. Consequently, after being filtered by the filtration system90B, the liquid coolant30flows back to the cooling tank20at the part of the cooling tank20above the surface37of the liquid coolant30. In some embodiments, the outlet B of the pipeline91B is connected to a sloping wall of the cooling tank20.

In sum, in the immersion cooling system of the present disclosure, the filtration system includes a cooling device installed before the pump, and the liquid coolant enters the pump after being cooled by the cooling device. By this arrangement, cavitation can be prevented.

Although the present disclosure has been described by way of the exemplary embodiments above, the present disclosure is not to be limited to those embodiments. Any person skilled in the art can make various changes and modifications without departing from the spirit and the scope of the present disclosure. Therefore, the protective scope of the present disclosure shall be the scope of the claims as attached.