Patent ID: 12256519

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 causing the vaporized coolant35to condense. 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.

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 vaporize 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 vaporize 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 a first 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 coolant30produced 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.

As shown inFIG.1, in some embodiments, the immersion cooling system10further includes a pressure sensor PT02and a controller80. The pressure sensor PT02is configured to provide a sensing signal indicative of the gas pressure inside the cooling tank20. The controller80is communicably connected to the pressure sensor PT02and is configured to receive the sensing signal from the pressure sensor PT02. The controller80is further configured to determine whether the gas pressure inside the cooling tank20exceeds the first upper limit based on the sensing signal. If it is determined that the gas pressure inside the cooling tank20exceeds the first upper limit, then the controller80instructs the valve61to open (e.g., by sending a control signal to the valve61). In some embodiments, the valve61is a solenoid valve. In some embodiments, the pressure sensor PT02is configured to measure a pressure difference between the cooling tank20and the enclosure56.

As shown inFIG.1, in some embodiments, the immersion cooling system10further includes a safety valve62. The safety valve62has two ports, one of which communicates with the enclosure56and the other communicates with the part of the cooling tank20above the liquid coolant30. The safety valve62is configured to open automatically in response to the gas pressure inside the cooling tank20exceeding a second upper limit. The second upper limit is higher than the first upper limit. By this arrangement, gas can be discharged at an accelerated rate from the cooling tank20to the enclosure56when the gas pressure inside the cooling tank20further increases. In addition, with the provision of the safety valve62, the reliability of the pressure control scheme of the immersion cooling system10can be improved. When the valve61malfunctions, the gas inside the cooling tank20can still be discharged to the enclosure56via the safety valve62. In some embodiments, the valve61and the safety valve62are disposed on a pipe. The pipe is connected to the cooling tank20on one end and extends into the enclosure56.

As shown inFIG.1, in some embodiments, the immersion cooling system10further includes a valve63. The valve63has two ports, one of which communicates with the cooling tank20and the other communicates with a surrounding environment external to the cooling tank20and the housing50. The valve63is configured to open in response to the gas pressure inside the cooling tank20dropping below a lower limit. As a result, when the gas pressure inside the cooling tank20is too low, air can be drawn into the cooling tank20from the surrounding environment to increase the gas pressure inside the cooling tank20and prevent structural damage of the cooling tank20.

In some embodiments, the valve63is a solenoid valve. In some embodiments, the controller80is configured to determine whether the gas pressure inside the cooling tank20drops below the lower limit based on the sensing signal provided by the pressure sensor PT02. If it is determined that the gas pressure inside the cooling tank20drops below the lower limit, then the controller80instructs the valve63to open (e.g., by sending a control signal to the valve63). When the gas pressure inside the cooling tank20does not fall below the lower limit, the valve63stays closed.

In some embodiments, when the gas pressure inside the cooling tank20does not exceed the first upper limit and does not drop below the lower limit, the immersion cooling system10can take other pressure control measures to maintain the gas pressure inside the cooling tank20. As shown inFIG.1, in some embodiments, when the valve61is closed (i.e., before the valve61is opened), the condenser41is configured to speed up or slow down the condensing operation as the gas pressure inside the cooling tank20changes, so as to control the gas pressure inside the cooling tank20. In some embodiments, the controller80is configured to control the condenser41to speed up or slow down the condensing operation based on the sensing signal provided by the pressure sensor PT02.

Specifically, when the gas pressure inside the cooling tank20increases but does not exceed the first upper limit, the condenser41is configured to speed up the condensing operation (e.g., increase the amount of the vaporized coolant35being condensed per unit time, or increase the amount of heat being removed from the cooling tank20per unit time) to lower the gas pressure inside the cooling tank20. On the other hand, when the gas pressure inside the cooling tank20decreases but does not drop below the lower limit, the condenser41is configured to slow down the condensing operation (e.g., reduce the amount of the vaporized coolant35being condensed per unit time, or reduce the amount of heat being removed from the cooling tank20per unit time) to raise the gas pressure inside the cooling tank20.

As shown inFIG.1, in some embodiments, the condenser41is configured to receive a working fluid through a delivery pipe11. The working fluid is configured to make heat exchange with the vaporized coolant35to cause the vaporized coolant35to condense and return to the liquid state, and the working fluid is discharged through the delivery pipe11after the heat exchange. In some embodiments, the delivery pipe11is provided with one or more flow control valves64. The one or more flow control valves64are configured to regulate the amount of the working fluid passing through the condenser41(e.g., regulate the mass/volume flow rate of the working fluid), such that the condensing operation can be sped up or slowed down. In some embodiments, the one or more flow control valves64include a motorized valve. In some embodiments, the controller80is configured to control the one or more flow control valves64based on the sensing signal provided by the pressure sensor PT02.

As shown inFIG.1, in some embodiments, the delivery pipe11is further provided with a pressure sensor PT01. The pressure sensor PT01is configured to measure a pressure of the working fluid. In some embodiments, the delivery pipe11is further provided with a filter13. The filter13is configured to filter the working fluid to remove pollutant from the working fluid before the working fluid enters the condenser41. In some embodiments, the delivery pipe11is further provided with a flowmeter15. The flowmeter15is configured to measure a flow rate of the working fluid. In some embodiments, the delivery pipe11is further provided with a check valve17. The check valve17is configured to prevent the backflow of the working fluid.

As shown inFIG.1, in some embodiments, the immersion cooling system10further includes an expansion device90. The expansion device90is disposed on the outside of the cooling tank20and the housing50, and the expansion device90communicates with the part of the cooling tank20above the liquid coolant30(the usage of “Element A communicates with Element B” herein refers to the relation that Element A is in fluid communication with Element B). When the valve61is closed, the expansion device90is configured to adjust its volume as the gas pressure inside the cooling tank20changes. In some embodiments, the expansion device90includes an elastic body. The internal space of the elastic body communicates with the cooling tank20. In response an increase of the gas pressure inside the cooling tank20, the elastic body is configured to automatically expand (i.e., increase its volume) to lower the gas pressure inside the cooling tank20. In response a decrease of the gas pressure inside the cooling tank20, the elastic body is configured to automatically shrink (i.e., decrease its volume) to raise the gas pressure inside the cooling tank20.

As shown inFIG.1, in some embodiments, the immersion cooling system10further includes a condenser42. The condenser42is connected between the cooling tank20and the expansion device90. Accordingly, gas flowing from the cooling tank20towards the expansion device90would pass through the condenser42. When the gas pressure inside the cooling tank20exceeds a threshold value, the condenser42is activated and is configured to condense at least part of a vapor (including the vaporized coolant35) flowing towards the expansion device90. The threshold value is lower than the first upper limit. By this arrangement, the burden of the expansion device90can be reduced. In some embodiments, the expansion device90is connected to the cooling tank20via a pipe. The pipe passes through the condenser42. When the condenser42is activated, the condensate produced by the condenser42(including the liquid coolant30) can flow back to the cooling tank20along the pipe.

In some embodiments, the controller80is configured to determine whether the gas pressure inside the cooling tank20exceeds the threshold value based on the sensing signal provided by the pressure sensor PT02. If it is determined that the gas pressure inside the cooling tank20exceeds the threshold value, then the controller80activates/turns on the condenser42. When the gas pressure inside the cooling tank20does not exceed the threshold value, the condenser42remains off.

Reference is made toFIG.2. The immersion cooling method100of the present embodiment includes a control flow in response to an increase of the gas pressure inside the cooling tank. With additional reference toFIG.1, in step101, control the gas pressure inside the cooling tank20by (i) increasing the volume of the expansion device90, which communicates with the cooling tank20, as the gas pressure inside the cooling tank20increases, and/or (ii) causing the condenser41in the cooling tank20to speed up the condensing operation as the gas pressure inside the cooling tank20increases.

As shown inFIGS.1and2, if the gas pressure inside the cooling tank20exceeds a threshold value, then the immersion cooling method100continues to step102, which includes activating the condenser42between the cooling tank20and the expansion device90. The condenser42, once activated, condenses at least part of a vapor flowing from the cooling tank20towards the expansion device90.

As shown inFIGS.1and2, if the gas pressure inside the cooling tank20further increases and exceeds a first upper limit, then the immersion cooling method100continues to step103, which includes opening the valve61. The opening of the valve61enables flow of gas from the cooling tank20to the enclosure56located on a side of the cooling tank20.

As shown inFIGS.1and2, if the gas pressure inside the cooling tank20further increases and exceeds a second upper limit, then the immersion cooling method100continues to step104, which includes opening the safety valve62. The opening of the safety valve62enables flow of gas from the cooling tank20to the enclosure56.

Reference is made toFIG.3. The immersion cooling method200of the present embodiment includes a control flow in response to a decrease of the gas pressure inside the cooling tank. With additional reference toFIG.1, in step201, control the gas pressure inside the cooling tank20by (i) decreasing the volume of the expansion device90, which communicates with the cooling tank20, as the gas pressure inside the cooling tank20decreases, and/or (ii) causing the condenser41in the cooling tank20to slow down the condensing operation as the gas pressure inside the cooling tank20decreases.

As shown inFIGS.1and3, if the gas pressure inside the cooling tank20drops below a lower limit, then the immersion cooling method200continues to step202, which includes opening the valve63. The opening of the valve63enables flow of gas from a surrounding environment to the cooling tank20. The surrounding environment is external to the cooling tank20and the enclosure56.

In sum, in the immersion cooling system of the present disclosure, when the gas pressure inside the cooling tank is too high, the gas inside the cooling tank can be discharged to an enclosure located on a side of the cooling tank, rather than being discharged directly to the atmosphere. By this arrangement, vaporized coolant would not be lost. The vaporized coolant can be collected by the enclosure and can be recycled to the cooling tank for reuse.

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.