Immersion cooling

• US 10,206,307 B2
• Filed: 05/02/2017
• Issued: 02/12/2019
• Est. Priority Date: 05/03/2016
• Status: Active Grant

• Current Assignee: Liquidstack Holding BV (LiquidStack, Inc.)
• Original Assignee: BitFury Group Limited
• Inventors: Lau, Kar-Wing
• Primary Examiner(s): Popovics, Robert J
• Application Number:
  US15/584,670
• Publication Number:
  US 20170325355A1
• Time in Patent Office: 651 Days
• Field of Search: None
• CPC Class Codes: H05K 7/2029 using a liquid coolant with phase change in electronic enclosures in cabinets of standardized dimensions H05K7/20536; in server cabinets H05K7/20709; in vehicle electronic casings H05K7/20845; in power control electronics H05K7/2089; in displays H05K7/20954
• CPC Class Codes: H05K 7/203 by immersion
• CPC Class Codes: H05K 7/20318 Condensers
• CPC Class Codes: H05K 7/20381 Thermal management, e.g. evaporation control
• CPC Class Codes: H05K 7/20818 within cabinets for removing heat from server blades

Abstract

A method of apparatus for immersion cooling electronic equipment including immersing the electronic equipment in a pressure-sealed tank containing a heat transfer fluid and including a vapor space fluidicly coupled to a condenser; operating the electronic equipment to generate heat and evaporate some of the heat transfer fluid, causing heat transfer fluid vapor to enter the condenser; condensing the heat transfer fluid vapor in the condenser to produce a condensate; returning the condensate to the tank; and increasing power consumption to increase heat generated by the electronic equipment and develop an increased pressure of the heat transfer fluid vapor to bring the apparatus into an equilibrium condition.

Claims

1. A method of immersion cooling a system comprising electronic equipment, the method comprising:

immersing the electronic equipment in a pressure-sealed tank holding heat transfer fluid in liquid form, and including a vapor space in a condenser above a surface of the liquid heat transfer fluid, the vapor space including condenser tubes disposed between the surface of the liquid heat transfer fluid and spaced from an upper portion of the condenser;

operating the electronic equipment to generate heat so as to evaporate some of the heat transfer fluid and cause heat transfer fluid vapor to contact an exterior surface of the condenser tubes;

condensing the heat transfer fluid vapor on the exterior surface of condenser tubes to produce heat transfer fluid condensate;

returning the heat transfer fluid condensate to the heat transfer fluid in the tank; and

controlling at least one of operation of and power consumption by the electronic equipment to operate the immersion cooling system at a substantially constant pressure, wherein

increasing at least one of operation of and power consumption by the electronic equipment increases heat generated thereby increasing pressure of the heat transfer fluid vapor and

decreasing at least one of operation of and power consumption by the electronic equipment decreases heat generated thereby decreasing pressure of the heat transfer fluid vapor,

wherein the increased pressure increases an effectiveness of the condenser to bring the system into the equilibrium condition.

2. The method of claim 1, further comprising reducing power consumption by the electronic equipment to reduce the heat generated and cause a decrease in pressure of the heat transfer fluid vapor, the lower pressure decreasing a boiling point of the heat transfer fluid to bring the system back to equilibrium.

3. The method of claim 2, wherein the reduced power consumption causes a degree of vacuum to be developed inside of the tank.

4. The method of claim 3, wherein power consumption by the electronic equipment is reduced substantially to zero, and the pressure of the heat transfer fluid vapor in the tank is reduced to about 0.4 bar (absolute).

5. The method of claim 1 further comprising filtering the condensate to remove at least one of moisture and metal particles before returning the condensate to the heat transfer fluid in the tank.

6. The method of claim 1, wherein the heat transfer fluid comprises a dielectric fluid.

7. The method of claim 1 further comprising removing, by a desiccant, moisture from air in the vapor space.

8. The method of claim 1, wherein the equilibrium condition comprises a condition having steady pressure.

9. The method of claim 1, wherein the equilibrium condition comprises atmospheric pressure.

10. A method of commencing immersion cooling of electronic equipment, comprising:

immersing the electronic equipment in a pressure-sealed tank holding heat transfer fluid in liquid form, and including a vapor space in a first condenser above a surface of the liquid heat transfer fluid, the vapor space including condenser tubes disposed between the surface of the liquid heat transfer fluid and spaced from an upper portion of the tank, wherein the vapor space is connected to a second condenser disposed above the tank and including a vapor outlet with a valve operable for sealing the vapor outlet;

commencing operation of the electronic equipment to generate heat, so as to evaporate some of the heat transfer fluid, to produce heat transfer fluid vapor in the vapor space;

opening the valve to allow the heat transfer fluid vapor generated to drive air from the vapor space through the second condenser and out through the vapor outlet until substantially all of the air has been driven out of the vapor space;

closing the valve;

continuing operation of the electronic equipment to generate heat so as to produce heat transfer fluid vapor;

condensing the heat transfer fluid vapor on an exterior surface of the condenser tubes to produce heat transfer fluid condensate;

returning the heat transfer fluid condensate to the heat transfer fluid in the tank; and

controlling at least one of operation of and power consumption by the electronic equipment to operate the immersion cooling system at a substantially constant pressure, wherein

increasing at least one of operation of and power consumption by the electronic equipment increases heat generated thereby increasing pressure of the heat transfer fluid vapor and

decreasing at least one of operation of and power consumption by the electronic equipment decreases heat generated thereby decreasing pressure of the heat transfer fluid vapor,

wherein the increased pressure increases an effectiveness of the condenser to bring the system into the equilibrium condition.

11. The method of claim 10, wherein the equilibrium condition comprises a condition having steady pressure.

12. The method of claim 10, wherein the equilibrium condition comprises atmospheric pressure.