Method and apparatus for cooling an equipment enclosure through closed-loop liquid-assisted air cooling in combination with direct liquid cooling

Abstract

A method and an apparatus for cooling, preferably within an enclosure, a diversity of heat-generating components, with at least some of the components having high-power densities and others having low-power densities. Heat generated by the essentially relatively few high-power-density components, such as microprocessor chips for example, is removed by direct liquid cooling, whereas heat generated by the more numerous low-power or low-watt-density components, such as memory chips for example, is removed by liquid-assisted air cooling in the form of a closed loop comprising a plurality of heating and cooling zones that alternate along the air path.

1 - 28 . (canceled) 
   
   
       29 . A method of cooling heat-generating electronic components in a thermally controlled interior of an enclosure shell, said method comprising:
 circulating a first cooling fluid along a closed first path within the enclosure shell, locating a plurality of centrifugal fans along said closed first path, said path having a plurality of heat-generating regions containing the heat-generating electronic components;   having a plurality of heat exchangers transferring heat from the first cooling fluid to a second cooling fluid; and   circulating the second cooling fluid through the heat exchangers and out of the enclosure shell along a second path;   wherein the first cooling fluid is alternately heated in the heat-generating regions and cooled by the heat exchangers a plurality of times as the first cooling fluid traverses the first closed path.   
   
   
       30 . A method as claimed in  claim 29 , wherein said first cooling fluid is air, locating air movers in the air flow path of said air cooling circulation loop, said air movers each comprising said centrifugal fans, which are arranged to prevent interference with their respective air-streams flowing through said path. 
   
   
       31 . A method as claimed in  claim 30 , wherein said air-to-liquid heat exchangers are interleaved with rows of packages for cooling the flow of air in each said row passage prior to said flow of air entering a subsequent row passage, said packages comprising blades mounting said heat-generating components and diverse operative components, said rows of blades being attached to at least one side of at least one or more midplanes comprising circuit cards for electrical interconnections. 
   
   
       32 . A method as claimed in  claim 31 , wherein, referring to an imaginary Cartesian coordinate system having axes x, y, and z, stacking a first stack of said rows of blades and heat exchangers along the z axis on a −y side of said one or more midplanes that lie in a central plane parallel to the x and z axes, similarly stacking a second stack of said rows of blades and heat exchangers along the z axis on a +y side of said one or more midplanes, a first set of air movers is located at a +z end of said first stack, locating a first plenum at a +z end of said second stack, locating a second set of air movers at a −z end of said second stack, and locating a second plenum at a −z end of said first stack, such that said flow of air is conveyed, by means of said air movers, along a closed loop comprising, in stream-wise order, said first stack of blades through which air flows toward the +z direction, said first set of air movers into which air flows toward the +z direction and from which it exhausts toward the +y direction, said first plenum into which air flows toward the +y direction and from which it exhausts toward the −z direction, said second stack of blades through which air flows toward the −z direction, said second set of air movers into which air flows toward the −z direction and from which it exhausts toward the −y direction, and finally said second plenum into which air flows toward the −y direction and from which it exhausts toward the +z direction into said first stack, thereby completing said closed loop. 
   
   
       33 . A method as claimed in  claim 32 , wherein in a blade, the electronic components are mounted on a blade circuit card and further the corresponding power converters for one or more electronic components are mounted on the directly opposite surface of said blade circuit card. 
   
   
       34 . A method as claimed in  claim 30 , wherein said centrifugal fans are arranged in an over-and-under, fore-and-aft, orientation in, respectively, upper and lower housings for turning the flow of air in said air circulation loop. 
   
   
       35 . A method as claimed in  claim 29 , wherein interior surfaces in said enclosure are equipped with acoustic insulation so as to attenuate the amount of acoustical noise, produced by said centrifugal fans, that is transmitted across said surfaces to the outside of said enclosure. 
   
   
       36 . A method as claimed in  claim 30 , wherein said air movers divert the flow of air streaming through said air circulation loop into an alternate path upon failure of a centrifugal fan so as to inhibit an aerodynamic short-circuiting of the remaining centrifugal fans.