Patent Publication Number: US-10314199-B2

Title: Conduitless, liquid phase, internal circulation, immersion cooling system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
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     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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     REFERENCE TO A SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
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     BACKGROUND 
     As society uses more and more electronic equipment, the problems associated with the technology become challenges for maintenance. For instance, many components of the electronics are heat producers. Excessive heat can damage the equipment. Cooling of the entire electronics equipment is cumbersome and can be energy wasteful with cooling of components that are not self-heating. Hence separation of the heat producing components from the rest of the equipment while still in working contact can be helpful. The heat producing components can then be set up in a cooling device which can maintain the optimal temperature range for the working of the components as they are in use such as with gaming technology. 
     Many such devices have been developed. Some use two phase cooling such as air and water or liquid/vapor transitioning coolant (e.g. U.S. Pat. Nos. 8,369,091, 8,179,677, 6,906,919, 5,285,347). Most use pipe systems to transfer the primary coolant along paths where contact with heat transferring material [thermal interface material TIM] can bleed the heat from the components to the coolant (e.g. U.S. Pat. No. 7,667,969). Another slightly different approach is immersion cooling. For those systems using fluid circulation, the circulation loop tends to be out of the tank for cooling of warmed primary coolant and return to the tank after cooling (e.g. U.S. Pat. No. 7,983,040). 
     As would be expected, sensors are used as needed to provide thermostatic control [e.g. 20120111034]. For instance, rate of flow of the coolant might be varied. Related computer programmed control of the necessary processes could then automate the system. 
     However, to date, no system has used liquid dielectric primary coolant in totally internal circulation with a conduitless flow path and without TIM. The present invention simplifies immersion cooling to such a system with a unique physical layout of the tank and its constituents which includes at least one cross-flow circulation inducer [e.g. pump] and secondary cooling of all of the warmed primary coolant within the tank set up. In some embodiments, additional circulation impetus comes from the natural rising of warmed liquid and sinking of cooled liquid. 
     SUMMARY 
     An immersion cooling tank for cooling at least one heat producing electronic component is described. In a first embodiment, a partial divider is attached at least to two sides of a tank but not completely to the top nor the bottom and defines two sub-chambers of the tank. The two sides for attachment may be opposite or adjacent to each other. Gaps at the top and bottom between the divider and the top or bottom respectively allow for passage of the liquid contained in the tank. In one sub-chamber, the at least one electronic component is appropriately secured in the tank which is filled with dielectric fluid that maintains liquid form throughout the cooling procedure. Beneath the component[s] is at least one cross-flow wave inducer. 
     In the second sub-chamber is a secondary heat exchanger which is set up so that all warmed dielectric liquid leaving the electronic component[s] must flow through the secondary heat exchanger. Optionally, a mechanical filter may be placed prior to the secondary heat exchanger. If so, the filter is set up so that all of the dielectric liquid flows through the filter prior to flowing through the secondary heat exchanger. 
     Flow is caused in part by the heat differentials in the sub-chambers and in part by the cross-flow wave inducer function. Cooled dielectric liquid sinks to the tank bottom after leaving the secondary heat exchanger. It then flows into the first sub-chamber by virtue of the function of the cross-flow wave inducer[s]. The flow continues upward in the first sub-chamber cooling the at least one component as it flows. The cycle then repeats with warmed dielectric liquid rising and flowing into the second sub-chamber. In this embodiment, the flow is up and down with respect to the effects of gravity. 
     A second embodiment would have the at least one cross-flow wave inducer placed at ninety degrees to the previous configuration. Hence the circulation would then be in a horizontal plane with respect to the effects of gravity. This could be accomplished by using the apparatus of the first embodiment turned onto an appropriate side with the original top having a sealed cover lid containing appropriate passageways for attachments to any components, cross-flow inducers, heat exchange equipment, etc. as needed. Alternatively it could be built in the second configuration with the topmost side becoming the open ‘top’ with a sealing cover. 
     Either embodiment when used with the sealed cover lid can be made to be mobile for field work and carried at any convenient angle with respect to the effects of gravity. For instance the device could be transported in a vehicle or carried in a backpack. However it is preferred for better efficiency to have the cross-flow inducer in the lower portion of the device at whatever orientation it might be. 
    
    
     
       FIGURES 
         FIG. 1  depicts a side view of one embodiment of the inventive cooling immersion tank with vertical circulation. 
         FIG. 2  depicts a top down view of a second embodiment of the inventive cooling immersion tank with horizontal circulation. 
     
    
    
     DETAILED DESCRIPTION 
     An immersion cooling system [ 1 ] having a tank [ 3 ] for cooling at least one heat producing electronic component [ 2 ] is described. The tank has four sides, a top [ 6 ], an optional top cover and a bottom. In a first embodiment, as seen in  FIG. 1 , a partial divider [ 9 ] is attached at least to two sides of the tank but not completely to the top nor the bottom and defines two sub-chambers of the tank. The two sides for attachment may be opposite or adjacent to each other. Hence the divider defines a top gap [ 11 ] and a bottom gap [ 12 ] between the two chambers to allow for circulation i.e. the gaps at the top and bottom between the divider and the top or bottom respectively allow for passage of the liquid contained in the tank. In one sub-chamber [ 7 ], the at least one electronic component [ 2 ] is secured by an effective means to secure [ 10 ] the electronic component[s] in the tank [ 3 ] which is filled with dielectric fluid coolant [ 4 ] that maintains liquid form throughout the cooling procedure. A preferred dielectric fluid would be biodegradable, non-toxic, and basically inert. Beneath the component[s] is at least one cross-flow wave inducer pump [ 5 ]. 
     A passageway [ 15 ] at the top of the tank allows for ingress and egress of attachments needed for the electronic components and power source. These attachments allow for communication between the active electronics system[s] [ 18 ] and their heat producing component[s]. Alternatively the passageway[s] [ 20 ] go through a top cover [ 19 ]. All passageways and the top may be sealed hermetically in order to allow for safe and spill free mobility. However the cooling system works well in a top open configuration. In such a case, an optional spill catch gutter [ 23 ] may be useful to be included in the construction. If so, the gutter will direct all spill back into the tank. 
     In the second sub-chamber [ 8 ] is a secondary heat exchanger [ 13 ] which is set up so that all warmed dielectric liquid leaving the electronic component[s] must flow through the secondary heat exchanger. Optionally, a mechanical filter [ 14 ] may be placed prior to the secondary heat exchanger. If so, the filter is set up so that all the dielectric liquid flows through the filter prior to flowing through the secondary heat exchanger. As with the electronic components, there will be a passageway [ 16 ] for the ingress and egress of attachments to the secondary heat exchanger such as for secondary coolant to and from a secondary coolant cooling location [ 17 ]. A passageway for attachments to the pump is also present. It may be a separate passageway or combined with one of the others. Similarly power connections may be through any existing passageways or via a dedicated passageway. 
     Flow is caused in part by the heat differentials in the sub-chambers and in part by the cross-flow wave inducer [ 5 ] function. Cooled dielectric liquid sinks to the tank bottom after leaving the secondary heat exchanger. It then flows into the first sub-chamber by virtue of the function of the cross-flow wave inducer[s]. The flow continues upward in the first sub-chamber cooling the at least one component as it flows. The cycle then repeats with warmed dielectric liquid rising and flowing into the second sub-chamber. In this embodiment, the flow is up and down with respect to the effects of gravity. 
     A preferred, but not required, power source for the power consuming components of the system is a 24 V DC power supply. Sensors, motherboards, and other components for related computer programmed control to automate the system can be distributed within the tank as needed on or within the walls, the divider, the lid, etc. Uses for the above vertical configuration include, among others, PC gaming, PC appliances and computer work stations. 
     A second embodiment, such as in  FIG. 2 , would have the at least one cross-flow wave inducer [ 5 ] placed so that the circulation would then be in a horizontal plane with respect to the effects of gravity. This could be accomplished by using the apparatus of the first embodiment turned onto an appropriate side with the original top having a sealed cover lid containing appropriate passageways for attachments to any components, cross-flow inducers, heat exchange equipment, etc. as needed. Alternatively it could be built in a configuration such as the second configuration, seen in  FIG. 2 , with the topmost side of the vertical configuration becoming the open ‘top’ [ 6 ] with a sealing cover [ 19 ]. 
     As in the first embodiment, there are two subchambers [ 7 , 8 ] filled with liquid dielectric [ 4 ]. In the first subchamber [ 7 ] the at least one heat producing electronic component [ 2 ] is effectively secured by a means to do so [ 10 ]. At least one pump [ 5 ] assisted dielectric [ 4 ] flow cools the components and circulates from the first subchamber [ 7 ] through side gap [ 21 ] to the second subchamber [ 8 ]. It then flows through optional filter [ 14 ] and secondary heat exchanger [ 13 ]. It exits the second subchamber through side gap [ 22 ] into the at least one pump in the first subchamber to then start the cycle again. Passageways [ 15 ,  20 ] allow for the ingress and egress of attachments as needed, and are hermetically sealed against dielectric leakage as needed. Top cover [ 19 ] may be sealed onto the tank [ 3 ] if so desired. 
     The subchambers may have various shapes as desired. Depicted in  FIG. 2  is an L-shape subchamber in which the filter [ 14 ] and secondary heat exchanger [ 13 ] may be placed as in the first embodiment or as depicted here in the L portion adjacent to the at least one pump [ 5 ]. Uses convenient with this second embodiment include, among others: supercomputing, for a data center, HPC or other PC appliances. 
     Either embodiment when used with the sealed cover lid can be made to be mobile for field work and carried at any convenient angle with respect to the effects of gravity. For instance the device could be transported in a vehicle or carried in a backpack. However it is preferred for better efficiency to have the cross-flow inducer in the lower portion of the device at whatever orientation it might be. 
     In the preceding detailed description, reference has been made to the accompanying figures which illustrate specific embodiments of the presented invention. The system includes typical control sensors and adjustors such as a thermostat controller. Therefore these embodiments and variants thereof have been described in sufficient detail to enable those skilled in the art to practice the described invention. As would be evident to those skilled in the art, the preceding detailed description is not limited to the specifics of the embodiments described but rather is intended to cover such alternatives, modifications, and equivalents as can reasonably be included within the spirit and scope of the described invention and the appended claims.