Use of graphite foam materials in pumped liquid, two phase cooling, cold plates

Abstract

An improved cooling system provides cooling away from the surface of electrical and electronic components, by providing an available heat transfer surface area many times greater than that of a convoluted fin structure. The component to be cooled is in thermal contact with a cold plate evaporator device, and a graphite material is associated with the cold plate device. Refrigerant is circulated through the graphite material and the cold plate evaporator device, and the liquid refrigerant is at least partially evaporated by the heat generated by the component. Due to the open nature of the graphite material, the permeability of liquids and vapors is high, allowing for low pressure loss while still maintaining sufficient two phase flow to carry heat away from the electronics.

1 . An improved cold plate structure comprising: 
 at least one component generating heat and required to be cooled;    at least one cold plate evaporator device in thermal contact with the at least one component;    a thermally conductive graphite material associated with the at least one cold plate evaporator device for providing increased surface area for heat transfer within the cold plate structure; and    a vaporizable liquid refrigerant capable of being circulated to the at least one cold plate evaporator device and coming into contact with the graphite material.    
   
   
       2 . An improved cold plate structure as claimed in  claim 1  further comprising an outlet means for exporting the vaporizable liquid refrigerant from the graphite material as a vapor.  
   
   
       3 . An improved cold plate structure as claimed in  claim 1  further comprising an outlet means for exporting the vaporizable liquid refrigerant from the graphite material as a two phase mixture of liquid and vapor.  
   
   
       4 . An improved cold plate structure as claimed in  claim 1  further comprising an inlet means to receive the vaporizable liquid refrigerant into the cold plate structure.  
   
   
       5 . An improved cold plate structure as claimed in  claim 1  wherein the refrigerant comprises R-134a refrigerant.  
   
   
       6 . An improved cold plate structure as claimed in  claim 1  wherein the graphite material comprises a graphite foam.  
   
   
       7 . An improved cold plate structure as claimed in  claim 1  further comprising a convoluted fin structure used in combination with the graphite material.  
   
   
       8 . An improved cold plate structure as claimed in  claim 1  wherein the graphite material comprises multiple graphite elements.  
   
   
       9 . An improved cold plate structure as claimed in  claim 1  wherein the graphite material comprises a graphite material having corrugations.  
   
   
       10 . An improved cold plate structure as claimed in  claim 1  wherein the graphite material comprises a graphite material having one or more slots cut into the material.  
   
   
       11 . An improved cold plate structure as claimed in  claim 10  wherein the one or more slots cut into the material are in a direction of flow of the vaporizable liquid refrigerant.  
   
   
       12 . A method for cooling one or more electrical or electronic components generating heat and required to be cooled, the method comprising the steps of: 
 locating at least one cold plate evaporator device in thermal contact with the one or more electrical or electronic components;    locating a thermally conductive graphite material proximate to the at least one cold plate evaporator device for providing increased surface area for heat transfer within the cold plate structure; and    providing a vaporizable liquid refrigerant capable of being circulated to the at least one cold plate evaporator device, whereby the refrigerant is at least partially evaporated by the heat generated by the one or more electrical or electronic components.    
   
   
       13 . A method as claimed in  claim 12  further comprising the step of providing an outlet means for exporting the vaporizable liquid refrigerant from the graphite material as a vapor.  
   
   
       14 . A method as claimed in  claim 12  further comprising the step of providing an outlet means for exporting the vaporizable liquid refrigerant from the graphite material as a two phase mixture of liquid and vapor.  
   
   
       15 . A method as claimed in  claim 12  further comprising the step of providing an inlet means to receive the vaporizable liquid refrigerant into the cold plate structure.  
   
   
       16 . A method as claimed in  claim 12  wherein the step of providing a refrigerant comprises the step of providing R-134a refrigerant.  
   
   
       17 . A method as claimed in  claim 12  wherein the step of providing a graphite material comprises the step of providing a graphite foam.  
   
   
       18 . A method as claimed in  claim 12  further comprising the step of using a convoluted fin structure in combination with the graphite material.  
   
   
       19 . A method as claimed in  claim 12  wherein the graphite material comprises multiple graphite elements capable of being modified with corrugations or slots.  
   
   
       20 . A method as claimed in  claim 19  wherein slot modifications to the graphite material are in a direction of flow of the vaporizable liquid refrigerant.