Modular heat shield and heat spreader

Abstract

A modular heat shield and heat spreader (“MHS”) includes top and bottom panels, and a plurality of thermally conductive pillars located between the panels and which support the top panel. A continuous pool of liquid between the panels surrounds some portion of the pillars. Heat to which the top panel is exposed is conducted through the top panel and at least some of the pillars. The heat changes the phase of some of the liquid to a vapor, which spreads the heat to an area larger than that of the heat source and thereby dissipates the heat away from the source at a lower heat flux than that associated with the flux from the source. The MHS preferably includes wicking material on some of the pillars and on the underside of the top panel, such that the wicking material is saturated with the liquid and heated by the conducted heat.

We claim: 
     
         1 . A modular heat shield and heat spreader (MHS), comprising:
 a top panel;   a bottom panel;   a plurality of thermally conductive pillars located between said top and bottom panels such that said pillars support said top panel; and   a continuous pool of liquid between said top and bottom panels such that at least a portion of at least some of said pillars is surrounded by said liquid;   such that heat from a heat source to which said top panel is exposed is conducted through said top panel and at least some of said pillars and said heat changes the phase of at least some of said liquid to a vapor, said vapor spreading said heat to an area larger than the area of the heat source and thereby dissipating said heat away from said heat source at a lower heat flux than that associated with said heat flux from said heat source.   
     
     
         2 . The MHS of  claim 1 , further comprising wicking material on at least some of said pillars and on the underside of at least a portion of said top panel, such that at least some of said wicking material is saturated with said liquid and heat from said heat source is conducted through at least some of said liquid saturated wicking material. 
     
     
         3 . The MHS of  claim 2 , wherein additional wicking material is formed into columns adjacent to at least some of said pillars which connect said top and bottom panels such that the liquid can flow from said continuous pool of liquid to the top panel through said wicking material columns. 
     
     
         4 . The MHS of  claim 2 , further comprising a wicking material on the topside of at least a portion of said bottom panel, such that at least some of said liquid is transported against gravity via said wicking material when the heat shield and heat spreader is tilted. 
     
     
         5 . The MHS of  claim 1 , arranged such that said liquid pool includes only as much liquid as needed to fill the voids between said wicking material. 
     
     
         6 . The MHS of  claim 1 , wherein said top and bottom panels and said pillars form a single module, said MHS comprised of a plurality of said modules joined together at their edges such said modules share a common continuous pool of liquid and said vapor can dissipate heat away from the modules nearest said heat source towards other ones of said modules. 
     
     
         7 . The MHS of  claim 6 , wherein the top and bottom panels of each of said modules is arranged such that each module is hermetically sealed. 
     
     
         8 . The MHS of  claim 6 , wherein the modules making up said MHS have different sizes and shapes. 
     
     
         9 . The MHS of  claim 1 , further comprising a surface to be shielded, said MHS deployed atop said surface to be shielded. 
     
     
         10 . The MHS of  claim 9 , wherein said surface to be shielded is a landing spot on an amphibious ship or an aircraft carrier, such that said MHS shields the flight deck from airplane exhaust plumes. 
     
     
         11 . The MHS of  claim 9 , wherein said MHS is used to shield said surface from concentrated directed energy devices such as high power lasers. 
     
     
         12 . The MHS of  claim 1 , wherein the top panel of said MHS is used as a mounting surface for one or more electronic components. 
     
     
         13 . The MHS of  claim 1 , wherein said MHS includes heat sink fins on said bottom panel for improved heat dissipation to the environment. 
     
     
         14 . The MHS of  claim 1 , further comprising a conformable layer on the bottom side of said bottom panel. 
     
     
         15 . The MHS of  claim 1 , further comprising a pressure relief valve arranged to exhaust air or air and vapor from said MHS when the air and vapor pressure between said top and bottom panels exceeds a predetermined threshold. 
     
     
         16 . The MHS of  claim 1 , further comprising a ramp coupled to at least one MHS module. 
     
     
         17 . The MHS of  claim 1 , further comprising compressible pads located between said bottom plate and the bottoms of said pillars. 
     
     
         18 . The MHS of  claim 1 , wherein said top and bottom panel form a cylindrical shell which is deployed vertically such that it forms a cylindrical enclosure which surrounds said heat source with said top panel nearest said heat source, said pool of liquid located at the bottom of said enclosure, further comprising a wicking material on at least some of said pillars and on the inside of at least a portion of said top panel such that liquid from said liquid pool is transported up the sides of said enclosure via said wicking material. 
     
     
         19 . A modular heat shield and heat spreader (MHS), comprising:
 a plurality of modules, each of which comprises:
 a top panel; 
 a bottom panel; 
 a plurality of thermally conductive pillars located between said top and bottom panels such that said pillars support said top panel; and 
 wicking material on at least some of said pillars and on the underside of at least a portion of said top panel; 
   said modules joined together at their edges to form a MHS capable of being deployed atop a surface to be shielded; and   a common continuous pool of liquid between the top and bottom panels of said modules such that at least a portion of at least some of said pillars is surrounded by said liquid and at least some of said wicking material is saturated with said liquid;   such that heat from a heat source to which one or more of said top panels is exposed is conducted through the top panel and said liquid saturated wicking material, said liquid present in the voids of said wicking material changing to a vapor state when sufficiently heated such that said vapor dissipates said heat away from the modules nearest said heat source towards other ones of said modules where said vapor condenses and said condensate returns to said common continuous pool of liquid.   
     
     
         20 . The MHS of  claim 19 , wherein said modules are joined together so as to form a watertight seal along each module-to-module junction. 
     
     
         21 . A modular heat shield and heat spreader (MHS), comprising:
 a plurality of modules, each of which comprises:
 a top panel; 
 a bottom panel; 
 a plurality of pillars located between said top and bottom panels such that said pillars support said top panel, said top and bottom panels joined together to form a hermetically sealed enclosure; and 
 wicking material attached to said top and bottom panels and also formed into wick columns located between the pillars so that the wick columns connect the top panel wicking material and the bottom panel wicking material; 
   at least one of said modules including one or more areas to which heat generating electronic devices are to be attached and including heat sink fins which are attached to the opposite side of the module,   each of said modules charged with an amount of working fluid that is equal to or larger than the volume of all the voids in the wicking material;   a plurality of said modules of the same or different size placed next to each other to form a MHS;   such that heat from said heat generating electronic devices attached to one side of the MHS is conducted through the top panel and the wicking material and said liquid present in said voids such that said heat changes the phase of said working fluid to a vapor state, said vapor spreading the heat to the entire module, said heat sink fins dissipating the heat to the environment and thereby changing said vapor to a liquid which is wicked back to the top panel wicking material via said wick columns.   
     
     
         22 . The heat shield of  claim 21 , wherein at least some of the pillars located between the top and the bottom panels are bonded to both the top and the bottom panels to enable the MHS to operate at elevated pressures and prevent mechanical deformation of MHS panels. 
     
     
         23 . The heat shield of  claim 21 , wherein said modules and wicking material comprise aluminum or magnesium and said working fluid includes a corrosion inhibitor that promotes passivation of the wicking material during operation and prevents generation of non-condensable gas within the module.