Ultra-compact cooling systems based on phase change material heat reservoirs

Abstract

A cooling system includes a first stage heat reservoir arranged to absorb heat from a heat source. Heat is transferred from the first stage heat reservoir to a second stage heat reservoir. The first stage heat reservoir includes a material with a heat capacity lower than that of the second stage heat reservoir but with a thermal conductivity higher than that of the second stage heat reservoir. Heat transfer structure increases heat transfer rate from the first stage heat reservoir to the second stage heat reservoir.

What is claimed is: 
     
         1 . A cooling system comprising:
 a first stage heat reservoir arranged to absorb heat from a heat source;   a second stage heat reservoir to which heat is transferred from said first stage heat reservoir, said first stage heat reservoir comprising a material with a heat capacity lower than that of said second stage heat reservoir but with a thermal conductivity higher than that of said second stage heat reservoir; and   heat transfer structure that increases heat transfer rate from said first stage heat reservoir to said second stage heat reservoir.   
     
     
         2 . The cooling system according to  claim 1 , wherein said first stage heat reservoir comprises a sensible heat reservoir and said second stage heat reservoir comprises a phase change material (PCM) heat reservoir. 
     
     
         3 . The cooling system according to  claim 1 , wherein said heat transfer structure comprises cooling fins. 
     
     
         4 . The cooling system according to  claim 3 , wherein said cooling fins comprise a diamond and copper sandwich structure. 
     
     
         5 . The cooling system according to  claim 1 , wherein said PCM comprises gallium. 
     
     
         6 . The cooling system according to  claim 1 , wherein said PCM comprises hexadecane.