Heat exchanger

Abstract

According to an embodiment, a heat exchanger is provided with a manifold, a heat exchange unit and a first porous body. The manifold has an inlet for a medium and an outlet for the medium. The heat exchange unit has a channel which communicates with the outlet. The first channel has a cross section of a typical length which is not more than a predetermined constant. The porous body is provided between the inlet and the outlet, and contains a plurality of pores with a mean diameter which is not more than the typical length.

What is claimed is: 
     
         1 . A heat exchanger, comprising:
 a first manifold having a first inlet and a first outlet for a first medium;   a heat exchange unit having a first channel which communicates with the first outlet, the first channel having a cross section of a typical length H 1  which satisfies the following expression; and   a first porous body provided between the first inlet and the first outlet and contains a plurality of pores having a mean diameter not more than the typical length H 1 ,   where, in the following expression, σ f  is a surface tension of the first medium at the first outlet, g is a gravitational acceleration, ρ 1  is a liquid-phase density of the first medium at the first outlet, and ρ 2  is gas-phase density of the first medium at the first outlet.   
       
         
           
             
               
                 H 
                 1 
               
               ≤ 
               
                 
                   
                     σ 
                     1 
                   
                   
                     g 
                      
                     
                       ( 
                       
                         
                           ρ 
                           1 
                         
                         - 
                         
                           ρ 
                           2 
                         
                       
                       ) 
                     
                   
                 
               
             
           
         
       
     
     
         2 . The exchanger according to  claim 1 , wherein the first porous body is lyophilic. 
     
     
         3 . The exchanger according to  claim 1 , further comprising a heat receiving unit for receiving heat from a heat source, and a flow tube for connecting the heat receiving unit and the first inlet. 
     
     
         4 . The exchanger according to  claim 2 , further comprising a heat receiving unit for receiving heat from a heat source, and a flow tube for connecting the heat receiving unit and the first inlet. 
     
     
         5 . The exchanger according to  claim 1 , further comprising a second manifold and a second porous body, wherein
 the second manifold includes a second inlet and a second outlet for a second medium,   the second porous body is provided between the second inlet and the second outlet and contains a plurality of pores,   the heat exchange unit including a second channel which has a cross section of a typical length H 2  which satisfies the following expression, the second channel communicating with the second outlet and being provided in parallel with the first channel, and   the plurality of pores have a mean diameter not more than the typical length H 2 ,   where, in the following expression, σ 2  is a surface tension of the second medium at the second outlet, ρ 3  is a liquid-phase density of the second medium at the second outlet, and ρ 4  is a gas-phase density of the second medium at the second outlet.   
       
         
           
             
               
                 H 
                 2 
               
               ≤ 
               
                 
                   
                     σ 
                     2 
                   
                   
                     g 
                      
                     
                       ( 
                       
                         
                           ρ 
                           3 
                         
                         - 
                         
                           ρ 
                           4 
                         
                       
                       ) 
                     
                   
                 
               
             
           
         
       
     
     
         6 . The exchanger according to  claim 5 , wherein the second porous body is lyophilic. 
     
     
         7 . The exchanger according to  claim 1 , wherein the typical length H 1  of the cross section of the first channel is 20 μm or more. 
     
     
         8 . The exchanger according to  claim 5 , wherein the typical length H 1  of the cross section of the first channel and the typical length H 2  of the cross section of the second channel are 20 μm or more. 
     
     
         9 . The exchanger according to  claim 1 , wherein the first medium is water. 
     
     
         10 . The exchanger according to  claim 5 , wherein the first medium and the second medium are water.