Flat type heat pipe

Abstract

A flat type heat pipe ( 10 ) is disclosed which includes a metal casing ( 12 ) and a wick structure ( 16 ) arranged inside the metal casing. The metal casing has an evaporating section ( 123 ) and a condensing section ( 124 ). The wick structure extends from the evaporating section towards the condensing section of the metal casing and has a first section in conformity with the condensing section of the metal casing and a second section in conformity with the evaporating section of the metal casing. The first section has a pore size larger than that of the second section of the wick structure. The wick structure includes a metal foam.

1 . A flat type heat pipe comprising: 
 a metal casing having an evaporating section and a condensing section; and    a wick structure made of a metal foam and arranged inside the metal casing, the wick structure extending from the evaporating section towards the condensing section of the metal casing and having a pore size gradually increasing from the evaporating section towards the condensing section of the metal casing.    
   
   
       2 . The heat pipe of  claim 1 , wherein the wick structure extends along a longitudinal direction of the heat pipe and occupies a central region of an interior chamber defined in the metal casing.  
   
   
       3 . The heat pipe of  claim 1 , wherein the wick structure extends along a longitudinal direction of the heat pipe and is located near a sidewall of the metal casing.  
   
   
       4 . The heat pipe of  claim 1 , wherein the metal casing defines a plurality of grooves in an inner surface thereof.  
   
   
       5 . The heat pipe of  claim 4 , wherein the grooves extend along a longitudinal direction of the metal casing and at least one of the grooves have a width gradually increasing from the evaporating section towards the condensing section of the metal casing.  
   
   
       6 . A flat type heat pipe comprising: 
 a metal casing including a top plate and a bottom plate cooperating with the top plate to define a chamber inside the metal casing, the metal casing having an evaporating section and a condensing section; and    a wick structure located inside the casing and occupying a portion of the chamber, the wick structure having a first section in conformity with the condensing section of the metal casing and a second section in conformity with the evaporating section of the metal casing;    wherein the wick structure is sandwiched between the top and bottom plates of the metal casing and said first section has a pore size larger than that of the second section of the wick structure.    
   
   
       7 . The heat pipe of  claim 6 , wherein the wick structure is in the form of a metal foam.  
   
   
       8 . The heat pipe of  claim 6 , wherein the metal casing has a plurality of grooves formed in an inner surface thereof.  
   
   
       9 . The heat pipe of  claim 8 , wherein the grooves each have a width gradually increasing from the evaporating section towards the condensing section of the metal casing.  
   
   
       10 . The heat pipe of  claim 6 , wherein the wick structure occupies a central portion of the chamber.  
   
   
       11 . The heat pipe of  claim 6 , wherein the wick structure occupies a side portion of the chamber.  
   
   
       12 . A heat pipe, comprising: 
 an elongated casing having a flat plate, a plurality of grooves formed in an inner surface of the casing along a longitudinal direction thereof; and    a metal foam received in the casing and extending along the longitudinal direction thereof, the metal foam having a pore size which is gradually increased along the longitudinal direction of the casing, wherein the grooves and the metal foam cooperate as a wick structure for the heat pipe for moving a condensate in the heat pipe.    
   
   
       13 . The heat pipe of  claim 12 , wherein at least one of the grooves has a width which is gradually increased along the longitudinal direction of the casing.