Flat heat pipe with composite capillary structure

Abstract

A flat heat pipe with a composite capillary structure has a flat pipe with a flat and enclosed hollow pipe body including a top wall, a bottom wall, two lateral walls and a chamber. The flat pipe has an evaporation section and a condensation section. The elongated mesh grid is located onto either of the top and bottom walls in the chamber. The elongated mesh grid is extended from the evaporation section to the condensation section. The long porous sintered structure is located adjacent at least one lateral wall in the chamber. The long porous sintered structure is extended from the evaporation section to the condensation section. The porous sintered structure and the elongated mesh grid are prefabricated into a composite capillary structure. The flat heat pipe presents excellent diversion effect and stable positioning with its better vapor diversion space and simple manufacturing process.

1 . A flat heat pipe with composite capillary structure, comprising:
 a flat pipe, made of metal into a flat and enclosed hollow pipe body having a top wall, a bottom wall, two lateral walls and a chamber; the flat pipe having an evaporation section and a condensation section, and both ends of the flat pipe are enclosed; moreover, the chamber is at an evacuation state; alternatively, the chamber of the flat pipe is filled with working fluid;   an elongated mesh grid, made of metal, located in the chamber of the flat pipe; the elongated mesh grid is extended from the evaporation section to the condensation section of the flat pipe;   a long porous sintered structure, made of metal, located onto either position in the chamber of the flat pipe; the long porous sintered structure is extended from the evaporation section to the condensation section of the flat pipe;   the porous sintered structure and the elongated mesh grid are prefabricated securely into a composite capillary structure, and the composite capillary structure is placed between the top and bottom walls of the chamber of the flat pipe.   
     
     
         2 . The structure defined in  claim 1 , wherein a local hollowed portion is formed at the central section of the elongated mesh grid between the evaporation section and condensation section of the flat pipe; moreover, a coupling surface of sintered structure is reserved at the central section of the elongated mesh grid for coupling the long porous sintered structure. 
     
     
         3 . The structure defined in  claim 1 , wherein a single or a plurality of spacing notches is arranged at local section of the elongated mesh grid, in response to the bending state of the elongated mesh grid. 
     
     
         4 . The structure defined in  claim 1 , wherein at least a depressed portion is formed at the local or central section of the long porous sintered structure; said depressed portion is configured into either of an inclined, bended or stepped surface. 
     
     
         5 . The structure defined in  claim 1 , wherein the long porous sintered structure is located adjacent to two lateral walls, or one lateral wall, or at a spacing with the lateral wall in the chamber of the flat pipe. 
     
     
         6 . The structure defined in  claim 1 , wherein the inner wall of the flat pipe is provided with a smooth surface or a grooved capillary structure. 
     
     
         7 . The structure defined in  claim 1 , wherein said corrugated surface expanded portions are formed onto one or two sides of the long porous sintered structure, so as to improve the evaporation effect of the working fluid for the long porous sintered structure. 
     
     
         8 . The structure defined in  claim 1 , wherein the and the elongated mesh grid is placed between the top and bottom walls of the chamber of the flat pipe, and at one is placed at the interval space between the top and bottom walls. 
     
     
         9 . The structure defined in  claim 1 , wherein the molding process of the flat heat pipe comprises the following steps:
 (a) preparing a round pipe, one end pre-closed and the other end in open state;   (b) preparing an elongated mesh grid;   (c) preparing a metal powder grain of long porous sintered structure, and covering it onto the elongated mesh grid in a sintering mould;   (d) fixing the long porous sintered structure onto the surface of the elongated mesh grid by means of sintering, so to as prefabricate a composite capillary structure;   (e) placing the prefabricated composite capillary structure into the round pipe;   (f) pressing the round pipe already placed into the composite capillary structure, and convert the round pipe into a flat pipe, meanwhile enabling the composite capillary structure to be located in the flat pipe adjacent to the internal plane of the flat pipe;   (g) filling working fluid into the flat pipe and then evacuating said flat pipe for sealing.   
     
     
         10 . The structure defined in  claim 9 , wherein the elongated mesh grid of the composite capillary structure is bent to form a bending portion before the composite capillary structure is placed into the round pipe; then the round pipe is pre-pressed and bent to convert the round pipe into an embryo flat pipe, but the degree of pressing only reaches 60-90% of the preset degree; the composite capillary structure is then placed into the embryo flat pipe; then the embryo flat pipe is pressed again to convert itself into a flat pipe, meanwhile enabling the bending portion of the elongated mesh grid to be extended into a straight or nearly straight shape. 
     
     
         11 . The structure defined in  claim 9 , wherein the round pipe is pre-pressed to convert into an embryo flat pipe, with the flat cross section pressed by full or partial section. 
     
     
         12 . The structure defined in  claim 9 , wherein the composite capillary structure and the flat pipe are mated by means of sintering before the flat pipe is filled with working fluid and evacuated for sealing.