Modified heat pipe for phase change cooling of electronic devices

Abstract

Exemplary embodiments provide a heat pipe including a flexible chamber that is capable of expanding, compressing and/or restoring. In one embodiment, the heat pipe can include a hollow metal casing including a pipe structure connected to an expandable chamber at one end of the pipe structure. The other end of the pipe structure can include an evaporating section for receiving heat and the expandable chamber can include a condensing section for releasing the heat. The expandable chamber can be configured to change in volume to control one or both of a temperature and a pressure in the hollow metal casing. The heat pipe can also include a capillary system arranged at an inner surface of the hollow metal casing that includes the pipe structure and the expandable chamber.

1 . A heat pipe comprising:
 a hollow metal casing comprising a pipe structure and an expandable chamber connected to a first end of the pipe structure, wherein the expandable chamber is configured to change in volume to control one or both of a temperature and a pressure in the hollow metal casing; and   a capillary system disposed at an inner surface of the pipe structure and the expandable chamber.   
     
     
         2 . The heat pipe of  claim 1 , wherein the expandable chamber comprises one or more flexible corrugations so that the volume of the expandable chamber is changed by folding or unfolding the one or more flexible corrugations. 
     
     
         3 . The heat pipe of  claim 1 , wherein the expandable chamber comprises a spring-type mechanism. 
     
     
         4 . The heat pipe of  claim 3 , wherein the spring-type mechanism comprises a non-linear expansion and a non-linear restoration. 
     
     
         5 . The heat pipe of  claim 1 , wherein the expandable chamber comprises a cross sectional shape comprising a circle, a square, a rectangle, a triangle, or a polygon. 
     
     
         6 . The heat pipe of  claim 1 , further comprising a heat sink cooled heat pipe comprising the expandable chamber. 
     
     
         7 . The heat pipe of  claim 1 , further comprising a heat source at a second end of the pipe structure, wherein the second end of the pipe structure comprises an evaporating section for receiving heat from the heat source. 
     
     
         8 . The heat pipe of  claim 7 , wherein the heat source comprises a device within a cell phone, a MP3 device, a GPS device or a laptop computer. 
     
     
         9 . A heat pipe comprising:
 a pipe structure attached to an electronic device for receiving heat from the electronic device; and   an expandable chamber connected to the pipe structure for dissipating the received heat through a phase change of water that flows through the pipe structure and the expandable chamber,
 wherein the expandable chamber is configured to change in volume so as to control one or both of a temperature and a pressure in the pipe structure. 
   
     
     
         10 . The heat pipe of  claim 9 , wherein the expandable chamber comprises one or more flexible corrugations so that the volume of the expandable chamber is changed by folding or unfolding the one or more flexible corrugations. 
     
     
         11 . The heat pipe of  claim 9 , wherein the expandable chamber comprises a linear spring-type mechanism or a non-linear spring-type mechanism so as to control one or both of the temperature and the pressure in the pipe structure. 
     
     
         12 . The heat pipe of  claim 9 , wherein the expandable chamber comprises a cross sectional shape comprising a circle, a square, a rectangle, a triangle, or a polygon. 
     
     
         13 . The heat pipe of  claim 9 , further comprising a heat sink cooled heat pipe comprising the expandable chamber. 
     
     
         14 . The heat pipe of  claim 9 , wherein the electronic device comprises a device within a cell phone, a MP3 device, a GPS device or a laptop computer. 
     
     
         15 . A method for forming a heat pipe comprising:
 providing a hollow metal casing comprising a pipe structure, wherein a first end of the pipe structure comprises an evaporating section for receiving heat;   placing an expandable chamber in the hollow metal casing and connected at a second end of the pipe structure,
 wherein the expandable chamber comprises a condensing section for releasing the heat and is configured to change in volume to control one or both of a temperature and a pressure in the hollow metal casing; and 
   arranging a capillary system at an inner surface of the pipe structure and the expandable chamber.   
     
     
         16 . The method of  claim 15 , wherein the volume of the expandable chamber is changed by folding or unfolding one or more flexible corrugations of the expandable chamber. 
     
     
         17 . The method of  claim 15 , wherein the expandable chamber comprises a linear spring-type mechanism or a non-linear spring-type mechanism so as to control one or both of the temperature and the pressure in the hollow metal casing. 
     
     
         18 . A method for dissipating heat comprising:
 providing a hollow metal casing comprising a pipe structure and an expandable chamber connected at a first end of the pipe structure;
 wherein the expandable chamber is configured to change in volume to control one or both of a temperature and a pressure in the hollow metal casing; 
   packaging an electronic device at a second end of the pipe structure; and   flowing a fluid in the hollow metal casing to receive heat transmitted from the electronic device and thereby generating a vapor that is condensed in the expandable chamber to release the heat.   
     
     
         19 . The method of  claim 18 , further comprising controlling a vapor pressure in the hollow metal casing by controlling an amount of the fluid flowing in the hollow metal casing. 
     
     
         20 . The method of  claim 18 , further comprising controlling a boiling temperature of the fluid flowing in the hollow metal casing by adjusting a spring constant of a spring-type expandable chamber. 
     
     
         21 . The method of  claim 18 , further comprising adjusting an amount of the fluid flowing in the hollow metal casing such that the fluid evaporates at a power for a maximum length of an operation of the electronic device. 
     
     
         22 . The method of  claim 18 , wherein the fluid flowing in the hollow metal casing comprises water, alcohol, or combinations thereof.