Abstract:
A heat pipe structure includes a first tubular body and a second tubular body. The first tubular body has a first chamber and a working fluid. A first capillary structure is disposed on outer circumference of the second tubular body. The second tubular body is disposed in the first chamber and has a second chamber. In the heat pipe structure, the vapor-phase working fluid flows within the first chamber, while the liquid-phase working fluid flows within the second chamber in separation from the vapor-phase working fluid. Accordingly, the impedance against the vapor is greatly reduced and the heat transfer efficiency is greatly enhanced to achieve excellent heat dissipation effect.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to a heat pipe structure, and more particularly to an improved heat pipe structure having multiple chambers, whereby the vapor-phase working fluid and the liquid-phase working fluid independently separately flow within different chambers to transfer heat. Accordingly, the heat transfer effect is greatly enhanced to achieve better heat dissipation effect. 
         [0003]    2. Description of the Related Art 
         [0004]    Following the continuous development of scientific and technical industries, the operation speed and performance of all kinds of electronic components have been continuously enhanced. In the meantime, the waste heat generated by the electronic products has become higher and higher. In the conventional heat dissipation devices, heat pipe is a simple but very effective heat dissipation means. The heat pipe can quickly transfer a large amount of heat via latent heat. The heat pipe has the advantages of uniform distribution of temperature, simple structure, small size, light weight, no external action force, long lifetime, multiuse, etc. Therefore, different kinds of heat pipes have been widely applied in various fields for dissipating heat. 
         [0005]    The heat pipe has an evaporation end and a condensation end and an internal vacuumed chamber in which a working fluid is filled. The working fluid relatively has a lower boiling point due to the vacuumed state of the chamber. The heat is transferred via the latent heat by means of phase change between liquid phase and vapor phase of the working fluid. At the evaporation end, the working fluid carries away a large amount of heat from a heat source via latent heat. The vapor is full in the vacuumed chamber and is condensed into a liquid at the condensation end to release heat. Through the capillary attraction of the capillary structure in the chamber, the liquid working fluid flows back to the evaporation end to complete the phase change circulation. Accordingly, the vapor-liquid circulation is continued to effectively transfer the heat generated by the heat source to a remote end for heat exchange. 
         [0006]    The conventional heat pipe generally has one single chamber and one single capillary structure so that the heat transfer efficiency of the conventional heat pipe is limited. Moreover, the liquid phase working fluid and the vapor phase working fluid are mixed in the same sealed chamber. The backflow of the liquid will obstruct the vapor from smoothly flowing to deteriorate the heat transfer efficiency. Accordingly, the conventional heat pipe has the following shortcomings: 
         [0007]    1. The heat transfer efficiency is poor. 
         [0008]    2. The vapor-liquid circulation efficiency of the working fluid is poor. 
       SUMMARY OF THE INVENTION 
       [0009]    A primary object of the present invention is to provide an improved heat pipe structure, which has better heat transfer performance and is able to achieve excellent heat dissipation effect. 
         [0010]    To achieve the above and other objects, the heat pipe structure of the present invention includes a first tubular body, a second tubular body and a first capillary structure. 
         [0011]    The first tubular body has a first chamber and a working fluid. The second tubular body is disposed in the first chamber and has a second chamber. 
         [0012]    The first capillary structure is disposed on outer circumference of the second tubular body. 
         [0013]    At least one end of the heat pipe is in contact with a heat source for absorbing the heat generated by the heat source. When the end of the heat pipe is heated, the working fluid in the heat pipe is evaporated and converted from liquid phase into vapor phase. The vapor working fluid then flows through second chamber to the other end of the heat pipe. After reaching the other end, the vapor working fluid is cooled and condensed into the liquid working fluid. The liquid working fluid then flows through the first capillary structure back to the original end of the heat pipe. Accordingly, the vapor-liquid circulation of the working fluid is continuously performed to dissipate the heat. 
         [0014]    In the heat pipe structure of the present invention, the vapor-phase working fluid and the liquid-phase working fluid independently separately flow within different chambers to transfer heat. Accordingly, the heat transfer efficiency is greatly enhanced. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein: 
           [0016]      FIG. 1  is a longitudinal sectional view of a first embodiment of the heat pipe structure of the present invention; 
           [0017]      FIG. 2A  is a cross-sectional view of the first embodiment of the heat pipe structure of the present invention; 
           [0018]      FIG. 2B  is an enlarged view of circled area A of  FIG. 2A ; 
           [0019]      FIG. 3  is a sectional view of the first embodiment of the heat pipe structure of the present invention; 
           [0020]      FIG. 4  is a longitudinal sectional view of a second embodiment of the heat pipe structure of the present invention; 
           [0021]      FIG. 5A  is a cross-sectional view of the second embodiment of the heat pipe structure of the present invention; 
           [0022]      FIG. 5B  is an enlarged view of circled area B of  FIG. 5A ; 
           [0023]      FIG. 6  is a sectional view of the second embodiment of the heat pipe structure of the present invention; 
           [0024]      FIG. 7  is a longitudinal sectional view of a third embodiment of the heat pipe structure of the present invention; 
           [0025]      FIG. 8A  is a cross-sectional view of the third embodiment of the heat pipe structure of the present invention; 
           [0026]      FIG. 8B  is an enlarged view of circled area C of  FIG. 8A ; and 
           [0027]      FIG. 9  is a sectional view of the third embodiment of the heat pipe structure of the present invention; and 
           [0028]      FIG. 10  is a sectional view of a fourth embodiment of the heat pipe structure of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    Please refer to  FIGS. 1 ,  2 A and  2 B.  FIG. 1  is a longitudinal sectional view of a first embodiment of the heat pipe structure of the present invention.  FIG. 2A  is a cross-sectional view of the first embodiment of the heat pipe structure of the present invention.  FIG. 2B  is an enlarged view of circled area A of  FIG. 2A . According to the first embodiment, the heat pipe structure of the present invention includes a first tubular body  10 , a second tubular body  20  and a first capillary structure  202 . 
         [0030]    The first tubular body  10  has a first chamber  101  and a working fluid  2 . 
         [0031]    The second tubular body  20  is disposed in the first chamber  101  and has a second chamber  201 . 
         [0032]    The first capillary structure  202  is disposed on outer circumference of the second tubular body  20 . The first capillary structure  202  is selected from a group consisting of a sintered powder body, a structure formed with multiple channels, a mesh body and a coating. In this embodiment, the first capillary structure  202  is, but not limited to, a sintered powder body for illustration purposes only. 
         [0033]    The first tubular body  10  has an evaporation end  11  at one end and a condensation end  12  at the other end opposite to the evaporation end  11 . 
         [0034]    Please refer to  FIG. 3 . The evaporation end  11  is in contact with a heat source  3  for absorbing the heat generated by the heat source  3  and transferring the heat to the working fluid  2  in the first tubular body  10 . At this time, the working fluid  2  in the first tubular body  10  is evaporated and converted from the original liquid phase into vapor phase. Accordingly, a large amount of heat is transferred from the evaporation end  11  to the condensation end  12  with a heat sink  5 . The vapor working fluid  21  will enter the second chamber  201  to flow toward the condensation end  12  opposite to the evaporation end  11 . After flowing to the condensation end  12 , the vapor working fluid  21  is cooled and condensed into the liquid phase. The liquid working fluid  22  then flows through the first capillary structure  202  on the outer circumference of the second tubular body  20  back to the evaporation end  11 . Accordingly, the liquid phase-vapor phase circulation of the working fluid  2  is continued in a separate state. 
         [0035]    By means of the above arrangement, the heat transfer efficiency of the heat pipe structure can be greatly enhanced. 
         [0036]    Please refer to  FIGS. 4 ,  5 A and  5 B.  FIG. 4  is a longitudinal sectional view of a second embodiment of the heat pipe structure of the present invention.  FIG. 5A  is a cross-sectional view of the second embodiment of the heat pipe structure of the present invention.  FIG. 5B  is an enlarged view of circled area B of  FIG. 5A . According to the second embodiment, the heat pipe structure of the present invention includes a first tubular body  10 , a second tubular body  20  and a second capillary structure  102 . The first tubular body  10  has a first chamber  101  and a working fluid  2 . The second capillary structure  102  is disposed in the first chamber  101 . The second capillary structure  102  is selected from a group consisting of a sintered powder body, a structure formed with multiple channels, a mesh body and a coating. In this embodiment, the first capillary structure  202  is, but not limited to, a structure formed with multiple channels for illustration purposes only. 
         [0037]    The second tubular body  20  is disposed in the first chamber  101  and has a second chamber  201 . The first tubular body  10  has an evaporation end  11  at one end and a condensation end  12  at the other end opposite to the evaporation end  11 . 
         [0038]    Please refer to  FIG. 6 . The evaporation end  11  is in contact with a heat source  3  for absorbing the heat generated by the heat source  3  and transferring the heat to the working fluid  2  in the first tubular body  10 . At this time, the working fluid  2  in the first tubular body  10  is evaporated and converted from the original liquid phase into vapor phase. Accordingly, a large amount of heat is transferred from the evaporation end  11  to the condensation end  12  with a heat sink  5 . The vapor working fluid  21  will enter the second chamber  201  to flow toward the condensation end  12  opposite to the evaporation end  11 . After flowing to the condensation end  12 , the vapor working fluid  21  is cooled and condensed into the liquid phase. The liquid working fluid  22  then flows through the second capillary structure  102  in the first chamber  101  back to the evaporation end  11 . Accordingly, the liquid phase-vapor phase circulation of the working fluid  2  is continued in a separate state. 
         [0039]    By means of the above arrangement, the heat transfer efficiency of the heat pipe structure can be greatly enhanced. 
         [0040]    Please refer to  FIGS. 7 ,  8 A and  8 B.  FIG. 7  is a longitudinal sectional view of a third embodiment of the heat pipe structure of the present invention.  FIG. 8A  is a cross-sectional view of the third embodiment of the heat pipe structure of the present invention.  FIG. 8B  is an enlarged view of circled area C of  FIG. 8A . The third embodiment is substantially identical to the first and second embodiments in component and relationship between the components and thus will not be repeatedly described hereinafter. The third embodiment is different from the first and second embodiments in that both the first and second tubular bodies  10 ,  20  respectively have the first and second capillary structures  202 ,  102 . The first capillary structure  202  is disposed on the outer circumference of the second tubular body  20 , while the second capillary structure  102  is disposed in the first chamber  101 . The first and second capillary structures  202 ,  102  are selected from a group consisting of sintered powder bodies, structures formed with multiple channels, mesh bodies and coatings. In this embodiment, the first and second capillary structures  202 ,  102  are, but not limited to, structures formed with multiple channels for illustration purposes only. 
         [0041]    Please refer to  FIG. 9 . The evaporation end  11  is in contact with a heat source  3  for absorbing the heat generated by the heat source  3  and transferring the heat to the working fluid  2  in the first tubular body  10 . At this time, the working fluid  2  in the first tubular body  10  is evaporated and converted from the original liquid phase into vapor phase. Accordingly, a large amount of heat is transferred from the evaporation end  11  to the condensation end  12  with a heat sink  5 . The vapor working fluid  21  will enter the second chamber  201  to flow toward the condensation end  12  opposite to the evaporation end  11 . After flowing to the condensation end  12 , the vapor working fluid  21  is cooled and condensed into the liquid phase. The liquid working fluid  22  then flows through the second capillary structure  102  in the first chamber  101  and the first capillary structure  202  on the outer circumference of the second tubular body  20  back to the evaporation end  11 . Accordingly, the liquid phase-vapor phase circulation of the working fluid  2  is continued in a separate state. By means of the above arrangement, the heat transfer efficiency of the heat pipe structure can be greatly enhanced. 
         [0042]    The working fluid is selected from a group consisting of pure water, coolant and acetone. 
         [0043]    Finally, please refer to  FIG. 10 , which is a sectional view of a fourth embodiment of the heat pipe structure of the present invention. The fourth embodiment is substantially identical to the first and second embodiments in component and relationship between the components and thus will not be repeatedly described hereinafter. The fourth embodiment is different from the first and second embodiments in that the heat pipe structure further has a first section  41  and a second section  42  disposed at two ends of the first tubular body  10  respectively. The first and second sections  41 ,  42  communicate with the first and second chambers  101 ,  201 . The evaporation end  11  is attached to a heat source  3  for transferring the heat. After the working fluid  2  is evaporated and converted from liquid phase into vapor phase, a large amount of heat is transferred from the evaporation end  11  to the condensation end  12  with a heat sink  5 . The vapor working fluid  21  will enter the second chamber  201  to flow toward the condensation end  12  opposite to the evaporation end  11 . At this time, the vapor working fluid  21  is cooled and condensed into the liquid phase at the condensation end  12 . 
         [0044]    The liquid working fluid  22  then flows through the first capillary structure  202  on the outer circumference of the second tubular body  20  or the second capillary structure  102  in the first chamber  101  or both the first and second capillary structures  202 ,  102  back to the evaporation end  11 . Accordingly, the liquid phase-vapor phase circulation of the working fluid  2  is continued in a separate state. By means of the above arrangement, the heat transfer efficiency of the heat pipe structure can be greatly enhanced. 
         [0045]    According to the aforesaid, in comparison with the conventional heat pipe, the present invention has the following advantages: 
         [0046]    1. The heat transfer efficiency is increased. 
         [0047]    2. The vapor-liquid circulation efficiency of the working fluid is better. 
         [0048]    The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. It is understood that many changes and modifications of the above embodiments can be made without departing from the spirit of the present invention. The scope of the present invention is limited only by the appended claims.