Abstract:
A heat absorbing and radiating device includes a driving unit having communicable first fluid outlets and fourth fluid inlets, a heat-exchange unit communicating at an end with third fluid outlets of the driving unit and at another end with an inlet end of a liquid-gas confluence unit, which communicates at an outlet end with an inlet end of a liquid-gas separation chamber, while the latter communicates at an outlet end with one of two second fluid inlets of the driving unit. The driving unit is provided therein with reciprocatingly movable magnets to alternately push first and second fluids into the heat-exchange unit before them enter the fluid-gas confluence unit, so that hot air is finally released from the liquid-gas separation chamber. Since radiating fins and cooling fan are omitted, the device has reduced volume for use with a heat source in a small space, such as a CPU of a portable computer.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a heat absorbing and radiating device, and more particularly to a miniature heat absorbing and radiating device suitable for use with a heat source in a very small space, such as a central processing unit (CPU) of a portable computer or a personal digital assistant (PDA). The twenty-first century is an electronic information era. With developments in the semiconductor field, new models of various electronic products, such as desktop computers, portable computers, PDAs, mobile phones, and smart electrical appliances, have been continuously introduced into the markets. All these products are designed to have a compact volume for users to carry and use them at any time to access real-time information. All the above-mentioned electronic products developed for the information industry include a central processing unit (CPU) that controls the entire operation of the electronic products. The CPU generates a large amount of heat and accordingly high temperature that adversely affects the operating efficiency and usable life of the products. Thus, it is always an important issue among the manufacturers to effectively cool the CPU. The currently available solutions of cooling the CPU include the provision of a group of radiating fins and a cooling fan at outer side of the CPU, and the improvement of heat-radiating fins in their material and structure in order to more quickly radiate heat produced by the CPU. However, all these currently available solutions are passive ways with limited radiation efficiency. Moreover, the cooling fan occupies a considerable space and does not meet the requirement of compact design. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary object of the present invention to provide a miniature heat absorbing and radiating device having a driving unit for alternately pushing two types of fluid to actively and effectively lower the temperature of a heat-source in a very small space. 
     Another object of the present invention is to provide a miniature heat absorbing and radiating device that has a driving unit for alternately pushing two types of fluid and does not require conventional radiating fins and cooling fans, so as to occupy only very small space. 
     A further object of the present invention is to provide a method for absorbing and radiating heat produced by a heat source in a very small space. 
     To achieve the above and other objects, the present invention provides a miniature heat absorbing and radiating device that includes a first driving unit, a heat-exchange unit, a liquid-gas confluence unit, and a liquid-gas, separation chamber. The first driving unit includes a chamber in which an active magnet, a pair of fixed magnets, and a pair of passive magnets are provided. The chamber is also provided on a wall with a pair of first fluid outlets, a pair of second fluid inlets, a pair of third fluid outlets, and a pair of fourth fluid inlets. The heat-exchange unit communicates with the first driving unit and the liquid-gas confluence unit, and the liquid-gas separation chamber communicates with the liquid-gas confluence unit and one of the second fluid inlets. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     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 
     FIG. 1 schematically shows a first driving unit adopted in a miniature heat absorbing and radiating device according to a first preferred embodiment of the present invention; 
     FIGS. 2,  3  and  4  illustrate the operation of the first driving unit of FIG. 1; 
     FIG. 5 is a sectional view showing the structure of the miniature heat absorbing and radiating device according to the first preferred embodiment of the present invention including a first and second fluid storage; 
     FIG. 6 is a flowchart showing steps of operation of the miniature heat absorbing and radiating device of FIG. 5; 
     FIG. 7 is a sectional view showing the structure of the miniature heat absorbing and radiating device according to a second preferred embodiment of the present invention including the first and second fluid storage; 
     FIG. 8 is a flowchart showing steps of operation of the miniature heat absorbing and radiating device of FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to FIGS. 1 through 6. The present invention mainly relates to a miniature heat absorbing and radiating device that includes a driving unit for alternately driving two different fluids. 
     The present invention also relates to a method for absorbing and radiating heat in a very small space by pushing alternately two different fluids included in a miniature heat absorbing and radiating device. The device according to a first preferred embodiment of the present invention, as shown in FIGS. 1 to  5 , mainly includes a first driving unit  11 , a heat-exchange unit  12 , a liquid-gas confluence unit  13 , and a liquid-gas separation chamber  14 . 
     As can be seen in FIG. 1, the first driving unit  11  includes a chamber  15  that is in the form of a tube having a predetermined shape, length and internal space, an active magnet  16 , a pair of fixed magnets  17 , and a pair of passive magnets  18 . 
     The active magnet  16  has a predetermined length and an exterior shape corresponding to an interior shape of the chamber  15 , and is adapted to reciprocatingly move within a middle section of the chamber  15 . A coil  51  is provided around an outer wall of the chamber  15  at a portion corresponding to the active magnet  16 . 
     The coil  51  is electrically connected to a circuit to obtain from the circuit a cyclically variable current direction for the active magnet  16  to reciprocate in the chamber  15 . 
     The pair of fixed magnets  17  includes a left and a right magnet  17 , as viewed in front of the drawings, to separately fixedly locate at and space from two ends of the active magnet  16  by a predetermined distance. Each fixed magnet  17  has a predetermined length and an exterior shape corresponding to the interior shape of the chamber  15 . 
     The pair of passive magnets  18  includes a left and a right magnet  18 , as viewed in front of the drawings, to separately locate and reciprocatingly move between the active magnet  16  and the left and the right fixed magnet  17 , respectively. Each passive magnet  18  has a predetermined length and an exterior shape corresponding to the interior shape of the chamber  15 . 
     The active magnet  16 , the fixed magnets  17  and the passive magnets  18  are so arranged that ends thereof having the same polarity are located at the same side. 
     The chamber  15  is provided on its wall at portions between the active magnet  16  and the left fixed magnet  17  with a pair of first fluid outlets  52  and a pair of second fluid inlets  53 , such that when the active magnet  16  reciprocates in the chamber  15  and causes the left passive magnet  18  to move reciprocatingly, the following conditions are observed: 
     (A) When, the left passive magnet  18  is moved leftward to reach a maximum displacement thereof, as shown in FIG. 2, only a right one of the two first fluid outlets  52  that is located between the active magnet  16  and the left passive magnet  18  is opened; 
     (B) When the left passive magnet  18  is moved rightward not to reach a maximum displacement thereof, as shown in FIG. 3, a left one of the two first fluid outlets  52  that is located between the left fixed magnet  17  and the left passive magnet  18  as well as a right one of the two second fluid inlets  53  that is located between the active magnet  16  and the left passive magnet  18  are opened, while the right one of the two first fluid outlets  52  and a left one of the two second fluid inlets  53  are closed; and 
     (C) When the left passive magnet  18  is moved rightward to reach a maximum displacement thereof, as shown in FIG. 4, only the right one of the two first fluid outlets  52  that is located between the active magnet  16  and the left passive magnet  18  is closed. 
     The chamber  15  is also provided on its wall at positions between the active magnet  16  and the right fixed magnet  17  with a pair of third fluid outlets  54  and a pair of fourth fluid inlets  55 , such that when the active magnet  16  reciprocates in the chamber  15  and causes the right passive magnet  18  to move reciprocatingly, the following conditions are observed: 
     (D) When the left passive magnet  18  is moved leftward to reach a maximum displacement thereof, as previously described in (A) and shown in FIG. 2, only a left one of the two third fluid outlets  54  that is located between the active magnet  16  and the right passive magnet  18  is closed; 
     (E) When the left passive magnet  18  is moved rightward not to reach a maximum displacement thereof, as previously described in (B) and shown in FIG. 3, only a right one of the two third fluid outlets  54  that is located between the right fixed magnet  17  and the right passive magnet  18  is opened; and 
     (F) When the left passive magnet  18  is moved rightward to reach a maximum displacement thereof, as previously described in (C) and shown in FIG. 4, only the left one of the two third fluid outlets  54  that is located between the active magnet  16  and the right passive magnet  18  is opened. 
     Moreover, a first communicating tube  521  is provided to extend from the left one of the first fluid outlets  52  between the left fixed magnet  17  and the left passive magnet  18  to a right one of the fourth fluid inlets  55  between the right passive magnet  18  and the right fixed magnet  17 , in order to transfer a first fluid, such as air, provided in the chamber  15 . 
     A second communicating tube  522  is provided to extend from the right one of the first fluid outlets  52  between the active magnet  16  and the left passive magnet  18  to a left one of the fourth fluid inlets  55  between the active magnet  16  and the right passive magnet  18 , in order to transfer a second fluid, such as a type of refrigerant, provided in the chamber  15 . 
     The heat-exchange unit  12  includes at least an expansion tube  121  having a predetermined length. The expansion tube  121  is connected at an end, that is, an inlet end, to the pair of third fluid outlets  54  to communicate with the latter. An outer side of the expansion tube  121  is pressed against a heat source H, for example, a Central Processing Unit (CPU). 
     The liquid-gas confluence unit  13  is a tube having a predetermined length. The liquid-gas confluence unit  13  is connected at an end, that is, an inlet end, to the other end, that is, an outlet end, of the expansion tube  121  to communicate with the latter, so as to release a pressure from a mixed gas produced after a heat exchange in the heat-exchange unit  12 . 
     The liquid-gas separation chamber  14  has a predetermined internal space and is communicable with the other end, that is, an outlet end, of the liquid-gas confluence unit  13  and with the right one of the second fluid inlets  53  between the active magnet  16  and the left passive magnet  18 . The liquid-gas separation chamber  14  is provided on its wall with an opening covered with a thin venting layer, so that hot air is discharged from the liquid-gas separation chamber  14  and said second type of fluid, for example, a refrigerant, is condensed in the liquid-gas separation chamber  14 . 
     The method of the present invention for absorbing and radiating heat by alternately pushing two different fluids includes the following steps: 
     (I) Actuate the first driving unit  11  so as to alternately push first and second fluids in the chamber  15  for them to flow from the pair of first fluid outlets  52  to the pair of fourth fluid inlets  55  via the first communicating tube  521  and the second communicating tube  522 ; 
     (II) Alternately push the first and the second fluids for them to flow out of the pair of third fluid outlets  54  and into the expansion tube  121  of the heat-exchange unit  12 , at where heat exchange is proceeded and a mixed gas of the first and the second fluid is produced; 
     (III) Push the mixed gas-into the liquid-gas confluence unit  13 ; 
     (IV) Send the mixed gas from the liquid-gas confluence unit  13  into the liquid-gas separation chamber  14 ; 
     (V) Discharge the first fluid, for example, the air, in the mixed gas from the liquid-gas separation chamber  14 , and allow the second type of fluid, for example, the refrigerant, to condense into liquid phase; and 
     (VI) Allow the second fluid, for example, the refrigerant, to flow into the right one of the two second fluid inlet  53  between the active magnet  16  and the left passive magnet  18 . 
     The following are advantages of the miniature heat absorbing and radiating device and the heat absorbing and radiating method of the present invention by alternately pushing two different fluids with a driving unit: 
     (1) With the reciprocating motion of the first driving unit  11  and the provision of the first fluid outlets  52 , the second fluid inlets  53 , the third fluid outlets  54 , and the fourth fluid inlets  55 , two types of fluid, such as refrigerant and air, are alternately pushed through the device to proceed heat exchange. 
     (2) Heat produced from the heat source is brought away by the air, and low-temperature air is continuously sucked into the device to proceed effective heat exchange. 
     (3) The use of air to replace the thermal fins and cooling fans conventionally used in a heat-radiating unit largely reduces the space needed by the heat-radiating. unit and enables the same to be used in compact portable computers and mobile phones. 
     (4) The device of the present invention is an active heat-absorbing device operative to effectively lower temperature of a heat source. 
     In the above-described structure of the device according to the present invention, the expansion tube  121  further includes an uneven or a nap-finished inner wall surface to effectively hold the first and the second types of fluid to proceed a thorough heat exchange. 
     In the above-described structure of the device of the present invention, the liquid-gas separation chamber  14  further includes an uneven or a nap-finished inner wall surface to effectively enhance a structural strength thereof so as to bear the pressure from the mixed gas and to achieve the function of discharging the hot air and condensing the refrigerant into liquid. 
     In the above-described structure of the device of the present invention, the liquid-gas confluence unit  13  may include a goat-horn shaped tube having a diametrically expanded end and a diametrically reduced end. The expanded end of the liquid-gas confluence unit  13  is connected to and communicable with the outlet end of the expansion tube  121  and the reduced end of the liquid-gas confluence unit  13  is connected to and communicable with the liquid-gas separation chamber  14  to speed the flow of the mixed gas. 
     Please refer to FIG. 7 that schematically shows the structure of the miniature heat absorbing and radiating device according to a second preferred embodiment of the present invention and to FIG. 8 that is a flowchart showing steps included in the heat absorbing and radiating method according to a second preferred embodiment of the present invention. In the second preferred embodiment, the device of the present invention further includes a second driving unit  11 ′ structurally identical to the first driving unit  11 ; the liquid-gas confluence unit  13  is communicably connected at the outlet end to a pair of second fluid inlets of the second driving unit  11 ′; and the liquid-gas separation chamber  14  is communicably connected at an inlet end to a pair of third fluid outlets of the second driving unit  11 ′ and at an outlet end to the right one of the two second fluid inlets  53  between the active magnet  16  and the left passive magnet  18  of the first driving unit  11 ; such that the objects of the present invention could be more effectively achieved. In the method of the second preferred embodiment of the present invention, the following steps are included: 
     (I) Actuate the first and the second driving unit  11 ,  11 ′, so that the first driving unit  11  alternately pushes first and second fluids in the chamber  15  for them to flow from the pair of first fluid outlets  52  of the first driving unit  11  to the pair of fourth fluid inlets  55  of the first driving unit  11  via the first communicating tube  521  and the second communicating tube  522  of the first driving unit  11 ; 
     (II) Alternately push the first and the second fluid for them to flow out of the pair of third fluid outlets  54  of the first driving unit  11  and into the expansion tube  121  of the heat-exchange unit  12 , at where heat exchange is proceeded and a mixed gas of the first and the second types of fluid is produced; 
     (III) Push the mixed gas into the liquid-gas confluence unit  13 ; 
     (IV) Send the mixed gas from the liquid-gas confluence unit  13  into a pair of second fluid inlets of the second driving unit  11 ′; 
     (V) Push the mixed gas to pass a pair of third fluid outlets of the second driving unit  11 ′ into the liquid-gas separation chamber  14 ; and 
     (VI) Discharge the first fluid, for example, the air, in the mixed gas from the liquid-gas separation chamber  14 , and allow the second fluid, for example, the refrigerant, in the mixed gas to condense into liquid phase and flow into the right one of the two second fluid inlet  53  between the active magnet  16  and the left passive magnet  18 . 
     In the above-described structure of the device of the second preferred embodiment of the present invention having the second driving unit  11 ′, the liquid-gas confluence unit  13  may be communicably connected at the outlet end to only one of the second fluid inlets of the second driving unit  11 ′, permitting low-temperature air to be guided into another one of the second fluid inlets of the second driving unit  11 ′. This arrangement enables the device of the present invention to more effectively lower the temperature and to provide a pressurizing effect to separate the liquid from the air. 
     In this case, the above-described step (IV) is changed to send the mixed gas from the liquid-gas confluence unit  13  into one of a pair of second fluid inlets of the second driving unit  11 ′. 
     In the above-described structure of the device of the present invention, a first fluid storage L for storing the second type of fluid, for example, the refrigerant, may be further provided between the liquid-gas separation chamber  14  and the first driving unit  11  to obtain the same function of the present invention. 
     In the above-described structure of the device of the present invention, a second fluid storage A may be provided on the first communicating tube  521  to ensure accurate driving of the driving unit  11  and obtain the same function of the present invention.