TWI339257B - Heat pipe and method for making same - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of heat conduction, and more particularly to a heat pipe and a method of preparing the same. [Prior Art] [0002] A heat pipe is a heat-conducting element that realizes heat conduction by a phase change of its internal working fluid, and has excellent characteristics such as high thermal conductivity, excellent isothermality, good heat conduction effect, and wide application. [0003] In recent years, the rapid development of electronic technology, the high frequency, high speed of electronic devices and the intensive and miniaturization of integrated circuits have led to a sharp increase in the heat generation per unit volume of electronic devices. The heat pipe technology is characterized by its high efficiency, K compactness, flexibility and reliability. It is suitable for solving the heat dissipation problem caused by the current electronic device. It can be raised by the lifting. [0004] Referring to the first figure, the gravity heat pipe 10 is composed of a casing 11 and a working fluid 13 sealed in the casing 11. The heat pipe/10.-end is the evaporation section 10a (heating section), and the other end is the condensation section 10b (cooling section). The heat pipe 10 is normally placed at an angle perpendicular to the horizontal direction, the steaming section 10a is below, and the condensation section 10b is above. When the evaporation section 10a is heated, the working fluid 13 absorbs the heat 15 and is vaporized into the vapor 14, rises to the condensation section 10b under a slight pressure difference, and releases heat 15 to the outside, condenses into a liquid, and returns to the evaporation section 10a under the action of gravity. It is again heated and vaporized, and thus reciprocates, continuously transferring heat 15 from the evaporation section 10a to the condensation section 10b. Referring to the second drawing, the heat pipe 20 having the capillary wick is composed of a casing 21, a capillary wick 22, and a working fluid 23 sealed in the casing 21. One end of the heat pipe 20 is the evaporation section 20a (heating section), and the other end is the condensation section. Form No. A0101 Page 3 / Total 23 pages 1003015083-0 1339257 [Tnn year m 14th building tf袢 for hundred points 20b (cooling section) An insulating section may be disposed between the evaporation section 20a and the condensation section 20b depending on the application. When the evaporation section 20a of the heat pipe 20 is heated, the working fluid 23 in the capillary wick 22 evaporates to form a vapor 24, and the vapor 24 flows to the condensation section 20b of the heat pipe 20 under a slight pressure, condenses into the working fluid 23 and emits heat 25, and the working fluid 23 Then, by capillary action, it flows back along the capillary suction 22 to the evaporation section 20a. In this cycle, heat 25 is continuously transferred from the evaporation section 20a of the heat pipe 20 to the condensation section 20b and is absorbed by the cold source of the condensation section 20b. [0006] The operating temperature of a typical heat pipe is controlled in such a manner as to control the pressure inside the pipe. Take water as an example. At 1 atmosphere (latm), the boiling point of water is 100 degrees Celsius.

(100 ° C), as the pressure is reduced, the law; #点•. Generally, the working temperature of the heat pipe with water as the working fluid _ all: the test for &>£;. ff, so the heat pipe • r*· -t Γ ...

The pressure inside the tube should be less than 1 atm. When the working temperature is higher than the temperature set by the heat pipe, the working fluid in the heat pipe will all evaporate into gas and cannot be heated; on the contrary, when the working temperature is lower than the set temperature of the heat pipe, the working fluid cannot be evaporated, thereby Can't take away the heat. Therefore, if the operating temperature range of the heat pipe is too small, it will easily cause the heat pipe to fail. [0007] In view of this, it is necessary to provide a heat pipe capable of achieving a large operating temperature range. SUMMARY OF THE INVENTION [0008] Hereinafter, a heat pipe capable of realizing a large operating temperature range will be described by way of embodiments. [0009] And a method of preparing a heat pipe is explained by these embodiments. 094130332 Form No. A0101 Page 4 of 23 1003015083-0 Correction Replacement Page [0110] In order to achieve the above, a heat pipe including a casing having a first cavity and a second cavity is provided. The second cavity is disposed in parallel with the first cavity along the axial direction of the heat pipe; the first cavity is sealed with a first working fluid, the second cavity is sealed with a second working fluid, and the second cavity is The air pressure inside is different from the air pressure in the first cavity such that the first and second cavities have different operating temperature ranges. [0011] In order to achieve the above, the embodiment further provides a method for preparing a heat pipe, comprising the following steps: [0012] forming a casing having a first cavity and a second cavity; [0013] sealing one end of the casing And pumping the low pressure of the first cavity and the second cavity respectively, and the pressure of the first and second cavities is different; [0014] respectively to the first cavity Filling the first working fluid and the second working fluid with the second cavity; [0015] sealing the other end of the envelope. [0016] Compared with the heat pipe of the prior art, the first cavity of the heat pipe provided by the present embodiment is independent of the working fluid in the second cavity, and the air pressure is also independent of each other, so that only one heat pipe can reach two The function of the heat pipe makes the application of the heat pipe wider. In addition, since the operating temperature ranges of the first cavity and the second cavity are different, the operating temperature range of the entire heat pipe is increased, so that the heat pipe can be used in a heat dissipation environment with a large temperature variation range. [Embodiment] [0017] The technical solution will be further described in detail below with reference to the accompanying drawings. [0018] Referring to the third figure, the heat pipe 30 provided by the first embodiment of the present invention includes a form number A0101, page 5 of 23, 1003015083-0 1339257

I Q Q - C! On January 5, the replacement of the sheet I casing 31, the first working fluid 33, and the second working fluid 33' are corrected. [0019] The tube shell 31 is generally a copper tube, and different materials such as Ming, carbon steel, stainless steel, iron, magnet, silver, and the like may be used according to different needs. The envelope 31 includes a hollow structure of the first cavity 37 and the second cavity 37'.

[0020] The first working fluid 33 is sealed within the first cavity 37 and the second working fluid 33' is sealed within the second cavity 37'. The first working fluid 33 and the second working fluid 33' include water, acetone or heptane, and the like. According to actual needs, the materials of the first working fluid 33 and the second working fluid 33' may be the same or different σ [0021] The working principle of the heat pipe 3〇 and the prior art. The hot dream.] :,: .....'.'f: Same, where the evaporation section of the heat pipe 30 is read Oa::, the game is .b; the heat pipe 30 absorbs and releases heat of 35; the first X is fluid 3 The second working fluid 33' is vaporized by heat to form vapors 34 and 34'. [0022] The operating temperature range of the first cavity 37 and the second cavity 37' is different. When the heat source temperature is in the operating temperature range of the first cavity 37, the first cavity 37 acts in the heat pipe 30; when the heat source temperature When in the operating temperature range of the second cavity 37', the second cavity 37' functions in the heat pipe 30; when the operating temperature range of the first cavity 37 and the second cavity 37' is overlapped, and the temperature of the heat source is When the operating temperature range of the first cavity 37 and the second cavity 37' intersect, the first cavity 37 and the second cavity 37' will cooperate in the heat pipe 30. [0023] Referring to the fourth figure, a radial cross-sectional view of the internal structure of the heat pipe 30 of the present embodiment is shown. 094130332 The outer radial shape of the shell 31 is elliptical, rectangular or triangular, and the form number A0101 is 6 pages/total 23 pages 1003015083-0 [0024] 1339257 _ 100 years of January 14 correction replacement page can be based on actual needs For other shapes, it is not limited to the shape provided by the embodiment of the present invention, and the outer radial cross-sectional shape of the envelope 31 of the present embodiment is elliptical.

[0025] The radial shape of the first cavity 37 and the second cavity 37' is a standard circular shape, an elliptical shape, a rectangular shape, a triangular shape, or the like, and may be other shapes according to actual needs, and is not limited to the embodiment of the present invention. The shape provided. The radial shape of the first cavity 37 and the second cavity 37' may be the same or different depending on actual needs. The radial shape of the first cavity 37 and the second cavity 37' of this embodiment are both standard® shapes. [0026] Compared with the gravity heat pipe of the prior art, the heat pipe 30 provided in this embodiment has the first cavity 37 and the first cavity 37, and the two chambers have a hollow structure, and the air pressures in the two chambers can mutually Still control: system, the working fluid is also independent of each other, so the operating temperature range of the two chambers can be different, the two working temperature ranges can be crossed, or can not be crossed, so that the operating temperature range of the entire heat pipe 30 is increased, the heat pipe The 30 夂 application range is wider and can be used in a heat dissipation environment with a wide temperature range. [0027] In addition, since the first cavity 碴 碴 碴 碴 第二 碴 碴 第二 第二 第二 第二 第二 碴 碴 , , , , , , , , , , , , , , , 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二Within the cross range, one heat pipe 30 can function as two heat pipes. [0028] Referring to FIG. 5, a heat pipe 40 according to a second embodiment of the present invention includes a casing 41, a first capillary wick 42, a second capillary wick 42', a first working fluid 43, and a second Working fluid 43'. [0029] The casing 41 is a unitary structure including a first cavity 47 and a second cavity 47 094130332 Form No. A0I01 Page 7 / 23 pages 1003015083-0 1339257 Divination January 14 B Correction ^ 'The hollow structure. The casing 41, the first cavity 47, the second cavity 47', the first working fluid 43, the second working fluid 43' and the casing 31, the first cavity 37, and the second cavity 37 in the first embodiment ' The first working fluid 33 and the second working fluid 33' correspond to the same. [0030] The first capillary wick 42 and the second capillary wick 42' are respectively in close contact with the inner wall of the first cavity 47 and the inner wall of the second cavity 47', and the two may be groove type, mesh type or Sintered type, etc. According to actual needs, the first capillary wick 42 and the second capillary wick 42' may be of the same type or different types.

〇[0031] The working principle of the heat pipe 40 is basically the same as that of the heat pipe 20 with the capillary wick of the prior art, wherein the potential tube 4α is dedicated to the section 40a, the condensation ':.'ϋ〆, the section is 40b The heat pipe 40 absorbs and discharges &> the hot working fluid 43 and the second working fluid 43' are thermally evaporated to form vapors 44 and 44'. [0032] The operating temperature range of the first cavity 47 and the second cavity 47' is different. When the heat source temperature is in the operating temperature range of the first cavity 47, the first cavity 47 acts in the heat pipe 40; when the heat source temperature When in the operating temperature range of the second cavity 47', the second cavity 47' functions in the heat pipe 40; when the operating temperature range of the first cavity 47 and the second cavity 47' is overlapped, and the temperature of the heat source is When the operating temperature range of the first cavity 47 and the second cavity 47' intersect, the first cavity 47 and the second cavity 47' will cooperate in the heat pipe 40. Referring to the sixth drawing, a radial sectional view of the internal structure of the heat pipe 40 of this embodiment is shown. The peripheral shape of the envelope 41, the radial cross-sectional shape of the first cavity 47 and the second cavity 47', and the peripheral shape of the envelope 31 in the first embodiment, No. 094130332 Form No. 1010101 Page 8/Total 23 Page 1003015083 - 0 [0033] 1339257 On January 14, 10D, the shuttle is replacing the first cavity 37 and the second cavity 37' has the same radial cross-sectional shape. The difference is that the first capillary wick 42 and the second capillary wick 42 ′ are respectively in close contact with the inner walls of the first cavity 47 and the second cavity 47 ′, and the first capillary suction provided in this embodiment The radial cross-sectional shapes of the liquid core 42 and the second capillary wick 42' are both annular.

[0034] Compared with the prior art heat pipe with a capillary wick, the heat pipe 40 provided in this embodiment has a hollow structure of two cavities of the first cavity 47 and the second cavity 47', and the two cavities The air pressure can be controlled independently of each other, and the working fluids are also independent of each other, so the operating temperature ranges of the two chambers can be different, and the two working temperature ranges can be crossed or not crossed, so that the operating temperature range of the entire heat pipe 40 is added to the application range. It is more widely used and can be used in a wide range of temperature variations: the dilemma. [0035] In addition, since the first cavity 47 and the second cavity 47' of the heat pipe 40 are independent of each other, when the operating temperature range of the first cavity 47 and the second cavity 47' cross, and the operating temperature range of the heat source is further When in the crossover range, an i-root heat pipe 40 can achieve the function of two heat pipes.

Please refer to the seventh drawing, which is a flow chart of a method for preparing the heat pipe 30 according to the first embodiment of the present invention. The method will be described below in conjunction with the third and fourth figures: [0037] Step 1, forming a package 31 having two cavities. The two cavities are respectively a first cavity 37 and a second cavity 37', which are disposed in parallel along the axial direction of the heat pipe 30. The casing 31 includes a copper pipe, a Ming pipe, a steel pipe, a non-recorded steel pipe, an iron pipe, a pipe, a titanium pipe or an alloy pipe thereof. The radial cross section of the first cavity 37 and the second cavity 37' may be a standard circle, or may be elliptical, rectangular, or triangular. 094130332 Form No. A0101 Page 9 of 23 1003015083-0 1339257

The annual G1 month anniversaries are for the technical ones, and the radial cross-sections of the first cavity 37 and the second cavity 37' may be the same or different. Both of the embodiments adopt a standard circular shape; the outer periphery of the casing 31 The radial cross section may be elliptical, rectangular or triangular, etc., and the embodiment adopts an elliptical shape. Preferably, the envelope 31 is formed by an extrusion molding process.

[0038] In step 2, the end of the tube 31 is sealed, and the first chamber 37 and the second chamber 37' are respectively evacuated. The first cavity 37 and the second cavity 37' each have independent pumping control to bring the two chambers to two different operating temperatures. [0039] Step 3, filling the first cavity 37 and the second cavity 37' with the working fluid, respectively. The working fluid includes water, the acetal 37 is filled with the first working fluid 33, and the second working fluid 33'. The first working fluid 33 and the second working fluid 33' may be the same or different, and both of the embodiments employ water. [0040] Step 4, sealing the other end of the envelope 31 to form the heat pipe 30 shown in the third and fourth figures. [0041] It should be noted that the above preparation method can change the sequence of steps according to actual needs. For the steps 2 and 3, the tube 31 can be sealed at the end, and then the first cavity 37 and the second cavity 37 are respectively respectively. 'The working fluid is filled, and the first cavity 37 and the second cavity 37' are respectively pumped down. [0042] The present invention further provides a method for preparing the heat pipe 40 of the second embodiment, which is substantially the same as the method for preparing the heat pipe 30, the casing 41, the first working fluid 43, the second working fluid 43' and the casing 31, and the first The working fluid 33 and the second working fluid 33' are respectively prepared in the same manner, and the heat pipe 40 is sealed at both ends and pumped 094130332. Form No. 1010101 Page 10/23 pages 1003015083-0 1339257 January 14, 2014 Nuclear replacement page low pressure The method is the same as the method of sealing the ends of the heat pipe 30 and pumping the low pressure. The difference is that the following steps are added between step 1 and step 2: [0043] The first capillary wick 42 and the second capillary wick 42' are formed. The first capillary wick 42 and the second capillary wick 42' may be of a wire mesh type, a groove type or a sintered type. In the present embodiment, the first capillary wick 42 and the second capillary wick 4 2 'All formed by a sintering method. [0044] Taking the method of forming the first capillary wick 42 as an example, the sintering method is roughly as follows: a mandrel (a stainless steel mandrel can be inserted) in the center of the first cavity 47, and the thickness of the mandrel determines the inner diameter of the vapor cavity in the future. The size is then filled into the annular space formed by the mandrel and the tube wall, and the metal copper powder to be sintered is filled, and the core is fixed by a bracket and then sent to a heating furnace to protect the hydrogen gas. When the card is sintered by about half a small, the sintering temperature is 810 ° C ~ 880 ° C. The tube is taken out from the furnace, and after cooling, the mandrel is taken out, and then placed in the furnace for sintering for about one hour to obtain a sintered layer on the inner wall of the first cavity 47. The sintered layer has a capillary structure and can be used as the first Capillary wick 42. The second capillary wick 42' is formed in the same manner as the first capillary wick 42.

[0045] It should be noted that the above preparation method may change the sequence of steps according to actual requirements, and the first end of the tube 31 may be sealed, and then the first capillary wick 42 and the second capillary wick 42' may be formed. A cavity 47 and a second cavity 47' are respectively pumped down. [0046] In addition to the gravity heat pipe 30 and the heat pipe 40 having the capillary wick, there are also a rotating heat pipe and a separate heat pipe, etc., and the above-mentioned rotating heat pipe and the separate heat pipe are similar to the gravity heat pipe 30, and the heat pipe has no capillary. The wick of the structure, the working fluid is returned by gravity or centrifugal force during operation. The above-mentioned rotating heat pipe 094130332 Form No. A0101 Page 11 / 23 pages 1003015083-0 1339257 1100 01. On the 14th of the day, the shuttle page and the separate heat pipe can also be made into two cavity structures to increase its work. temperature range. It will be appreciated that the present invention can also be extended to heat pipes having three or more cavities such that the operating range of the heat pipes is further increased to meet actual needs.

[0048] In summary, the present invention has indeed met the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and those skilled in the art will be able to make equivalent modifications or changes in accordance with the spirit of the present invention. It should be covered by the following patent application. Λ'*· , <' . π [Simple description of the diagram] 4 .:,:.3⁄4丨.1 [0049] The first figure is the gravity of the prior art. [0050] The second figure is a schematic diagram of the working principle of a prior art heat pipe with a capillary wick. [0051] The third figure is a schematic diagram of the working principle of the heat pipe of the first embodiment of the present invention. The fourth drawing is a schematic view of a radial cross section of the internal structure of the heat pipe according to the first embodiment of the present invention. [0053] The fifth figure is a schematic diagram of the working principle of the heat pipe of the second embodiment of the present invention. [0054] Figure 6 is a schematic cross-sectional view showing the internal structure of the heat pipe of the second embodiment of the present invention. [0055] FIG. 7 is a flow chart showing a method of preparing a heat pipe according to a first embodiment of the present invention. [Main component symbol description] [0056] Heat pipe: 30, 40 094130332 Form number A0101 Page 12 of 23 1003015083-0 1339257 Correction replacement page on January 14, 100

[0058] [0086] [0064] [0064] [0067] [0067] Condensation section: 30b, 40b First capillary wick: 3 2, 4 2 First working fluid: 33, 43 Vapor: 34, 34', 44, 44' First cavity: 37, 47 Evaporation section: 30a, 40a Shell: 31,41 Second capillary wick: 32' 42' Second working fluid: 33', 43'. Heat: 35, 45 Second cavity: 37', 47'

094130332 Form No. A0101 Page 13 of 23 1003015083-0

Claims (1)

January 14 5 Correction wire q Patent application scope: The heat exchanger includes a casing having a first cavity, the first cavity is sealed with a first working fluid, and the improvement is that the casing is further advanced The first cavity is disposed parallel to the axial direction of the heat pipe, the second cavity is sealed with a second working fluid, and the air pressure in the second cavity is The air pressure in the first cavity is different in size so that the first and second cavities have different operating temperature ranges. The heat pipe of claim 1, wherein the heat pipe is further included And comprising a first capillary wick which is adhered to the inner wall of the first cavity and a second capillary wick which is in close contact with the inner wall of the second cavity. For example, the material of the shell is copper, iron, nickel, niobium, carbon spirit, ^%..fu or its alloy|, as described in the patent scope of the item! The warp direction of the body is a standard circular shape, an elliptical shape, a rectangular shape or a triangular shape, and the radial bearing surface of the two cavity is a standard circular shape, a rounded shape, a rectangular shape or a triangular shape. The heat pipe, wherein: the outer periphery of the shell is radially worn; the flf is circular, rectangular or triangular. The wire according to claim 2, wherein the first hair is a groove type, a wire mesh type or a sintered type, the second capillary liquid absorption; the groove type, the wire Mesh or sintered. The heat pipe according to the patent application, wherein the first bamboo fluid is water, (four) or a species, and the second turbine fluid is one of water acetone or heptane. • As stated in the scope of claim 1 of the patent application, "·, s where the outer radial section of the envelope is elliptical. Form No. A0101 Page 14 of 23 1003015083-0 Oops 257 100 The heat pipe according to claim 8, wherein the first first cavity has a radial cross section along a periphery of the casing with a radial load surface thereof. The heat pipe according to the first aspect of the invention, wherein the operating temperature range of the first and second cavities is overlapped. u • a heat pipe The preparation method comprises the steps of: forming a casing having a first cavity and a second cavity; and sealing one end of the casing, and respectively drawing a low pressure on the first cavity and the second cavity, Φ making the first The pressure of the second cavity is different; filling the first cavity and the second cavity with the first working fluid and the second working fluid respectively; sealing the other end of the casing. 12. As claimed in the scope of claim U The heat pipe preparation method: the method of forming the pipe and the casing The step of sealing and pressing the first cavity and the second cavity respectively includes the following steps: forming a first capillary wick close to the inner wall of the first cavity, and forming a second close to the inner wall of the second cavity The method of preparing a heat pipe according to the above aspect of the invention, wherein the method of forming a package having a first cavity and a second cavity is an extrusion process. The method of preparing a heat pipe according to the above aspect of the invention, wherein the heat pipe preparation method according to the invention of claim 14, wherein The first and second cavities are disposed in the casing in such a manner that their radial cross sections are arranged along the longitudinal axis of the outer circumference of the casing. B. The heat pipe according to the scope of claim π The preparation method, wherein the form bat number A0101 page 15 / total 23 pages 1 〇〇 3 〇 1 讣 83 0 0 1339257 [100 years of January 14th, according to the positive replacement page, the working temperature of the first and second cavities The range has a cross. 094130332 Form number A0101 Page 16 of 23 1003015083-0