JP4767105B2 - Loop type heat pipe - Google Patents

Description

  The present invention relates to a loop heat pipe, and more particularly to a loop heat pipe that improves cooling performance by preventing hydraulic fluid from passing through a wick and oozing out to the steam pipe side.

  Conventional loop heat pipes include, for example, LHP (loop heat pipe) and CPL (capillary pumped loop).

  For example, as shown in FIG. 6, the conventional LHP 101 includes an evaporator 103 that cools using latent heat when the working fluid is vaporized, and a gas vaporized by the evaporator 103 is a vapor pipe 105 ( Vapor line) and the condenser 107 (Condenser) that radiates and liquefies the gas, and the working fluid liquefied by the condenser 107 moves via the liquid return pipe 109 (Liquid Line) and the working fluid. Is supplied to the evaporator 103, and the working fluid returned from the liquid return pipe 109 is supplied to the inside of the evaporator 103. The system including the bayonet tube 113 forms one loop, and the evaporator 103 and the reservoir unit 111 are integrally formed.

  Also, an O-ring 115 for preventing backflow of hydraulic fluid is installed between the evaporator 103 and the reservoir unit 111 to prevent the gas vaporized by the evaporator 103 from returning to the reservoir unit 111. . Further, a working fluid is introduced into the LHP 101. Examples of the hydraulic fluid include alcohol, ammonia, and water. In the CPL, the evaporator 103 and the reservoir unit 111 are configured separately.

  In the LHP 101, when the evaporator 103 is heated by the heat generated in the surroundings, for example, water as a working fluid becomes steam in the evaporator 103, and the ambient temperature at this time is used to cool the ambient temperature. . Vapor generated in the evaporator 103 moves to the condenser 107 through the vapor pipe 105 and is dissipated in the condenser 107, whereby the vapor is returned to water. This water moves again to the reservoir 111 and the evaporator 103 via the liquid return pipe 109, and the above operation is repeated.

  Further, the evaporator 103 is basically the same as the principle shown in, for example, Patent Document 1, and opens at one end side and communicates with the steam pipe 105 to close the other end side. A cylindrical groove tube 117 and a wick 119 that forms a cylindrical shape that contacts and inserts into the cylindrical shape of the groove tube 117 and supplies the working fluid to the cylindrical shape are provided.

  The groove tube 117 is provided with groove portions 121 on the inner peripheral surface of the groove tube 117 which are alternately uneven in the circumferential direction in a cross section perpendicular to the longitudinal direction of the groove tube 117 and extended in the longitudinal direction. ing. On the other hand, the outer peripheral surface of the wick 119 is in contact with the inner peripheral surface of the convex portion of the groove portion 121 of the groove tube 117, and the concave portion of the groove portion 121 serves as a steam flow path 123.

  The cylindrical interior of the wick 119 forms a liquid storage chamber 125 that communicates with the above-described reservoir 111 and whose front end is closed. In addition, since the bayonet tube 113 communicating with the liquid return pipe 109 is inserted through the reservoir 111 to a little before the front end of the liquid storage chamber 125, the water returned from the liquid return pipe 109 A liquid storage chamber 125 is supplied from the front end of the net tube 113. This water is turned 180 ° from the front end of the bayonet tube 113, passes between the liquid reservoir chamber 125 and the bayonet tube 113 and fills the liquid reservoir chamber 125, and is retained in the reservoir unit 111.

  The wick 119 is made of, for example, a porous sintered metal body, metal fiber, glass fiber or the like.

Therefore, when the groove tube 117 is heated by the heat around the evaporator 103, the heat of the groove tube 117 is conducted from the contact portion with the inner peripheral surface of the convex portion of the groove portion 121 to the wick 119, and the wick 119 is Heated. As a result, water that has penetrated from the liquid storage chamber 125 into the wick 119 is heated to become steam, and moves to the steam pipe 105 through the groove portion 121 of the groove pipe 117, that is, the steam flow path 123, as described above. It will be.
JP 2004-53062 A

  By the way, the conventional LHP 101 increases the flow rate and pressure of the working fluid that returns from the liquid return pipe 109 at the time of start-up and when the amount of input heat increases abruptly, as indicated by the solid line arrows in FIG. There was a problem that the vapor passed through the front end portion of the wick 119 in the evaporator 103 and exited to the steam pipe 105. That is, in the structure of the conventional wick 119, since the internal working fluid easily flows from the front end portion to the steam pipe 105 side, the amount of working fluid supplied to the groove pipe 117 and the pressure of the working fluid are reduced. There was a problem that the performance deteriorated.

In order to achieve the problem to be solved by the invention, a loop heat pipe of the invention includes an evaporator that cools using latent heat when the working fluid is vaporized, and a gas that is vaporized by the evaporator. A condenser that moves through the steam pipe and radiates and liquefies the gas, and a working liquid liquefied by the condenser moves through the liquid return pipe and is reserved for supplying the working liquid to the evaporator. A loop heat pipe comprising a reservoir section, wherein the evaporator has a cylindrical groove pipe whose front end side communicates with the steam pipe and whose rear end side communicates with the reservoir section, and the groove pipe And a wick having a tissue structure that has a cylindrical shape in which the front end side is closed while being in contact with and inserted into the inside of the cylindrical shape, and the inner peripheral surface of the group tube has a longitudinal length of the group tube Hanging in the direction A concave portion and a convex portion are alternately formed in the circumferential direction in the cross section, and the concave and convex portions are provided with a group portion extending in the longitudinal direction of the group tube, and the outer surface of the wick is a convex portion of the group portion. The wall member for preventing the passage of the hydraulic fluid inserted into the cylindrical shape of the wick is in non-contact with the inner peripheral surface of the convex portion of the group portion. It is provided on the front end surface of the wick, and a plurality of pressing shafts are interposed between the wall member and the front end wall of the evaporator to press the wall member against the front end surface of the wick. is there.

The loop heat pipe of the present invention includes an evaporator that cools by using latent heat when the working fluid is vaporized, and a gas vaporized by the evaporator moves through a vapor pipe and dissipates the gas to be liquefied. A condenser-type heat pipe, and a reservoir section that holds the working liquid liquefied in the condenser through the liquid return pipe and holds the working liquid for supplying the working liquid to the evaporator, The evaporator has a cylindrical groove tube whose front end communicates with the steam pipe and whose rear end communicates with the reservoir portion, and is inserted in contact with the inside of the cylindrical shape of the groove tube, and the front end side is closed. A wick having a textured structure and having a fine void, and an inner circumferential surface of the group tube having a concave portion and a convex portion in a circumferential direction in a cross section perpendicular to the longitudinal direction of the group tube Alternately uneven The concavo-convex shape is provided with a group portion extending in the longitudinal direction of the group tube, and the outer peripheral surface of the wick is in contact with the inner peripheral surface of the convex portion of the group portion. A wall member for preventing the passage of hydraulic fluid inserted into the shape is provided on the front end surface of the wick so as not to contact the inner peripheral surface of the convex portion of the group portion, and the wall member and the front end of the evaporator The wall member is pressed against the front end surface of the wick by biasing means at a plurality of locations between the wall and the wall.
In the loop heat pipe of the present invention , the urging means is a spring.

In the loop heat pipe of the present invention, the loop-type heat pipe includes a bayonet tube that is inserted into the reservoir portion in communication with the liquid return tube and supplies the working fluid returned from the liquid return tube to the evaporator. The front end side of the bayonet tube is inserted to the front of the front end surface of the wick.

In the loop heat pipe according to the present invention, an O-ring for preventing backflow of hydraulic fluid is mounted between the wick and the reservoir portion.

In the loop heat pipe of the present invention, the wall member is a polymer body.

In the loop heat pipe of the present invention, the wick is a polymer body having a gap.

As will be understood from the means for solving the above problems, according to the loop heat pipe of the present invention, it is possible to prevent the passage of the hydraulic fluid inserted into the cylindrical shape of the wick at the front end portion of the wick. Since the wall member is provided, the hydraulic fluid can be prevented from passing through the front end portion of the wick, and the flow rate and pressure of the hydraulic fluid in the wick can be prevented from being lowered. As a result, the amount of working fluid supplied to the groove tube and the working fluid pressure can be maintained or increased, so that the pressure of the working fluid that oozes out to the groove tube is improved, and the cooling performance can be improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  Referring to FIG. 1, examples of the loop heat pipe according to this embodiment include LHP (loop heat pipe) and CPL (capillary pumped loop).

  For example, in the LHP 1, the evaporator 5 that cools using the latent heat generated when the working fluid 3 </ b> L as the refrigerant is vaporized, and the gas 3 </ b> V vaporized in the evaporator 5 moves through the vapor pipe 7 (Vapor Line). At the same time, the condenser 9 (Condenser) that radiates and liquefies the gas 3V, and the hydraulic fluid 3L liquefied by the condenser 9 moves through the liquid return pipe 11 (Liquid Line) and the hydraulic fluid 3L is transferred to the evaporator. A reservoir section 13 (or an accumulator, CC (Compensation Chamber), etc.) that is reserved for supply to 5 and a bayonet tube that supplies the working fluid 3L returned from the liquid return pipe 11 to the inside of the evaporator 5 15, a single loop is formed, and the evaporator 5 and the reservoir unit 13 are integrally formed.

  In addition, an O-ring 17 for preventing backflow of hydraulic fluid is installed between the evaporator 5 and the reservoir unit 13 to prevent the gas 3V vaporized by the evaporator 5 from returning to the reservoir unit 13. Yes. Further, 3 L of hydraulic fluid is introduced into the LHP 1. Examples of the hydraulic fluid 3L include alcohol, ammonia, and water. In this embodiment, the hydraulic fluid 3L is water from the viewpoint of the global environment. In FIG. 1, the flow direction of water, which is the hydraulic fluid 3L, is indicated by a solid arrow, and the flow direction of vapor, which is a gas 3V obtained by vaporizing the hydraulic fluid 3L, is indicated by a dotted arrow.

  Further, as the CPL, the evaporator 5 and the reservoir unit 13 are configured separately, and the other basic configuration is the same as that of the LHP 1.

  That is, in the LHP 1, when the evaporator 5 is heated by the heat generated in the surroundings, for example, water as the working liquid 3L becomes steam in the evaporator 5, and the ambient temperature is cooled using the latent heat at this time. Is. The steam generated in the evaporator 5 moves to the condenser 9 through the steam pipe 7 and is dissipated in the condenser 9 so that the steam is returned to water. This water moves again through the liquid return pipe 11 to the reservoir section 13 and the evaporator 5 and repeats the above operation. Therefore, LHP1 and CPL use latent heat and have a high heat transport capability without an external power source. Moreover, the piping of the steam pipe 7 and the liquid return pipe 11 is free, and the heat transmission direction behaves like a diode in one direction from the evaporator 5 to the condenser 9.

  The evaporator 5 has a cylindrical evaporator main body 19 that is closed at the front end side (left end side in FIG. 1) by communicating with the steam pipe 7 and that opens at the rear end side and communicates with the reservoir unit 13; A cylindrical groove tube 21 accommodated in the evaporator main body 19 and a cylindrical shape inserted into contact with the cylindrical shape of the groove tube 21 and a working fluid 3L are supplied to the cylindrical shape. And a wick 23.

  As shown in FIGS. 2 and 3, the groove tube 21 has an inner circumferential surface alternately arranged in the circumferential direction by the concave portions 25 </ b> A and the convex portions 25 </ b> B in a cross section perpendicular to the longitudinal direction of the groove tube 21. The groove portion 25 is provided with an uneven shape, and the uneven shape is extended in the longitudinal direction of the groove tube 21. On the other hand, the outer peripheral surface of the wick 23 is in contact with the inner peripheral surface of the convex portion 25B of the groove portion 25 of the groove tube 21, and the concave portion 25A of the groove portion 25 serves as a steam flow path 27.

  The cylindrical interior of the wick 23 constitutes a liquid storage chamber 29 that communicates with the above-described reservoir portion 13 and whose front end is closed, and the bayonet tube 15 can be inserted into the liquid storage chamber 29. . The rear end side of the bayonet tube 15 communicates with the liquid return pipe 11 and is inserted into the reservoir 13. The front end side of the bayonet tube 15 is slightly in front of the front end portion of the liquid storage chamber 29 of the wick 23. Has been inserted.

  In the present embodiment, the wick 23 is made of a polymer material in order to reduce the weight, and the polymer material has a fine void (hereinafter simply referred to as “pore”). It has a structure. Further, as the polymer, for example, a sintered product of polyethylene powder having a diameter of 10 to 20 μm is used. In addition, a nickel sintered body made of nickel metal, for example, sintered powder having a diameter of 5 μm, a copper sintered body obtained by sintering copper powder, or a metal sintered body made of other metals is also used. In such a polymer, since each powder has a hydrophilic group, a + α pumping force is added to the wettability and the surface tension. Becomes larger.

  In addition, as a material of the other wick 23, a porous sintered metal body, a metal fiber, a glass fiber, or the like may be used, but a polymer body is desirable for the reason described above.

  Next, a prevention method for preventing the hydraulic fluid 3L from passing through the wick 23 constituting the main part of this embodiment and its structure will be described in detail.

  As one of the methods, as shown in FIG. 1, a wall 31 that can prevent, for example, the passage (stain) of water as the hydraulic fluid 3 </ b> L is provided on the front end surface of the wick 23. The wall 31 is composed of a separate member from the wick 23. Accordingly, it is possible to prevent the flow rate and pressure of the water passing through the front end portion 23 </ b> A of the wick 23 from being separated from the wick 23 by the wall 31.

  For example, the wall 31 is a flat plate member having a thickness of, for example, 2 to 3 mm, and the wall 31, which is a flat plate member, is attached in contact with the front end surface of the wick 23. As a method for attaching the wall 31 which is a flat plate member, for example, the wall 31 which is a flat plate member can be fixed to the front end surface of the wick 23 with an adhesive.

  Alternatively, as shown in FIG. 4, the wall 31, which is a flat plate member, abuts the front end surface of the wick 23, and the wall 31 which is a flat plate member and the front end wall 19 </ b> A of the evaporator body 19 A plurality of rod-shaped pressing shafts 33 can be interposed therebetween to press the wall 31, which is a flat plate member, against the front end surface of the wick 23.

  Alternatively, as shown in FIG. 5, the wall 31 that is a flat plate-like member is brought into contact with the front end surface of the wick 23, and the wall 31 that is a flat plate-like member and the front end wall 19 </ b> A of the evaporator main body 19 are The wall 31 that is a flat plate member can be urged at a plurality of positions between the wick 23 in a direction in which the wall 31 is always pressed against the front end surface of the wick 23.

  Moreover, the wall 31 which is said flat member can be comprised with polymeric materials, such as glass, Teflon (trademark), a plastics, polyethylene, etc. which have low heat conductivity. Thereby, even if the wall 31 which is a flat plate member contacts the inner peripheral surface of the convex portion 25B of the groove portion 25 of the groove tube 21, the wall 31 which is a flat plate member is a low thermal conductivity material. This makes it difficult for the heat of the groove tube 21 to be conducted to the front end portion 23A of the wick 23, so that the front end portion 23A of the wick 23 is less likely to change water into steam, and the force to be evacuated is less likely to be generated. That is, it contributes to weakening the force that water oozes out from the front end 23A of the wick 23, that is, the passing force.

  However, in order to prevent the heat of the groove tube 21 from being further conducted to the front end portion 23A of the wick 23 even if the wall 31 which is a flat member is a polymer material having low thermal conductivity, It is desirable to prevent the wall 31 that is a flat member from contacting the inner peripheral surface of the groove tube 21.

  Moreover, the wall 31 which is the said flat member can also be comprised with the same material as the evaporator main body 19 and the groove pipe | tube 21, for example, metal materials, such as copper. In this case, water can be prevented from oozing out from the front end portion 23A of the wick 23 as compared with the above-described polymer material, but for the reason described above, the heat of the groove tube 21 is not conducted to the front end portion 23A of the wick 23. In order to do so, it is necessary to prevent the wall 31, which is a flat member, from coming into contact with the inner peripheral surface of the convex portion 25 </ b> B of the groove portion 25 of the groove tube 21.

  As another method for preventing the passage of the hydraulic fluid, a wall for preventing the passage of the hydraulic fluid 3L is formed of the same material as that of the wick 23 in the wick 23. And this wall can be set as the structure | tissue structure which obstruct | occluded the pore of the front-end part 23A of the wick 23, for example. For example, by heating the front end portion 23 </ b> A of the wick 23, the polymer powder constituting the wick 23 can be dissolved to close the pores to form walls. Alternatively, the wall may have a tissue structure in which the pores are closed by pouring and filling an adhesive into the pores of the front end portion 23A of the wick 23.

  Therefore, even if the wall formed in the front end portion 23A of the wick 23 has any of the above-described tissue structures, since the pores are blocked, it is possible to prevent water from passing through the front end portion 23A of the wick 23. Further, it is possible to prevent a decrease in the flow rate and pressure of water in the liquid storage chamber 29 of the wick 23.

  With the above configuration, in the LHP 1, when the groove tube 21 of the evaporator 5 is heated by ambient heat, the heat of the groove tube 21 is heated from the contact surface between the wick 23 and the convex portion 25 </ b> B of the groove portion 25 of the groove tube 21. The wick 23 is heated by conduction.

  On the other hand, the water in the liquid storage chamber 29 is improved in wettability and a + α pumping force on the surface tension because each powder of the polymer of the wick 23 has a hydrophilic group as described above. It is evacuated. Since the water inside the wick 23 that has permeated by this evacuation has a reduced pressure, when heated, the water boils at a low boiling point and becomes steam. The ambient temperature is cooled by the latent heat when water becomes steam.

  As described above, the steam is pushed out by the force of the vacuum drawn into the polymer body of the wick 23 and moves in the polymer body of the wick 23, and comes into contact with the groove portion 25 of the groove tube 21 from the surface of the wick 23. It flows to the steam flow path 27 through the surface. Furthermore, the steam in the steam flow path 27 moves to the condenser 9 through the steam pipe 7 as described above, and the steam is returned to the water by radiating heat in the condenser 9.

  Next, the water in the condenser 9 returns to the evaporator 5 again through the liquid return pipe 11. That is, since the bayonet tube 15 communicating with the liquid return pipe 11 is inserted to a position just before the front end of the liquid storage chamber 29 of the wick 23, the water returned from the liquid return pipe 11 It is supplied from the front end to the liquid storage chamber 29 of the wick 23. This water is inverted 180 ° from the front end of the bayonet tube 15, passes between the liquid storage chamber 29 and the bayonet tube 15, fills the liquid storage chamber 29, and is retained in the reservoir unit 13.

  At this time, for example, when the flow rate or pressure of water returning from the liquid return pipe 11 increases at the time of start-up of the LHP 1 or when the amount of input heat suddenly increases, the hydraulic fluid 3L is applied to the front end face of the wick 23 as described above. Since the wall 31 that is a flat plate-like member that prevents the passage of water is provided, the flow rate and pressure of water passing through the front end portion 23A of the wick 23 can be blocked, and the deterioration of the cooling performance can be prevented.

  That is, the water in the liquid storage chamber 29 of the wick 23 repeats the heat exchange action described above again in the wick 23 and the groove tube 21. For the above reasons, the amount of water supplied to the groove tube 21 and the water pressure Therefore, the pressure of water that oozes out to the groove portion 25 of the groove tube 21 is improved, leading to an improvement in cooling performance.

  The wall formed in the wick 23 is the same member as the other wick 23 different from the wall 31 that is the flat plate member, and is similar to the case of the wall 31 that is the flat plate member. There is an effect.

It is a schematic block diagram of the loop heat pipe of embodiment of this invention. It is a schematic perspective view including the principal part cross section of the evaporator in the loop heat pipe of FIG. It is sectional drawing of the arrow III-III line | wire of FIG. It is an expanded sectional view of the prevention structure which prevents passage of hydraulic fluid from the front end part of the wick of other embodiments of this invention. It is an expanded sectional view of the prevention structure which prevents passage of hydraulic fluid from the front end part of the wick of another embodiment of this invention. It is a schematic block diagram of the conventional loop heat pipe.

Explanation of symbols

1 LHP (loop heat pipe)
3L Working fluid 3V Gas 5 Evaporator 7 Vapor tube 9 Condenser 11 Liquid return tube 13 Reservoir unit 15 Bionict tube 17 O-ring (for preventing backflow of hydraulic fluid)
19 Evaporator body 19A Front end wall (Evaporator body 19)
21 Groove tube 23 Wick 23A Front end portion 25 Groove portion 25A Recess portion 25B Protrusion portion 27 Steam flow path 29 Liquid storage chamber 31 Wall 33 Pressing shaft 35 Spring (biasing means)

Claims (7)

An evaporator that cools using the latent heat generated when the hydraulic fluid is vaporized, a condenser that moves through the vapor pipe while the gas vaporized in the evaporator moves and liquefies by radiating the gas, and this condenser A liquefied hydraulic fluid moves through a liquid return pipe and retains the hydraulic fluid to be supplied to the evaporator, and a loop heat pipe comprising:
The evaporator has a cylindrical groove tube whose front end communicates with the steam pipe and whose rear end communicates with the reservoir portion, and is inserted in contact with the inside of the cylindrical shape of the groove tube, and the front end side is closed. A wick of a tissue structure having a cylindrical shape and having fine voids,
On the inner peripheral surface of the group tube, in the cross section perpendicular to the longitudinal direction of the group tube, concave and convex portions are alternately formed in the circumferential direction, and the concave and convex shape is extended in the longitudinal direction of the group tube. The outer peripheral surface of the wick is in contact with the inner peripheral surface of the convex portion of the group portion,
A wall member that prevents the passage of the hydraulic fluid inserted into the cylindrical shape of the wick is provided on the front end surface of the wick in a non-contact manner with the inner peripheral surface of the convex portion of the group portion ,
A loop type heat pipe , wherein a plurality of pressing shafts are interposed between the wall member and the front end wall of the evaporator to press the wall member against the front end surface of the wick . An evaporator that cools using the latent heat generated when the hydraulic fluid is vaporized, a condenser that moves through the vapor pipe while the gas vaporized in the evaporator moves and liquefies by radiating the gas, and this condenser A liquefied hydraulic fluid moves through a liquid return pipe and retains the hydraulic fluid to be supplied to the evaporator, and a loop heat pipe comprising:
The evaporator has a cylindrical groove tube whose front end communicates with the steam pipe and whose rear end communicates with the reservoir portion, and is inserted in contact with the inside of the cylindrical shape of the groove tube, and the front end side is closed. A wick of a tissue structure having a cylindrical shape and having fine voids,
On the inner peripheral surface of the group tube, in the cross section perpendicular to the longitudinal direction of the group tube, concave and convex portions are alternately formed in the circumferential direction, and the concave and convex shape is extended in the longitudinal direction of the group tube. The outer peripheral surface of the wick is in contact with the inner peripheral surface of the convex portion of the group portion,
A wall member that prevents the passage of the hydraulic fluid inserted into the cylindrical shape of the wick is provided on the front end surface of the wick in a non-contact manner with the inner peripheral surface of the convex portion of the group portion,
A loop type heat pipe, wherein the wall member is pressed against the front end surface of the wick by biasing means at a plurality of locations between the wall member and the front end wall of the evaporator. The loop heat pipe according to claim 2, wherein the biasing means is a spring. A bayonet tube that is inserted into the reservoir portion in communication with the liquid return tube and supplies the working fluid returned from the liquid return tube into the evaporator;
The loop heat pipe according to any one of claims 1 to 3, wherein a front end side of the bayonet tube is inserted to a position before a front end surface of the wick. The loop heat pipe according to any one of claims 1 to 4, wherein an O-ring for preventing backflow of hydraulic fluid is mounted between the wick and the reservoir portion. The loop heat pipe according to any one of claims 1 to 5, wherein the wall member is a polymer. The loop heat pipe according to any one of claims 1 to 6 , wherein the wick is a polymer body having a gap.

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