JP2013011363A - Flat heat pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pipe capable of improving maximum heat transport performance by performing protection against the intrusion of a wick in a thin groove formed at the inner peripheral surface of a container to reduce overall heat resistance losses.SOLUTION: In the heat pipe 10, a working fluid which is heated, evaporated, dissipated in heat, and condensed is filled, and a wick 17 which generates a capillary force that returns the working fluid in a liquid phase to a position where the working fluid is evaporated is disposed, and a plurality of thin grooves 15 are formed at the inner peripheral surface in an axial direction. An interposing member 18 for preventing the intrusion of the wick 17 into the thin groove 15 is disposed at the inner peripheral surface. Thus, in the thin groove 15 not clogged by the wick 17, the working fluid is easily returned. As a result, the overall heat resistance losses are reduced, and the maximum heat transfer performance is improved.

Description

  The present invention relates to a heat pipe configured to transport heat by a working fluid enclosed in a container, and in particular, a wick for generating a capillary force for returning the working fluid to an evaporation unit is configured by a thin wire bundle, And it is related with the heat pipe comprised by the flat shape as a whole.

  The basic structure of a heat pipe is a working fluid filled with a fluid that evaporates and condenses in a target temperature range, such as water or alcohol, in a container (container) that has been degassed of non-condensable gas such as air. In addition, a wick for generating a capillary force for refluxing the liquid-phase working fluid is provided inside the container. Therefore, in the heat pipe, the working fluid receives heat from the outside and evaporates, and the vapor flows toward a low pressure portion and then dissipates heat and condenses. As a result, the working fluid transports heat by its latent heat. The condensed working fluid penetrates into the wick. On the other hand, since the capillary force due to the wick is generated at the location where evaporation occurs, the working fluid that has permeated the wick is returned to the location where evaporation occurs due to the capillary force.

  As described above, in the heat pipe, a vapor flow is generated between the evaporation portion where heat is transferred from the outside and the heat dissipation portion where the working fluid radiates heat to the outside, and a liquid flow is generated in the opposite direction. As a result, heat is transported. Therefore, in order to improve the heat transport capability or reduce the thermal resistance, it is preferable to generate the vapor flow and the liquid flow smoothly and sufficiently. As an example, Patent Document 1 describes a heat pipe in which a wick formed by sintering metal powder is provided in a container in which a groove along the axial direction of the inner peripheral surface is formed.

JP 2011-43320 A

  The groove formed on the inner peripheral surface of the container as described in Patent Document 1 enhances the capillary force of the flat heat pipe, facilitates the return of the working fluid, and improves the heat dissipation efficiency. ing. However, a wick obtained by sintering metal powder or a wick in which a large number of fine wires are bundled easily enters a groove along the axial direction of the inner peripheral surface of the container, and is easily fixed in a state of being embedded in the fine groove. For this reason, the groove blocked by the wick hinders the working fluid from recirculating between the evaporation section and the condensation section, and as a result, increases the overall thermal resistance loss, thereby increasing the maximum heat transport capacity. There is a possibility that it will be lowered, and there is room for improvement in this respect.

  This invention has been made paying attention to the above technical problem, and by protecting the narrow groove formed on the inner peripheral surface of the container from the ingress of the wick, the overall thermal resistance loss is reduced, and the maximum It aims at providing the heat pipe which improves heat transport capability.

  In order to achieve the above object, the invention of claim 1 is a wick that encloses a working fluid that is heated to evaporate, dissipates heat and condenses, and generates a capillary force that causes the working fluid in a liquid phase to return to a position to evaporate. In the heat pipe in which a plurality of narrow grooves along the axial direction are formed on the inner peripheral surface, an interposition member for preventing the wick from entering the narrow groove is provided on the inner peripheral surface. It is characterized by that.

  The invention of claim 2 is the heat pipe according to claim 1, wherein the wick is a porous structure obtained by sintering a large number of powder particles.

  The invention of claim 3 is the heat pipe according to claim 1, wherein the wick is configured by bundling a plurality of thin wires.

  According to a fourth aspect of the present invention, there is provided the heat pipe according to any one of the first to third aspects, wherein the interposition member is a spiral body that is continuous in a spiral direction of the inner peripheral surface. .

  The invention of claim 5 is the heat pipe according to any one of claims 1 to 3, wherein the interposition member has a fine mesh shape having a mesh opening width smaller than that of the wick.

  The invention of claim 6 is characterized in that, in any one of the inventions of claims 1 to 5, a fixing member is provided for pressing and fixing the wick to the radially inner surface side. It is a heat pipe.

  The invention of claim 7 is the heat pipe according to the invention of claim 6, wherein the fixing member is a spiral body continuous in the spiral direction of the inner peripheral surface.

  The invention of claim 8 is the heat pipe according to claim 6, wherein the fixing member has a fine mesh shape with a mesh opening width smaller than that of the wick.

  According to this invention, the interposition member for preventing the wick from entering the plurality of narrow grooves formed along the axial direction on the inner peripheral surface of the heat pipe is provided on the inner peripheral surface of the heat pipe. Therefore, the intervening member provided between the wick and the narrow groove protects the narrow groove from entering the wick, so that the wick does not block the gap. Since the flow area of the working fluid is not narrowed, the liquid-phase working fluid is easily refluxed. As a result, the overall thermal resistance loss can be reduced, and the maximum heat transport capability can be improved.

It is sectional drawing which shows an example of the flat type heat pipe which concerns on this invention. It is a perspective view which shows an example of the heat pipe which concerns on this invention. It is a schematic diagram which shows an example of the interposition member which concerns on this invention. It is a perspective view which shows the other example of the heat pipe which concerns on this invention. It is a schematic diagram which shows the example of the interposed member and fixing member which concern on this invention. It is a top view which shows the shape of each heat pipe in the characteristic test about the Example and comparative example of this invention. It is a graph which shows the thermal performance result about the Example of this invention, and a prior art example.

  Next, the heat pipe according to the present invention will be described. In the heat pipe according to the present invention, a working fluid that heats and evaporates, dissipates heat and condenses is enclosed, and a wick that generates a capillary force that returns the liquid-phase working fluid to a position to evaporate is disposed inside the container. ing. The container is basically an airtight hollow container, and a hollow pipe is used for a heat pipe used for transporting heat between locations apart from each other. Since it is necessary to transfer heat between the inside and the outside of the container, the container is preferably made of a material having high thermal conductivity, and for example, a copper tube is preferably used. In addition, this container may have a flat shape in its longitudinal section.

  In addition, the inner peripheral surface of the heat pipe, that is, the inner peripheral surface of the container is a flow path through which the liquid-phase working fluid flows, and a plurality of capillarities are caused to return the liquid-phase working fluid to the evaporation section. The narrow grooves are formed along the axial direction of the inner peripheral surface and at predetermined intervals in the circumferential direction. The cross-sectional shape of the narrow groove may be an appropriate shape such as a semicircle, a quadrangle, a fan shape, a sawtooth shape, or a triangle.

  The working fluid enclosed in the heat pipe is a fluid that heats and evaporates, dissipates heat and condenses, thereby transporting heat in the form of latent heat, and it is appropriate depending on the temperature at which the heat pipe is used. Selected. For example, water, alcohol, methanol, alternative chlorofluorocarbon, and ammonia are used as the working fluid. The evaporated working fluid is called a gas-phase working fluid or working fluid vapor, and the condensed working fluid is called a liquid-phase working fluid or condensate.

  The wick is a porous structure obtained by sintering a large number of powder particles that generate a capillary force when the condensate permeates, and is configured by sintering copper powder, for example. Further, this wick may be configured by bundling a large number of thin wires that generate capillary force when the condensate permeates. The fine wire may be any wire that has excellent wettability with the condensate sealed inside the container, such as a metal wire such as copper or carbon fiber.

  In addition, an interposition member that prevents the wick from entering the narrow groove is provided on the inner peripheral surface of the container such that the outer peripheral surface thereof is in total contact with the inner peripheral surface of the container. That is, an interposition member is provided between the wick and the fine groove to prevent or suppress the granular material or fine wire constituting the wick from entering the fine groove. The shape of the interposition member is a fine mesh shape in which the opening width of the mesh is smaller than the particle size of the granular material or the diameter of the fine wire. In other words, the opening width of the interstitial member that is in the form of a fine mesh is the diameter of the fine line constituting at least the outermost peripheral part of the bundle consisting of a plurality of fine wires, or the particle diameter of the granular material constituting at least the outermost peripheral part of the porous structure In other words, the diameter is set to be approximately equal to or smaller than the diameter of the fine wire or the particle diameter of the granular material. Further, the interposition member may have a shape that continues in a spiral direction along the inner peripheral surface of the container, and the number of windings may be set so that the powder or fine line does not enter the fine groove. The intervening member is, in essence, between the wick and the narrow groove so that the flow area of the condensate in the narrow groove is not reduced by the entrance of the wick, and the flow of the condensate in the narrow groove is smoothed. As long as it is provided.

  Furthermore, the heat pipe which concerns on this invention may be provided with the fixing member which presses and fixes a wick to the inner peripheral surface side of a container. The fixing member has a fine mesh shape in which the opening width of the mesh is smaller than the particle size of the granular material or the diameter of the fine wire. In other words, the opening width of the fixing member that is in the form of a fine mesh is the diameter of the fine wire that constitutes at least the outermost peripheral part of the bundle consisting of a plurality of fine wires, or the particle diameter of the granular material that constitutes at least the outermost peripheral part of the porous structure. In other words, the diameter is set to be approximately equal to or smaller than the diameter of the fine wire or the particle diameter of the granular material. Further, the fixing member may have a shape that presses the granular material or thin wire constituting the wick to the inner peripheral surface side of the container and is continuous in the spiral direction of the inner peripheral surface of the container.

  The wick has a cylindrical shape and is arranged in a state in which an outer peripheral surface thereof is in contact with an inner peripheral surface of the interposed member. A space excluding the wick, the fixing member, the interposition member, and the narrow groove formed in the inner peripheral portion of the container is a steam flow path through which the working fluid steam flows. Further, the wick, the fixing member, the interposition member inside the container, and the narrow groove formed in the inner peripheral portion of the container serve as a liquid flow path through which the condensate flows. In addition, while a wick is cylindrical shape, you may adhere | attach in the state which the outer peripheral surface contacts the inner peripheral surface of an interposition member entirely. Specifically, the wick is heated to a predetermined temperature in a state where the wick is disposed inside the container, thereby causing sintering between the wick and the interposition member and joining them together. In addition, when the fixing member is provided, the wick has its outer peripheral surface entirely in contact with the inner peripheral surface of the interposed member, and its inner peripheral surface is in total contact with the outer peripheral surface of the fixing member. The state is fixed. Specifically, by heating the wick to a predetermined temperature with the wick disposed inside the container, the wick and the interposed member are sintered and joined between the wick and the fixing member. .

  Therefore, in the heat pipe according to the present invention, when heat is applied to a part of the container and the other part is cooled, the working fluid is heated and evaporated, and the steam flows toward a place where the temperature and pressure are low. Then, it dissipates heat and condenses. The steam flow path is a flow path along the wick, and the fixing member presses the wick against the inner peripheral surface of the container, or the wick and the inner peripheral surface of the interposition member, the outer peripheral surface of the interposition member, and the container Since the inner peripheral surface is fixed by sintering, a steam flow path is ensured even if deformation such as bending is applied to the heat pipe, and as a result, the working fluid vapor flows as necessary and sufficiently as a heat pipe. The heat transport characteristics of the are improved.

  On the other hand, the condensed working fluid permeates into the wick and flows toward a portion where evaporation occurs using the gap between the thin wires constituting the wick or the gap of the porous structure as a flow path. That is, when evaporating from the liquid-phase working fluid, the meniscus formed between the wick thin wires or in the gaps in the porous structure is reduced, so that a capillary force is generated, and the capillary force is used as a pumping force for the liquid phase. The working fluid returns to the evaporation unit side. And since a larger capillary force is generated when the gap between the thin wires or the gap between the porous structures is small, so-called reflux characteristics are improved.

  Further, the condensed working fluid flows toward a location where evaporation occurs using a narrow groove formed in the inner peripheral surface of the container as a flow path. That is, when evaporating from the liquid-phase working fluid, the meniscus formed in the narrow groove is reduced, so that a capillary force is generated, and the liquid-phase working fluid is returned to the evaporation portion side using the capillary force as a pumping force. . The intervening member provided between the wick and the narrow groove protects the narrow groove from entering the wick, so that the wick does not block the gap. Since the flow area is not narrowed, the liquid-phase working fluid is easily refluxed. As a result, the overall thermal resistance loss can be reduced, and the maximum heat transport capability can be improved.

  Next, the first embodiment of the present invention will be described separately for the configuration and operation of the first embodiment and the manufacturing procedure thereof. First, the configuration and operation of the first embodiment will be described.

  The heat pipe according to the present invention is a flat heat pipe, which is filled with a working fluid that is heated and evaporated, and that dissipates heat and condenses, and that returns the liquid phase working fluid to a position where it evaporates. A wick formed by a porous structure obtained by sintering a large number of powder particles so as to generate force is disposed inside the container.

  The container 2 of the heat pipe 1 is an airtight hollow container, and is a hollow tube (for example, a copper tube) that transports heat between locations separated from each other. Inside the container 2, a condensable fluid (not shown) such as pure water or alcohol is sealed as a working fluid in a vacuum deaerated state. One end of the heat pipe 1 is an evaporation unit 3, the other end is a condensing unit 4, and an intermediate part thereof is a heat insulating unit 5.

  Further, a rectangular narrow groove 6 is formed on the inner peripheral surface of the inner peripheral surface of the container 2 to form a flow path through which the condensate flows and to cause a capillary phenomenon to recirculate the liquid-phase working fluid toward the evaporation section. It is formed at predetermined intervals along the axial direction and in the circumferential direction.

  A cylindrical porous structure 8 is disposed inside the container 2. The porous structure 8 is a wick configured by sintering a large number of powder particles 7 that generate capillary force when the condensed liquid permeates. The porous structure 8 is configured by sintering copper powder as the granular material 7, for example. In addition, a wick may be comprised by bundling many thin wires which produce capillary force when a condensed liquid osmose | permeates.

  An interposition member 9 that prevents the wick 8 from entering the narrow groove 6 is provided on the inner peripheral surface of the container 2 such that the outer peripheral surface is in contact with the inner peripheral surface of the container 2. That is, as shown in FIG. 3A, the interposition member 9 that prevents or suppresses the granular material 7 constituting the wick 8 from entering the fine groove 6 between the wick 8 and the fine groove 6. Is provided. As shown in FIG. 3B, the interposition member 9 is a copper mesh having a mesh opening width S smaller than the particle size of the granular material 7 and a small thickness. In other words, the opening width S of the copper mesh is equal to or smaller than the particle diameter of the powder body 7 constituting at least the outermost peripheral portion of the porous structure 8, that is, the diameter of the fine wire or the particle diameter of the powder body 7 Is set smaller than. By setting the mesh in this way, a granular material 7 (for example, copper powder) having a diameter smaller than the opening width of the narrow groove 6 is embedded in the narrow groove 6 to thereby fill the working fluid in the narrow groove 6. The flow area is not narrowed. Therefore, the flow of the condensate by the narrow groove 6 is smoothed. The interposition member may be a spiral body. Moreover, the fixing member which presses and fixes a wick to the inner peripheral side of a container may be provided.

  The wick 8 is fixed so that its outer peripheral surface is in contact with the inner peripheral surface of the interposition member 9. Specifically, by heating the wick 8 to a predetermined temperature in a state where the wick 8 is disposed inside the container 2, sintering occurs between the wick 8 and the interposition member 9, and both are joined. A space excluding the wick 8 and the interposition member 9 inside the container 2 and the narrow groove 6 formed in the inner peripheral portion of the container 2 is a steam flow path through which the working fluid steam flows. Further, the wick 8 and the interposition member 9 inside the container 2 and the narrow groove 6 formed in the inner peripheral portion of the container 2 serve as a liquid flow path through which the condensate flows.

  Therefore, in the heat pipe according to the present invention, when heat is applied to a part of the container and the other part is cooled, the working fluid is heated and evaporated, and the steam flows toward a place where the temperature and pressure are low. Then, it dissipates heat and condenses. The steam channel is a channel along the wick 8, and the inner peripheral surface of the wick 8 and the interposed member 9, the outer peripheral surface of the interposed member 9, and the inner peripheral surface of the container 2 are fixed by sintering. Therefore, even if deformation such as bending is applied to the heat pipe 1, the steam flow path is secured, and as a result, the working fluid vapor flows sufficiently and sufficiently, and the heat transport characteristics as the heat pipe are improved.

  On the other hand, the condensed working fluid permeates into the wick 8 and flows toward a location where evaporation occurs using the gap between the porous structures constituting the wick 8 as a flow path. That is, when evaporating from the liquid-phase working fluid, the meniscus formed in the gaps in the porous structure 8 is lowered, so that a capillary force is generated and the liquid-phase working fluid is pumped by the capillary force. Reflux to the side. And since the gap between the porous structures is small, a larger capillary force is generated, and so-called reflux characteristics are improved.

  Furthermore, the condensed working fluid flows toward the location where evaporation occurs using the interposition member 9 and the narrow groove 6 formed in the inner peripheral surface of the container 2 as a flow path. That is, when evaporating from the liquid-phase working fluid, the meniscus formed in the interposition member 9 and the narrow groove 6 is lowered, so that a capillary force is generated, and the liquid-phase working fluid is pumped by the capillary force. Reflux to the evaporation section side. Then, the interposition member 9 provided between the wick 8 and the narrow groove 6 prevents the wick 8 from entering the narrow groove 6 so that the wick 8 does not block the gap. Since the flow area of the condensate in the narrow groove 6 is not narrowed, the liquid-phase working fluid is easily refluxed. As a result, the overall thermal resistance loss can be reduced, and the maximum heat transport capability can be improved.

  Next, the manufacturing procedure of the first embodiment of the present invention will be described. First, a pipe having a predetermined length that forms the container 2 in accordance with product specifications is prepared. The interposition member 9 is disposed inside the pipe and the copper powder 7 is introduced. In that case, first, the interposition member 9 is arranged along the inner peripheral surface of the pipe 2 in order to prevent the copper powder 7 from entering the narrow groove 6 formed on the inner peripheral surface of the pipe 2. Thereafter, a shaft (not shown) or a small-diameter tube (not shown) or a small diameter tube (running on the mandrel along the central axis of the pipe 2 is secured in order to secure the flow path of the vapor generated by the evaporation of the working fluid on the center side of the porous structure 8 A copper powder is poured between the mandrel and the inner peripheral surface of the interposition member 9. After filling the copper powder 7 in this manner, the pipe 2 is put into a sintering furnace and sintered. In other cases, a shaft provided with an interposing member on the outer peripheral surface that runs on the mandrel along the central axis of the pipe or a small-diameter pipe provided with an interposing member on the outer peripheral surface is disposed inside the pipe, and the mandrel and Copper powder may be poured between the inner peripheral surface of the member 9.

  After the sintering process is completed, a predetermined amount of condensate is sealed in the pipe in consideration of the length of the pipe 2, the volume of the wick 8 and the interposition member 9, or the porosity. The condensate can be sealed by a conventionally known method such as a vacuum degassing method or an evaporation driving method. Then, the end of the pipe 2 is closed by welding or the like according to the product length. Further, as described above, since the particle diameter of the copper powder 7 is larger than the opening width S of the mesh, it is possible to easily obtain a configuration in which the porous structure 8 does not fill the narrow groove 6 only by sintering the pipe 2. be able to.

  When the heat pipe 1 thus manufactured is made into a flat heat pipe, it is crushed in the radial direction. For example, when it is set as a linear flat type heat pipe, the manufactured heat pipe 1 is crushed as it is and flattened. On the other hand, in the case of a flat or bent flat heat pipe, the manufactured heat pipe 1 is bent or bent into a predetermined shape, and then flattened by being crushed in the radial direction. Even when the wick 8 is curved or bent in this manner, the wick 8 is sintered and fixed to the inner surface of the interposition member 9, so that it deforms in accordance with the deformation of the container 2 in which the interposition member 9 is sintered. As a result, a vapor channel and a liquid channel along the wick 8 are secured.

  Next, referring to FIG. 1 and FIGS. 4 to 7, the second embodiment of the present invention will be described separately for the configuration and operation of the second embodiment, its manufacturing procedure, and its test. . First, the configuration and operation of the second embodiment will be described.

  The heat pipe according to the present invention is a wick formed by bundling a plurality of thin wires that enclose a working fluid that is heated and evaporated, and that dissipates and condenses, and that generates a capillary force when the condensed liquid permeates. Is placed inside the container.

  As shown in FIG. 4, the container 11 of the heat pipe 10 is an airtight hollow container, and is a hollow tube (for example, a copper tube) that transports heat between locations separated from each other. Inside the container 11, a condensable fluid (not shown) such as pure water or alcohol is sealed as a working liquid in a vacuum deaerated state. One end of the heat pipe 10 is an evaporation unit 12, the other end is a condensing unit 13, and an intermediate part thereof is a heat insulating unit 14. As a typical example of the heat pipe 10 according to the present invention, as shown in FIG.

  In addition, a rectangular narrow groove 15 that forms a flow path through which condensate flows and returns a working fluid in a liquid phase toward the evaporation unit 12 is formed on the inner peripheral surface of the container 11. Are formed at predetermined intervals in the circumferential direction.

  Inside the container 11, as shown in FIG. 4, a wick 17 configured in a cylindrical shape by bundling a large number of copper fine wires 16 is arranged so that a capillary force is generated when the condensate permeates.

  Further, an interposition member 18 that prevents the wick 17 from entering the narrow groove 15 is provided on the inner peripheral surface of the container 11 such that the outer peripheral surface thereof is in contact with the inner peripheral surface of the container 11. That is, as shown in FIG. 5A, an interposition member 18 is provided between the wick 17 and the narrow groove 15 to prevent or suppress the fine wire 16 constituting the wick 17 from entering the narrow groove 15. Yes. The interposition member 18 is a spiral body whose outer peripheral surface is in general contact with the inner peripheral surface of the container 11, and the fine wire 16 constituting the wick 17 passes through the gap in the axial direction of the spiral body and enters the fine groove 15. The number of turns is set so that it does not. In other words, in order to prevent the fine wire 16 from entering the narrow groove side in the radial direction of the container, as shown in FIG. 5 (b) which is a cross section in the axial direction of the container at the broken line portion B in FIG. 5 (a), A gap P of the spiral body 18 is formed shorter than the length of the thin wire 16. By setting the spiral body 18 in this way, the fine wire 16 does not stick into the fine groove 15 and is not filled, and thereby the flow area of the working fluid in the fine groove 15 is not narrowed. Therefore, the flow of the condensate by the narrow groove 15 is smoothed.

  Furthermore, the heat pipe which concerns on this invention is provided with the fixing member which presses and fixes a wick to the inner peripheral surface side of radial direction. As shown in FIG. 4 or FIG. 5, the fixing member 19 presses a large number of fine wires 16 against the inner peripheral surface of the container 11 so that a large number of fine copper wires constituting the wick 17 are adjacent to each other to generate a capillary force. It is a helical body that binds and holds. When the fixing member 19 presses a large number of thin wires 16 against the inner peripheral surface in the radial direction of the container 11, the thin wires 16 are arranged uniformly in the radial direction and the circumferential direction of the inner peripheral surface. That is, the wick 17 constituted by a large number of thin wires 16 has a cylindrical shape by being pressed against the inner peripheral surface of the interposition member 18 against the fixing member 19.

  The cylindrical wick 17 is in a state where the thin wire 16 constituting the outermost peripheral side thereof is in contact with the inner peripheral surface of the interposing member 18, and the thin wire 16 constituting the innermost peripheral surface side is the outer peripheral surface of the fixing member 19. It is arranged in a state where it touches. A space excluding the wick 17, the interposition member 18, the fixing member 19, and the narrow groove 15 formed in the inner peripheral portion of the container 11 is a steam flow path in which the working fluid steam flows. In addition, the wick 17, the interposition member 18, the fixing member 19 inside the container 11, and the narrow groove 15 formed in the inner peripheral portion of the container 11 serve as a liquid flow path through which the condensate flows. The wick is heated between the wick and the interposition member and between the wick and the fixing member by heating to a predetermined temperature in the state of being placed inside the container, and the wick is joined. May be.

  Therefore, in the heat pipe according to the present invention, when heat is applied to a part of the container 11 and the other part is cooled, the working fluid is heated and evaporated, and the steam is directed toward a place where the temperature and pressure are low. It flows and then dissipates heat and condenses. The steam flow path is a flow path along the wick 17, and the fixing member 19 presses the wick 17 against the inner peripheral surface of the container 11. Therefore, even if the heat pipe 10 is deformed such as bending, the steam flow path. As a result, the working fluid vapor flows as necessary and sufficiently, and the heat transport characteristics of the heat pipe 10 are improved.

  On the other hand, the condensed working fluid permeates into the wick 17 and flows toward a portion where evaporation occurs using a gap between the thin wires constituting the wick 17 as a flow path. That is, when evaporating from the liquid-phase working fluid, the meniscus formed between the thin wires of the wick 17 is reduced, and thus a capillary force is generated, and the liquid-phase working fluid is evaporated using the capillary force as a pumping force. Reflux partly. When the fixing member 19 presses a large number of thin wires 16 against the inner peripheral surface in the radial direction of the container 11, the gaps between the fine wires uniformly distributed in the radial direction and the circumferential direction of the inner peripheral surface are uniform and small. In particular, a larger capillary force can be generated and so-called reflux characteristics can be improved.

  Furthermore, the condensed working fluid flows toward the location where evaporation occurs using the interposition member 18, the fixing member 19, and the narrow groove 15 formed on the inner peripheral surface of the container 11 as a flow path. That is, when evaporating from the liquid-phase working fluid, the meniscus formed in the interposing member 18, the fixing member 19, and the narrow groove 15 is lowered, so that a capillary force is generated, and the capillary force is used as a pumping force to generate a liquid phase. The working fluid recirculates to the evaporation unit 12 side. The interposition member 18 provided between the wick 17 and the narrow groove 15 prevents the wick 17 from entering the narrow groove 15 so that the narrow wire 16 of the wick 17 does not block the gap. 15, the flow area of the condensate in the narrow groove 15 is not narrowed, and a liquid flow path is secured even when the heat pipe 10 is deformed, such as bending. It becomes easy to reflux. As a result, the overall thermal resistance loss can be reduced, and the maximum heat transport capability can be improved.

  Next, the manufacturing procedure of the second embodiment of the present invention will be described. First, a pipe having a predetermined length that forms the container 11 according to the product specifications is prepared. An interposition member 18 is disposed inside the pipe 11, a plurality of fine wires 16 are inserted, and a fixing member 19 is disposed. In that case, first, in order to prevent the fine wire 16 from entering the fine groove 15 formed on the inner peripheral surface of the pipe 11, the interposition member 18 is provided on the outer peripheral surface that runs on the mandrel along the central axis of the pipe 11. A shaft (not shown) provided or a small-diameter pipe (not shown) provided with an interposing member 18 on the outer peripheral surface is inserted, and the interposing member 18 is disposed along the inner peripheral surface of the pipe 11. After disposing the interposing member 18 and extracting the shaft or the small diameter tube, the ends of the plurality of thin wires 16 are bonded in the circumferential direction of a ring (not shown) having an outer diameter smaller than the inner diameter of the pipe 11, The ring is inserted from one end side of the pipe 11 provided with the interposing member 18 on the inner peripheral surface, and the ring is extracted from the other end side of the pipe 11. After extracting the ring, the shaft provided with the fixing member 19 on the outer peripheral surface running on the mandrel along the central axis of the pipe 11 or the small-diameter pipe provided with the fixing member 19 on the outer peripheral surface is inserted, and the radial direction of the pipe 11 A fixing member 19 that presses and fixes the wick 17 to the inner peripheral surface side is disposed. After the fixing member 19 is arranged and the shaft or the small-diameter pipe is extracted, the ends of the plurality of fine wires 16 attached to the small ring are separated from the ring. In addition, after arrange | positioning a fixing member or separating the edge part of a thin wire | line from a ring, a pipe | tube may be thrown into a sintering furnace and you may sinter.

  After the fixing member 19 is arranged or after the end of the thin wire 16 is separated from the ring or after the sintering process is completed, the length of the pipe 11, the volume of the wick 17 and the interposition member 18, the porosity, etc. are taken into consideration. Then, a predetermined amount of condensate is sealed in the pipe. The condensate can be sealed by a conventionally known method such as a vacuum degassing method or an evaporation driving method. Then, the end of the pipe is closed by welding or the like according to the product length. Further, as described above, since the interposition member 18 prevents the wick 17 from entering the narrow groove 15, it is possible to easily obtain a configuration in which the thin wire 16 constituting the wick 17 does not fill the narrow groove 15.

  When the heat pipe 10 thus manufactured is made into a flat heat pipe as shown in FIG. 1, it is crushed in the radial direction. For example, when it is set as a linear flat heat pipe, the manufactured heat pipe 10 is crushed as it is and flattened. On the other hand, in the case of a flat or bent flat heat pipe, the manufactured heat pipe 10 is bent or bent into a predetermined shape, and then flattened by being crushed in the radial direction. Even when the wick 17 is bent or bent in this manner, the wick 17 is pressed and fixed to the inner surface of the interposition member 18 by the fixing member 19, so that it deforms in accordance with the deformation of the container 11, and as a result, the wick A steam flow path and a liquid flow path along 17 are secured. Or, when being sintered, the wick 17 is sintered and fixed to the inner surface of the interposition member 18, so that the wick 17 is deformed in accordance with the deformation of the container 11 in which the interposition member 18 is sintered. As a result, a steam flow path and a liquid flow path along the wick 17 are secured.

  Next, a performance test comparing the second embodiment and the comparative example in the present invention will be described. In this performance test, a thermal performance test related to “thermal resistance”, that is, “thermal performance” was performed.

  The heat pipe of the second embodiment is a flat heat pipe and has the same configuration as described above. Next, the heat pipe to be compared is the same as the configuration of the second embodiment except that the interposition member is not provided on the inner peripheral surface of the container. As shown in FIG. 6, both flat heat pipes have a total length of 250 mm, the thickness when flattened is 3.5 mm, and the length in the width direction when flattened is 7.7 mm. Furthermore, two places that are bent at 135 degrees are provided. The working fluid was water.

Further, as shown in FIG. 6A, one end of the heat pipe to be tested is brought into contact with the surface (15 mm × 15 mm) of the electric heater 20, and the other end of the heat pipe is connected to the upper surface of the heat radiating plate 21. (40 mm × 40 mm) was placed in contact. In addition, a heat insulating portion was provided between the electric heater 20 and the heat radiating plate 21. As shown in FIG. 6 (b), the electric heater 20 is energized to heat the evaporation part of the heat pipe, the amount of heat input Q (W), the surface temperature Th (° C.) of the electric heater 20, and the heat insulation. Temperature Ta (° C.), the temperature Te (° C.) of one end of the heat pipe disposed in the electric heater 20, and the temperature Tc (° C.) of the other end of the heat pipe disposed on the heat sink 21 And measured. From these measurement data, the thermal resistance R (° C / W) of each heat pipe is
R = (Te−Tc) / Q (1)
Can be expressed as Further, the maximum heat input amount Qmax (W) in a range where no so-called dry out of each heat pipe occurs was obtained. In FIG. 7, the test result of the heat pipe of 2nd Example and a comparison object is shown. Moreover, the number of the heat pipes which tested was 5 each, and the average value is shown as a test result.

  From the test result of FIG. 7, it can evaluate as follows. The maximum heat input Qmax is 40 W in the heat pipe of the second embodiment, whereas the maximum heat input Qmax is 36 W in the heat pipe to be compared, so the maximum heat input Qmax is higher in the second embodiment. . Further, in the heat pipe of the second embodiment, the thermal resistance R is about 0.1 ° C./W, whereas in the heat pipe for comparison, the thermal resistance R is about 0.2 ° C./W, The thermal resistance R is lower in the second embodiment. This is presumed that when the working fluid flows from the condensing part to the evaporating part, it recirculates through the narrow groove where the gap is not blocked by the wick, so that the flow resistance is lower than that of the comparative example. From these results, it can be seen that it is desirable to provide an interposition member for preventing the wick from entering the narrow groove on the inner peripheral surface of the heat pipe.

  In addition, the heat pipe according to the present invention is not limited to the above specific example. In short, in order to smooth the flow of the condensate through the narrow groove, the flow area of the condensate in the narrow groove is narrowed by the entrance of the wick. It is sufficient that an interposition member is provided between the wick and the narrow groove so as not to do so. Therefore, the shape of the wick need not be a cylindrical shape.

  DESCRIPTION OF SYMBOLS 1,10 ... Heat pipe, 2,11 ... Container, 6,15 ... Fine groove, 8, 17 ... Wick, 9, 18 ... Interposition member, 19 ... Fixing member.

Claims (8)

A working fluid that heats, evaporates, dissipates and condenses is enclosed, and a wick is provided that generates a capillary force that recirculates the liquid-phase working fluid to a position where it evaporates. In heat pipes with grooves,
The heat pipe, wherein an interposition member for preventing the wick from entering the narrow groove is provided on the inner peripheral surface.   The heat pipe according to claim 1, wherein the wick is a porous structure obtained by sintering a large number of powder particles.   The heat pipe according to claim 1, wherein the wick is configured by bundling a plurality of thin wires.   The heat pipe according to any one of claims 1 to 3, wherein the interposition member is a spiral body that is continuous in a spiral direction of the inner peripheral surface.   The heat pipe according to any one of claims 1 to 3, wherein the interposition member has a fine mesh shape with a mesh opening width smaller than that of the wick.   The heat pipe according to claim 1, further comprising a fixing member that presses and fixes the wick to the inner peripheral surface side in the radial direction.   The heat pipe according to claim 6, wherein the fixing member is a spiral body that is continuous in a spiral direction of the inner peripheral surface.   The heat pipe according to claim 6, wherein the fixing member has a fine mesh shape with a mesh opening width smaller than that of the wick.

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