JP2015048979A - Loop heat pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit flowing of air bubbles into a duct side of small diameter, and to maintain the flowing of a liquid phase refrigerant in the conduit by dividing the air bubbles.SOLUTION: A loop heat pipe includes a first flow passage (4), a second flow passage (8) and projection pieces (12). The first flow passage is formed on an upstream side of a circulation path on a liquid pipe (2) side, and flows a liquid phase refrigerant (10) inside. The second flow passage is communicated with an opening (6) having diameter smaller than that of the first flow passage, and takes in the refrigerant flowed in from the first flow passage. The plurality of projection pieces are arranged around the opening so that one part of them face with each other via the opening, and tip parts (14) project toward the first flow passage side to lock air bubbles flowing in the first flow passage, or to divide a part of the air bubbles. The projection pieces are extended and formed, with a projection amount being decreased toward a diameter direction from a center (central axis O) side of the opening, and they are formed in a taper-shape with respect to the tip part of the first flowing passage from the opening side.

Description

The technique of the present disclosure relates to a technique for preventing the blockage of a flow path by a large bubble with respect to a liquid phase flow path of a loop heat pipe.

  The loop heat pipe is filled with a liquid refrigerant such as water, and the refrigerant flows to the evaporation side close to the heating element to be cooled and vaporizes. The heat of vaporization (latent heat) of the refrigerant cools the heating element. I do. The heat pipe is used as a means for cooling a component that is heated to a high temperature, such as a processor mounted in an information processing apparatus. Such information processing apparatuses are becoming smaller and thinner, and accordingly, it is required to reduce the size and height of the components mounted inside, and the diameter of the pipe through which the refrigerant flows is also reduced. It is illustrated.

  For example, the heat pipe repeatedly evaporates and condenses with respect to the refrigerant in the pipe line, so that the gas phase and the liquid phase refrigerant are mixed, the temperature of the heating element, or a sudden temperature change, etc. Bubbles are likely to be generated inside. Bubbles generated in the liquid pipe may block the flow path in the pipe, for example, and hinder circulation of the liquid phase refrigerant.

  A large number of protrusions that generate capillary force are projected in a row toward the gas flow path side with respect to the bubbles in such a duct, and bubbles are retained in the protrusions by forming the protrusions into a prismatic shape. Even so, what secures the flow path of the refrigerant is known (for example, Patent Document 1). Moreover, what makes the bubble produced | generated in the pipe line contact between the flow-path control valves installed in the pipe line is known (for example, patent document 2). One having a tapered slope on the entrance side of the evaporator is known (for example, Patent Document 3). There is known one in which a partition plate having an inclined surface is formed in a liquid pipe (for example, Patent Document 4).

JP 2004-028508 A JP 2003-269876 A JP 2007-315740 A JP-A-4-203893

  By the way, a loop heat pipe is known that sucks up a liquid-phase refrigerant by using a capillary force acting on the inside of a fine tube or the like formed in the pipe as power for circulating the refrigerant inside the pipe, for example. It has been. By using such capillary force, it is possible to prevent the addition of components such as a pump using electric power. In order to generate a capillary force on the liquid surface of the liquid phase refrigerant, it is necessary to always supply the liquid phase refrigerant toward the pipe line side. In other words, the liquid refrigerant needs to be filled in the pipe line in order to cause the refrigerant to flow using the capillary force. Therefore, in the loop heat pipe, when a large bubble is generated inside the pipe line or grows and the liquid refrigerant in the pipe line is interrupted, there is a possibility that the refrigerant circulation is hindered.

  In particular, since the diameter of the inlet of the fine pipe that generates the capillary force suddenly decreases from the flow path of the liquid-phase refrigerant, for example, bubbles that have flowed through the liquid pipe may be easily clogged at the inlet. is there. Some of such micro ducts are provided with, for example, a plurality of protrusions that are brought into contact with flowing bubbles and prevent the bubbles from flowing on the front surface on the entrance side. However, for example, in the case of a simple rod-shaped projection, if a large bubble is caught or if the bubble develops over time, the bubble will surround the projection due to the projection entering the bubble. May end up. Thus, with a simple rod-shaped protrusion, it is impossible to prevent the bubble from becoming large, and it will be caught inside the bubble. Then, for example, a part of the enlarged bubbles comes into contact with the opening side of the fine tube.

  When the circulation of the liquid phase refrigerant in the pipe line is hindered by the bubbles in this way, the refrigerant does not flow to the evaporation unit side, the refrigerant is not supplied into the evaporation unit, the inside of the evaporation unit falls into a so-called dry-out state, and the heating element There is a possibility that it becomes impossible to cool.

Therefore, the purpose of the technology of the present disclosure is to prevent the flow of bubbles to the side of the pipe having a small diameter with respect to the bubbles generated in the liquid pipe, and to break the bubbles, thereby causing the flow of the liquid-phase refrigerant in the pipe Is to maintain.

In order to achieve the above object, one aspect of the configuration of the present disclosure is a loop heat pipe that cools a heating element using heat of vaporization of a refrigerant circulated therein, the first flow path, 2 flow paths and a protruding piece. The first flow path is formed on the upstream side of the circulation path on the liquid pipe side, and allows a liquid-phase refrigerant to flow inside. The second flow path is communicated with an opening having a diameter smaller than that of the first flow path, and takes in the refrigerant that has flowed in from the first flow path. A plurality of protruding pieces are arranged around the opening so as to face each other through the opening, and a tip portion protrudes toward the first flow path side to pass the first flow path. The flowing bubbles are locked or a part of the bubbles is broken. The protruding piece is formed to extend from the center side of the opening in the radial direction while reducing the protruding amount, and is tapered from the opening side to the tip portion on the first flow path side. Formed.

  According to the configuration of the present disclosure, any of the following effects can be obtained.

  (1) By inserting the tip of the protruding piece into the bubble and contacting the bubble surface, the entire bubble is deformed and divided into a predetermined size to prevent the inside of the small-diameter pipe from being blocked by the bubble.

  (2) By changing the thickness and the protruding amount of the protruding piece along the opening, the function of dividing the bubbles is enhanced, and it is possible to prevent the bubbles from growing while being locked to the protruding pieces.

Other objects, features, and advantages of the present invention will become clearer with reference to the accompanying drawings and each embodiment.

It is a figure which shows the structural example inside the liquid pipe | tube of the loop heat pipe which concerns on 1st Embodiment. It is a figure which shows an example of the latching and division | segmentation state of the bubble by a protrusion piece. It is a figure which shows the structural example of the loop heat pipe which concerns on 2nd Embodiment. It is a figure which shows the structural example of an evaporation part. It is a figure which shows an example of the shape and arrangement | positioning state of a protrusion piece. It is a figure which shows an example of the latching state of the bubble by a protrusion piece. It is a figure which shows an example of arrangement | positioning and surface property of a protrusion piece. It is a figure which shows an example of the state by which the bubble was latched by the protrusion piece. It is a figure which shows an example of the division state of the bubble in a P1-P1 line cross section. It is a figure which shows the division | segmentation state of a bubble seeing from the liquid part side. It is a figure which shows the structural example at the time of making the several protrusion piece connect. It is a figure which shows an example of the protrusion piece of the loop heat pipe which concerns on 3rd Embodiment. It is a figure which shows the example of arrangement | positioning structure of a protrusion piece. It is a figure which shows the example of a state by which a bubble flows into the opening part side according to the flow of a refrigerant | coolant. It is a figure which shows the example of a state by which the bubble was latched by the protrusion piece. It is a figure which shows an example of the division state of the bubble in the Q3-Q3 line cross section. It is a figure which shows an example of the division state of a bubble. It is a figure which shows the comparative example of a protrusion piece. It is a figure which shows an example of the evaporation part which concerns on other embodiment.

  [First Embodiment]

  FIG. 1 shows a configuration example inside the liquid pipe of the loop heat pipe according to the first embodiment, and FIG. 2 shows an example of a state where the bubbles are locked and divided by the protruding pieces. The configurations shown in FIGS. 1 and 2 are examples, and the present invention is not limited to such configurations.

  A liquid pipe 2 shown in FIG. 1 is an example of a functional component that forms a loop heat pipe of the present disclosure, and is a pipe line that allows a liquid-phase refrigerant 10 to flow while transferring heat from a cooling target. The loop heat pipe absorbs and evaporates heat from the object to be cooled with the liquid-phase refrigerant 10 flowing in the liquid pipe 2, condenses the refrigerant evaporated at a position away from the object to be cooled, changes it to the liquid phase, and circulates it. . Thereby, the loop heat pipe is cooled by taking heat from the heating element to be cooled using the heat of vaporization of the refrigerant 10. The liquid pipe 2 includes, for example, a first flow path 4 formed to have a large diameter, a second flow path 8 communicating with the first flow path 4 through an opening 6 having a small diameter, and the opening A plurality of protruding pieces 12 are provided around the portion 6.

  For example, in the loop heat pipe, the liquid pipe 2 forms a circulation path through which the liquid-phase refrigerant 10 flows between a condensing part (not shown) and an evaporation part arranged in the vicinity of the object to be cooled. In the circulation path formed in the liquid pipe 2, the condensation part side where the refrigerant 10 is liquefied by condensation is upstream, and the evaporation part side where the refrigerant 10 is vaporized by heat absorption is downstream. The liquid pipe 2 is formed in a part of a circulation path through which the liquid-phase refrigerant 10 flows, and may be formed, for example, on the upstream side of the evaporation unit.

  The first flow path 4 is formed on the upstream side of the liquid pipe 2 and is filled with the refrigerant 10 inside. The first flow path 4 flows inside or stores the stored refrigerant 10 toward the second flow path 8. In addition, the 1st flow path 4 is not restricted to the pipe line which flows the refrigerant | coolant 10 from the condensation part directly to the opening part 6, The storage means which accumulates the refrigerant | coolant 10 in the middle of a circulation path may be sufficient.

  The second flow path 8 is formed so that at least the opening 6 side is smaller in diameter than the first flow path 4, and the refrigerant 10 is taken in through the opening 6. The second flow path 8 is formed by a conduit that supplies the refrigerant 10 toward the evaporation unit, for example.

  The protruding piece 12 is an example of the protruding piece of the present disclosure. The protruding piece 12 locks the bubbles in the first flow path 4 or divides a part of the bubbles so that the opening 6 is blocked by the bubbles. To prevent. A large number of bubbles are mixed in the first flow path 4 together with the refrigerant 10, and flows through the circulation path along the flow of the refrigerant 10. For example, the bubbles are generated by the change of the refrigerant 10 to the liquid phase in a condensing unit (not shown), and the air dissolved in the refrigerant 10 is eluted by the temperature of the refrigerant 10 or the temperature of the liquid pipe 2. The small diameter bubble passes through the opening 6 and flows into the second flow path 8. However, bubbles larger in diameter than the opening 6 cannot pass through the opening 6 due to, for example, the surface tension of the refrigerant 10 in the second flow path 8 and stay in the first flow path 4. The protruding piece 12 stays in, for example, the first flow path 4 and further separates the bubbles that have grown by taking in other bubbles.

  The first conduit 4, the second conduit 8, the opening 6 and the protruding piece 12 may be formed of the same member, or each component formed of a separate member may be installed and integrated. Also good.

  For example, as shown in FIG. 2, a plurality of the projecting pieces 12 are arranged along the periphery of the opening 6. Each protrusion piece 12 is disposed so that one surface thereof is opposed to the front surface side of the second flow path 8 according to the opening diameter of the opening 6, for example. The opposing surfaces of the protruding pieces 12 are formed, for example, in parallel with the central axis O (FIG. 1) of the opening 6. As a result, a flow space surrounded by the plurality of protruding pieces 12 is formed in the first flow path 4 on the front surface side of the opening 6, and the refrigerant 10 from the first flow path 4 toward the opening 6 is formed. Flow is not hindered.

  <About the shape of the protruding piece 12>

  The protruding piece 12 is formed integrally with the case forming the liquid pipe 2 on the peripheral side of the opening 6 or is installed on the inner wall of the case, and the liquid pipe 2 with respect to the inside of the first flow path 4. The front end portion 14 projects in the upstream direction. Each of the protruding pieces 12 is formed by extending in the radial direction with respect to the central axis O. The tip end portion 14 of the protruding piece 12 is formed so that the protruding amount of the portion close to the central axis O is set to the maximum, and the protruding amount decreases as the distance from the central axis O in the radial direction increases.

  Further, the protruding piece 12 has a so-called taper shape in which the thickness of the surface toward the central axis O side is reduced by a predetermined ratio from the bottom surface formed on the opening 6 side toward the distal end portion 14, for example. And the front-end | tip part 14 is formed in the acute angle shape with respect to the flow surface of the refrigerant | coolant 10. FIG. As a result, the protruding piece 12 engages and inserts a bubble having a diameter larger than that of the opening 6, and the contact surface with the bubble becomes inclined, thereby increasing the deformation amount of the contacting bubble surface.

  For example, when the diameter of the bubble main body 16 flowing into the first flow path 4 is larger than that of the second flow path 8, the bubble main body 16 comes into contact with the front end portion 14 of each protruding piece 12 on the front side of the opening 6. At this time, the bubble main body 16 is pressed and deformed by the flow of the refrigerant 10 along the side surface portion from the distal end portion 14 of the protruding piece 12. Further, when the bubble main body 16 is greatly deformed, for example, a fracture surface 18 is generated at a part of the contact portion with the tip end portion 14 of the projection piece 12, and a part thereof is divided to form a bubble split body 20. When the bubble main body 16 and the bubble splitting body 20 have a diameter smaller than that of the opening 6, for example, even when the diameter is larger than that of the opening 6, the opening 6 It is divided into the size which does not block.

  According to such a configuration, the distal end portion 14 of the projecting piece 12 is inserted into the inside of the bubble and contacted with the surface of the bubble, whereby the bubble main body 16 is deformed and divided into a predetermined size, so that the inside of the second flow path 8 is the bubble. To block it. By changing the thickness and the protruding amount of the protruding piece 12 along the opening 6, the function of dividing the bubbles is enhanced, and the bubbles can be prevented from growing in a state of being locked to the protruding pieces 12.

  [Second Embodiment]

  FIG. 3 is a diagram illustrating a configuration example of a loop heat pipe according to the second embodiment. The configuration shown in FIG. 3 is an example, and the present invention is not limited to such a configuration.

  A loop heat pipe 30 illustrated in FIG. 3 is an example of the loop heat pipe of the present disclosure, and the liquid phase refrigerant 10 that has flowed to the cooling target side absorbs heat to vaporize and change the phase to a gas phase refrigerant 40. Then, the refrigerant 40 is condensed at a position away from the object to be cooled, and the phase is changed to the liquid phase refrigerant 10. The loop heat pipe 30 uses the latent heat associated with the phase change of the refrigerants 10 and 40 to perform heat transfer of the heat h generated by the heating element 34 and cools it. The loop heat pipe 30 includes, for example, an evaporator 32, a condenser 42, a liquid pipe 36, and a steam pipe 38.

  <Configuration Example of Evaporating Unit 32>

  The evaporating unit 32 is an example of a heat absorbing means that is installed in the vicinity of the heat generating element 34 and causes the refrigerant 10 that causes the heat h generated by the heat generating element 34 to flow therein to absorb heat. For example, a liquid pipe 36 to which the refrigerant 10 is supplied is connected to one end side of the evaporation unit 32, and a vapor pipe 38 that discharges the refrigerant 40 that has been vaporized by heat absorption is connected to the other end side. For example, a liquid portion 44 formed at a connection portion with the liquid pipe 36 and a connection portion with the heat absorption pipe 48 and the steam pipe 38 having a diameter smaller than the liquid portion 44 are connected to the evaporation portion 32. The vapor | steam part 52 (FIG. 4) etc. which are formed in are included.

  The liquid part 44 is an example of a means for retaining the liquid-phase refrigerant 10 on the evaporation part 32 side, and is upstream of the flow direction of the refrigerant 10 in the evaporation part 32, and is the first flow path of the present disclosure. It is an example. The liquid part 44 may be formed with an inner diameter equivalent to that of the liquid pipe 36, for example.

  The endothermic pipe 48 is formed with an opening 46 having a diameter smaller than that of the liquid part 44, and the refrigerant is supplied from the liquid part 44 through the opening 46. The heat absorption pipe 48 is an example of a means for transferring the heat h taken in by the evaporating unit 32 to the refrigerant 10 that accumulates or flows inside. Further, the endothermic pipe 48 is formed to have a diameter smaller than at least the liquid pipe 36 and the liquid portion 44 through which the liquid-phase refrigerant 10 flows, and generates a capillary force with respect to the refrigerant 10 inside the pipe. It is an example of the flow means which flows the refrigerant | coolant 10 from the side. The endothermic pipe line 48 may be formed, for example, to be equal to the inner diameter of the opening 46, and the liquid level of the refrigerant 10 is formed on the communication side with the vapor part 52 side.

  When the refrigerant 10 is vaporized and the liquid level is retracted in the direction of the liquid pipe 36 in the endothermic pipe 48, a capillary force acts on the endothermic pipe 48 so that the liquid level is pulled back to the communicating part with the vapor part 52. By taking in the refrigerant 10 from the 44 side, the refrigerant 10 is circulated in the loop heat pipe 30.

  Inside the liquid part 44, a plurality of protruding pieces 50 are erected around the opening 46 toward the upstream side in the flow direction of the refrigerant 10. The protruding piece 50 is an example of a unit that locks or divides the bubbles contained in the refrigerant 10 into a predetermined size, and may be formed integrally with a case member that forms the heat absorption pipe 48.

  For example, as shown in FIG. 4, the evaporation section 32 has a plurality of heat absorption pipes 48 formed in the flow direction of the refrigerant 10, and protrusions 50 are respectively provided in the openings 46 of the heat absorption pipes 48. Yes. The heat absorption pipe 48 is an example of the second flow path of the present disclosure, and the number of installed pipes, the pipe diameter, and the like are set based on the flow amount of the refrigerant 10 set in the loop heat pipe 30 and the cooling function, for example. That is, the evaporator 32 increases the amount of heat absorption by increasing the flow amount of the refrigerant 10 by increasing the number of the heat absorption pipes 48, and the cooling function is enhanced. For example, the heat absorption pipes 48 are formed in parallel to the upper surface side of the heating element 34, so that the heat absorption pipes 48 can absorb heat substantially uniformly.

  The vapor section 52 joins the gas-phase refrigerant 40 discharged from the heat absorption pipes 48 to flow toward the vapor pipe 38 side.

  <About the structure of the condensation part 42>

  The condensing unit 42 is an example of a unit that is formed apart from the evaporation unit 32, takes in the gas-phase refrigerant 40 through the vapor pipe 38, and condenses the refrigerant 40. The condensing unit 42 may be provided with heat radiating means such as a heat radiating fin or a fan (not shown). Inside the condensing part 42, the refrigerant 10 that has been condensed by heat dissipation and changed to a liquid phase flows, and a liquid level of the refrigerant 10 is formed.

  The refrigerant 10 condensed in the condensing unit 42 flows to the evaporation unit 32 side through the liquid pipe 36. As a result, the loop heat pipe 30 circulates the liquid-phase refrigerant 10 and the gas-phase refrigerant 40 in different flow paths of the liquid pipe 36 and the vapor pipe 38 between the evaporator 32 and the condenser 42.

  <Regarding the configuration example of the protruding piece 50>

  FIG. 5 shows an example of the shape and arrangement state of the protruding pieces. The configuration shown in FIG. 5 is an example.

  As shown in FIG. 5A, the protruding piece 50 is installed along the periphery of the opening 46 in the liquid portion 44 or is formed integrally with the case, and on the upstream side with respect to the flow direction of the refrigerant 10. An acute-angled tip portion 54 is projected toward the end. The tip 54 of the protruding piece 50 is inclined with respect to the radial direction of the opening 46 so that the protruding amount near the central axis O is large and the protruding amount decreases as the distance from the central axis O increases. Further, the thickness of the protruding piece 50 in the protruding direction is formed in a tapered shape so that the tip end portion 54 protrudes at an acute angle, and the two side wall portions 56 may be inclined at an equivalent angle. In other words, the cross section in the protruding direction of the protruding piece 50 may be formed in an isosceles triangular shape by the two side wall portions 56.

  The thickness d1 on the bottom side of the protruding piece 50 may be formed, for example, in the radial direction from the opening 46 side, or may be formed in a so-called triangular prism shape. Further, the protruding piece 50 may be formed so as to decrease the thickness d1 of the bottom as the distance from the opening 46 increases.

  The protruding piece 50 is formed to be opposed linearly in the radial direction via the central axis O of the opening 46. A plurality of protruding pieces 50 are arranged on the periphery of the opening 46 at an equal angle or close to it.

  The protruding piece 50 is formed so that at least the surface property of the side wall portion 56 is high in wettability of the refrigerant 10, that is, hydrophilic. For example, the protrusion piece 50 may be entirely formed of a highly hydrophilic material, or may be subjected to a hydrophilic treatment such as glass coating on the surface of the side wall portion 56. In addition, the material for improving wettability with the refrigerant | coolant 10 made to flow into the loop heat pipe 30 is set for a hydrophilic material and a hydrophilic process.

  For example, as shown in FIG. 5B, the protruding piece 50 has a maximum protruding amount H at least in the vicinity of the opening 46 set to be larger than the opening diameter φA of the opening 46, and the inner diameter of the liquid part 44. Or, it is set to be larger than half of the vertical or horizontal width L2. That is, when the protruding piece 50 comes into contact with the surface of a bubble having a size that cannot pass through the opening 46 and is inserted into the inside, the tip 54 reaches the center side of the bubble and greatly deforms the bubble. Formed as follows. The width L2 of the liquid part 44 is an example of the size of a path through which bubbles flow. For example, when there is one heat absorption pipe 48, the inner diameter is set, and a plurality of heat absorption pipes 48 are installed in parallel. In this case, the smaller one of the upper and lower sides or the left and right sides of the liquid part 44 is set.

The sum of the lengths of the two protruding pieces 50 installed in a straight line through the opening 46 is set to be at least half of the width L2 of the liquid part 44. That is, the length of the protruding piece is set under the following conditions.
(Width L2 of liquid portion 44) ≦ 2 × [(Installation width L1 of two protruding pieces 50) − (Opening diameter φA)]
... (Formula 1)
By this formula 1, the protruding piece 50 can be contacted and deformed with a length of more than half with respect to the direction of the width L2 of the bubbles flowing to the liquid portion 44, and exhibits the function of locking and dividing the bubbles. To do.

  <Locking of bubbles by the protruding piece 50>

  Bubbles 60 having a diameter larger than that of the opening 46 shown in FIG. 6A flow toward the opening 46 as the refrigerant 10 in the liquid part 44 flows. Since the refrigerant 10 in the liquid part 44 flows so as to be concentrated in the opening 46 having a diameter smaller than that of the liquid part 44, the bubbles 60 are, for example, from a direction close to a straight line with respect to the front side of the opening 46. Led. Accordingly, a part of the bubble 60 is disposed at a position close to the central axis O of the opening 46, so that the position with the highest protrusion amount of some or all of the protruding pieces 50 comes into contact with the bubble 60. Then, for example, as shown in FIG. 6B, when the bubble 60 comes into contact with the protruding piece 50, the bubble 60 flows to the opening 46 side along with the flow of the refrigerant 10 to the opening 46 side, and is crimped to the protruding piece 50. Then, the protrusion piece 50 is inserted into the bubble 60 and is locked. At this time, the bubble 60 is in a deformed state in which the contact portion with the protrusion piece 50 and the periphery thereof are largely inward along the tip portion 54 and the side wall portion 56 of the protrusion piece 50.

  As shown in A of FIG. 7, the contact portion of the bubble 60 is pressed at a predetermined angle α by the plurality of projecting pieces 50 to be in a deformed state. Further, the refrigerant 10 flows toward the opening 46 in the aggregation direction, whereby the bubbles 60 are pressed in the reduction direction. Further, the side wall portion 56 of the protruding piece 50 is in a hydrophilic state as shown in FIG. 7B, for example, and the refrigerant 10 easily flows along the surface side of the side wall portion 56. Thereby, the refrigerant 10 flows into the deformed portion of the bubble 60 along the side wall 56 because the side wall 56 is in a state of being easily wetted.

  FIG. 8 shows an example of a state in which bubbles are locked to the protruding pieces. The shape of the bubble and the state of the force acting on the bubble shown in FIG. 8 are examples.

  As shown in FIG. 8A, a part of the surface of the bubble 60 is brought into a pressure-bonded state with the protruding piece 50, and deforms along the shape of the protruding piece 50. The tip 54 of the protruding piece 50 presses a part of the surface of the bubble 60 toward the inside of the bubble 60 so as to be in a depressed state. At this time, the refrigerant 10 flows along the surface side of the side wall portion 56 of the protruding piece 50, and the refrigerant 10 also enters a minute portion between the protruding piece 50 and the deformed portion of the surface of the bubble 60.

  The bubble 60 is distorted because a part of the outer shape is pressed by the flow toward the protruding piece 50 side. At this time, a part of the surface of the bubble 60 receives the pressing force F <b> 1 on the inner side of the bubble 60, for example, by being brought into contact with the protruding piece 50 and being depressed. In addition, the surface of the bubble 60 is deformed so that the surface of the bubble 60 becomes spherical due to, for example, surface tension F <b> 2 acting on the boundary portion with the surrounding refrigerant 10 at a portion away from the protrusion 50.

  On the opening 46 side, for example, as shown in FIG. 8B, the bubble 60 is deformed along the distal end portion 54 of the protruding piece 50 in the radial direction. The protruding piece 50 can greatly distort the shape of the bubble 60 by, for example, bending the entire bubble 60 by changing the protruding amount in the radial direction from the opening 46 side. Further, the protruding piece 50 makes the side wall 56 hydrophilic, for example, so that the surface tension F3 due to the refrigerant 10 acts on the front side of the opening 46 and makes it difficult for the bubbles 60 to enter. As a result, as shown in FIG. 8C, the protruding piece 50 prevents the opening 46 from being blocked by the locking of the bubble 60 and secures the flow path of the refrigerant 10 between the adjacent protruding pieces 50. Thus, the circulation of the refrigerant 10 in the loop heat pipe 30 is maintained.

  <About the divided state of the bubble 60>

  FIG. 9 and FIG. 10 show an example of a state where the bubbles are divided by the protruding pieces. The shape of the bubble and the action state of the force shown in FIGS. 9 and 10 are examples.

  The bubble 60 that has flowed to the opening 46 side is pressed by the pressing surface 62 that contacts the tip 54 as shown in FIG. 9A, and the peripheral portion of the pressing surface 62 extends along the side wall portion 56 of the protruding piece 50. And deform. Further, the bubble 60 tends to be deformed into a spherical shape so that a surface area is reduced by a surface tension F2 in which a part of the outer shape acts on the boundary with the water surface. Such deformation of the bubble 60 occurs between adjacent protruding pieces 50 arranged at a predetermined angle α, for example, as shown in FIG. At this time, the bubble 60 receives the pressing force F1 from the refrigerant 10 flowing into the deformed portion and the contact with the surface side of the side wall portion 56 of each protruding piece 50, and the pressing surface 62 expands.

  9B, when the bubble 60 is caused to flow toward the opening 46 due to the flow of the refrigerant 10 as shown in FIG. 9B, the adjacent surface to the protruding piece 50 expands, and the protruding piece extends toward the inner side of the bubble 60. 50 is inserted deeply. The side wall portion 56 of the protruding piece 50 is formed in a tapered shape toward the tip end portion 54, so that a part of the bubble 60 is pushed and expanded in accordance with the insertion amount of the protruding piece 50 and enters the side wall portion 56. The range in which the pressing force F1 is received by the incoming refrigerant 10 increases, and deformation of the bubble surface proceeds. And the surface tension F2 which acts on the outer peripheral side of the bubble 60 becomes large with the increase in the pressing force F1.

  10B, as the pressing force F1 and surface tension F2 acting on the surface increase, for example, a part of the bubble surface is greatly distorted along the pressing surface 62, and the bubble 60 It becomes a distorted shape.

  Then, as shown in FIG. 9C, the bubble 60 becomes unstable when a part of the pressing surface 62 by the protruding piece 50 becomes unstable and the refrigerant 10 penetrates into the bubble, so that the penetration portion is expanded and the penetration path is A part of the bubble 60 is divided as the fracture surface 64. As shown in FIG. 10C, the divided bubble 60 is deformed into a spherical shape by surface tension F2 acting on the surface side. In addition, the fracture surface 64 newly becomes a boundary surface with the refrigerant 10 on the main body side of the original bubble 60, and the surface tension F2 acts from the refrigerant 10 around the outer shape including the boundary surface, so that the spherical shape is deformed again. To do.

  For example, if the inner diameter of one or both of the divided bubbles 60 is smaller than the opening diameter φA, the opening 46 is taken together with the refrigerant 10 and flows toward the heat absorption pipe 48. Further, the bubble 60 larger than the opening diameter φA is again locked by the protruding piece 50 and divided.

  In this embodiment, four projection pieces 50 are installed on the periphery of the opening 46, and each of the arrangement angles is about 90 degrees with respect to the central axis O. It is not limited to this. Four or more protruding pieces 50 may be arranged, preferably formed in an even number, and may be arranged linearly two by two with the central axis O interposed therebetween.

  <Regarding other configuration examples of adjacent protruding pieces>

  FIG. 11 shows a configuration example in the case where a plurality of projecting pieces are continuously provided. The configuration shown in FIG. 11 is an example.

  As shown in FIG. 11A, the liquid portion 44 is provided with a plurality of heat absorption pipes 48 in parallel in the horizontal direction, for example, and an opening 46 is formed. The opening 46 is formed with a protruding piece 50 for locking and dividing the bubble 60 on the periphery side. Moreover, between the adjacent opening parts 46, the protrusion piece 70 which made the end surfaces contact is formed, for example. The extending length of the protruding piece 70 is set by the formation interval between adjacent openings 46, and may be set so as to contact at a position equidistant from the center of the opening 46, for example.

  For example, as shown in FIG. 11B, the tip end portion 54 of the protruding piece 70 protrudes most on the opening 46 side, and is formed in an inclined shape by decreasing the protruding amount as the distance from the opening 46 increases. ing. As a result, the adjacent protruding pieces 70 are in contact with each other with a small protruding amount, for example, so that the tip 54 forms a “V” shape between the openings 46. The protrusion amount of the tip portion 54 of the protrusion piece 70 may be formed to be reduced to be equal to the protrusion amount of the tip portion 54 of the protrusion piece 50 that is not disposed between the openings 46. Thereby, when the bubble 60 to be locked has a diameter larger than the extending length of the tip end portion 54, for example, the protrusion piece 70 also contacts the tip portion 54 side of the adjacent protrusion piece 70, so that the surface of the bubble 60 is Can be distorted into a more complex shape, increasing the cutting function. Further, the protruding piece 70 can prevent the bubble 60 from increasing in diameter due to the retention between the openings 46 by always locking the protruding pieces 70 to the bubbles 60 between the openings 46 arranged in parallel. it can.

  In addition, although the case where the protrusion piece 70 shown in FIG. 11 is formed shorter than the protrusion piece 50 formed in a part other than between the openings 46 is not limited thereto. The length of the protruding piece 70 may be set longer than that of the protruding piece 50.

  According to such a configuration, the surface of the bubble 60 flowing along the refrigerant 10 is greatly deformed by the pressure by the protruding piece 50 and the hydrophilicity of the side wall portion 56, and further acts on the liquid surface with the refrigerant 10. Part of the bubble 60 can be divided by the tension. By making it possible to divide the large-diameter bubble 60 by the protruding piece 50, it is possible to prevent the heat absorption duct 48 from being blocked by the bubble 60. By making the protruding amount of the tip of the protruding piece constant, and further forming the side wall portion 56 in a tapered shape, and expanding the pressing surface 62 and increasing the distortion of the bubble 60 as the protruding piece 50 enters the bubble 60, The function of dividing bubbles is enhanced. The evaporating unit 32 locks the flowing bubble 60 with the protruding piece 50 and prevents it from coming into contact with the opening 46, thereby preventing the bubble 60 from being blocked and maintaining the supply of the refrigerant 10 into the heat absorption pipe 48. Thus, the capillary force that acts on the refrigerant 10 in the heat absorption pipe line 48 can be maintained. As a result, the loop heat pipe 30 maintains the circulation of the refrigerant 10 between the evaporator 32 and the condenser 42 by causing the refrigerant 10 to flow using the capillary force against the vaporization of the refrigerant 10 generated in the heat absorption pipe 48. In addition, the cooling function can be exhibited.

  [Third Embodiment]

  12 and 13 show a configuration example of the protruding piece of the loop heat pipe according to the third embodiment. The configuration shown in FIGS. 12 and 13 is an example.

  As shown in FIG. 12A, for example, as shown in FIG. 12A, the opening 46 allows the coolant 10 flowing in the liquid portion 44 to flow, and also locks the bubbles 60 flowing together with the coolant 10 to divide a part thereof. The protrusion piece 80 is formed. A plurality of the projecting pieces 80 are formed, for example, at the same arrangement angle along the periphery of the opening 46. Each projection piece 80 has, for example, two flat projection components 81 formed in the same shape and installed in parallel, and forms a slit 82 that guides the refrigerant 10 between the side wall portions 84 of the opposed projection components 81. Yes. The slit 82 is formed toward the center side of the opening 46, and guides the coolant 10 flowing along the opposing side wall 84 into the opening 46.

  The tip part 86 of the projecting component 81 projects the largest part near the center of the opening 46, and forms an inclined surface by reducing the amount of protrusion as the distance from the opening 46 increases. The end portion 88 of the outer edge portion of the protruding part 81 is formed, for example, inclined at a predetermined angle toward the center side of the opening 46. In addition, the protruding component 81 has, for example, a surface of the side wall portion 84 on which the slit 82 is formed parallel to the central axis O. In contrast, the protruding component 81 is formed in a so-called taper shape by inclining the side wall portion 84 of the surface where the slit 82 is not formed toward the slit 82 side. This taper shape is formed, for example, such that the thickness of the protruding part 81 decreases from the bottom side toward the tip end 86 side, and the tip end 86 has an acute angle.

  Further, a guide wall 90 that guides the flow of the refrigerant 10 by connecting the adjacent protruding pieces 80 to each other is formed on the periphery of the opening 46. The guide wall 90 is erected along the protruding direction of the protruding part 81 from the wall part side where the opening 46 is formed on the opening 46 side with respect to the protruding parts 81 adjacent to each other at a predetermined arrangement angle. Accordingly, the guide wall 90 prevents the coolant 10 from flowing into the opening 46 from between the protruding parts 81. For example, as shown in FIG. 12B, the distal end portion 92 of the guide wall 90 is formed so that the central portion has a convex shape and protrudes higher than the distal end portion 86 of the protruding component 81.

The guide wall 90 is formed, for example, with the wall surface on the opening 46 side parallel to the central axis of the opening 46. The protrusion amount H2 of the guide wall 90 is set to be larger than, for example, the opening diameter φA of the opening 46, and is larger than half of the inner diameter of the liquid part 44 or the width L2 in the vertical or horizontal direction (FIG. 5). Set to In addition, the total length of the two protruding pieces 80 installed in a straight line through the opening 46 is set to be at least half or more than the width L2 of the liquid part 44. That is, the length of the protruding piece is set under the following conditions.
(Width L2 of liquid portion 44) ≦ 2 × [(Installation width L3 of two protrusion pieces 80) − (Opening diameter φA)]
... (Formula 2)

  The protruding parts 81 and the guide walls 90 are formed of hydrophilic members or are subjected to hydrophilic treatment, and the refrigerant 10 is easy to flow along the wall surfaces.

  For example, as shown in FIG. 13A, four protrusion pieces 80 are formed at the same angle on the periphery of the opening 46, and are opened through a space formed between the opposing protrusion parts 81 and the guide wall 90. The refrigerant 10 flows to the part 46 side.

  For example, as shown in FIG. 13B, the guide wall 90 has an inner wall directed to the opening 46 side parallel to the central axis O and an outer wall side formed in a tapered shape in a tapered shape. . In this guide wall 90, for example, the thickness on the outer wall side is reduced from the wall surface side where the opening 46 is formed toward the tip portion 92 side, and the outer wall side is inclined toward the central axis O to make the tip portion 92 an acute angle. To form.

  With such a shape, the projecting piece 80 and the guide wall 90 do not narrow the flow path of the coolant 10 on the front side of the opening 46 and in the slit 82, for example. The fluid state can be maintained. Further, the formation width L4 of the slit 82 formed by the protrusion piece 80 is formed to be equal to or smaller in diameter than the opening 48, for example. Thereby, the slit 82 prevents passage of the bubble 60 having a diameter larger than that of the opening 46 inside, for example, as shown in FIG.

  <Regarding Locking and Dividing of Bubble 60 by Protruding Piece 80>

  FIG. 14 shows the appearance of the state in which the bubble 60 is locked to the protrusion piece 80. When the bubble 60 in the liquid part 44 flows toward the opening 46 according to the flow of the refrigerant 10, for example, as shown in FIG. 14A, the bubble 60 contacts the tip part 86 of the protruding part 81 and the tip part 92 of the guide wall 90. . Then, for example, as shown in FIG. 14B, when the bubble 60 flows to the opening 46 side together with the refrigerant 10, a part of the surface is pressed toward the center side, and the protruding shape 80 is deformed in a state where the entire shape is distorted. It becomes a locked state.

  At this time, as shown in FIG. 15A, for example, a part of the surface of the bubble 60 is crimped from the tip end portion 86 of the protruding component 81 along the side wall portion 84, and is deformed. The tip end portion 86 of the protruding component 81 presses a part of the surface of the bubble 60 toward the inside of the bubble 60 so as to be depressed. The refrigerant 10 flows along the surface of the side wall 84, and the refrigerant 10 enters between the protruding part 81 and the deformed portion of the bubble 60. At this time, a part of the surface receives the pressing force F <b> 1 on the inner side of the bubble 60, for example, when the bubble 60 comes into contact with the protruding part 81 and is in a depressed state. Further, the surface of the bubble is deformed so as to be spherical due to the surface tension F2 acting on the boundary portion with the surrounding refrigerant 10, for example, at a portion away from the protruding piece 80.

  Since the refrigerant 10 flows inside the slit 82, the large-sized bubble 60 enters when the surface tension F <b> 3 acts along the side wall portion 84 on the front end side of the opposed protruding component 81. It has become difficult.

  For example, as shown in FIG. 15B, the refrigerant 10 flows into the opening 46 through the side wall 84 of the protruding component 81 that forms the slit 82. At this time, the bubble 60 is deformed along the inclined tip portion 86 of the protruding component 81 and the tip portion 92 of the guide wall 90. In addition, a space in which the refrigerant 10 flows is formed on the front side of the opening 46 by the slit 82, the distal end portion 86 of the protrusion piece 80, and the guide wall 90. Further, the surface tension F3 that acts on the refrigerant 10 along the protruding piece 80 and the wall surface of the guide wall 90 acts on the front surface side of the opening 46, thereby preventing the bubbles 60 from entering the opening 46.

  <About the divided state of the bubble 60>

  The bubble 60 that has flowed to the opening 46 side is pressed by the pressing surface 62 that contacts the tip 86 as shown in FIG. 16A, and the peripheral portion of the pressing surface 62 extends along the side wall 84 of the protruding component 81. And deform. The bubble 60 tends to deform into a spherical shape so that a part of the outer shape has a small surface area due to the surface tension F2 acting on the boundary with the water surface of the refrigerant 10. The bubble 60 receives the pressing force F <b> 1 from the refrigerant 10 flowing into the deformed portion in contact with the surface side of the side wall portion 84 of the protruding component 81, and the pressing surface 62 expands.

  When the bubble 60 is caused to flow toward the opening 46 due to the flow of the refrigerant 10 as shown in FIG. 16B, the contact surface with the protruding component 81 spreads, and the protruding component against the inner side of the bubble 60 81 is inserted deeply. By forming the side wall portion 84 of the protruding component 81 in a tapered shape toward the distal end portion 86, the bubble 60 is partially expanded according to the insertion depth of the protruding component 81. In addition, the range of the bubble 60 that receives the pressing force F <b> 1 by the refrigerant 10 entering between the deformed portion by the side wall portion 84 increases and the deformation of the surface proceeds. And the surface tension F2 which acts on the outer peripheral side of the bubble 60 becomes large with the increase in the pressing force F1.

  Then, as shown in FIG. 16C, the bubble 60 becomes unstable when a part of the pressing surface 62 by the protruding component 81 becomes unstable and the refrigerant 10 penetrates into the inside thereof, and the permeation portion is enlarged and the permeation path is broken. A part of the bubble 60 is divided as a cross section 64.

  For example, as shown in FIG. 17, the divided bubble 60 is deformed into a spherical shape by the surface tension F2 acting on the surface side. Further, the dividing surface 64 newly becomes a boundary surface with the refrigerant 10 on the main body side of the original bubble 60, and the surface tension F2 acts from the refrigerant 10 around the outer shape including the boundary surface, so that the spherical shape is deformed again. To do.

  For example, if the inner diameter of one or both of the divided bubbles 60 is smaller than the opening diameter A or the width L4 of the slit 82, the opening 46 is taken together with the refrigerant 10 and flows toward the heat absorption pipe 48. Also, the bubble 60 larger than the opening diameter A or the width L4 of the slit 82 is again locked by the protrusion piece 80 and divided.

  According to such a configuration, in the liquid portion 44, the front end portion of the opening 46 is surrounded by the plurality of protruding parts 81 and the guide wall 90, so that the tip portion inserted into the bubble 60 and the wall surface along the bubble surface are included. By increasing, the amount of deformation of the bubbles can be increased and the dividing function can be enhanced. In addition, by making the surface properties of the protruding component 81 and the guide component 90 hydrophilic, the coolant 10 is allowed to flow along the deformation surface of the bubble that deforms along the wall surface, so that the breakage of the bubble can be promoted. . Further, by surrounding the front surface of the opening 46 with the plurality of protruding parts 81 and the guide wall 90, the flow path of the refrigerant 10 can be secured even when the bubbles of the refrigerant 10 are locked, and the inside of the loop heat pipe 30. Circulation of the refrigerant 10 can be maintained.

  [Comparative Example]

  Next, a comparative example with a configuration inside the evaporation unit using a conventional protruding piece will be described. FIG. 18 shows a comparative example of the protruding pieces.

  In the evaporation section 120 shown in FIG. 18, for example, a large diameter liquid section 44 on the upstream side of the flow path of the refrigerant 10 communicates with a small diameter heat absorption pipe 48 on the downstream side, and along the opening portion of the communication section. One or a plurality of columnar protrusions 122 are erected. The protruding pieces 122 are formed, for example, at an interval equivalent to the opening diameter of the heat absorbing pipe line 48.

  As shown in FIG. 18A, the protruding piece 122 can be locked by bringing the tip portion into contact with the large-sized bubble 60 that has flowed through the liquid portion 44, thereby preventing entry into the opening. it can. At this time, the protruding piece 122 is in contact with a part of the surface of the bubble 60 at the tip. The bubble 60 is pressed against the protruding piece 122 by the flow of the refrigerant 10, for example, and a pressing surface 62 is formed at a part in contact with the protruding piece 122 and a part of the periphery thereof, and deforms.

  For example, if the flow state of the refrigerant 10 in the evaporation unit 120 does not change, the bubble 60 is maintained in the locked state by the protruding piece 122.

  For example, as shown in FIG. 18B, the bubble 60 may develop in a large diameter due to the passage of time, a change in the amount of air contained in the refrigerant 10, or the like. For example, when the bubbles 60 contained in the refrigerant 10 are collected, or when the internal pressure changes in accordance with the temperature change of the refrigerant 10 in the heat pipe in which the evaporation unit 120 is mounted, the bubbles 60 become large. There is.

  For example, when the bubble 60 has a large diameter, the protruding piece 122 may penetrate into the inside of the bubble because the contact angle with the bubble surface becomes large or the surface becomes difficult to deform. The protrusion piece 122 through which the bubble 60 penetrates cannot deform the bubble surface because the surface of the tip portion is separated from the refrigerant 10. Accordingly, the bubble 60 comes into contact with the opening 46 of the heat absorption pipe 48 having a small diameter in a state where the surface is maintained in a spherical shape, and prevents the refrigerant 10 from entering.

  The heat absorption pipe line 48 in which the opening 46 is closed by the bubble 60 is cut off from the refrigerant 10 on the liquid part 44 side, for example, so that the capillary force does not act on the liquid level of the refrigerant 10 inside. Further, the heat absorption pipe 48 is heated by heat from a heating element (not shown), and the internal refrigerant 10 is vaporized. Therefore, the heat absorption pipe 48 may be in a so-called dry-out state in which the heat absorption function is lost when the internal refrigerant 10 is completely vaporized.

  With respect to such a configuration, the loop heat pipe of the present disclosure forms a plurality of protruding pieces 50 and 80 along the opening 46 of the heat absorption pipe 48 to lock and divide the bubble 60. The projecting pieces 50 and 80 are locked by reducing the protruding amount of the tip part contacting the surface of the bubble 60 in the radial direction from the opening 46 side and by forming the taper shape toward the tip part. The deformed bubble surface is greatly deformed to promote fragmentation. Further, by forming the surface properties of the protrusions 50 and 80 to be hydrophilic, the coolant 10 is allowed to flow along the pressing surface 62 against the bubbles 60, so that the protrusions can be prevented from penetrating into the bubbles, It is possible to promote the division of the bubbles 60 by the coolant 10 that has passed through the water.

  Since the air bubble 60 is divided by the protruding piece 50 in this manner, the opening 46 is not blocked, so that the circulation of the refrigerant 10 in the loop heat pipe can be maintained.

  [Other Embodiments]

  With respect to the embodiment described above, the features and modifications thereof are listed below.

  (1) In the above embodiment, as the second pipe line where the protruding piece 50 is installed, the pipe diameter is reduced, and the refrigerant 10 is applied by the capillary force acting on the liquid level as the refrigerant 10 is vaporized. Although the case where the endothermic pipe 48 to be circulated is used is shown, the present invention is not limited to this. For example, as shown in FIG. 19, the evaporating unit may include a wick 100 on the downstream side of the liquid unit 44 as a means for causing the refrigerant 10 to flow. In the evaporating part, for example, an opening 46 having a small diameter with respect to the upstream liquid part 44 is formed, and a steam part 102 for housing the wick 100 is formed on the downstream side.

  The wick 100 is formed in a multilayer structure, and the liquid flow path 104 formed inside communicates with the opening 46. The liquid flow path 104 is an example of the second flow path of the present disclosure. For example, the liquid flow path 104 has a dead end inside, and is filled with the refrigerant 10. A porous body is formed on the outer layer side of the liquid flow path 104. For example, minute holes are formed, and the refrigerant 10 in the liquid flow path 104 is sucked up by a capillary force acting on the holes. In the evaporation section, the refrigerant 10 sucked up to the surface side of the wick 100 is vaporized by the heat generated from the heating element 34. The vaporized refrigerant 40 flows to the steam pipe side (not shown) through the periphery of the wick 100.

  By providing a plurality of projecting pieces 50 on the peripheral side of the opening 46 with respect to the pipe line provided with such a wick 100, the opening 46 can be blocked by the bubbles 60, and the circulation of the refrigerant 10 can be maintained. Can do.

  (2) In the above-described embodiment, the case where the protruding pieces 12 arranged along the opening 6 are formed with the same shape and dimensions is shown, but the present invention is not limited thereto. The protruding pieces 12 may be formed with different protruding lengths or different extending lengths in the radial direction. The shape and size of the protruding piece 12 may be set according to the generation state and flow state of bubbles flowing in the first flow path 4 such as the shape in the flow path and the influence of gravity. For example, when the number of times the bubbles flow into the opening 6 from above is large, the protruding length of the protruding piece 12 and the extending length of the protruding piece 12 on the upper side of the opening 6 may be increased. Thereby, in the 1st flow path 4, possibility that the projection piece 12 will contact with the flow of a bubble can be raised, and a bubble can be divided.

  Next, the following additional notes are disclosed with respect to the embodiment described above. The present invention is not limited to the following supplementary notes.

(Appendix 1) A loop heat pipe that cools a heating element using the heat of vaporization of the refrigerant circulated inside,
A first flow path formed on the upstream side of the circulation path on the liquid pipe side, and flowing a liquid-phase refrigerant therein;
A second channel that is communicated with an opening having a smaller diameter than the first channel, and that takes in the refrigerant that has flowed in from the first channel;
A plurality of bubbles are arranged around the opening so as to face each other through the opening, and the tip portion protrudes toward the first flow path side to flow bubbles flowing in the first flow path. A protruding piece that locks or breaks part of the bubble;
The projecting piece is formed by extending from the center side of the opening in the radial direction while reducing the protruding amount, and from the opening side to the tip portion on the first flow path side. A loop heat pipe characterized by being formed into a tapered shape.

  (Supplementary note 2) The loop heat pipe according to supplementary note 1, wherein at least a surface of the protruding piece is formed of a hydrophilic member.

  (Additional remark 3) While the said protrusion piece crimps | bonds the said front-end | tip part to the bubble surface in a said 1st flow path, a part of bubble is made into the shape of the said protrusion piece by sticking a side part to the bubble surface. The loop heat pipe according to appendix 1 or appendix 2, wherein the loop heat pipe is deformed along the line and divided.

  (Additional remark 4) The said protrusion piece is arrange | positioned linearly in the radial direction of the said opening part with respect to the other said protrusion piece which opposes. Any one of Additional remark 1 thru | or Additional remark 3 characterized by the above-mentioned. The described loop heat pipe.

  (Additional remark 5) The said 2nd flow path forms the evaporating part which evaporates a refrigerant | coolant with the heat | fever from the adjacent heat generating body while flowing the refrigerant | coolant which flowed in by capillary force, Additional remark 1 thru | or Additional remark characterized by the above-mentioned. The loop heat pipe according to any one of 4.

  (Supplementary note 6) The loop heat pipe according to any one of supplementary notes 1 to 5, wherein the protruding pieces are formed at equal angles around the opening.

  (Additional remark 7) The said protrusion piece is formed in any one of Additional remark 1 thru | or Additional remark 6 characterized by the length of the largest protrusion part of the said front-end | tip part being larger than the diameter of the said opening part. Loop heat pipe.

  (Supplementary note 8) Any one of Supplementary notes 1 to 7, wherein the protruding piece is set such that a radial extension length of the opening portion is at least larger than an opening diameter of the opening portion. Loop heat pipe as described in.

  (Supplementary note 9) Any one of Supplementary notes 1 to 8, wherein the extension lengths of the plurality of projecting pieces facing each other through the opening are set to be longer than the radius of the first flow path. The loop heat pipe according to any one of the above.

  (Additional remark 10) The said protrusion piece arrange | positions several protrusion components with the same shape in parallel with the fixed interval along the circumferential direction of the said opening part, and lets a refrigerant pass between these protrusion components. The loop heat pipe according to any one of appendices 1 to 9, wherein a slit for guiding the refrigerant from the first flow path to the opening side is formed.

(Additional remark 11) Further, provided with a guide wall that is formed along the opening and prevents the refrigerant from flowing into the opening between the adjacent protrusions,
The guide wall connects adjacent projecting parts to each other on the opening side, and the amount of projection to the first duct side is set to be larger than that of the projecting part. The described loop heat pipe.

  (Supplementary note 12) The supplementary note 11 is characterized in that the guide wall is formed so as to be inclined in the direction of the center line of the second flow path with the outer wall side directed from the opening side toward the distal end side. Loop heat pipe.

As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to the above description, and the gist of the invention described in the claims or disclosed in the specification. It goes without saying that various modifications and changes can be made by those skilled in the art based on the above, and such modifications and changes are included in the scope of the present invention.

2, 36 Liquid pipe 4 First flow path 6, 46 Opening 8 Second flow path 10, 40 Refrigerant 12, 50, 70, 80 Protrusion piece 14, 54, 86, 92 Tip 16 Bubble body 18 Cross section 20 Bubble fraction 30 Loop heat pipe 32 Evaporating part 34 Heating element 38 Steam pipe 42 Condensing part 44 Liquid part 48 Endothermic pipe 52, 102 Steam part 56, 84 Side wall part 60 Bubble 62 Press surface 64 Fracture surface 81 Projection part 82 Slit 88 end 90 guide wall 100 wick 104 liquid flow path

Claims (5)

A loop heat pipe that uses the heat of vaporization of the refrigerant circulated inside to cool the heating element,
A first flow path formed on the upstream side of the circulation path on the liquid pipe side, and flowing a liquid-phase refrigerant therein;
A second channel that is communicated with an opening having a smaller diameter than the first channel, and that takes in the refrigerant that has flowed in from the first channel;
A plurality of bubbles are arranged around the opening so as to face each other through the opening, and the tip portion protrudes toward the first flow path side to flow bubbles flowing in the first flow path. A protruding piece that locks or breaks part of the bubble;
The projecting piece is formed by extending from the center side of the opening in the radial direction while reducing the protruding amount, and from the opening side to the tip portion on the first flow path side. A loop heat pipe characterized by being formed into a tapered shape.   The loop heat pipe according to claim 1, wherein at least a surface of the protruding piece is formed of a hydrophilic member.   The projecting piece causes the tip portion to be crimped to the bubble surface in the first flow path, and the side surface portion is brought into close contact with the bubble surface, thereby deforming a part of the bubble along the shape of the projecting piece. The loop heat pipe according to claim 1 or 2, wherein the loop heat pipe is divided.   The projecting piece has a plurality of projecting parts having an equivalent shape arranged in parallel at regular intervals along the circumferential direction of the opening, and allows the coolant to pass between the projecting parts. The loop heat pipe according to any one of claims 1 to 3, wherein a slit for guiding the refrigerant from the flow path to the opening side is formed. Furthermore, provided with a guide wall that is formed along the opening and prevents the refrigerant from flowing into the opening between the adjacent protrusions,
5. The guide wall connects adjacent projecting parts on the opening side, and has a projecting amount to the first pipe side set larger than that of the projecting part. Loop heat pipe as described in.

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