JP4370179B2 - Heat pipe heat sink - Google Patents

Description

  The present invention relates to a heat pipe type heat sink, and more particularly to a heat pipe type heat sink that can secure a high cooling performance in a low temperature environment and can narrow an installation space in a vertical direction. is there.

  Conventionally, in power equipment, substation equipment, vehicle power supply devices, etc., a cooler for cooling large heat-generating parts has been provided, and one of such coolers is a heat pipe type. A sheet sink can be mentioned. Such a heat pipe type seat sink extends upward from a heat receiving block installed on a heating element (cooled member) by assembling an assembly in which a large number of heat radiation fins are integrally attached to the heat pipe. The heat generated in the heating element is transferred from the heating element to the heat receiving block, and the heat transferred to the heat receiving block is transmitted to one of the heat pipes attached to the heat receiving block. By moving from the end (heat-absorbing part side) to the other end side (heat-dissipating part side) and being released to the outside air through the heat-dissipating fins, heat is radiated or removed.

  By the way, in recent years, as a countermeasure against environmental problems, cases of using water as a working fluid (working fluid) in a heat pipe are increasing. However, when water is used as the working fluid, there is a problem that when the water is used in a low temperature environment, that is, at an ambient temperature of 0 ° C. or less, the water as the working fluid is frozen and cannot function as a heat pipe. there were. In such a low temperature environment, when a device including a heating element (cooled member) is operated and a heat pipe type heat sink is used, the following problems have occurred. That is, first, water, which is a working fluid, is frozen on the heat receiving block side in the heat pipe and melts by the heat from the heating element. And if temperature rises further, water will evaporate and it will become a vapor | steam and will move to the radiation fin side of a heat pipe. Next, the steam that has moved to the heat radiating fin side condenses by coming into contact with the container (container) of the heat pipe, and releases heat to the container. At this time, if the heat capacity for lowering the container temperature to 0 ° C or higher exceeds the total latent heat of the working fluid, all the working fluid evaporated on the heat receiving block side will freeze on the heat radiating fin side in the heat pipe, and the heat receiving block The working fluid on the side will disappear. For this reason, the function as a heat pipe cannot be achieved, and as a result, heat generated from the heating element cannot be sufficiently released, and there is a fear that the heating element is seriously damaged.

  For this reason, in order to avoid the occurrence of such a problem, a freeze-preventing heater has been used in the past. However, when using a freeze-preventing heater, there is a concern about freezing. In particular, heater power is required from the night until the start of operation of the device incorporating the member to be cooled. Also, depending on the device, there is not enough power, and such a freeze prevention heater may not be used. .

  Further, in order to prevent freezing of water, which is a working fluid, in Patent Document 1, a non-condensable gas is put together with a working fluid (pure water) in a normal heat pipe having the structure described above and a container of the heat pipe. The use of a heat pipe heat sink in combination with an enclosed variable conductance heat pipe (VCHP) has been proposed. There, a normal heat pipe and VCHP in which non-condensable gas is not enclosed are arranged in parallel with respect to the heat absorption block.

  Here, when the heating element generates heat in the state where the temperature around the heat pipe heat sink is greatly lowered from 0 ° C., the frozen working fluid is melted in the VCHP as well as the normal heat pipe. Although a part will evaporate, since the non-condensable gas is enclosed in the container of VCHP, the water vapor | steam with a low partial pressure cannot move to the other upper end side. For this reason, it is prevented that the working fluid freezes at the portion of the heat dissipating fin, so that the original function of the heat pipe can be maintained even in a low temperature environment.

  However, in the heat pipe type heat sink of Patent Document 1, since VCHP and a normal heat pipe are used in combination, VCHP functions in a low temperature environment, but a normal heat pipe stops functioning. Cooling performance is low for the number of installed heat pipes.

  In addition, VCHP is often arranged so as to be vertical or close to an angle from the past, and an inclination angle when arranging VCHP with respect to a horizontal plane has not been specified so far. However, the VCHP is generally provided with a gas reservoir at the end opposite to the heat receiving block mounting side. Therefore, when the VCHP is disposed vertically, a large installation space is required in the height direction. There was a drawback that it was necessary. Especially in devices such as electric power equipment, substation equipment, and vehicle power supply devices, there are many cases where the installation space of the heat pipe heat sink is limited due to its use. However, it is difficult to apply to the apparatus as described above, and further, there is a problem that it cannot be arranged and cannot be applied.

Japanese Patent Application Laid-Open No. 11-289039

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is that it is possible to ensure high cooling performance in a low temperature environment and in the vertical direction. An object of the present invention is to provide a heat pipe type heat sink capable of reducing the installation space.

And this invention was made | formed in order to solve the above subjects, Comprising: The place made into the summary is attached to one end part used as the heat absorption side of a longitudinal heat pipe and this heat pipe. A heat pipe heat sink composed of a heat receiving block and a heat radiation fin attached so that a fin surface is perpendicular to the longitudinal direction of the heat pipe at a heat radiation side portion of the heat pipe , The heat pipe is composed of a variable conductance heat pipe in which a non-condensable gas is sealed together with water as a working fluid , and an end of the heat pipe on the heat receiving block mounting side is from the other end. be positioned below, the heat pipe is inclined at an angle of 5 to 20 ° to the horizontal plane, along with make placement allowed comprising structure, the heating In the form bent at the other end of the pipe so as to be substantially perpendicular to the longitudinal direction of the heat pipe, the gas is directed upward without protruding outward from the peripheral edge of the fin surface of the radiating fin. The heat pipe heat sink is characterized in that a reservoir is provided .

Also, according to one of the desirable aspects of the heat pipe heat sink according to the present invention , a plurality of the heat pipes are arranged in a horizontal direction or a vertical direction, while the plurality of heat pipes are the radiating fins. A configuration is adopted in which the plurality of sheets are attached to the radiating fins, and according to one of the other desirable modes, the radiating fins have a rectangular plate shape, A configuration in which the gas reservoir is provided so as to be inclined with respect to the longitudinal direction of the rectangular plate surface of the radiation fin is adopted.

  In the heat pipe heat sink according to the present invention as described above, since a variable conductance heat pipe (VCHP) is used as the heat pipe, only a normal heat pipe in which non-condensable gas is not enclosed is used. Unlike the case of using or using a normal heat pipe, it is possible to surely prevent the working fluid in the low temperature environment from freezing on the heat radiating side. For this reason, even in such a low temperature environment, the function of the heat pipe can be demonstrated to an advantage, and the cooling capacity or the cooling capacity of the heat pipe heat sink is highly secured with a small number of installed heat pipes. I can do it.

  Further, in the heat pipe type heat sink according to the present invention, the VCHP is arranged at a small inclination angle of 5 to 20 ° with respect to the horizontal plane, compared to the conventional case where the VCHP is arranged at an angle close to vertical or near vertical. Thus, the installation space in the height direction can be reduced.

  In addition, by adopting the inclination angle as described above, a plurality of heat radiation fins mounted perpendicular to the longitudinal direction of the heat pipe are arranged substantially perpendicular to the horizontal plane (installation surface). Natural convection air easily flows between the radiation fins, the ventilation resistance of the radiation fins can be reduced, and the cooling performance of the heat pipe heat sink can be improved.

  As described above, the heat pipe heat sink according to the present invention operates normally even in a low temperature environment in which the working fluid in the heat pipe freezes, and can exhibit high cooling performance. At the same time, the installation space in the vertical direction can be reduced.

In addition, according to the onset bright, gas storage unit is such that a substantially right angle to the longitudinal direction of the heat pipe, from where are arranged in bent form, the longitudinal direction of the heat pipe type heat sink The installation space in can also be reduced.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 is a front view showing a state in which an example of a heat pipe type heat sink having a structure according to the present invention is mounted on a heating element (not shown) as a member to be cooled. In FIG. As is clear from FIG. 1, the heat pipe type heat sink 10 includes a longitudinal heat pipe 12, a heat receiving block 14 integrally attached to one end of the heat pipe 12 on the heat absorption side, The heat pipe 12 includes a plurality of heat radiation fins 16 that are integrally attached to a heat radiation side portion of the heat pipe 12.

  More specifically, the heat pipe 12 according to the present embodiment is configured by a container (container) having a structure in which both ends of a long cylindrical pipe are sealed, as in the conventional case. The inside of such a container is evacuated by decompression, and a predetermined amount of working fluid is sealed in the container of the heat pipe 12 and a predetermined amount of non-condensable gas is sealed. Has been. Furthermore, the presence of such non-condensable gas can advantageously prevent the working fluid from freezing in the heat radiating portion of the heat pipe 12 even in a low temperature environment where the working fluid solidifies. Even under the environment, the performance of the heat pipe 12 and, in turn, the heat transport performance of the heat pipe heat sink 10 can be advantageously expressed. Further, even if a sensor or the like is not used due to the presence of the non-condensable gas, as long as the heat absorption part of the heat pipe 12 (the portion on the left side of the heat pipe 12 in FIG. 1) does not reach a certain temperature, it is substantially It does not operate, in other words, the amount of heat transport can be variably controlled by the temperature of the heat absorption part of the heat pipe 12. That is, in the present embodiment, a so-called variable conductance heat pipe (VCHP) is employed as the heat pipe 12.

  Thus, by adopting VCHP as the heat pipe 12 constituting the heat pipe heat sink 10, it is possible to reliably prevent the working fluid freezing on the heat radiation side in a low temperature environment. Compared to the case of using only a normal heat pipe that does not contain condensable gas or the case of using a normal heat pipe and VCHP together, the function of the heat pipe 12 can be utilized to the maximum, and less heat is required. A large cooling capacity can be obtained with the number of pipes installed.

  Further, since the heat pipe 12 is a VCHP in which a non-condensable gas is sealed, similarly to the conventional VCHP, the heat pipe 12 is not condensed on the end portion on the heat absorption side opposite to the end portion on the heat receiving block 14 mounting side. In the present embodiment, the container end portion of the heat pipe 12 is directed upward in the longitudinal direction (a direction in FIG. 1). The end portion bent at a substantially right angle with respect to the end portion is a gas reservoir portion 18 of noncondensable gas sealed in the heat pipe 12.

  By the way, as the working fluid sealed in the heat pipe 12 as described above, water is preferably employed from the viewpoint of being environmentally friendly and excellent in heat transport performance. On the other hand, the non-condensable gas is not particularly limited as long as it is a gas that does not condense in the use environment, and specific examples include nitrogen gas, argon gas, and the like.

  Moreover, even if it exists in the material of the heat pipe 12 as mentioned above, it does not specifically limit, Generally, the metal material etc. which were excellent in thermal conductivity will be selected suitably, and will be used.

  And in this embodiment, four such heat pipes (VCHP) 12 are arrange | positioned in parallel at predetermined distance, as FIG. 2 (A arrow line view in FIG. 1) shows. Further, a thick rectangular plate-shaped heat receiving block 14 is fixedly attached to a portion of the heat absorbing portion (the left end portion in FIG. 2) of the heat pipe 12 with a predetermined length. A plurality of heat dissipating fins 16 having a thin rectangular plate shape and arranged at a predetermined distance in the longitudinal direction of the heat pipe 12 are disposed at a predetermined length portion of the heat dissipating part that is a predetermined distance away from the heat dissipating part. It is fixedly attached in the same manner as in the prior art so that the angle between the surface of the fin 16 and the longitudinal direction of the heat pipe 12 is a right angle.

  Here, the heat receiving block 14 fixed to the heat absorption side of the heat pipe 12 is formed of a material having excellent thermal conductivity, as in the prior art, and in a substantially central portion of the plane in the thickness direction. A circular hole 20 is formed at a predetermined depth. The hole 20 is an attachment hole for attaching a heating element (cooled member) (not shown), and heat generated from the heating element is conducted to the heat absorbing portion of the heat pipe 12 through the heat receiving block 14. It is supposed to be done. On the other hand, the radiating fins 16 fixed to the heat radiating side of the heat pipe 12 are formed of a material having excellent thermal conductivity, as in the prior art. Here, as shown in FIG. In addition, four attachment holes 22 for attaching the four heat pipes 12 are formed at a predetermined distance in the longitudinal direction at a substantially central portion of the thin plate-like surface.

  And in the heat pipe type heat sink 10 of this embodiment comprised by the heat pipe 12, the heat receiving block 14, and the radiation fin 16 as mentioned above, as FIG. 1 shows, especially the heat pipe 12 and a horizontal surface. The angle (θ in FIG. 1) formed with (H in FIG. 1) is inclined to be 5 to 20 °, for example, about 7 °. At this time, a configuration is employed in which the end portion of the heat pipe 12 on the heat receiving block 14 mounting side is positioned below the other end portion, so that the working fluid recirculates well. Will be realized.

  Thus, in the present embodiment, since the heat pipe 12 is inclined so as to have a specific angle with respect to the horizontal plane (H), the installation space for the entire heat pipe heat sink 10 in the height direction is reduced. Compared with the conventional VCHP, it can be made extremely small. Moreover, the radiating fins 16 attached so as to be orthogonal to the longitudinal direction of the heat pipe 12 are disposed substantially perpendicular to the installation surface, and natural convection air flows between the radiating fins 16. Thus, the ventilation resistance of the radiating fin 16 can be reduced, and the cooling performance of the heat pipe heat sink 10 can be further improved.

  When the angle (θ) in the longitudinal direction of the heat pipe 12 with respect to the horizontal direction is smaller than the above range, the working fluid is difficult to return to the heat absorbing portion of the heat pipe 12 and the heat transport performance is deteriorated. Furthermore, although depending on the amount of the working fluid enclosed, the liquid working fluid that has not evaporated reaches the portion of the heat dissipating fin 16 that is the heat dissipating part. For this reason, when operating in a low temperature environment, some of the working fluid remains frozen. For example, even if VCHP is used as the heat pipe 12, there is a concern that it may interfere with the start-up of the low temperature. is there. On the other hand, when the inclination angle (θ) of the heat pipe 12 with respect to the horizontal plane (H) exceeds the above range, the installation of the heat pipe heat sink 10 in the height direction or the vertical direction (vertical direction in FIG. 1). As the space increases, the ventilation resistance of the radiating fins 16 increases, and the amount of air flowing between the radiating fins 16 due to natural convection is remarkably reduced, so the performance of the heat pipe heat sink 10 is greatly reduced and the heat dissipation efficiency is increased. Get worse.

  Further, in the heat pipe heat sink 10 according to the present embodiment, the gas reservoir 18 for storing the non-condensable gas is arranged in a bent form at the end portion of the heat pipe 12 as described above. Therefore, the installation space in the longitudinal direction of the heat pipe heat sink 10 is also reduced. Further, as shown in FIG. 3, the gas reservoir 18 is provided so as to be inclined with respect to the longitudinal direction of the plate surface of the radiating fin 16 and so as not to protrude outward from the four sides of the plate surface. Therefore, the length of the gas reservoir 18 can be sufficiently secured, and the installation space of the heat pipe heat sink 10 as a whole can be further reduced.

  The heat pipe heat sink 10 as described above is suitable as a cooler for cooling a heating element (a member to be cooled) built in a device such as a power device, a transformer device, or a vehicle power supply device. Therefore, the present invention can be advantageously applied even to an apparatus that could not be applied due to the limitation of installation space.

  The exemplary embodiments of the present invention have been described in detail above. However, the embodiments are merely examples, and the present invention is limited in any way by specific descriptions according to such embodiments. It should be understood that it is not interpreted.

  For example, in the heat pipe heat sink 10 of the above embodiment, the four heat pipes 12 are arranged at a predetermined distance in the horizontal direction (the direction orthogonal to the paper surface in FIG. 1). In the invention, since the installation space in the height direction or the vertical direction is advantageously reduced, the four heat pipes 12 can be arranged in the vertical direction (see FIG. 4). ). In this case, the gas reservoir 18 disposed at the end of the heat pipe 12 is normally positioned so as to face upward.

  In the above example, the heat pipe heat sink 10 is formed of a single heat sink structure. However, as shown in FIGS. 4 to 6, the heat pipe heat sink 10 has the same structure as the heat pipe heat sink 10. In addition, the heat pipe heat sink 30 can be configured by assembling two heat sink structures 24 a and 24 b having symmetrical structures with each other through the heating element 26. Further, in FIGS. 4 to 6, the two heat sink structures 24a and 24b are arranged side by side in the horizontal direction. However, in the present invention, as described above, the installation in the height direction or the vertical direction is performed. Since the space is reduced, the heat sink structures 24a and 24b can be arranged in the vertical direction. However, even in such a case, as described above, the angle (θ) formed between the heat pipe and the horizontal plane (H) is set such that the heat absorbing portion of the heat pipe 12 is positioned below the heat radiating portion. 5 to 20 °.

  In any case, in the heat pipe type heat sink according to the present invention, VCHP is adopted as the heat pipe, the heat absorption part of the heat pipe is positioned below the heat radiation part, and the heat pipe is As long as it is arranged so as to be 5 to 20 ° with respect to the horizontal plane (H), the shape and number of arrangements of the heat pipe, the heat radiating fin, the heat receiving block, the heat sink structure, etc. It is not limited. Accordingly, conventionally known various shapes of heat pipes, heat radiating fins, heat receiving blocks, heat sink structures, etc. can be adopted, and the number of them can be arranged as necessary. It will be set appropriately.

  In addition, although not listed one by one, the present invention can be implemented in a mode with various changes, modifications, improvements, and the like based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the invention.

It is a front view showing roughly an example of a heat pipe type heat sink according to the present invention. It is A arrow directional view in FIG. It is a B arrow view in FIG. It is a front view which shows roughly another example of the heat pipe type heat sink according to this invention. It is C arrow line view in FIG. Ru D arrow view der in Fig.

Explanation of symbols

10,30 heat pipe heat sink
12 heat pipe 14 heat receiving block 16 heat radiation fin
18 gas reservoir 20 hole 22 mounting hole 24a, 24b heat sink component 26 heating element

Claims (3)

A longitudinal heat pipe, a heat receiving block attached to one end on the heat absorption side of the heat pipe , and a fin surface at a right angle with respect to the longitudinal direction of the heat pipe at a heat radiation side portion of the heat pipe in the heat pipe type heat sink composed of a radiating fin which is attached such that,
The heat pipe is composed of a variable conductance heat pipe in which a non-condensable gas is sealed together with water as a working fluid , and an end of the heat pipe on the heat receiving block mounting side is from the other end. The heat pipe is inclined at an angle of 5 to 20 ° with respect to a horizontal plane so that the heat pipe is disposed at the other end of the heat pipe. In a form bent so as to be substantially perpendicular to the longitudinal direction of the pipe, the gas reservoir portion is provided so as to face upward without protruding outward from the peripheral edge of the fin surface of the radiating fin. Heat pipe type heat sink. A plurality of the heat pipes are arranged in a horizontal direction or a vertical direction, and the plurality of heat pipes are attached to the heat radiation fins so as to penetrate through the plurality of the heat radiation fins. The heat pipe type heat sink according to claim 1. 3. The gas reservoir portion according to claim 1, wherein the gas reservoir is provided so as to be inclined with respect to a longitudinal direction of a rectangular plate surface of the radiation fin while the radiation fin has a rectangular plate shape. Heat pipe type heat sink.

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