JP2007071425A - Cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device capable of properly circulating working fluid even when it is used in a top heat mode, as a result, reducing temperature rise in a room. <P>SOLUTION: In this cooling device 1 wherein an evaporating portion container 3 is set on a panel, a condensing portion container 5 is set on a heat radiating portion formed on a place lower than the panel, and heat is transported to perform cooling, the evaporating portion container 3 and the condensing portion container 5 are communicated by a liquid return pipe 8 and a steam pipe 9 in a state of forming a circular flow channel as a whole, the working fluid 10 evaporated by being heated and condensed by radiating heat is enclosed in the circular flow channel, further a wick is disposed inside of the evaporating portion container 3 to form a loop type heat pipe 1A, and the plurality of evaporating portion containers 3 are set to the panel. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a loop heat pipe (or heat transport loop) type in which an evaporating part for evaporating a working fluid that transports heat as latent heat and a condensing part for condensing the working fluid vapor are connected by a circulation line. The present invention relates to a cooling device.

  The fluid enclosed in the sealed container or pipe line is evaporated by the heat supplied from the outside, and the vapor flows to a low temperature and low pressure location to dissipate the heat. An apparatus for transporting heat as latent heat of the fluid by recirculating it to the input evaporation section is conventionally known. The most common configuration of this type is that after degassing air and other gases that do not condense at the operating temperature, a condensable fluid such as water, alcohol, or ammonia is sealed inside the pipe-shaped container. It is a heat pipe.

  The so-called thermosiphon heat pipe is configured to recirculate condensed liquid phase working fluid to the lower evaporation section by gravity, so there is no wick that generates capillary pressure as a pumping force. However, since a general heat pipe is not necessarily used in the bottom heat mode in which the evaporation part with heat input from the outside is on the lower side, the pump action for returning the liquid-phase working fluid to the evaporation part A wick that produces

  Since the wick generates capillary pressure, it is preferable that the wick has a structure in which the effective capillary radius at the meniscus formed at the opening is as small as possible. ) Or the like formed on the inner surface of the metal), a bundled ultrafine wire, a porous material, or the like is used. In the part of the wick on the evaporation part side, the meniscus is lowered due to the evaporation of the working fluid, and a capillary pressure is generated accordingly, so that the liquid-phase working fluid flows back to the evaporation part side in the wick. become. On the other hand, the working fluid vapor flows from the evaporation portion side toward the condensing portion where the working fluid condenses, and therefore, the flow direction of the liquid working fluid flowing back along the wick and the working fluid vapor flow direction. Are opposite to each other. Therefore, the working fluid in the liquid phase is blown off or blown back by the working fluid vapor on the surface of the wick, and this may become a so-called scattering limit, which may limit the heat transport capability of the heat pipe.

  Conventionally, a loop type heat pipe capable of solving such inconvenience has been developed. This is configured by separating the evaporation section having heat input from the outside and the condensation section in which the working fluid dissipates heat and condenses, and a liquid flow pipe through which these liquid-phase working fluid flows toward the evaporation section; It is a heat pipe having a structure connected in a loop (loop shape) with a steam flow tube through which working fluid vapor flows. With such a structure, the liquid-phase working fluid and the working fluid vapor do not flow through the same location, and thus there is no restriction on the heat transport capability due to the scattering limit described above.

  An example of this type of loop-type heat pipe is described in Patent Document 1. The heat pipe described in this publication includes an evaporator in which a liquid pipe and a steam pipe are connected, and a cylindrical wick is accommodated in the evaporator.

  Therefore, in the heat pipe described in the above publication, the working fluid in contact with the inner surface of the container is heated and evaporated by the heat transferred to the evaporator, and the steam is sent out from the evaporator through the steam pipe. It is. On the other hand, the liquid-phase working fluid is supplied from the liquid pipe to the wick, and a capillary pressure is generated in the wick. As a result, the liquid-phase working fluid is supplied to the container. Then, since the liquid-phase working fluid is heated and evaporated and flows through the vapor pipe to the condensing part, heat can be transported as latent heat of the working fluid.

The loop heat pipe having the above-described structure is installed as a cooling device that cools indoor air, for example, indoors and outdoors, and is used in a top heat mode in which the evaporation unit is relatively above the condensing unit. In such a case, the liquid phase working fluid is sucked upward by the capillary pressure generated in the wick inside the evaporation section and circulates in the annular flow path. As a result, indoor heat is released to the outside.
Japanese Patent Laid-Open No. 10-246583

  In the above cooling device, if the heat input area in the evaporator, that is, the heat exchange area with the external heat source is increased, the heat transport capacity of the cooling device as a whole can be increased. In that case, the axial length of the evaporator is lengthened to increase the surface area, and at the same time, the axial length of the evaporator container is also increased. However, when the axial length of the evaporation section container increases, the pressure difference at both ends in the axial direction of the evaporation section container increases, and the flow distance of the working fluid increases, so the pressure loss inevitably increases. End up. As a result, it becomes difficult for the working fluid to circulate, and the cooling performance of the cooling device cannot be maintained, which may impair indoor comfort.

  The present invention has been made paying attention to the above technical problem, and even when used in the top heat mode, the working fluid can be circulated satisfactorily, and as a result, an increase in indoor temperature can be reduced. The object is to provide a cooling device.

  In order to achieve the above object, according to the first aspect of the present invention, an evaporator is disposed in the cooled part, and a condensing part is disposed in a heat dissipating part provided at a location lower than the cooled part, A cooling device that transports heat from a cooled part to the heat radiating part and performs cooling, and the evaporation part and the condensing part are formed by a liquid return pipe and a steam pipe so as to form an annular channel as a whole. A working wick that is communicated, is heated in the annular flow path, evaporates, dissipates heat, and condenses, and a liquid phase working fluid is infiltrated into the evaporating portion to generate capillary pressure. By doing so, a loop heat pipe is formed, and a plurality of the evaporating parts are arranged for at least one of the cooled parts.

  In addition to the configuration of claim 1, the invention of claim 2 is characterized in that the condensing unit, the liquid return pipe, and the steam pipe communicate with the plurality of evaporation units, respectively. The cooling device is characterized in that a loop heat pipe is formed.

  Furthermore, the invention of claim 3 is a cooling device characterized in that, in addition to the configuration of claim 1, the number of the condensing parts communicating with each of the plurality of evaporation parts is one.

  The invention of claim 4 is characterized in that, in addition to the configuration of claim 2, the plurality of loop heat pipes are arranged so that the liquid return pipes and the steam pipes are adjacent to each other. It is a cooling device.

  Moreover, in addition to the structure in any one of Claim 1 thru | or 4, the invention of Claim 5 arrange | positions the heat-receiving board connected so that heat transfer is possible with the said to-be-cooled part and each said some evaporation part. The cooling device characterized by the above.

  According to the first aspect of the present invention, since the plurality of evaporation parts of the loop heat pipe installed as the cooling device are arranged in the cooled part, the evaporation part can be formed smaller than the conventional one. Therefore, the pressure difference between the inlet and the outlet of the working fluid in the evaporator can be reduced. As a result, pressure loss in the evaporation section can be reduced, so that the operation of the loop heat pipe is stabilized. For this reason, the degree of freedom in setting the evaporation unit with respect to the cooled portion is improved. Furthermore, since the heat of the part to be cooled can be divided by each evaporation part and transported to the condensing part and cooled, the operating temperature of the loop heat pipe can be set low. As a result, since the operation of the entire cooling device can be stabilized, the cooling capacity of the cooling device can be improved. Therefore, the heat in the room can be radiated to the outside, and the continuous temperature rise in the room can be prevented.

  According to a second aspect of the present invention, the condensing unit, the liquid return pipe, and the steam pipe are communicated with the plurality of evaporation units to form a plurality of the loop heat pipes. Therefore, each loop heat pipe can be shared as a component constituting the cooling device.

  Further, according to the invention of claim 3, the condensing part is formed for each of the plurality of evaporation parts. Therefore, the evaporation unit can be shared, and the evaporation unit corresponding to the indoor portion to be cooled can be formed.

  And according to invention of Claim 4, the difference of the temperature inside each adjacent tube in a some loop type heat pipe becomes a very small thing, and can reduce the heat exchange between each adjacent tube. As a result, the working fluid efficiently circulates through the annular flow path of each loop heat pipe, and the cooling performance of the cooling device can be further improved.

  Further, according to the invention of claim 5, since the heat receiving plate having good heat conduction is provided in the cooled part and is connected to each of the evaporation parts, the heat of the cooled part is reduced. It can be efficiently transferred to each loop heat pipe and cooled. As a result, the cooling performance of the cooling device can be further improved.

  The best mode for carrying out the present invention will be described below. The cooling device 1 according to the present invention is attached indoors and outdoors (inside and outside the casing). Specifically, the cooling device 1 is configured by a plurality of loop heat pipes 1A, and the evaporation section container 3 forming the loop heat pipes 1A is provided indoors (inside the casing). It is attached to the surface of a panel (not shown). In addition, the panel is arrange | positioned near the place which receives direct sunlight, and the apparatus which generate | occur | produces heat. Moreover, the condensation part container 5 is arrange | positioned at the thermal radiation part which is provided in the outdoor (outside of a housing | casing) and which is not shown in figure. The heat dissipating part is located below the panel. Therefore, the evaporating part container 3 is disposed relatively above the condensing part container 5. That is, the cooling device 1 is used as a top heat mode. According to this specific example, the panel corresponds to the cooled portion of the present invention, the evaporation portion container 3 corresponds to the evaporation portion of the present invention, and the condensing portion container 5 corresponds to the condensing portion of the present invention.

  The loop heat pipe 1A is formed in an annular shape in which the evaporation section container 3 and the condensation section container 5 are communicated with each other by a liquid return pipe 8 and a steam pipe 9 having a larger diameter than that, and are sealed as a whole. The inside of the heat pipe 1 is almost completely degassed, and then a condensable fluid such as water or alcohol is enclosed as a working fluid 10.

  The evaporation section container 3 is configured in a cylindrical shape, and a plurality of wicks 11 and wicks 12 are accommodated therein. The wick 11 generates a capillary pressure for circulating the working fluid 10 inside the loop heat pipe 1. For example, the wick 11 is a porous material made of ceramic, nickel, copper, copper oxide, or the like, or a polyethylene resin ( For example, it is a porous material made of a polymer material such as Ultra High Molecular Weight polyethylene, and has an effective capillary radius smaller than that of the wick 12 and a larger capillary pressure. On the other hand, the wick 12 is, for example, a wire mesh or a fiber wick, and has an effective capillary radius larger than that of the wick 11 and a relatively large flow path. A wick 12 is arranged in the outer peripheral direction of the wick 11. A hollow portion 13 is formed in the inner peripheral direction of the wick 11.

  FIG. 2 shows a cross-sectional view of the evaporation section container 3. A large number of grooves 3 </ b> A are formed on the inner peripheral surface of the evaporation section container 3. These grooves 3 </ b> A function to increase the area of the inner peripheral surface of the evaporation unit container 3 and serve as a flow path for the working fluid vapor, and are formed toward the axial direction of the evaporation unit container 3. Yes. The groove 3A may be formed in a spiral shape or may be formed on a part of the inner peripheral surface of the wick 11. Moreover, you may form in the outer peripheral surface of the wick 12.

  Here, the arrangement of the loop heat pipes 1A in the room will be described. The panel is provided with a heat receiving plate (not shown). This heat receiving plate is formed of a material having good thermal conductivity such as a copper alloy or an aluminum alloy. On the other hand, as described above, the evaporator containers 3 in the plurality of loop heat pipes 1A are arranged on the panel. Each evaporation part container 3 is arrange | positioned along the outer edge of a panel, and is connected with the heat receiving plate. Specifically, each evaporator section container 3 is disposed along the axial direction of the evaporator section container 3, and is disposed adjacent to the steam pipe 9 in the loop heat pipe 1A and the loop heat pipe 1A. The liquid return pipe 8 of the other loop heat pipe 1A is adjacent. That is, the loop heat pipes 1A are arranged in the same direction.

  Inside the liquid return pipe 8 of the cooling device 1, a wick 14 is arranged on the pipe wall surface in the radial direction. Examples of the wick 14 include a porous sintered body using fiber wick, ceramic, metal powder, or the like.

  When each of the loop heat pipes 1 </ b> A has no heat input to the evaporation section container 3, the working fluid 10 does not evaporate. Therefore, the working fluid 10 stays in the condensing unit container 5 disposed in a relatively lower position than the evaporation unit container 3 in a liquid phase state. The condensing unit container 5 and the liquid return pipe 8 are communicated with each other. Therefore, the working fluid 10 comes into contact with the wick 14 in the liquid return pipe 8 and a capillary pressure is generated in the wick 14. The working fluid 10 is sucked upward by this capillary pressure.

  On the other hand, when the panel is heated by incident light or the like entering the room, heat Q is applied from the outside to each evaporation container 3 via the heat receiving plate. Since the liquid-phase working fluid 10 is held in the liquid return pipe 8 by the wick 14, the liquid return pipe 8 to the inside of the evaporation section container 3 from the beginning of heat input to the evaporation section container 3. The held liquid-phase working fluid 10 is efficiently supplied, and the wick 12 is wet with the working fluid 10.

  When heat Q is applied to each evaporation unit container 3 from the outside, the liquid-phase working fluid 10 in contact with the inner surface of the evaporation unit container 3 or in the vicinity thereof is heated and evaporated. The working fluid vapor 15 generated in the outer peripheral portion of each wick 11 passes through a space between the outer peripheral surface of the wick 12 and the inner peripheral surface of the evaporation unit container 3, and then passes from the outlet of the evaporation unit container 3 to the steam pipe 9. To leak. The wick 12 is supplied with the liquid-phase working fluid 10 from the wick 11 through the hollow portion 13 and is distributed so as to be dispersed toward the respective outer peripheral surfaces. As a result, the liquid-phase working fluid 10 is supplied to substantially the entire inner peripheral surface of the evaporation section container 3, and the substantial heat input area in the evaporation section container 3 can be widened. The working fluid vapor 15 reaches the condensing unit container 5 through the vapor pipe 9. Here, the heat Q is released to the outside, and the working fluid vapor 15 condenses into a liquid phase.

  On the other hand, the evaporation of the working fluid 10 at the outer peripheral portion of the wick 12 inside each evaporation container 3 causes a meniscus at the opening end in the hole of the wick 12, or the liquid level in the hole decreases. Pumping force is generated by capillary pressure. With this pump pressure, the working fluid 10 inside the liquid return pipe 8 is sucked upward.

  In the cooling device 1 described above, since the evaporation section containers 3 in the plurality of loop heat pipes 1A are arranged on the panel, the panel can be divided and cooled by each loop heat pipe 1A. Therefore, the cooling performance of each loop heat pipe 1A can be set low, and the operating temperature can be set low. As a result, the operation of the entire cooling device 1 can be stabilized.

  In addition, by arranging a plurality of loop heat pipes 1A on the panel, the evaporation section container 3 can be formed smaller than when one loop heat pipe is arranged on the panel. Therefore, the pressure difference between the connection part with the liquid return pipe 8 and the connection part with the steam pipe 9 in the evaporation unit container 3 can be reduced. Furthermore, the pressure loss when the working fluid flows inside the evaporator container 3 is reduced, and the working fluid circulates efficiently and smoothly in the annular flow path of the loop heat pipe 1A. As a result, the operation of the loop heat pipe 1A is stabilized and the panel can be cooled efficiently. Therefore, the heat of the panel can be radiated to the outside, and the panel can be efficiently cooled. As a result, the continuous temperature rise in the room can be prevented, and the room can be brought to a comfortable temperature.

  In addition, a condenser container 5, a liquid return pipe 8, and a steam pipe 9 are communicated with each of the plurality of evaporator containers 3 to form a plurality of loop heat pipes 1 </ b> A. Therefore, each loop heat pipe 1 </ b> A can be shared as a component constituting the cooling device 1. Furthermore, since the evaporation part container according to the shape of a panel and the emitted-heat amount can be formed, the freedom degree of a setting improves.

  Furthermore, since the heat receiving plate having good heat conduction is provided on the panel and is connected to each evaporation unit container 3, the heat of the panel can be efficiently transmitted to each loop heat pipe 1A and cooled.

  Further, the steam pipe 9 in the loop heat pipe 1A and the liquid return pipe 8 of the other loop heat pipe 1A are arranged adjacent to each other, and each loop heat pipe 1A is arranged in the same direction, so that cooling Work mistakes during manufacturing of the device 1 can be reduced. As a result, the manufacturability of the cooling device 1 is improved.

  FIG. 3 shows another example of the cooling device 1. In the example shown in FIG. 3, the loop heat pipes 1A are arranged so that the liquid return pipes 8 and the steam pipes 9 of the loop heat pipes 1A are adjacent to each other.

  When each loop heat pipe 1A is arranged as shown in FIG. 3, the temperature difference between the adjacent tubes becomes very small, and the heat exchange between the adjacent tubes can be reduced. As a result, the working fluid 10 efficiently circulates in the annular flow path of each loop heat pipe 1A, and the cooling performance of the cooling device 1 can be further improved.

  In addition, this invention is not limited to said specific example. That is, in the above specific example, the evaporation unit container 3 is attached to the panel and the condensing unit container 5 is attached to a predetermined place outside the room, but the cooling device of the present invention is not limited to this specific example. That is, as long as the evaporation part container 3 or the condensation part container 5 can be attached, it may be attached to any part of the shape. Therefore, for example, various panels and shield rooms can be cooled by the cooling device of the present invention.

It is a front view which shows one specific example of the loop type heat pipe of this invention. It is sectional drawing which shows the evaporation part container of the loop type heat pipe of FIG. It is a top view which shows simply the other specific example of the cooling device of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Cooling device, 1A ... Loop type heat pipe, 3 ... Evaporating part container, 5 ... Condensing part container, 8 ... Liquid return pipe, 9 ... Steam pipe, 10 ... Working fluid, 11, 12, 14 ... Wick.

Claims (5)

An evaporation unit is disposed in the cooled part, and a condensing unit is disposed in a heat radiating part provided at a position lower than the cooled part, and cooling is performed by transporting heat from the cooled part to the heat radiating part. A cooling device,
A working fluid in which the evaporating part and the condensing part are communicated by a liquid return pipe and a steam pipe so as to form an annular flow path as a whole, heated in the annular flow path to evaporate, and radiated and condensed. And a wick that causes the working fluid in the liquid phase to permeate into the evaporation unit to generate capillary pressure is formed, thereby forming a loop heat pipe and at least one of the cooled parts On the other hand, a plurality of the evaporation units are arranged.   The plurality of loop heat pipes are formed by connecting the condensing unit, the liquid return pipe, and the steam pipe to the plurality of evaporation units, respectively. The cooling device as described.   The cooling device according to claim 1, wherein the condensing unit communicates with each of the plurality of evaporation units.   The cooling device according to claim 2, wherein the plurality of loop heat pipes are arranged so that the liquid return pipes and the steam pipes are adjacent to each other.   The cooling device according to any one of claims 1 to 4, wherein a heat receiving plate connected to the cooled portion and each of the plurality of evaporation portions so as to be able to transfer heat is disposed.

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