JP6805438B2 - Heat exchangers, evaporators, and equipment - Google Patents

Description

The present invention relates to heat exchangers, evaporators, and devices.

As an example of the heat exchanger, the following loop heat pipes and the like (see Patent Documents 1 to 3 below) are known.
Patent Document 1 discloses a loop type heat pipe. This loop type heat pipe is provided inside the evaporation part, the condensing part, and the liquid return pipe in order to efficiently cool the heat-generating parts regardless of the installation angle, and has a wick that generates capillary force. ..

Further, Patent Document 2 discloses an evaporator for a mini loop heat pipe. This mini loop heat pipe evaporator includes a tubular body, upper, side and lower wicks, and liquid injection means and steam flow path means. The tubular body is a flat cylinder and has a space in which the liquid can be stored. Further, the upper wick, the upper circumference wick, and the lower wick are the inner surfaces of the lower part of the tubular body in order to form a space portion along the inner surface of the upper part of the tubular body, along the circumference on the side portion, and inside so that liquid can be stored. It is given along with.

Further, Patent Document 3 discloses a micro loop heat pipe. The inside of the evaporator in this micro loop heat pipe is partitioned by a partition wall made of a porous member, one section is a reservoir section, and the other section is formed by the porous member, and the working fluid is vaporized. The channel portion is configured so that the working fluid can horizontally separate the liquid phase and the vapor phase across the partition partition portion.

Japanese Unexamined Patent Publication No. 2008-215702 Japanese Unexamined Patent Publication No. 2005-233480 Japanese Unexamined Patent Publication No. 2010-78259

As described above, as the evaporator of the loop type heat pipe, a cylindrical type and a flat plate type have been conventionally proposed. Then, when a loop type heat pipe is mounted on an electronic device such as a mobile phone (smartphone) or a transportation device such as a vehicle or an airplane, a flat plate type that can further reduce the thickness of the evaporator may be adopted.

By the way, a structure can be assumed in which a groove for flowing a working fluid of a liquid phase is formed on an outer peripheral surface of an evaporator such as a wick in an evaporator adopting a flat plate type. However, when such a groove is formed on the plate surface, only the plate surface on the side opposite to the plate surface on which the groove is formed is used for cooling.
Further, a structure in which the evaporator in the evaporator adopting the flat plate type is hollow can be assumed. However, when the space is formed hollow in this way, for example, if the space becomes too large, the flow of the working fluid may be disturbed, for example, a part of the working fluid of the liquid phase flowing into the space may flow back. Then, when the flow of the working fluid is disturbed, the heat exchange rate decreases.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a heat exchanger or the like capable of cooling by both plate surfaces of an evaporator while suppressing a decrease in heat exchange rate. To do.

In order to achieve the above object, the inventions described below can be mentioned as means for solving the above problems. That is, the invention according to claim 1 has an evaporator that absorbs heat from the outside and evaporates the working fluid from the liquid phase to the gas phase, and condenses the working fluid of the gas phase derived from the evaporator. in the heat exchanger to circulate in the evaporator as a working fluid was liquid phase is, the evaporator is formed in a plate shape, and the outer body that have a space in which the working fluid flows inside the liquid phase, said space The outer peripheral body and the partition portion are provided inside and have a partition portion for partitioning the space, and the outer peripheral body and the partition portion are formed by a porous body that evaporates the working fluid of the liquid phase in the space to the gas phase while moving it by capillary force. The outer peripheral body is formed from a first covering portion provided on the downstream side in the inflow direction of the working fluid flowing into the space partitioned by the partition portion and covering the space, and from both sides of the first covering portion. It is a heat exchanger characterized by having a second covering portion that rises along the inflow direction and covers the space .
The invention according to claim 2 is characterized in that a plurality of the partition portions are provided in the space, and the distance between the partition portions is smaller than the thickness of the outer peripheral body formed in a flat plate shape. Item 1 is the heat exchanger.
The invention according to claim 3 is the heat exchanger according to claim 1 or 2, wherein the partition portion supports between the portions of the outer peripheral body that sandwich the space.
According to the fourth aspect of the present invention, the outer peripheral body has a first surface which is an outer peripheral surface orthogonal to the thickness direction of the outer peripheral body and a second surface which is an outer peripheral surface facing the first surface. The partition portion is continuous between the first surface side and the second surface side, and the working fluid of the liquid phase in the space is moved toward the first surface and the second surface by capillary force. The heat exchanger according to any one of claims 1 to 3, characterized in that.
In the invention according to claim 5, the partition portion is arranged such that the longitudinal direction of the partition portion on a plane orthogonal to the thickness direction of the outer peripheral body is along the direction in which the working fluid of the liquid phase flows into the space. The heat exchanger according to any one of claims 1 to 4, wherein the heat exchanger is made.
In the invention according to claim 6, the outer peripheral body is formed on the outer peripheral surface of the outer peripheral body along a direction intersecting the direction in which the working fluid of the liquid phase flows into the space, and the working fluid of the gas phase flows. The heat exchanger according to any one of claims 1 to 5, wherein the heat exchanger has a groove in a crossing direction.
According to a seventh aspect of the present invention, the evaporator has a housing for accommodating the outer peripheral body, and the housing has a direction in which the working fluid of the liquid phase flows into the space on the inner peripheral surface of the housing. The heat exchanger according to any one of claims 1 to 6, wherein the heat exchanger is formed along the line and has an inflow direction groove through which the working fluid of the gas phase flows.
The invention according to claim 8, before Symbol partition portion than said outer peripheral member is a heat exchanger according to any one of claims 1 to 7, wherein the effective pore diameter is small.
The invention according to claim 9 is the heat exchanger according to any one of claims 1 to 8, wherein the partition portion is provided as a separate body from the outer peripheral body.
According to a tenth aspect of the present invention, the outer peripheral body has a first surface which is an outer peripheral surface orthogonal to the thickness direction of the outer peripheral body and a second surface which is an outer peripheral surface facing the first surface. The heat exchanger according to any one of claims 1 to 9, wherein the surface side of the first surface and the second surface located on the upper side is thicker than the other surface side located on the lower side. is there.
The invention according to claim 11 is formed by a porous body which is housed in an evaporator of a heat exchanger, absorbs heat from the outside, and evaporates the working fluid of the liquid phase into the vapor phase while moving it by capillary force. a plate-shaped evaporation body which is an outer peripheral member having a space in which the working fluid flows inside the liquid phase, provided in said space, possess a partition portion for partitioning the space, the outer peripheral body A first covering portion provided on the downstream side in the inflow direction of the working fluid flowing into the space partitioned by the partition portion and covering the space, and rising from both sides of the first covering portion along the inflow direction. It is an evaporator characterized by having a second covering portion that covers the space .
The invention according to claim 12 is to absorb heat from a housing, a heating element housed inside the housing, and evaporate a working fluid from a liquid phase to a gas phase and flow out through a liquid tube. In a device including an evaporator for condensing a working fluid of a gas phase derived from the evaporator and a heat exchanger for circulating the working fluid of a liquid phase to the evaporator via a steam pipe as a working fluid of a liquid phase, the evaporator Has a housing body formed in a flat plate shape and a space formed in a flat plate shape and inserted into the housing, and a space in which the working fluid of the liquid phase flows into the housing, and the working fluid of the liquid phase in the space. It is provided with an evaporator formed by a porous body that evaporates into a gas phase while moving the fluid by a capillary force, and the evaporator includes a plurality of partition portions provided in the space and partitioning the space, and the evaporator. The first and second surfaces, which are the outer peripheral surfaces orthogonal to the thickness direction of the above, and the first surface and the first surface provided on the downstream side in the inflow direction of the working fluid flowing into the space partitioned by the partition portion. The third surface, which is the outer peripheral surface covering the space between the two surfaces, and the outer peripheral surface covering the space between the first surface and the second surface rising from both sides of the third surface along the inflow direction. and a fourth surface and the fifth surface is, the interval between the partitioning portion is smaller than the distance between the first surface side and the second surface side in the thickness direction of the evaporator body sandwiching the space It is a device characterized by this.

According to the invention of claim 1, it is possible to provide a heat exchanger capable of cooling by both plate surfaces of the evaporator while suppressing a decrease in the heat exchange rate.
According to the second aspect of the invention, it is possible to suppress a decrease in the heat exchange rate as compared with the case where the distance between the partition portions is thicker than the thickness of the heating element.
According to the invention of claim 3, deformation of the evaporator can be suppressed.
According to the invention of claim 4, the vaporization of the working fluid on the first surface and the second surface of the evaporator can be promoted.
According to the invention of claim 5, the working fluid of the liquid phase can be guided.
According to the invention of claim 6, the flow of the working fluid in the gas phase is promoted.
According to the invention of claim 7, the flow of the working fluid in the gas phase is promoted.
According to the invention of claim 8, the flow of the working fluid in the liquid phase is promoted.
According to the invention of claim 9, the material of the evaporator is suppressed.
According to the invention of claim 10, the transport resistance on the surface side of the evaporator located on the gas phase side is reduced.
According to the invention of claim 11, it is possible to provide an evaporator capable of cooling by both plate surfaces while suppressing a decrease in heat exchange rate.
According to the invention of claim 12, it is possible to provide an apparatus capable of cooling the evaporator by both plate surfaces while suppressing a decrease in the heat exchange rate.

It is a schematic block diagram which shows the loop type heat pipe which concerns on this embodiment. It is a schematic block diagram which shows the evaporator which concerns on this embodiment. (A) and (b) are diagrams for explaining the housing. (A) and (b) are perspective views of the wick. (A) and (b) are detailed views of the wick. (A) and (b) are detailed views of the flow of the working fluid in the wick. It is a simulation result of the relationship between the heat load and the pressure loss in the wick. (A) to (c) are diagrams for explaining a modified example of the wick. (A) to (b) are diagrams for explaining a modified example of the wick. (A) and (b) are diagrams illustrating an apparatus including a loop type heat pipe.

Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings.
<Structure of loop type heat pipe 100>
First, the configuration of the loop type heat pipe 100 to which the present embodiment is applied will be described with reference to FIG. Here, FIG. 1 is a schematic configuration diagram showing a loop type heat pipe 100 according to the present embodiment.
The loop type heat pipe 100 to which the present embodiment is applied includes a heating element (heating component, for example, a CPU of a computer) (not shown) provided inside a housing of an electronic device such as a mobile phone (smartphone) or a tablet terminal. , It is configured to circulate the working fluid in the annular device to cool it without supplying power from the outside.

More specifically, the loop type heat pipe 100 includes an evaporator 101 that evaporates the working fluid to cool the heating element (not shown) by utilizing the latent heat when the working fluid vaporizes, and the evaporator 101. It has a condenser 107 that dissipates heat from the vaporized working fluid and liquefies it. Further, the loop type heat pipe 100 includes a steam pipe (Vapor Line) 105 that sends the working fluid vaporized by the evaporator 101 to the condenser 107 and a liquid pipe that sends the working fluid liquefied by the condenser 107 to the evaporator 101. (Liquid Line) 109 is provided. The loop type heat pipe 100 of the present invention is filled with a working fluid that undergoes a phase change between the liquid phase and the gas phase. As the working fluid, for example, water, alcohol, ammonia or the like is used.

<Operation of loop type heat pipe 100>
Next, the operation in the loop type heat pipe 100, which is an example of the heat exchanger, will be described with reference to FIG.
First, the heat generated in the heating element (not shown) is transferred to the evaporator 101 (see arrow H1). The working fluid that has absorbed heat in the evaporator 101 is vaporized and sent to the condenser 107 through the steam pipe 105 (see arrow A1) (see arrow A2). The working fluid sent to the condenser 107 releases heat (see arrow H2) and liquefies. Then, the liquefied working fluid is sent to the evaporator 101 again through the liquid pipe 109 (see arrow A3) (see arrow A4).

<Structure of evaporator 101>
FIG. 2 is a schematic configuration diagram showing an evaporator 101 according to the present embodiment.
Next, the configuration of the evaporator 101 to which the present embodiment is applied will be described with reference to FIG.
As shown in FIG. 2, the evaporator 101 is provided inside an electronic device (not shown), and has a housing 110 that receives heat from a heating element (not shown) and a wick that is inserted inside the housing 110. It has 130 and.

Although the details will be described later, the housing 110 according to the present embodiment has a flat plate shape in general. Further, in the housing 110, the steam pipe 105 is connected to one side surface (end surface) 110a along the thickness direction of the flat plate, and the liquid pipe 109 is connected to the facing surface 110b facing the one side surface 110a.
Further, the inside of the housing 110 is filled with a working fluid. Then, in the internal space of the housing 110, the space on the liquid pipe 109 side of the wick 130 functions as a liquid reservoir 150 in which the working fluid of the liquid phase is housed.

<Operation of evaporator 101>
Next, the operation in the evaporator 101 will be described with reference to FIGS. 1 and 2.
The working fluid of the liquid phase that has permeated the wick 130 is heated and vaporized by the heat of a heating element (not shown) while moving in the wick 130 by the capillary force of the wick 130. The vaporized working fluid moves to the steam pipe 105 side (see arrow C1) and then is sent to the condenser 107 (see FIG. 1) via the steam pipe 105.

On the other hand, the working fluid liquefied by the condenser 107 (see FIG. 1) flows into the housing 110 through the liquid pipe 109 (see arrow A4). The working fluid that has flowed into the housing 110 permeates the wick 130 via the liquid reservoir 150. In this way, the above cycle is repeated without interruption of the flow of the working fluid on the outer peripheral surface of the wick 130. Then, the heat generated in the heating element (not shown) is transported from the evaporator 101 to the condenser 107 (see FIG. 1).

In the following description, the direction in which the working fluid is transferred from the liquid pipe 109 side to the vapor pipe 105 side in the evaporator 101 may be simply referred to as a transfer direction (see FIG. 2). Further, when explaining the position of the evaporator 101 in the internal space, the steam pipe 105 side in the transfer direction may be referred to as the downstream side, and the liquid pipe 109 side may be referred to as the upstream side.

Further, as shown in FIG. 2, the thickness direction of the housing 110, which is a flat plate-shaped member, may be simply referred to as the thickness direction. Further, in this thickness direction, the surface on one side (upper side in the drawing) may be referred to as the first surface side, and the side opposite to the first surface side (lower side in the drawing) may be referred to as the second surface side.
Further, the direction intersecting the transfer direction and the thickness direction, that is, the width direction of the housing 110 may be simply referred to as the width direction. Further, one side (left side in the figure) and the other side (right side in the figure) in the width direction may be simply referred to as one side and the other side, respectively.

<Structure of housing 110>
3A and 3B are diagrams for explaining the housing 110. More specifically, FIG. 3A is a perspective view of the main body 111 of the housing 110, and FIG. 3B is a perspective view of the lid 113 of the housing 110.

Next, the housing 110 will be described with reference to FIGS. 2, 3 (a) and 3 (b).
First, as shown in FIG. 2, the housing (evaporator housing) 110 is a hollow member having a substantially rectangular parallelepiped shape (plate shape), and has a main body 111 having one side opening and an opening of the main body 111. It has a lid 113 to cover. The housing 110 is formed of, for example, a metal such as aluminum or a resin.

Further, as shown in FIG. 3A, a substantially rectangular parallelepiped space is formed inside the main body 111. An outlet 111b, which is a through hole, is formed on the side surface (bottom surface) of the main body 111 facing the opening 111a.
Further, steam grooves 112 formed along the transfer direction are formed on both the first surface side and the second surface side of the inner peripheral surface of the main body 111. A plurality of steam grooves 112 (17 in the illustrated example) are arranged side by side at predetermined intervals in the width direction, which is an example of the inflow direction grooves. The steam groove 112 is provided on the downstream side in the transfer direction in the internal space of the main body 111, and is not provided on the upstream side. To be further described, the steam groove 112 is provided in a region facing the wick 130 and is provided on the downstream side of the wick 130 on the upstream side in the transfer direction (see FIG. 5B described later).

Further, as shown in FIG. 3B, the lid 113 is a plate-shaped member formed with dimensions covering the opening 111a of the main body 111, and an inflow port 113a which is a through hole is formed in the center of the plate surface. ing. In the illustrated example, the lid 113 is provided with the protruding portion 113b on the surface of the lid 113 facing the main body 111.

In addition, the housing 110 is composed of, for example, a plate surface having a side of about 60 mm to 550 mm and a thickness of about 20 mm to 200 mm. Further, the housing 110 is configured such that the ratio of the thickness to one side of the plate surface is, for example, about 3 to 333%.

Next, the assembly process of the housing 110 in the illustrated example will be described. First, as a preliminary step, the steam pipe 105 is connected to the outflow port 111b of the main body 111, and the liquid pipe 109 is connected to the inflow port 113a of the lid 113. After that, the wick 130 is inserted into the inside of the main body 111 through the opening 111a of the main body 111. Then, the opening 111a of the main body 111 is covered with the lid 113, and the lid 113 is fixed to the main body 111 by a well-known technique using, for example, welding or an adhesive. By this fixing, leakage of the working fluid from the inside of the housing 110 is suppressed.

As shown in FIG. 2, the wick 130 is arranged inside the main body 111 at a position separated from the lid 113. Further, by separating the wick 130 and the lid 113, it is possible to prevent the wick 130 from being damaged by the influence of heat and strain generated when the lid 113 is fixed to the main body 111.

<Structure of Wick 130>
4 (a) and 4 (b) are perspective views of the wick 130. More specifically, FIG. 4A is a perspective view of the wick 130 viewed from the downstream side in the transfer direction, and FIG. 4B is a perspective view of the wick 130 viewed from the upstream side in the transfer direction.
5 (a) and 5 (b) are detailed views of the wick 130. More specifically, FIG. 5A is a plan view of the wick 130 as viewed from the first plate surface 130a side, and FIG. 5B is a cross-sectional view taken along the line Vb-Vb of FIG. 5A.

Next, the configuration of the wick 130 will be described with reference to FIGS. 4 (a) and 4 (b) and FIGS. 5 (a) and 5 (b).
The wick 130, which is an example of the evaporator, is formed of a porous body made of a resin such as polytetrafluoroethylene (PTFE). The wick 130 generates capillary forces in the working fluid, resulting in movement of the working fluid.

The wick 130 is a flat plate-shaped (thin, substantially rectangular parallelepiped) member. The wick 130 has a first plate surface (first surface) 130a which is a plate surface facing one side in the thickness direction and a second plate surface (back surface, second surface) which is a surface along the first plate surface (front surface) 130a. Surface) 130b, one end surface 130c which is an end surface facing one side in the width direction, the other end surface 130d which is a surface along one end surface 130c, a downstream end surface 130e which is a side surface facing the downstream side in the transfer direction, and a downstream end surface 130e. It is provided with an upstream end surface 130f which is a surface along the above.

The effective pore diameter of the wick 130 is 0.1 to 20 μm. The wick 130 is not limited to the above-mentioned resin-made porous body, and has a large number of voids (pores) inside the porous metal (porous metal), ceramic porous, glass porous, porous fiber, and the like. ) Is formed as long as it is a material. The porosity of the wick 130 is 25% to 70%. Further, when a material having a low thermal conductivity is used as the wick 130, heat leakage in the evaporator 101 can be reduced. If it is desired to further reduce the heat leak, it is generally preferable to use a non-metal material having a thermal conductivity lower than that of the metal.

In addition, the wick 130 is composed of, for example, a plate surface having a long side of about 50 mm to 500 mm, a short side of about 10 mm to 400 mm, and a thickness of about 10 mm to 150 mm. Further, the wick 130 is configured such that the ratio of the thickness to the long side of the plate surface is, for example, about 2 to 300%.

Further, as shown in FIG. 4A, the wick 130 is provided along the width direction on each of the first plate surface (one side plate surface) 130a and the second plate surface (the other side plate surface) 130b. The lateral groove 133 to be formed is provided.

A plurality of lateral grooves 133, which is an example of crossing direction grooves, are formed side by side at predetermined intervals in the transfer direction. Further, in the illustrated example, three each are formed on the first plate surface 130a and the second plate surface 130b.

Here, the lateral groove 133 is formed at the central portion in the transfer direction on the first plate surface 130a, and is not formed at the end portion on the upstream side in the transfer direction.
As a result, an area in contact with the inner peripheral surface of the main body 111 is secured at the end portion of the wick 130 on the upstream side in the transfer direction of the first plate surface 130a. As a result, the sealing property between the first plate surface 130a of the wick 130 and the inner peripheral surface of the main body 111 is improved.

Further, as shown in FIG. 4A, the wick 130 is formed in a hollow shape with an opening at the downstream end surface 130e. In other words, the wick 130 has an introduction space 135 that opens at the upstream end face 130f. The introduction space 135 is covered with the downstream end surface 130e.

The introduction space 135 is continuous with the liquid reservoir 150 (see FIG. 2). As a result, the working fluid of the liquid phase contained in the liquid reservoir 150 can flow into the introduction space 135. As a result, a space for accommodating the working fluid of the liquid phase flowing in from the liquid reservoir 150 is secured. So to speak, by forming the introduction space 135, the capacity of the liquid reservoir 150 is increased.

In addition, unlike the illustrated example, the introduction space 135 is provided inside the wick 130 as shown in the illustrated example, as compared with the case where a groove (not shown) for flowing the working fluid of the liquid phase is formed on the outer peripheral surface of the wick 130. By providing the wick 130, it is possible to prevent the area where the outer peripheral surface of the wick 130 and the inner peripheral surface of the housing 110 come into contact with each other from being reduced.

Here, the illustrated introduction space 135 is formed in a substantially rectangular parallelepiped shape. The portion that sandwiches the introduction space 135 in the width direction is the side wall portion 136. Further, a portion that sandwiches the introduction space 135 in the thickness direction is a plate portion 138. In other words, the introduction space 135 is a space sandwiched between the side wall portions 136 and the plate portions 138. Further, the portion of the wick 130 other than the introduction space 135 is an example of the outer peripheral body.

Further, inside the illustrated introduction space 135, a plurality of support portions 137, which are examples of partition portions that partition the introduction space 135 apart from each other, are provided. Each of the support portions 137 has an elongated shape. More specifically, the support portion 137 is formed in a substantially rectangular parallelepiped shape whose longitudinal direction is along the transfer direction. In other words, the support portion 137 is arranged along the inflow direction of the working fluid (along the transfer direction) in a plane orthogonal to the thickness direction of the wick 130.

Here, the support portion 137 that partitions the introduction space 135 guides the working fluid that flows into the introduction space 135. This prevents the flow of the working fluid from being disturbed, such as the backflow of the working fluid flowing into the introduction space 135, as compared with a configuration in which the support portion 137 is not provided, for example.

Further, the support portion 137 makes the plate portions 138 sandwiching the introduction space 135 continuous in the thickness direction. Further, the support portion 137 supports the plate portion 138 from the inside of the wick 130. In other words, it supports between the portions of the wick 130 that sandwich the introduction space 135. As a result, the support portion 137 suppresses the deformation of the introduction space 135.

By forming the support portion 137, the introduction space 135 is partitioned (divided) into a plurality of introduction chambers 139. Each introduction chamber 139 has a substantially rectangular parallelepiped shape whose longitudinal direction is along the transfer direction. Further, the introduction chamber 139 opens at the upstream end surface 130f, but does not open at the downstream end surface 130e.

Further, as shown in FIG. 5A, the introduction chambers 139 are provided at predetermined intervals in the width direction. Further, the introduction chamber 139 is formed so as to extend from the end of the wick 130 on the upstream side in the transfer direction toward the downstream side. In other words, the introduction chamber 139 is not formed through the entire transfer direction of the wick 130. In addition, the introduction chamber 139 is formed only on the upstream side in the transfer direction in the wick 130.

Further, as shown in FIG. 5A, the introduction chamber 139 is formed so as to extend to a position overlapping the lateral groove 133 in the transfer direction. In other words, the introduction chamber 139 extends downstream of the lateral groove 133 in the transfer direction.

Next, the dimensions and arrangement of the support portion 137 and the introduction chamber 139 in the illustrated example will be described with reference to FIG. 5 (b).
The width L1 of the support portion 137 is smaller than the interval L2 of the support portion 137. Further, the width L1 of the support portion 137 is smaller than the thickness L3 of the wick 130. As a result, a space in the introduction chamber 139, that is, a space for accommodating the working fluid of the liquid phase is secured.

Further, the width L1 of the support portion 137 is smaller than the thickness L4 of the plate portion 138. As a result, the liquid transport capacity of the support portion 137 is enhanced, and the transport resistance of the plate portion 138 is reduced.
Further, the width L1 of the support portion 137 is larger than the interval L6 of the steam grooves 112. As a result, the heating of the working fluid that has reached the plate portion 138 from the support portion 137 is suppressed from being hindered by the steam groove 112.

Further, the distance L2 between the support portions 137 is smaller than the thickness L3 of the wick 130. This configuration will be described in detail later.
Further, the distance L2 between the support portions 137 is smaller than the width L7 of the side wall portion 136. As a result, the support portion 137 supports between the plate portions 138 while securing a space for accommodating the working fluid of the liquid phase.

Further, the distance L2 between the support portions 137 is smaller than the height L8 in the thickness direction of the introduction chamber 139. As a result, the transport resistance in the plate portion 138 is suppressed while ensuring a space for accommodating the working fluid of the liquid phase.
Further, the distance L2 between the support portions 137 is larger than the width L9 of the steam groove 112. More specifically, the distance L2 between the support portions 137 is larger than the sum of the width L9 of the steam groove 112 and the distance L6 of the steam groove 112. As a result, the heating of the working fluid that has reached the plate portion 138 from the support portion 137 is suppressed from being hindered by the steam groove 112.

By the way, the wick 130 configured in this way is inserted and provided inside the main body 111 (see FIG. 2) of the housing 110 as described above. More specifically, the wick 130 is fixed by being fitted inside the housing 110. Here, the wick 130 of the illustrated example is fixed between the wick 130 and the housing 110 without using a seal member (not shown). In addition, unlike this example, the wick 130 may be fixed by using a seal member.

When the wick 130 configured in this way is arranged in the main body 111 (see FIG. 2), the surfaces other than the upstream end surface 130f of the wick 130, that is, the first plate surface 130a, the second plate surface 130b, and one end surface The four surfaces of 130c and the other end surface 130d come into contact with the inner peripheral surface of the main body 111.
In addition, the wick 130 is arranged so that both side surfaces in the thickness direction and both side surfaces in the width direction are sandwiched by the main body 111.

Further, the wick 130 is arranged on the downstream side in the transfer direction in the internal space of the main body 111, and is formed with a size that leaves a space on the upstream side in the transfer direction (see FIG. 2). That is, the wick 130 is formed so as to be separated from the lid 113 in the transfer direction. Then, the gap formed between the wick 130 and the lid 113 constitutes the liquid reservoir 150 (see FIG. 2) as described above.

Further, as shown in FIG. 2, the wick 130 is arranged inside the main body 111 at a position separated from the inner peripheral surface on the one side surface 110a side. By forming a space inside the main body 111 on the downstream side in the transfer direction from the wick 130, a flow path for the working fluid vaporized by the wick 130 toward the steam pipe 105 is secured.

The wick 130 may be formed into a flat plate shape, and then an introduction chamber 139 or the like may be formed by using a well-known technique such as die-sinking electric discharge machining. Alternatively, the wick 130 may be formed by a so-called 3D printer or the like in which materials are laminated to form a three-dimensional object based on three-dimensional data.

<Flow of working fluid in Wick 130>
Next, the flow of the working fluid in the wick 130 will be described with reference to FIGS. 5 (a) and 5 (b).

First, as shown in FIG. 5A, the working fluid vaporized in the wick 130 flows in the steam groove 112 toward the downstream side in the transfer direction (see arrow C1). Further, a part of the vaporized working fluid flows through the lateral groove 133 along the width direction (see arrow C5), then passes through the steam groove 112, and flows toward the downstream side in the transfer direction.

On the other hand, the working fluid of the liquid phase supplied from the liquid reservoir 150 (see FIG. 2) flows through the introduction chamber 139 downstream in the transfer direction (see arrow C3) and permeates the wick 130. Then, the working fluid that has permeated the wick 130 permeates (flows) in the thickness direction in addition to the transfer direction and the width direction of the wick 130.

More specifically, as shown in FIG. 5B, the working fluid moves from the introduction chamber 139 toward both sides in the thickness direction via the support portion 137. That is, the working fluid moves toward the first plate surface 130a and the second plate surface 130b. In addition, the working fluid moves from the support portion 137 toward the heating element (not shown) (in the direction across the wick 130 in the thickness direction) (see arrow C7 in the figure).

Here, in the present embodiment, the length of the working fluid crossing the wick 130 in the width direction is shortened by forming the support portion 137. As a result, the pressure loss (pressure resistance, transport resistance) of the working fluid is reduced, and as a result, the decrease in heat exchange efficiency in the loop type heat pipe 100 is suppressed. In addition, in the illustrated example, the decrease in heat exchange efficiency is suppressed by reducing the interval L2 of the support portions 137.

<Details of working fluid flow>
6 (a) and 6 (b) are detailed views of the flow of the working fluid in the wick 130. More specifically, FIG. 6 (a) is a diagram for explaining the flow of the working fluid on the other side of the wick 130 in the width direction in FIG. 5 (b), and FIG. 6 (b) shows the wick 130 placed vertically. It is a figure explaining the flow of the working fluid at the time.

Next, the flow of the working fluid in the wick 130 will be described with reference to FIGS. 6 (a) and 6 (b).
First, with reference to FIG. 6A, the operation in which the working fluid of the liquid phase at the position P0 of the plate portion 138 is transported to the position P1 of the plate portion 138, that is, the position opposite to the introduction chamber 139. I will explain. In the illustrated example, a support portion 137 is arranged between the position P0 and the position P1. As a result, the working fluid is transported from the position P0 to the position P1 via the support portion 137 (see the path R1 in the figure).

On the other hand, unlike the illustrated example, when the support portion 137 is not formed, it is necessary to transport the support portion 137 from the position P0 to the position P1 via the side wall portion 136 (see route R2 in the figure). In this configuration, the route through which the working fluid is transported becomes longer as compared with the case where the fluid is transported via the support portion 137 (see route R1 in the figure). In addition, the farther the distance from the position P0 (position P1) to the side wall portion 136 (the farther the position is from the side wall portion 136), the longer the path through which the working fluid is transported. As a result, the transport efficiency of the working fluid is reduced.

Therefore, as shown in FIG. 6A, the transport efficiency of the working fluid is improved by providing the support portion 137. Further, as described with reference to FIG. 5B, the distance L2 between the support portions 137 is smaller than the thickness L3 of the wick 130. By arranging the support portion 137 in this way, the plate surface of the plate portion 138 can be effectively used and the transport efficiency of the working fluid can be improved.

Here, the distance L2 between the support portions 137 may be about the thickness L3 of the wick 130. Alternatively, the distance L2 between the support portions 137 may be about the height L8 in the thickness direction of the introduction chamber 139. More specifically, the distance L2 between the support portions 137 may be about 0.5 to 1.5 times the thickness L3 of the wick 130. Further, the distance L2 between the support portions 137 may be 0.8 to 1.2 times the thickness L3 of the wick 130.

Next, the flow of the working fluid when the wick 130 is vertically placed will be described with reference to FIGS. 1 and 6 (b).
Depending on the usage mode of the electronic device (not shown) provided with the housing 110, it is assumed that the transfer direction of the wick 130 is along the vertical direction, that is, it is installed vertically.

In this way, even when the wick 130 is placed vertically, the support portion 137 assists the moving fluid in the transfer direction (see arrow C9 in the figure). As a result, the plate surface of the plate portion 138 can be effectively used and the transport efficiency of the working fluid can be improved.

<Pressure loss>
FIG. 7 is a simulation result of the relationship between the heat load and the pressure loss in the wick 130.
Next, the simulation result of the pressure loss in the wick 130 will be described with reference to FIG. 7. In FIG. 7, the simulation result of the wick 130 provided with the support portion 137 as in the present embodiment is shown by a solid line as “with the support portion”, and the support portion 137 is shown as a comparative example different from the present embodiment. The simulation result of the wick 130 not provided is shown by a broken line as "no support". Further, in this simulation, the penetration rate is 6 × ^10-13 m ² , the width L1 of the support portion 137 is 7 mm, the distance L2 of the support portion 137 is 7 mm, the thickness L3 of the wick 130 is 10 mm, and the transfer direction of the wick 130. The length of the was 50 mm.

As shown in FIG. 7, it was confirmed that the pressure loss increased as the heat load increased, both with and without the support portion. On the other hand, it was confirmed that the pressure loss with the support portion was suppressed as compared with the case without the support portion. That is, it was confirmed that the pressure loss in the wick 130 is reduced by providing the support portion 137 in the wick 130. For example, in FIG. 7, when the heat load is 200 W, the pressure loss in the wick 130 is about 80% as compared with the case where the support portion 137 is not provided in the wick 130 by providing the support portion 137 in the wick 130. It was confirmed that it was reduced.

<Modification example>
8 (a) to 8 (c) and FIGS. 9 (a) to 9 (b) are diagrams for explaining a modification of the wick 130.
Next, a modified example of the wick 130 will be described with reference to FIGS. 8 (a) to 8 (c) and FIGS. 9 (a) to 9 (b). The same parts as those of the wick 130 shown in FIG. 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

First, the wick 130 shown in FIG. 4A is formed as a whole of the wick 130, but it may be formed by a plurality of members.
For example, as in the wick 230 shown in FIG. 8A, the support portion 237 is configured as a separate member (separate body), and the support portion 237 is inserted into the introduction space 235 formed in the wick 230. Good. By separating the support portion 237 in this way, the amount of material used when manufacturing the wick 230 is suppressed.

Here, the support portion 237 may be formed of a member different from the side wall portion 136 and the plate portion 138. For example, the effective pore diameter of the support portion 237 may be larger than that of the side wall portion 136 and the plate portion 138. Specifically, the effective pore diameter of the support portion 237 may be 10 to 20 μm, and the effective pore diameter of the side wall portion 136 and the plate portion 138 may be 1 to 2 μm. This promotes liquid transport by the support portion 237, while promoting vaporization of the working fluid in the plate portion 138 and the like.

Further, although it has been explained that the wick 130 shown in FIG. 4 (a) forms a substantially rectangular parallelepiped introduction chamber 139, the shape of the introduction chamber 139 can be changed as long as the working fluid of the liquid phase can flow in. There is no particular limitation.
For example, as in the wick 330 shown in FIG. 8B, a substantially columnar introduction chamber 339 may be formed. The inner diameter of the introduction chamber 339 is, for example, 25 mm. The thickness of the wick 330 is, for example, 30 mm. Therefore, the minimum distance from the introduction chamber 339 to the outer peripheral surface of the wick 330 is 2.5 mm.

Further, as in the wick 330 shown in FIG. 8B, in addition to the horizontal groove 333 extending in the width direction, the vertical groove 334 extending in the transfer direction is formed on the first plate surface 330a and the second plate surface 330b. It may be. That is, on the first plate surface 330a and the second plate surface 330b, the horizontal groove 333 and the vertical groove 334 may be formed in directions intersecting each other. Then, the working fluid vaporized on the outer peripheral surface of the wick 330 flows through the vertical groove 334 toward the downstream side in the transfer direction.

The vertical groove 334 is formed so as to extend from the end of the wick 330 on the downstream side in the transfer direction toward the upstream side. That is, the flute 334 is formed only on the downstream side in the transfer direction of the wick 330. This prevents the liquid phase working fluid from flowing into the flutes 334.

Here, the depth L12 of the vertical groove 334 is formed deeper than the depth L11 of the horizontal groove 333. By forming the vertical groove 334, the distance L13 from the surface of the first plate surface 330a side (second plate surface 330b side) to the introduction chamber 339 is shortened. As a result, the transport resistance of the working fluid is reduced.
Further, by adjusting the depth L12 of the vertical groove 334, the minimum distance of the working fluid from the introduction chamber 339 to the outer peripheral surface of the wick 330 can be adjusted to a predetermined distance or less (10 mm or less, etc.).

Further, although it has been explained that the wick 130 shown in FIG. 4A has a substantially rectangular parallelepiped shape, the shape thereof is not particularly limited as long as it is a plate-shaped member. Further, although it has been explained that the wick 130 shown in FIG. 4A includes a plurality of support portions 137, the number of support portions 137 is not particularly limited.

For example, as in the wick 430 shown in FIG. 8C, both ends in the width direction may be configured so as not to form corners. That is, both ends of the wick 430 in the width direction may be formed by rounding. In addition, as long as it has a flat plate shape, it may have another shape. For example, it may be a circular flat plate (disk), a polygonal flat plate, or the like.
Further, as in the wick 430 shown in FIG. 8C, one support portion 437 may be provided in the introduction space 435.

Further, in the wick 130 shown in FIG. 4A, the plate portion 138 on the first plate surface 130a side and the plate portion 138 on the second plate surface 130b side have the same configuration, but are different from each other. You may.
For example, as in the wick 530 shown in FIG. 9A, the thickness L21 of the first plate portion 538 on the first plate surface 530a side and the thickness L23 of the second plate portion 539 on the second plate surface 530b side. May be different.

In this example, the working fluid of the liquid phase collects on the 539 side (lower side in the figure) of the second plate portion. Then, the thickness L23 of the facing first plate portion 538 is formed thicker than the thickness L21 of the second plate portion 539 in which the working fluid of the liquid phase is collected. As a result, the transport resistance in the first plate portion 538 is suppressed.

Further, although the wick 130 shown in FIG. 4A explained that the support portion 137 extends continuously in the transfer direction, the support portion 137 may be configured to be divided in the transfer direction.
For example, as in the wick 630 shown in FIG. 9B, a plurality of columnar support portions 637 may be provided in the introduction space 635. In this example, a plurality of support portions 637 (three support portions 637) are arranged along the transfer direction. Further, a plurality (two rows) of rows of the support portions 637 are provided.

Although not shown, the direction in which the lateral groove 133, the support portion 137, the introduction chamber 139, and the like extend is not particularly limited. For example, each may be formed obliquely with respect to the transfer direction.
Further, although the support portion 137 has been described as a configuration formed along a plane orthogonal to the width direction, the support portion 137 is formed in another direction in another direction, for example, a configuration formed along a plane orthogonal to the thickness direction. May be done.

Further, the lateral groove 133 may be formed on one end face 130c and the other end face 130d of the wick 130.
Further, the steam groove 112 may be provided on one end surface 130c of the wick 130 and a surface facing the other end surface 130d.

10 (a) and 10 (b) are diagrams illustrating an apparatus including a loop type heat pipe 100. More specifically, FIG. 10A is a diagram illustrating a mobile phone 800 including a loop type heat pipe 100, and FIG. 10B is a diagram illustrating a transportation device 900 including the loop type heat pipe 100. is there.
Next, the mobile phone 800 and the transportation device 900, which are examples of electronic devices including the loop type heat pipe 100, will be described with reference to FIGS. 10 (a) and 10 (b).

As shown in FIG. 10A, the loop type heat pipe 100 is provided in an electronic device such as a mobile phone 800. The illustrated mobile phone 800 is a so-called smartphone, and includes a central processing unit (CPU) 801 and a loop type heat pipe 100 for cooling the central processing unit 801 and a housing 803 for accommodating these. Then, the heat generated in the central processing unit 801 which is an example of the heat generating component is transferred to the evaporator 101 and discharged by the condenser 107. The condenser 107 in the illustrated example has a plurality of folded portions in order to secure a heat dissipation area.
As shown in the illustrated example, the thickness of the mobile phone 800 can be suppressed by forming the evaporator 101 provided in the mobile phone 800 in a flat plate shape.

Further, as shown in FIG. 10B, the loop type heat pipe 100 may be provided in a transportation device 900 such as an automobile or an airplane. The transportation device 900, which is an example of the device, has heat generating parts 901 and 903 such as an internal combustion engine. Further, each of the heat generating parts 901 and 903 is fixed to both plate surfaces of the plate-shaped evaporator 101 formed in a plate shape by applying grease, screws, or the like. Then, the evaporator 101 cools the heat generating parts 901 and 903 on both plate surfaces thereof.

By the way, although various embodiments and modifications have been described above, it is of course possible to combine these embodiments and modifications.
Further, the present disclosure is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist of the present disclosure.

100 ... Loop type heat pipe, 101 ... Evaporator, 105 ... Steam pipe, 107 ... Condenser, 109 ... Liquid pipe, 110 ... Housing, 130 ... Wick, 133 ... Horizontal groove, 135 ... Introduction space, 137 ... Support, 139 … Introduction room

Claims (12)

It has an evaporator that absorbs heat from the outside and evaporates the working fluid from the liquid phase to the gas phase, and condenses the working fluid of the gas phase derived from the evaporator to the evaporator as the working fluid of the liquid phase. In the recirculating heat exchanger
The evaporator is
Formed in a plate shape, and the outer body that have a space in which the working fluid flows inside the liquid phase,
A partition provided in the space and partitioning the space is provided .
The outer peripheral body and the partition portion are formed of a porous body that evaporates the working fluid of the liquid phase in the space into the gas phase while moving it by capillary force.
The outer peripheral body is provided on the downstream side in the inflow direction of the working fluid flowing into the space partitioned by the partition portion, and covers the space with a first covering portion and both sides of the first covering portion in the inflow direction. A heat exchanger characterized by having a second covering portion that rises along and covers the space . A plurality of the partition portions are provided in the space.
The heat exchanger according to claim 1, wherein the distance between the partition portions is smaller than the thickness of the outer peripheral body formed in a flat plate shape. The heat exchanger according to claim 1 or 2, wherein the partition portion supports between the portions of the outer peripheral body that sandwich the space. The outer peripheral body has a first surface which is an outer peripheral surface orthogonal to the thickness direction of the outer peripheral body and a second surface which is an outer peripheral surface facing the first surface.
The partition portion is continuous between the first surface side and the second surface side, and the working fluid of the liquid phase in the space is moved toward the first surface and the second surface by capillary force. The heat exchanger according to any one of claims 1 to 3, wherein the heat exchanger is characterized. The partition portion is characterized in that the longitudinal direction of the partition portion on a plane orthogonal to the thickness direction of the outer peripheral body is arranged along the direction in which the working fluid of the liquid phase flows into the space. The heat exchanger according to any one of 1 to 4. The outer peripheral body is characterized by having an intersecting direction groove formed on the outer peripheral surface of the outer peripheral body along a direction intersecting the direction in which the working fluid of the liquid phase flows into the space and in which the working fluid of the gas phase flows. The heat exchanger according to any one of claims 1 to 5. The evaporator has a housing that houses the outer peripheral body, and has a housing.
The housing has an inflow direction groove formed on the inner peripheral surface of the housing along the direction in which the working fluid of the liquid phase flows into the space, and the working fluid of the gas phase flows. The heat exchanger according to any one of 6. Before Symbol partition portion, said from the outer circumferential member, the heat exchanger of any one of claims 1 to 7, wherein the effective pore diameter is small. The heat exchanger according to any one of claims 1 to 8, wherein the partition portion is provided as a separate body from the outer peripheral body. The outer peripheral body has a first surface which is an outer peripheral surface orthogonal to the thickness direction of the outer peripheral body and a second surface which is an outer peripheral surface facing the first surface.
The heat exchanger according to any one of claims 1 to 9, wherein the surface side of the first surface and the second surface located on the upper side is thicker than the other surface side located on the lower side. It is a flat plate-shaped evaporator that is housed in the evaporator of a heat exchanger and is formed of a porous body that absorbs heat from the outside and evaporates to the gas phase while moving the working fluid of the liquid phase by capillary force. hand,
An outer peripheral body having a space for the working fluid of the liquid phase to flow inside,
Provided in the space, it possesses a partition portion for partitioning the space,
The outer peripheral body is provided on the downstream side in the inflow direction of the working fluid flowing into the space partitioned by the partition portion, and covers the space with a first covering portion and both sides of the first covering portion in the inflow direction. An evaporator characterized by having a second covering portion that rises along the space and covers the space . With the housing
A heating element housed inside the housing and
It is provided with an evaporator that absorbs heat from the heating element, evaporates the working fluid from the liquid phase to the gas phase, and flows out through the liquid pipe, and condenses the working fluid of the vapor phase guided from the evaporator to condense the working fluid of the liquid phase. In a device including a heat exchanger that circulates as a working fluid to the evaporator via a steam pipe.
The evaporator is
The housing formed in a flat plate shape and
It is formed in a flat plate shape and inserted into the housing, and has a space inside where the working fluid of the liquid phase flows in. At the same time, the working fluid of the liquid phase in the space is moved to the gas phase by the capillary force. With an evaporator formed by a porous body to be evaporated,
The evaporative fluid is partitioned by a plurality of partition portions provided in the space and partitioning the space, first and second surfaces which are outer peripheral surfaces orthogonal to the thickness direction of the evaporative fluid, and the partition portions. The third surface, which is provided on the downstream side in the inflow direction of the working fluid flowing into the space and covers the space between the first surface and the second surface, and the third surface from both sides of the third surface. It has fourth and fifth surfaces that rise along the inflow direction and are outer peripheral surfaces that cover the space between the first surface and the second surface .
An apparatus characterized in that the distance between the partition portions is smaller than the distance between the first surface side and the second surface side that sandwich the space in the thickness direction of the evaporator.

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