Heat exchanger, evaporator, device and manufacturing method

Abstract

To provide a heat exchanger, etc. with improved heat exchange efficiency.SOLUTION: A heat exchanger includes an evaporator that evaporates liquid-phase work fluid by absorbing heat from outside. In the heat exchanger, a gas-phase work fluid flowing out from the evaporator is condensed and recirculated to the evaporator as a liquid-phase work fluid. The evaporator includes: an evaporation body that is formed by a porous body and guides the liquid-phase work fluid to an outer surface by using capillary force for evaporation; and an accommodation body that accommodates the evaporation body and has an inner surface opposing to the outer surface. A guide passage for guiding the gas-phase work fluid to a predetermined direction is provided on the outer surface side of the evaporation body. The heat exchanger includes a guide layer that is a porous layer provided along the inner surface of the accommodation body and covering at least part of the guide passage and that guides the liquid-phase work fluid toward the guide passage.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a heat exchanger, an evaporator, an apparatus, and a manufacturing method.

Background Art

[0002] Patent Document 1 discloses a loop heat pipe provided with wicks that generate capillary force and are respectively provided inside an evaporation section, a condensation section, and a liquid return pipe in order to efficiently cool a heat generating component regardless of the installation angle.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in recent years, with the miniaturization and high performance of devices such as electronic devices, the heat generation density of heat generating bodies provided in the devices has been increasing. Therefore, it is required to efficiently remove a high heat flux from the heat generating bodies provided in the devices. Therefore, an object of the present invention is to provide a heat exchanger or the like with an improved heat exchange rate.

Means for Solving the Problems

[0005] For this purpose, the technology disclosed in this specification has an evaporator that absorbs heat from the outside to evaporate the working fluid in the liquid phase, and a heat exchanger that condenses the gaseous working fluid flowing out of the evaporator and recirculates it as the working fluid in the liquid phase to the evaporator. The evaporator includes an evaporator body formed by a porous body that guides the working fluid in the liquid phase to the outer surface by capillary force and evaporates it, and a housing that houses the evaporator body and has an inner surface facing the outer surface. A guide path for guiding the gaseous working fluid in a predetermined direction is provided on the outer surface side of the evaporator body, and a porous layer provided along the inner surface of the housing and covering at least a part of the guide path, the porous layer including a guide layer for guiding the working fluid in the liquid phase toward the guide path, is a heat exchanger. Here, the thickness of the guide layer is preferably 50 μm or less. Further, the thickness of the guide layer is preferably 1 / 10 or less of the dimension of the guide path in the direction orthogonal to the inner surface. Further, the evaporator body is provided with a plurality of the guide paths arranged side by side, and the thickness of the guide layer is preferably 10 times or less of the effective pore diameter of the sandwiched portion sandwiched between two of the guide paths in the evaporator body. Further, the thickness of the guide layer is preferably thicker on the end side than on the central side of the guide path. Further, the evaporator body is provided with a plurality of the guide paths arranged side by side, and the effective pore diameter of the guide layer is preferably larger than that of the sandwiched portion sandwiched between two of the guide paths in the evaporator body. Further, the guide layer is preferably fused to the inner surface of the housing. Further, the housing and the evaporator body are preferably integrally formed. Further, the evaporator body is provided with a plurality of the guide paths arranged side by side, and the sandwiched portion sandwiched between two of the guide paths in the evaporator body and the guide layer are preferably integrally formed.

[0006] From another perspective, the technology disclosed in this specification has an evaporator that absorbs heat from the outside to evaporate the working fluid in the liquid phase, and a heat exchanger that condenses the gaseous working fluid flowing out of the evaporator and recirculates it as the working fluid in the liquid phase to the evaporator. The evaporator includes an evaporator body formed of a porous body that guides the working fluid in the liquid phase to the outer surface by capillary force and evaporates it, and a housing that houses the evaporator body and has an inner surface facing the outer surface. The evaporator body is integrally formed with the housing, and a plurality of guide paths for guiding the gaseous working fluid in a predetermined direction are provided on the outer surface side, and a porous layer provided along the inner surface of the housing and covering at least a part of the guide paths, having a thickness of 50 μm or less, and including a guide layer for guiding the working fluid in the liquid phase toward the guide paths. The guide layer has a larger effective pore diameter than the sandwiched portion sandwiched between two of the guide paths in the evaporator body. It is a heat exchanger.

[0007] From another perspective, in an evaporator that absorbs heat from the outside to evaporate the working fluid in the liquid phase and causes it to flow out as a gaseous working fluid, and the gaseous working fluid that has flowed out condenses and recirculates as the working fluid in the liquid phase, it includes an evaporator body formed of a porous body that guides the working fluid in the liquid phase to the outer surface by capillary force and evaporates it, and a housing that houses the evaporator body and has an inner surface facing the outer surface. On the outer surface side of the evaporator body, guide paths for guiding the gaseous working fluid in a predetermined direction are provided, and it is an evaporator including a porous layer provided along the inner surface of the housing and covering at least a part of the guide paths, and including a guide layer for guiding the working fluid in the liquid phase toward the guide paths.

[0008] From another perspective, the technology disclosed in this specification has a heating element and an evaporator that absorbs heat from the heating element to evaporate a working fluid in a liquid phase. The device condenses the gaseous working fluid flowing out of the evaporator and recirculates it as a liquid-phase working fluid to the evaporator. The evaporator is formed of a porous body and includes an evaporator body that guides the liquid-phase working fluid to the outer surface by capillary force for evaporation, and a container that houses the evaporator body and has an inner surface facing the outer surface. A guide path for guiding the gaseous working fluid in a predetermined direction is provided on the outer surface side of the evaporator body, and a porous layer provided along the inner surface of the container and covering at least a part of the guide path, the porous layer including a guide layer for guiding the liquid-phase working fluid toward the guide path.

[0009] From another perspective, the technology disclosed in this specification is a manufacturing method for manufacturing a heat exchanger that has an evaporator that absorbs heat from the outside to evaporate a working fluid in a liquid phase, and condenses the gaseous working fluid flowing out of the evaporator and recirculates it as a liquid-phase working fluid to the evaporator. The evaporator is formed of a porous body and includes an evaporator body that guides the liquid-phase working fluid to the outer surface by capillary force for evaporation, and a container that houses the evaporator body and has an inner surface facing the outer surface. A guide path for guiding the gaseous working fluid in a predetermined direction is provided on the outer surface side of the evaporator body, and a porous layer provided along the inner surface of the container and covering at least a part of the guide path, the porous layer including a guide layer for guiding the liquid-phase working fluid toward the guide path. The manufacturing method includes a step of forming the container and a step of forming the guide layer by an additive manufacturing apparatus.

Advantages of the Invention

[0010] According to the technology disclosed in this specification, it is possible to manufacture a heat exchanger with an improved heat exchange rate.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0012] Hereinafter, with reference to the accompanying drawings, this embodiment will be described in detail. <Schematic Configuration of Loop Heat Pipe 1> FIG. 1 is a schematic configuration diagram showing a loop heat pipe 1 according to this embodiment. First, with reference to FIG. 1, the configuration of the loop heat pipe 1 to which this embodiment is applied will be described. The loop heat pipe 1 to which this embodiment is applied is a heat exchanger, and is configured to circulate a working fluid in order to cool a heat generating body 10 such as a central processing unit (CPU) provided in, for example, an electronic device, etc., without supplying power from the outside.

[0013] Specifically, the loop heat pipe 1 has an evaporator 101 that evaporates the working fluid in order to cool the heat generating body 10 by using the latent heat when the working fluid vaporizes, and a condenser 107 that dissipates heat from the working fluid vaporized in the evaporator 101 and liquefies it.

[0014] In addition, the loop heat pipe 1 includes a vapor line 105 that sends the working fluid vaporized in the evaporator 101 to the condenser 107, and a liquid line 109 that sends the working fluid liquefied in the condenser 107 to the evaporator 101. The loop heat pipe 1 is filled with a working fluid that undergoes a phase change between the liquid phase and the gas phase. Note that, for example, water, alcohol (e.g., ethanol), ammonia, acetone, etc. are used as the working fluid.

[0015] <Operation of the loop heat pipe 1> Next, with reference to FIG. 1, the operation inside the loop heat pipe 1 will be described. The heat generated in the heating element 10 is transmitted to the evaporator 101 (see arrow C1). The working fluid that has absorbed heat in the evaporator 101 vaporizes and is sent to the condenser 107 via the vapor line 105 (see arrow A1) (see arrow A2). The working fluid sent to the condenser 107 releases heat through the radiator 70 (see arrow C2) and liquefies. Then, the liquefied working fluid is sent back to the evaporator 101 via the liquid line 109 (see arrow A3) (see arrow A4).

[0016] In this way, the loop heat pipe 1 functions as a powerless fluid device. Additionally, the loop heat pipe 1 is a two-phase heat transfer device that uses the capillary force of the fluid by a porous body as a driving source. Further, the loop heat pipe 1 is a two-phase fluid loop that performs heat transfer by utilizing the condensation and evaporation of the working fluid, and can perform long-distance and large-volume heat transfer. Also, the loop heat pipe 1 has a simple structure and can be arranged flexibly.

[0017] <Configuration of the evaporator 101> Next, with reference to FIG. 1, the configuration of the evaporator 101 to which the present embodiment is applied will be described. As shown in FIG. 1, the evaporator 101 has an evaporator main body 110 provided to transmit heat from the heating element 10, and a wick 130 provided inside the evaporator main body 110.

[0018] The evaporator body 110 is a hollow member with a generally rectangular parallelepiped shape (flat plate shape). To explain further, the evaporator body 110 is an example of a container that houses the wick 130. This evaporator body 110 is formed of, for example, a metal such as aluminum or copper, or a resin. The evaporator body 110 has, for example, a length of one side of the plate surface of about 10 mm to 500 mm and a dimension in the thickness direction of about 2 mm to 50 mm. Also, the evaporator body 110 is configured with a ratio of the length of one side of the plate surface of the evaporator body 110 to the thickness of the evaporator body 110 of about 0.4 to 20%.

[0019] Here, the evaporator body 110 includes a first side plate 113 that constitutes a first plate surface, and a second side plate 114 that is provided at a predetermined distance from the first side plate and constitutes a second plate surface. Here, the heating element 10 is provided on the first side plate 113. That is, the first side plate 113 functions as a heat receiving surface in the evaporator body 110.

[0020] Inside the evaporator body 110, that is, in the region sandwiched by the first side plate 113 and the second side plate 114, a substantially rectangular parallelepiped-shaped internal space R0 is formed. Inside this internal space R0, the wick 130 is provided. This wick 130 divides the internal space R0 of the evaporator body 110 into a liquid phase region R1 and a gas phase region R3. To explain further, in the internal space R0 of the evaporator 101, the space on the liquid pipe 109 side of the wick 130 is the liquid phase region R1 through which the liquid-phase working fluid passes. Also, in the internal space R0 of the evaporator 101, the space on the vapor pipe 105 side of the wick 130 is the gas phase region R3 through which the gas-phase working fluid passes.

[0021] The wick 130 according to this embodiment is generally flat-plate-shaped. Further, the wick 130 is formed of a porous body such as a porous metal. This wick 130 generates a capillary force in the working fluid, and as a result, moves the working fluid. The effective pore diameter of the wick 130 is 0.1 to 20 μm. Further, the porosity of the wick 130 is 25 to 70%. Note that the method for measuring the effective pore diameter and the porosity is not particularly limited. For example, it may be measured by apparent density measurement by the immersion method in water, pore diameter distribution measurement by capillary flow, or pore observation by X-ray CT.

[0022] Further, the wick 130 is not limited to the above-described porous body made of metal, and may be a porous body made of resin such as polytetrafluoroethylene (PTFE), a ceramic porous body, a glass porous body, porous fibers, etc., as long as it is a material in which a large number of pores, that is, voids are formed inside. Also, when a material with low thermal conductivity is used as the wick 130, heat leakage in the evaporator 101 can be reduced. Note that when it is desired to further reduce heat leakage, it is generally preferable to use a non-metal material with a lower thermal conductivity than that of metal. Further, the wick 130 may be formed of a material with a lower thermal conductivity than that of the first side plate 113.

[0023] Here, the wick 130 is provided with its plate surface sandwiched between the first side plate 113 and the second side plate 114. Further, the wick 130 is configured, for example, to have a size such that one side is about 5 mm to 400 mm and the thickness is about 1 mm to 40 mm. Further, the wick 130 is configured to have a size such that the ratio of the thickness to one side of the plate surface is, for example, about 0.25 to 20%.

[0024] <Operation of the evaporator 101> Next, the operation inside the evaporator 101 will be described. First, the liquid-phase working fluid sent to the evaporator 101 by the liquid pipe 109 flows into the liquid-phase region R1 of the evaporator main body 110 (see arrow B1).

[0025] The working fluid flowing into the evaporator main body 110 penetrates into the wick 130 within the evaporator main body 110. The penetrated working fluid moves toward the first side plate 113, which is the heat receiving surface, by the capillary force of the wick 130 (see arrow B2), and is heated by the heat of the heating element 10 and vaporized. This vaporized working fluid moves toward the vapor pipe 105 side while passing through a vapor groove 133 (described later) (see arrow B4).

[0026] Here, on the wick outer surface (outer surface) 135 side of the wick 130, as the vaporized working fluid moves toward the vapor pipe 105, the liquid-phase working fluid that has penetrated into the wick 130 moves toward the wick outer surface 135 of the wick 130. Then, this liquid-phase working fluid vaporizes and moves to the vapor pipe 105. In this way, the cycle described above is repeated without interruption of the flow of the working fluid on the wick outer surface 135 side of the wick 130. And the heat generated in the heating element 10 is transported from the evaporator 101 to the condenser 107 as described above.

[0027] In the following description, the thickness direction of the evaporator 101, that is, the vertical direction in FIG. 1, may be simply referred to as the vertical direction. Also, the upper side in FIG. 1 may be simply referred to as the upper side, and the lower side in FIG. 1 may be simply referred to as the lower side. Further, the direction in which the working fluid is transferred (the flowing direction) in the evaporator 101, that is, the left-right direction in FIG. 1, may be referred to as the transfer direction (flow direction). Also, the liquid pipe 109 side in the evaporator 101, that is, the right side in FIG. 1, may be referred to as the upstream side, and the vapor pipe 105 side in the evaporator 101, that is, the left side in FIG. 1, may be referred to as the downstream side. Further, the direction intersecting the vertical direction and the transfer direction, that is, the depth direction of the paper surface in FIG. 1, may be referred to as the width direction. Also, the front side of the paper surface in FIG. 1 may be referred to as one side, and the back side of the paper surface may be referred to as the other side.

[0028] <Detailed Configuration of Wick 130> FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. FIG. 3 is an enlarged view within the circle III of FIG. 2. Next, with reference to FIGS. 1 to 3, the detailed configuration of the wick 130 will be described.

[0029] First, as shown in FIG. 2, the first side plate 113 of the evaporator main body 110 has an inner body surface 115 facing the wick 130. Further, the wick 130 has a wick outer surface 135 facing the inner body surface 115 of the evaporator main body 110. The wick outer surface 135 of the illustrated wick 130 is fixed to the inner body surface 115 of the evaporator main body 110. More specifically, the wick outer surface 135 of the wick 130 is thermally connected to the inner body surface 115 of the evaporator main body 110.

[0030] In addition, the wick 130 has a vapor groove 133 on the wick outer surface 135 side. The longitudinal direction of this vapor groove 133 is formed along the transfer direction. In other words, the vapor groove 133 is formed in a direction along the outflow direction (see arrow B4) of the vapor-phase working fluid flowing out through the vapor pipe 105 (see FIG. 1). Alternatively, the vapor groove 133 is formed in a direction along the inflow direction (see arrow B1) of the liquid-phase working fluid flowing in through the liquid pipe 109 (see FIG. 1).

[0031] Here, as shown in FIG. 2, a plurality of the illustrated vapor grooves 133 are provided on the wick outer surface 135 side of the wick 130. More specifically, in the width direction, a plurality of vapor grooves 133 are provided at a predetermined interval. Also, each of the vapor grooves 133 has a substantially rectangular (rectangular) cross section. In the following description, the portion of the wick 130 sandwiched between the vapor grooves 133 may be referred to as the wick main body 141.

[0032] Although not particularly limited, for example, the groove width L1 of the vapor groove 133 is 0.1 mm to 5 mm, the groove depth L2 of the vapor groove 133 is 0.1 to 10 mm, and the interval L3 between the vapor grooves 133 is 0.1 mm to 5 mm.

[0033] When the loop heat pipe 1 operates, as described above, the working fluid that has moved from the inside of the wick 130 toward the outer surface 135 of the wick by capillary force is heated and vaporized, and then flows out into the vapor groove 133. Then, the working fluid moves along the vapor groove 133 and escapes to the side of the vapor pipe 105 (see FIG. 1). Incidentally, the vapor groove 133 is a flow path for the working fluid in the gas phase.

[0034] Here, the vapor groove 133 is defined by the wick main body side surface 145 which is a surface along the thickness direction of the wick 130 and the bottom surface 146 located at the bottom of the vapor groove 133. Also, the vapor groove 133 is covered by the wick guide layer 143 in a region facing the first side plate 113 of the evaporator body 110. In other words, the wick 130 in the present embodiment includes the wick guide layer 143 on the bottom surface 146 side in the vapor groove 133, that is, on the opening side of the vapor groove 133.

[0035] As shown in FIG. 3, the wick guide layer 143 is a layer member with a small dimension in the thickness direction. This wick guide layer 143 is formed with a predetermined thickness. The wick guide layer 143 is, for example, the thickness corresponding to one particle constituting the porous wick 130. That is, the illustrated wick guide layer 143 is configured as a single layer (monolayer).

[0036] Although not particularly limited, the thickness L11 of the wick guide layer 143 is from 1 μm to 50 μm, more preferably from 3 μm to 30 μm, and even more preferably from 5 μm to 10 μm. Further, the thickness L11 of the wick guide layer 143 is a dimension that is 0.1 times to 10 times the effective pore diameter of the wick 130, more preferably 0.5 times to 5 times the dimension, and even more preferably 1 time to 3 times the dimension. Further, the thickness L11 of the wick guide layer 143 is 1 / 1000 to 1 / 10 of the depth of the vapor groove 133, that is, the dimension in the vertical direction of the vapor groove 133, preferably 1 / 500 to 1 / 50, and more preferably 1 / 300 to 1 / 100. Note that when the thickness L11 of the wick guide layer 143 is below a predetermined value, the flow resistance due to the wick guide layer 143 increases, and the guiding of the working fluid may become insufficient. Further, when the thickness L11 of the wick guide layer 143 is above a predetermined value, the distance from the evaporation surface to the heat source becomes long, and the thermal efficiency decreases.

[0037] Also, although details will be described later, the wick guide layer 143 is formed integrally with the first side plate 113. In other words, the wick guide layer 143 is fixedly provided with respect to the first side plate 113. Thereby, the contact thermal resistance in the wick guide layer 143 and the first side plate 113 is reduced.

[0038] The wick guide layer 143 is a structure that improves the wettability of the first side plate 113. This wick guide layer 143 guides the liquid-phase working fluid that has penetrated inside the wick 130 and reached the first side plate 113 side of the evaporator body 110 along the first side plate 113. For further explanation, the wick guide layer 143 guides the liquid-phase working fluid to the vapor groove 133. Additionally, the wick guide layer 143 is a structure that guides the liquid-phase working fluid that has reached the first side plate 113 side toward the center side in the width direction of the vapor groove 133 (see arrow B5). Note that the direction in which the liquid-phase working fluid moves inside the wick 130 toward the first side plate 113 (see arrow B2) and the direction in which it moves along the wick guide layer 143 (see arrow B5) are directions that intersect (are orthogonal) to each other.

[0039] In the following description, as shown in FIG. 3, a portion where the inner guide surface 147, which is the lower surface of the wick guide layer 143 inside the vapor groove 133, intersects with the wick body side surface 145 may be referred to as a corner portion 149.

[0040] Now, when the loop heat pipe 1 operates, as shown in FIG. 3, the liquid-phase working fluid Lq may ooze out, that is, exude, to the corner portion 149 in the vapor groove 133. The liquid-phase working fluid Lq that has exuded to this corner portion 149 has a surface that connects between the inner guide surface 147 of the guide layer and the wick body side surface 145. Further, the surface that connects between the inner guide surface 147 of the guide layer and the wick body side surface 145 is curved by the action of the surface tension of the liquid-phase working fluid Lq. Here, the curved surface (interface) of the liquid-phase working fluid Lq can be regarded as a crosslink (liquid crosslink Lq1) of the liquid-phase working fluid Lq formed at the common boundary of the inner guide surface 147 of the guide layer, the wick body side surface 145, and the vapor groove 133.

[0041] In the present embodiment, due to the provision of the wick guide layer 143, the crosslink Lq1 of the liquid-phase working fluid Lq extends toward the center side in the width direction of the vapor groove 133. That is, in the present embodiment, compared with a configuration in which the wick guide layer 143 is not provided, the vapor groove side end portion Lq5 of the crosslink Lq1 moves to the center side in the width direction of the vapor groove 133 (see arrow B5). As a result, the evaporation surface area of the liquid-phase working fluid Lq can be increased.

[0042] Here, although details will be described later, in the evaporator body 110, since the wick 130 and the first side plate 113 are integrally formed, the thermal resistance generated between the wick 130 and the first side plate 113 is reduced. With this configuration, since the heat path between the wick 130 and the first side plate 113 is ensured even during high heat flux, the performance of the maximum heat flux in the loop heat pipe 1 (see FIG. 1) can be improved.

[0043] Also, when the wick 130 and the first side plate 113 are integrally shaped, a wick guide layer 143 is formed. Here, in the structure where the wick 130 and the first side plate 113 are integrally shaped, there is a concern that in the region where the wick 130 and the first side plate 113 face each other, that is, at the contact portion of the two surfaces, the escape of vapor becomes poor and the performance deteriorates. Therefore, by providing the wick guide layer 143, a cavity can be formed, the evaporation of the liquid-phase working fluid can be promoted, and the heat transfer coefficient can be improved.

[0044] <Manufacturing process of the evaporator body 110> FIG. 4 is a diagram showing the process of manufacturing the evaporator body 110. Next, with reference to FIG. 4, an example of the manufacturing process of the evaporator body 110 in the present embodiment will be described. Note that the manufacturing process of the evaporator body 110 in the present embodiment uses a laminating apparatus, a so-called 3D printer. More specifically, the manufacturing process of the evaporator body 110 integrally forms the wick 130 and the first side plate 113 in the evaporator body 110 using a metal 3D printer. That is, in the present embodiment, the wick guide layer 143 and the first side plate 113 are formed as a continuous body. As a result, for example, compared with a mode different from the present embodiment, that is, a mode in which the wick 130 and the evaporator body 110 are formed separately and then the wick 130 is inserted into the evaporator body 110, the thermal resistance of the first side plate 113 and the wick 130 in the evaporator body 110 is reduced. Further, the performance of the loop heat pipe 1 can be improved.

[0045] Hereinafter, the manufacturing process of the evaporator body 110 will be specifically described. First, as shown in FIG. 4(A), the first side plate 113 is formed using a 3D printer. Then, as shown in FIG. 4(B), the wick guide layer 143 is laminated on the first side plate 113.

[0046] Next, as shown in FIG. 4(C), the wick body 141 is formed at a predetermined position in the wick guide layer 143. Then, as shown in FIG. 4(D), the wick 130 and the first side plate 113 are integrally formed.

[0047] In the illustrated example, the wick guide layer 143 and the wick body 141 in the wick 130 are formed of a common member. And in the process shown in FIG. 4(B), lamination is also performed on the portion of the first side plate 113 other than the wick guide layer 143, that is, the region where the wick body 141 is formed. This can improve the manufacturing efficiency.

[0048] Note that the manufacturing process shown in FIG. 4 is formed with the plate surface of the first side plate 113 along the horizontal direction. However, if it is possible to be formed by a 3D printer, the orientation in the manufacturing process is not particularly limited. For example, in the manufacturing process, the plate surface of the first side plate 113 may be formed along the vertical direction. Also, different from the manufacturing process shown in FIG. 4, after the wick 130 is formed, the first side plate 113 may be laminated. Further, either the wick 130 or the first side plate 113 may be formed by a 3D printer.

[0049] <Operation test> FIG. 5 is a diagram for explaining the operation test of the evaporator body 110. Next, with reference to FIG. 5, the operation test of the evaporator body 110 will be described. Note that FIG. 5(A) is a diagram showing the schematic configuration of the test sample in the operation test. Also, FIG. 5(B) is a diagram showing the test results of the operation test. Note that the horizontal axis in FIG. 5(B) indicates the heat flux (W / cm 2 ), and the vertical axis indicates the heat transfer coefficient (W / m 2 / K).

[0050] First, as shown in FIG. 5(A), in this operation test, a sample SP1 which is a test sample of a comparative example different from this embodiment, a sample SP2 having a predetermined configuration of this embodiment, and a sample SP3 having another configuration of this embodiment were used.

[0051] As shown in Fig. 5(A-1), in the sample SP1 of the comparative example, the wick 130 and the first side plate 113 are formed as separate bodies, and the wick 130 separate from the first side plate 113 is fixed thereto. Further, as shown in Fig. 5(A-2), in the sample SP2, the wick 130 and the first side plate 113 are integrally formed. Also, in the sample SP2, the wick guide layer 143 is not formed. Further, as shown in Fig. 5(A-3), in the sample SP3, the wick 130 and the first side plate 113 are integrally formed. Also, in the sample SP3, the wick guide layer 143 is formed.

[0052] As shown in Fig. 5(B), the experimental results using the samples SP1 to SP3 were obtained. From the experimental results, it was confirmed that the heat exchange rates of the samples SP2 and SP3 were improved in comparison with the sample SP1. Specifically, it was confirmed that the maximum heat fluxes of the samples SP2 and SP3 increased in comparison with the sample SP1. Further elaborating, it was confirmed that by forming the wick 130 and the first side plate 113 integrally as in the samples SP2 and SP3, the maximum heat flux became about 1.5 times.

[0053] Also, in comparison between the sample SP1 and the sample SP3, it was confirmed that the maximum value of the heat transfer coefficient increased. Further elaborating, it was confirmed that by forming the wick guide layer 143, the heat transfer coefficient of the sample SP3 became about 1.3 times that of the sample SP1 in comparison. Also, it was confirmed that the heat transfer coefficient of the sample SP3 became about 1.4 times that of the sample SP2 in comparison.

[0054] From the above, in the present embodiment, it was confirmed that performance improvement is expected from the viewpoints of the maximum heat flux and the heat transfer coefficient.

[0055] <Other Embodiments> Fig. 6 is a schematic configuration diagram showing the wick 130 in another embodiment. Next, with reference to FIG. 6, the configuration of the wick 130 in another embodiment will be described. In FIG. 6, the same parts as those in the loop heat pipe 1 in the above embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0056] In the above embodiment, it has been described that the wick guide layer 143 has a constant thickness, but the present invention is not limited thereto. For example, the thickness of the wick guide layer 143 may change according to the position in the width direction. Further, as shown in FIG. 6(A), a wick 1130 may be configured. In the wick 1130, the thickness of the wick guide layer 1143 decreases from the end in the width direction of the vapor groove 133 toward the center in the width direction. Further, in the wick 1130, in the direction from one side to the other side in the width direction of the vapor groove 133, three-layer regions 1151, two-layer regions 1153, one-layer regions 1155, two-layer regions 1153, and three-layer regions 1151 are formed in this order. Each of the three-layer region 1151, the two-layer region 1153, and the one-layer region 1155 has a thickness corresponding to three, two, and one particles of the porous wick 130, respectively.

[0057] Also, as shown in FIG. 6(B), a wick 2130 may be configured. This wick 2130 is integrally formed with the first side plate 113. Further, the wick 2130 does not include the wick guide layer 143 (see FIG. 3).

[0058] Also, as shown in FIG. 6(C), a wick 3130 may be configured. In the wick 3130, the wick guide layer 3143 and the wick body 3141 are formed as separate bodies. Further, the wick 3130 includes a wick guide layer 3143 integrally formed with the first side plate 113 in a region facing the vapor groove 133, and a wick body 3141 integrally formed with the first side plate 113 in a region other than the wick guide layer 3143. Note that the wick guide layer 3143 and the wick body 3141 may be separated from each other as long as the liquid-phase working fluid is allowed to move therebetween.

[0059] <Electronic device> FIG. 7 is a diagram for explaining a mobile phone 800 including a loop heat pipe 1. Next, a mobile phone 800 including a loop heat pipe 1 will be described with reference to FIG. 7.

[0060] As shown in FIG. 7, the loop heat pipe 1 is provided in an electronic device such as the mobile phone 800. The illustrated mobile phone 800 is a so-called smartphone having a flat plate shape. This mobile phone 800 includes a central processing unit (CPU) 810, a loop heat pipe 1 for cooling the central processing unit 810, and an evaporator body 830 that houses these inside. Then, the heat generated in the central processing unit 810, which is a heat generating body, is transmitted to the evaporator 101 and released at the condenser 107. Note that the condenser 107 in the illustrated example has a plurality of folded portions in order to secure a heat radiation area.

[0061] Here, the device in which the loop heat pipe 1, which is an example of a heat exchanger, is provided is not limited to the above-described mobile phone 800. For example, the loop heat pipe 1 may be provided in various devices including heat generating components such as electronic devices such as personal computers and projectors, and transportation devices such as automobiles.

[0062] <Modification example> Now, in the above description, it has been described that the wick 130 and the first side plate 113 are integrally formed, but the present invention is not limited to this. For example, either one of the wick body 141 and the wick guide layer 143 in the wick 130 may be integrally formed with the first side plate 113. Further, a layer corresponding to the thickness of the wick guide layer 143 may be formed on the entire inner surface 115 (see FIG. 2) of the main body of the first side plate 113, and the wick body 141 formed separately may be disposed.

[0063] In the above description, it has been described that the wick guide layer 143 is provided over the entire width direction of each vapor groove 133, but the present invention is not limited thereto. For example, a configuration in which the wick guide layer 143 is provided in a part of the width direction of each vapor groove 133 may be adopted. More specifically, for example, a configuration in which the wick guide layer 143 is formed only on both end sides in the width direction of each vapor groove 133 and not formed on the central side in the width direction may be adopted.

[0064] In the above description, it has been described that the cross section of the vapor groove 133 is substantially rectangular (a rectangle), but the present invention is not limited thereto. As long as it is possible to guide the vapor-phase working fluid in a predetermined direction, for example, it may have a circular shape, a polygonal shape including a triangle, or a substantially U-shaped cross section with a curved bottom.

[0065] In the above description, it has been described that the vapor groove 133 is provided in the wick 130, but the present invention is not limited thereto. Instead of being provided in the wick 130, or in addition to being provided in the wick 130, the vapor groove 133 may be provided in the first side plate 113. And a configuration in which a wick guide layer 143 for guiding the liquid-phase working fluid toward the vapor groove 133 formed between the wick 130 and the first side plate 113 is provided on the first side plate 113 may be adopted.

[0066] In the above description, it has been described that the evaporator body 110 and the wick 130 are flat, but the present invention is not limited thereto. For example, the evaporator body 110 and the wick 130 may have other shapes such as a cylindrical shape.

[0067] Note that the first side plate 113 is an example of a container. The inner surface 115 of the main body is an example of the inner surface of the container. The vapor groove 133 is an example of a guide path. The outer surface 135 of the wick is an example of the outer surface of the evaporator. The wick main body 141 is an example of a sandwiched portion. The wick guide layer 143 is an example of a guide layer. The mobile phone 800 is an example of an apparatus.

[0068] Now, although various embodiments and modifications have been described above, it is of course possible to combine and configure these embodiments and modifications with each other. Furthermore, the present disclosure is not limited to the above-described embodiments at all, and can be implemented in various forms without departing from the gist of the present disclosure.

Description of Reference Numerals

[0069] 100... Heat exchanger, 110... Evaporator main body, 113... First side plate, 130... Wick, 133... Vapor groove, 143... Wick guide layer

Claims

1. A heat exchanger having an evaporator that absorbs heat from the outside to evaporate a liquid-phase working fluid, and condensing the vapor-phase working fluid flowing out of the evaporator and circulating it as the liquid-phase working fluid back to the evaporator, wherein the evaporator comprises an evaporator body formed of a porous body that guides the liquid-phase working fluid to the outer surface by capillary force for evaporation, and a housing that houses the evaporator body and has an inner surface facing the outer surface ; a guide path for guiding the vapor-phase working fluid in a predetermined direction is provided on the outer surface side of the evaporator body, and a porous layer provided along the inner surface of the housing and covering at least a part of the guide path, the porous layer comprising a guide layer for guiding the liquid-phase working fluid toward the guide path heat exchanger.

2. The heat exchanger according to claim 1, wherein the thickness of the guide layer is 50 μm or less.

3. The heat exchanger according to claim 1, wherein the thickness of the guide layer is 1 / 10 or less of the dimension of the guide path in the direction orthogonal to the inner surface.

4. The evaporator body is provided with a plurality of guide paths arranged side by side with each other, and the heat exchanger according to claim 1, wherein the thickness of the guide layer is 10 times or less of the effective pore diameter of the sandwiched portion sandwiched between two of the guide paths in the evaporator body.

5. The heat exchanger according to any one of claims 1 to 4, wherein the thickness of the guide layer is thicker on the end side than on the central side of the guide path.

6. The evaporator body is provided with a plurality of guide paths arranged side by side with each other, and the guide layer has a larger effective pore diameter than the sandwiched portion sandwiched between two of the guide paths in the evaporator body, the heat exchanger according to claim 1.

7. The heat exchanger according to claim 1, wherein the guide layer is fused to the inner surface of the housing.

8. The heat exchanger according to claim 1, wherein the housing and the evaporator body are integrally formed.

9. The evaporator body is provided with a plurality of guide paths arranged side by side with each other, and the heat exchanger according to claim 7 or 8, wherein the sandwiched portion sandwiched between two of the guide paths in the evaporator body and the guide layer are integrally formed.

10. A heat exchanger having an evaporator that absorbs heat from the outside to evaporate a liquid-phase working fluid, and condensing the vapor-phase working fluid flowing out of the evaporator and circulating it as the liquid-phase working fluid back to the evaporator, wherein the evaporator comprises an evaporator body formed of a porous body that guides the liquid-phase working fluid to the outer surface by capillary force for evaporation, and a housing that houses the evaporator body and has an inner surface facing the outer surface ; The evaporator is formed integrally with the container, a plurality of guide paths for guiding the gaseous working fluid in a predetermined direction are provided side by side on the outer surface side, and a porous layer provided along the inner surface of the container and covering at least a part of the guide path, having a thickness of 50 μm or less, and including a guide layer for guiding the liquid-phase working fluid toward the guide path, the effective pore diameter of the guide layer is larger than that of the sandwiched portion sandwiched between the two guide paths in the evaporator, a heat exchanger.

11. In an evaporator that absorbs heat from the outside to evaporate the liquid-phase working fluid and discharges it as the gaseous working fluid, and the discharged gaseous working fluid condenses and circulates as the liquid-phase working fluid, an evaporator formed of a porous body that guides the liquid-phase working fluid to the outer surface by capillary force and evaporates it, a container that houses the evaporator and has an inner surface facing the outer surface, and guide paths for guiding the gaseous working fluid in a predetermined direction are provided on the outer surface side of the evaporator, a porous layer provided along the inner surface of the container and covering at least a part of the guide path, and including a guide layer for guiding the liquid-phase working fluid toward the guide path an evaporator.

12. a heating element, a device having an evaporator that absorbs heat from the heating element to evaporate the liquid-phase working fluid, and condensing the gaseous working fluid flowing out of the evaporator and circulating it as the liquid-phase working fluid to the evaporator, the evaporator is formed of a porous body and includes an evaporator body that guides the liquid-phase working fluid to the outer surface by capillary force and evaporates it, a container that houses the evaporator body and has an inner surface facing the outer surface, and guide paths for guiding the gaseous working fluid in a predetermined direction are provided on the outer surface side of the evaporator body, a porous layer provided along the inner surface of the container and covering at least a part of the guide path, and including a guide layer for guiding the liquid-phase working fluid toward the guide path a device.

13. A manufacturing method for manufacturing a heat exchanger having an evaporator that absorbs heat from the outside to evaporate the liquid-phase working fluid, and condensing the gaseous working fluid flowing out of the evaporator and circulating it as the liquid-phase working fluid to the evaporator, the evaporator is formed of a porous body and includes an evaporator body that guides the liquid-phase working fluid to the outer surface by capillary force and evaporates it, a container that houses the evaporator body and has an inner surface facing the outer surface, and A guide path for guiding a vapor-phase working fluid in a predetermined direction is provided on the outer surface side of the evaporator body. A porous layer provided along the inner surface of the container and covering at least a part of the guide path, the porous layer including a guide layer for guiding a liquid-phase working fluid toward the guide path. A step of forming the container. A step of forming the guide layer by a laminated manufacturing apparatus. including manufacturing method.

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