JP6764765B2 - Heat transfer member - Google Patents

Description

The present invention relates to a heat transfer member having a heat transfer surface that is brought into contact with a flow of a liquid refrigerant such as a coolant and exchanges heat with the liquid refrigerant, and is particularly suitable for a heat sink and a heat exchanger. It relates to a heat transfer member used.

Conventionally, power semiconductor modules such as IGBT modules have been used for inverters that control high-power motors such as motors used in hybrid vehicles and electric vehicles, but such power semiconductor modules generate high heat. Therefore, a large cooling capacity is required for the cooling, and therefore, a cooling method by water cooling has been clarified in JP-A-2004-349324 and JP-A-2007-36214. There is.

Then, there, a plurality of plate-shaped heat radiating fins having a predetermined height are integrally opposed to each other on the surface of the plate-shaped metal base opposite to the mounting side of the power semiconductor, which is a heating element in the power semiconductor module. A heat sink is constructed, and a cover is attached so as to surround the heat radiation fins to form a closed space on the metal base surface, and cooling water is introduced into the closed space to form such a closed space. A water-cooled structure is adopted in which cooling water is brought into direct contact with a metal base with heat-dissipating fins to cool it.

By the way, in such a water-cooled power semiconductor module structure, in order to meet the demand for high output of a heating element such as an inverter, it is necessary to further improve the cooling performance of the metal base with radiating fins. However, the conventional heat sink structure in which a plurality of simple plate-shaped heat-dissipating fins are erected and arranged in parallel with each other on a plate-shaped metal base has a limit in its structure.

Further, as a heat exchanger that exchanges heat via a heat transfer tube that is a heat transfer member, various types such as a plate type, a shell & tube type, and a fin tube type are known. A combination of two heat transfer tubes, a first heat transfer tube that circulates one fluid and a second heat transfer tube that circulates a second fluid, heats between the first fluid and the second fluid. Various heat exchangers configured to perform exchange have been used, and one of them is clarified in Japanese Patent Application Laid-Open No. 2002-228370. There, the refrigerant pipe through which the refrigerant flows is spirally wound around the outer circumference of the heart tube through which water flows, or the heart tube and the refrigerant pipe are arranged parallel to the pipe axis direction and heat-conducted. In, heat exchange between the water and the refrigerant is performed. However, if a heat transfer tube used in such a conventional heat exchanger, particularly a heat transfer tube for circulating water inside, is used as a tube having a simple circular cross section and a smooth inner surface, a refrigerant flowing outside the heat transfer tube is used. There is a problem that the heat exchange performance with such a fluid is not sufficient.

Therefore, in such a heat exchanger, various measures have been conventionally made in order to improve the heat exchange efficiency. For example, in Japanese Patent Application Laid-Open No. 2009-270755, the outer surface of the pipe is oriented in the axial direction. A spiral continuous ridge is provided on the inner surface of the pipe corresponding to the dent extending continuously in a spiral shape, and a plurality of protrusions are formed at a predetermined interval and a predetermined size on the top of the ridge. A heat transfer tube for a heat exchanger having a structure of the above has been proposed, and in Japanese Patent Application Laid-Open No. 2011-12909, a convex portion corresponding to a corrugated groove spirally provided on the outer peripheral surface of the tube is spirally formed on the inner peripheral surface of the tube. A heat transfer tube is clarified in which a protrusion corresponding to a plurality of recesses provided adjacent to the corrugated groove is formed on the inner peripheral surface of the tube.

However, even in the heat transfer tubes for heat exchangers disclosed in those patent publications, the heat exchange performance cannot be said to be sufficient, and further improvement in heat exchange performance is required. Further, FIGS. 7 of JP-A-2009-270755 and FIGS. 3 to 6 of JP-A-2011-12909 are different from the heat exchanger having the configuration shown in JP-A-2002-228370. Although so-called double-tube heat exchangers have been clarified, the same problem is inherent in the heat transfer tubes used in such double-tube heat exchangers.

Japanese Unexamined Patent Publication No. 2004-349324 JP-A-2007-36214 JP-A-2002-228370 JP-A-2009-270755 Japanese Unexamined Patent Publication No. 2011-12909

Here, the present invention has been made in the context of such circumstances, and the problem to be solved thereof is that the heat exchange performance can be further improved with a simple structure. In providing a heat member, another issue is to provide a heat sink having excellent cooling characteristics and a heat exchanger having excellent heat exchange characteristics using such a heat transfer member. There is also.

Then, in the present invention, in order to solve such a problem, a heat transfer member having a heat transfer surface that is brought into contact with the flow of the liquid refrigerant and exchanges heat with the liquid refrigerant is used. The wall portion is formed so that the width is narrowed from the upstream side to the downstream side of the flow of the liquid refrigerant and the depth is gradually increased, and the wall portion rises at the end point of the gradual change in the depth. A heat transfer member characterized in that a plurality of gradually deepened recesses having a V-shaped planar shape that expand toward the upstream side of the flow of the liquid refrigerant are arranged on the heat transfer surface. It is a summary.

According to one of the desirable embodiments of the heat transfer member according to the present invention, the plurality of the gradual deepening recesses are linearly arranged in a direction parallel to the flow direction of the liquid refrigerant.

Further, according to one of the other desirable embodiments of the heat exchange member according to the present invention, the plurality of the gradual deepening recesses are linearly arranged in a direction orthogonal to the flow direction of the liquid refrigerant.

Further, according to another desirable embodiment of the heat transfer member according to the present invention, the plurality of the gradual deepening recesses are linearly arranged in two directions intersecting each other.

Then, in the heat transfer member according to the present invention, preferably, the heat transfer surface is composed of two corresponding plate surfaces of the plate-like body, and the gradual deepening recess is formed on at least one of the two plate surfaces. A plurality of are arranged. Further, in the heat transfer member in which a plurality of the gradual deepening recesses are arranged on at least one surface of such a plate-like body, heat generating parts are thermally connected to one surface and arranged. It will be advantageously used as the plate-shaped fin in a heat sink provided with a plate-shaped base plate and a plate-shaped fin erected on the other surface of the base plate.

Further, according to another aspect according to the present invention, the heat transfer surface is formed by the inner peripheral surface of the pipe body through which the liquid refrigerant is circulated in the pipe, and the gradual deepening recess is formed on the inner peripheral surface. A structure in which a plurality of the above is arranged will be adopted. A heat transfer member in which a plurality of the gradual deepening recesses are arranged on the inner peripheral surface of such a tube body is also advantageous as a heat transfer tube in a heat exchanger in which a predetermined coolant is circulated in the tube. Will be used for.

As described above, in the heat transfer member having the configuration according to the present invention, the V-shaped gradual deepening recess in the form of expanding upstream with respect to the flow of the liquid refrigerant in contact with the heat transfer surface. Since the plurality are arranged on the heat transfer surface, the flow of the liquid refrigerant is formed so that such a gradual deepening recess gradually becomes deeper toward the downstream side of the flow of the liquid refrigerant. In combination with this, the V-shaped opening of the deepening recess is converged along the walls that make up the V-shape to the base, which is the corner of the V-shape, and its The flow is such that it goes over the wall part of the V-shaped base, and as a result, the thin temperature boundary layer generated near the surface of the heat transfer surface (heat transfer surface) is effectively disturbed and destroyed. As a result, heat transfer between the liquid refrigerant and the heat transfer surface is advantageously promoted, and thus the heat exchange performance can be advantageously improved.

Since the heat transfer member according to the present invention as described above is formed of a plate-like body, the heat exchange fins exhibit excellent heat exchange performance. Therefore, such heat transfer fins are specified. The function as a heat sink arranged on the base plate can also be advantageously enhanced, and the heat transfer member according to the present invention can be formed as a tubular body and exhibit excellent heat exchange performance. It can also be configured as a heat transfer tube, so that the heat transfer coefficient can be effectively improved even in a heat exchanger in which a predetermined liquid refrigerant is allowed to flow in the tube of such a heat transfer tube. It can be done.

Moreover, in the present invention, the structure in which such an effect of improving the heat exchange performance is realized is a simple structure composed of V-shaped recesses in which the depth gradually increases. In addition to having the advantage that the pressure loss of the liquid refrigerant in contact with the hot surface can be effectively reduced (especially in tubular heat transfer members), by relatively simple machining, the purpose is Since it is possible to easily form a V-shaped gradual deepening recess, it is possible to manufacture a heat transfer member exhibiting excellent heat exchange characteristics in a relatively simple structure at low cost. It also has the feature that the production cost can be advantageously reduced and the productivity can be effectively increased.

It is explanatory drawing which shows an example of the gradual deepening recess formed in the heat transfer surface of a heat transfer member according to this invention, (a) is the plan view explanatory view, (b) is (a). It is sectional drawing which shows each of AA cross section, BB cross section, CC cross section, DD cross section, and EE cross section. Further explanatory view of the gradual depression shown in FIG. 1, FIG. 1A is a perspective explanatory view of such a gradual depression, and FIG. 1B is a perspective explanatory view of such a gradual depression. It is a development view of the wall part of. It is a plane partial explanatory view which shows the different arrangement form of a plurality of gradual deepening recesses according to this invention, (a) is an example of a grid grid arrangement form, (b) is an example of a staggered arrangement form. , And (c) show examples of irregular arrangement forms, respectively. Further explanatory view of the gradual deepening recess according to the present invention, (a) is an explanatory view of the arrangement distance in the flow direction of the liquid refrigerant, and (b) is such a gradual deepening recess. It is explanatory drawing about the shape of. It is a plane partial explanatory view which shows the form in which a plurality of gradual deepening recesses according to the present invention are continuously formed in a direction parallel to and perpendicular to a flow direction of a liquid refrigerant. 5 is a cross-sectional explanatory view showing an A'-A'cross section, a B'-B'cross section, a C'-C'cross section, a D'-D'cross section, and an E'-E'cross section in FIG. It is a partially enlarged explanatory view which shows the modification of the A'-A'cross section and the E'-E'cross section in FIG. It is a partial perspective view which shows an example of the heat sink made by using the plate-shaped heat transfer member according to this invention. It is a perspective part explanatory drawing which shows an example of the heat transfer tube composed of the heat transfer member according to this invention. It is a perspective explanatory view which shows a different example of a conventional heat sink, (a) shows an example of a comb-shaped heat sink in which plate-shaped heat radiating fins are arranged parallel to each other, (b) is It is a partial explanatory view which shows the example which the plate-shaped heat radiating fin is divided into a predetermined length, and is composed of a plurality.

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

First, FIG. 1 shows one of the examples of the gradual deepening recesses arranged on the heat transfer surface according to the present invention. There, (a) shows one of such gradual deepening recesses in planar form, and (b) shows the cross-sectional form of each part in (a). Then, as is clear from the figures shown in those (a) and (b), the gradual deepening recess 10 is directed from the upstream side to the downstream side with respect to the flow of the liquid refrigerant indicated by the white arrow. The width is gradually narrowed, the depth is gradually deepened, and the walls 12 and 12 rising at the end point of the gradual change in the depth are directed toward the upstream side of the flow of the liquid refrigerant. It is arranged on the heat transfer surface 14 in a V-shaped plane form that expands.

In other words, as is clear from the perspective view shown in FIG. 2 (a) and the developed view of the gradually deepened recess wall portion shown in FIG. 2 (b), the gradually deepened recess 10 is the flow of the liquid refrigerant. It has a V-shaped plane shape that opens toward the upstream side of the above, and the depth gradually increases from the V-shaped opening ends (free ends) 10b and 10b toward the V-shaped base 10a. It is configured so that the depth d at the V-shaped base 10a provided in the form is the deepest, in other words, the base 10a at the corner of the V-shape becomes the end point of the gradual change in depth. Has been done. Therefore, the wall portions 12, 12 on both sides that give such a V-shape are configured so that the height (depth) gradually increases from the V-shaped opening end portion 10b toward the base portion 10a. It is.

Then, in the heat transfer member according to the present invention, a plurality of the gradual deepening recesses 10 as described above are arranged on the heat transfer surface 14 in an arbitrary pattern, for example, as shown in FIGS. 3 (a) to 3 (c). In the form, it will be provided. Specifically, in (a), the plurality of gradual deepening recesses 10 linearly transfer heat in a direction orthogonal to the direction parallel to the flow direction of the liquid refrigerant indicated by the white arrow. It has a grid-like arrangement form in which it is arranged on the surface 14, and in (b), it is arranged linearly in a direction orthogonal to the flow of the liquid refrigerant indicated by the white arrow, and is also arranged. In the direction parallel to the flow direction of the liquid refrigerant, it is formed on the heat transfer surface 14 in the staggered arrangement form, and in (c), with respect to the flow of the liquid refrigerant indicated by the white arrow. , A plurality of gradual deepening recesses 10 are provided on the heat transfer surface 14 in an irregular (random) arrangement form. In particular, as shown in FIGS. 3A and 3B, a form in which a plurality of gradually deepened recesses 10 are linearly arranged in two directions intersecting each other is advantageous in the present invention. By doing so, it will contribute to the improvement of heat transfer characteristics. Although the gradual deepening recesses 10 are arranged independently here, it is also possible to connect a plurality of them in a direction orthogonal to the flow of the liquid refrigerant and arrange them continuously. Is.

By the way, as is well known, the heat transfer member that provides the heat transfer surface 14 on which such a plurality of gradually deepened recesses 10 are arranged is made of a material having good heat conductivity. Therefore, for example, copper or its alloy, aluminum or its alloy, iron, stainless steel, cobalt alloy, nickel alloy, metal mixed plastic or the like will be appropriately selected. Further, the material constituting such a heat transfer member preferably has a thermal conductivity of 5 W / mK or more, and more preferably 20 W / mK or more, particularly 80 W / mK or more. Further, from the viewpoint of the coefficient of thermal expansion, it is also possible to use metallic silicon (Si) or a silicon alloy.

Further, the depth (height of the wall portion 12) d of the V-shaped base portion 10a, which is the deepest portion in the gradual deepening recess 10 according to the present invention, is appropriately selected according to the thickness of the heat transfer member. However, it is generally about 0.1 mm to 0.5 mm. This is because if the depth d becomes too shallow, it becomes difficult to sufficiently exert the effect of improving the heat transfer characteristics by forming the gradually deepened recess 10, while if d becomes too large, the gradually deepened recess 10 is formed. It takes time and effort, and it causes problems such as difficulty in forming it. Then, the depth of the gradual deepening recess 10 gradually becomes deeper in the flow direction of the liquid refrigerant, and if it reaches each wall portion 12, it changes linearly as in the example, and also has a curved line. It doesn't matter what kind of form it changes.

Further, as shown in FIG. 4A, the angle formed by the V-shape in the gradual deepening recess 10, in other words, the angle θ formed by the wall portions 12 and 12 on both the left and right sides, is generally 40 degrees to 140 degrees. It is within the range of degrees, which results in effective heat exchange characteristics. As the V-shape, the corner portion of the V-shape as shown in the drawing, that is, the base portion 10a may have a square shape or a rounded curved shape. Further, as shown in FIG. 4B, the angles θ ₁ and θ ₂ formed by the wall portions 12 and 12 forming the V shape with respect to the direction parallel to the flow direction of the liquid refrigerant (however, θ = θ _1). + Θ ₂ ) is generally equalized (θ ₁ = θ ₂ ), but it does not matter if the angles θ ₁ and θ ₂ are different from each other, and any of these angles θ ₁ and θ ₂ It is also possible to set one to 0 degrees.

Further, when arranging a plurality of such V-shaped gradual deepening recesses 10 in the flow direction of the liquid refrigerant, the intervals between the gradual deepening recesses 10 and 10 adjacent to each other, that is, shown in FIG. 4A. The distance S can be appropriately selected, but in general, the heat transfer coefficient can be advantageously improved by setting the distance S to 10 mm or less. However, when the value of the distance S becomes smaller than 0.1 mm, the effect of such a deepening recess 10 becomes saturated. Therefore, in the present invention, the adjacent deepening recess 10, The distance S between 10 is about 0.1 mm to 10 mm, preferably about 0.1 mm to 1 mm. On the other hand, even if the arrangement spacing of the gradual deepening recesses 10 is in the direction orthogonal to the flow of the liquid refrigerant, it is appropriately selected, and is the same as the arrangement form in the direction parallel to the flow of the liquid refrigerant described above. , But in particular, in the direction orthogonal to the flow of the liquid refrigerant, in the form in which the V-shaped opening end portions 10b are connected to each other, a plurality of gradually deepened recesses 10 are linearly arranged. A configuration in which the components are arranged in a continuous manner (see FIG. 5) is advantageously adopted in order to improve the heat transfer characteristics.

In addition, the lengths l ₁ , l ₂ [see FIG. 4 (b)] of the left and right wall portions 12, 12 that give the V-shape of the deepening recess 10 are equivalent (l ₁ = l ₂ ). Although it is desirable that they are different in length (l ₁ ≠ l ₂ ), it is also possible. The lengths of l ₁ and l ₂ are generally selected appropriately within a range of about 0.1 mm to 20 mm.

Then, the gradual deepening recess 10 having such a configuration is arranged in a predetermined pattern with respect to the heat transfer surface 14 of the heat transfer member by appropriately adopting various conventionally known processing methods. It becomes. For example, a plate-shaped heat transfer member (flat heat transfer surface 14) is subjected to a large number of gradual deepening recesses in a desired arrangement form by machining such as cutting, pressing, or turret punching, or by etching. Place 10 will be formed. It is also possible to manufacture the heat transfer surface 14 in which a large number of such deepening recesses 10 are arranged according to a three-dimensional modeling method using a 3D printer.

Therefore, in the heat transfer surface 14 of the heat transfer member in which a plurality of the gradual deepening recesses 10 according to the present invention as described above are arranged, water, due to the characteristic shape of the gradual deepening recesses 10 A flow of liquid refrigerant such as liquids such as LLC and oil is collected from the V-shaped opening of the gradual deepening recess 10 along the wall portions 12 and 12 constituting the V-shape, and has a V-shape. After being converged on the base portion 10a, it is guided to the downstream side so as to get over the wall portion portion of the V-shaped base portion 10a. Therefore, in the conventional flat heat transfer surface, a thin temperature boundary layer is formed in the vicinity of the surface of the heat dissipation plane. However, the heat transfer surface 14 of the heat transfer member according to the present invention is as described above. Due to the change in the flow of the liquid refrigerant due to the presence of the gradual depression 10, especially the flow away from the heat transfer surface 14 due to the presence of the V-shaped walls 12, 12, such a thin temperature boundary layer is created. It will be destroyed in an advantageous way. Then, the thickness of such a temperature boundary layer increases from the upstream side to the downstream side of the liquid refrigerant according to the square root of the distance, so that the refrigerant that is not involved in heat exchange on the heat transfer surface is directly downstream. Since it is guided to the side, it becomes difficult to sufficiently exhibit the heat exchange performance, but in the present invention, such removal or elimination of the temperature boundary layer can be effectively achieved. As a result, the outflow of the refrigerant that is not involved in heat exchange to the downstream side can be effectively suppressed, so that the heat transfer coefficient can be improved advantageously.

By the way, in the heat transfer member according to the present invention, as shown in FIGS. 5 and 6, a plurality of gradually deepened recesses 10 are linear in a direction parallel to the flow of the liquid refrigerant indicated by the white arrow. In a direction orthogonal to the flow of the liquid refrigerant, the plurality of deepening recesses 10 are formed continuously and continuously, and the V-shaped opening end portion 10b of the adjacent deepening recesses 10 is formed. In the form in which the two are connected to each other, a configuration in which the components are linearly and continuously arranged is advantageously adopted. That is, there, the gradual deepening recesses 10 arranged parallel to the flow of the liquid refrigerant are apparent from the B'-B'cross section, the C'-C'cross section and the D'-D' cross section in FIG. Immediately from the walls 12 and 12 that give the V-shape of the gradual deepening recess 10 on the upstream side to the walls 12 and 12 that give the V-shape of the gradual depression 10 on the downstream side adjacent to each other. Are arranged continuously and linearly in a form in which is gradually changing. Further, as is clear from FIG. 5, the gradual deepening recesses 10 arranged in the direction orthogonal to the flow of the liquid refrigerant are adjacent to each other at the V-shaped opening end 10b of the wall portion 12 that gives the V-shape. It is connected to the corresponding opening end portion 10b of the deepening recess 10, and is formed in a form in which a V shape is continuously and repeatedly formed in a direction orthogonal to the flow of the liquid refrigerant.

Therefore, the plurality of deepening recesses 10 arranged in the direction orthogonal to the flow of the liquid refrigerant exhibit a sawtooth-like planar form as shown in FIG. 5 by connecting the respective wall portions 12. The arrangement form shows a continuous shape, and in the direction parallel to the flow of the liquid refrigerant, such a sawtooth shape is repeatedly expressed at predetermined intervals. Then, by adopting such an arrangement form of the plurality of gradual deepening recesses 10, even more excellent heat transfer characteristics or heat exchange characteristics can be exhibited.

In addition, in FIGS. 5 and 6, the depth of the V-shaped opening end portion 10b in the gradual deepening recess 10 is as clear from the A'-A'cross section and the E'-E' cross section in FIG. It is set to 0 mm and is considered to be the highest portion on the heat transfer surface. In particular, as in the present embodiment, a plurality of gradually deepened recesses 10 are V-shaped open ends in a direction orthogonal to the flow of the liquid refrigerant. In the form in which the continuous sawtooth-shaped wall portion 12 is formed by being connected to each other in the portion 10b, even at the opening end portion 10b, as shown in FIG. 7, it is preferably about 0.1 mm or less. It is desirable that a wall portion having a depth (height) d'of 0.05 mm or less is formed. That is, in a direction parallel to the flow direction of the liquid refrigerant, the depth is gradually increased even between the adjacent opening ends 10b, so that the flow of the liquid refrigerant is on the line connecting the opening ends 10b. The linear flow can be effectively eliminated, and therefore, it can also contribute to the improvement of the heat transfer characteristic or the heat exchange characteristic.

Further, the heat transfer member according to the present invention advantageously exhibits a plate-like body in which the plate surfaces on both sides are heat transfer surfaces, and at least one of the two plate surfaces is gradually according to the present invention. A form in which a plurality of deepening recesses 10 are arranged is adopted, and it is suitably used as a plate-shaped heat transfer fin in a heat sink as shown in FIG.

That is, the heat sink shown in FIG. 8 has a comb-shaped structure in which a plurality of heat radiating fins 22 are erected on the plate-shaped base plate 20 and one surface thereof so as to face each other and extend in parallel. Therefore, a predetermined heat generating component is arranged in a form in which the base plate 20 is thermally connected to the other surface (lower surface in the drawing), and the heat generated from the heat generating component is generated. The heat is transferred from the base plate 20 to the heat radiating fins 22, and the heat is exchanged with the liquid refrigerant distributed along the plate surface of the heat radiating fins 22 to dissipate heat. Then, as shown in the figure, a plurality of gradually deepened recesses 10 are linearly formed on at least one plate surface of the heat radiating fin 22 that performs such heat dissipation in a direction parallel to the flow of the liquid refrigerant and in a direction orthogonal to the flow of the liquid refrigerant. It is formed symmetrically and continuously. The arrangement form of such a gradual deepening recess 10 is the same as the arrangement form shown in FIGS. 5 and 6 here.

Further, the heat transfer member according to the present invention can also be realized in the form of a pipe body in which a predetermined liquid refrigerant is circulated in the pipe and heat exchange is performed through the pipe wall, where such a heat transfer member can be realized. A plurality of gradually deepened recesses 10 are arranged in a predetermined pattern on the inner peripheral surface of the tubular body. Then, as shown in FIG. 9, such a tubular heat transfer member is applied to various heat exchangers as a heat transfer tube through which a predetermined liquid refrigerant is circulated in the tube. .. In such a heat transfer tube 24, for example, a plurality of gradual deepening recesses 10 are arranged on one surface of an elongated strip plate (the surface on the side that becomes the inner surface of the tube when it is a tube body) according to the present invention. After being installed (formed in the arrangement form of the gradual deepening recess 10 as shown in FIGS. 5 and 6), such a band is formed according to a known method for manufacturing an electric sewing tube (see, for example, Japanese Patent Application Laid-Open No. 9-236395). By joining both ends in the width direction of the plate, it can be easily manufactured by a method of forming a pipe body or the like.

The typical embodiments of the present invention have been described in detail above, but they are merely examples, and the present invention is interpreted in a limited manner by specific descriptions relating to such embodiments. It should be understood that it is not something that is done.

For example, in the exemplary embodiment, the plurality of deepening recesses 10 are all of the same size and shape, but the plurality of deepening recesses 10 are of different sizes and shapes. It is also possible to dispose of it.

Further, the present invention can be carried out in a mode in which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art, and further, such a mode of implementation deviates from the gist of the present invention. Unless otherwise specified, it goes without saying that all of them belong to the category of the present invention.

Examples of the present invention will be shown below to further clarify the features of the present invention, but it is also possible that the present invention is not subject to any restrictions by the description of such examples. Needless to say.

First, as a water pipe through which cooling water is circulated, a copper pipe having an outer diameter of 10 mm, an inner diameter of 9 mm, and a length of 10 m is used, and a CO ₂ pipe through which a carbon dioxide refrigerant at 80 ° C. is circulated on the outer peripheral surface thereof. An outer-wound heat exchanger (see JP-A-2002-228370) constructed by winding and fixing four copper tubes having an outer diameter of 3.4 mm at a pitch of 10 mm was prepared and evaluated. did.

Then, as the above-mentioned water pipe, a round pipe having a smooth inner and outer surfaces, a spiral pipe having a spiral groove having a depth of 0.5 mm formed spirally on the pipe wall at a pitch of 10 mm, and a V-shape on the inner surface of the pipe. At an angle θ: 90 degrees, a maximum depth d: 0.3 mm, and a pipe axial pitch: 1 mm, V-shaped gradual deepening recesses 10 are continuously formed in the pipe axial direction and the pipe circumferential direction, respectively. Using the inner V-shaped recessed pipe as shown in 9, low temperature water at 17 ° C is circulated in each pipe at a flow rate of 1.7 L / min, while carbon dioxide at 80 ° C is passed through the small diameter CO ₂ pipe. By allowing the refrigerant to flow in opposition to the flow of the low-temperature water in the water pipe, heat exchange was performed between the low-temperature water and the carbon dioxide refrigerant, and the heat exchange performance was evaluated. The evaluation of heat exchange performance is based on how many times the temperature of the water in the water pipe rises from 17 ° C when the temperature of the carbon dioxide refrigerant circulating in the CO ₂ pipe changes from 80 ° C to 20 ° C. After evaluation, the amount of heat exchange on the water side was obtained from the temperature difference and heat capacity, and the heat exchange performance was determined. Then, the obtained results are shown in Table 1 below together with the results of pressure loss.

In addition, the heat transfer coefficient of each heat sink as shown in FIGS. 8 and 10, which uses a plate-shaped heat transfer member as a heat radiation fin, was evaluated by simulation. As the base plate 20, an aluminum plate material having a size of 50 mm × 100 mm is used, and plate-shaped aluminum fins having a height of 10 mm and a thickness of 1 mm are used as heat radiation fins on the base plate 20. As shown in the figure, the structure is arranged in a comb shape with an interval of 1 mm.

Specifically, as shown in FIG. 8, the V-shaped recess forming type heat sink according to the present invention has a V-shaped angle θ: 90 degrees and a V-shaped maximum depth on both sides of the flat plate-shaped heat radiation fins 22, respectively. At d: 0.3 mm and V-shaped interval S: 1 mm, a large number of gradually deepened recesses 10 are continuously formed in a direction parallel to and orthogonal to the flow of the liquid refrigerant (water), respectively. In the simple flat type heat sink shown in FIG. 10A, smooth fins 26 having a smooth surface without any processing on the plate surface are used as heat dissipation fins. Further, in the heat sink of the heat dissipation fin division type shown in FIG. 10B, the division fins 28 having a length of 10 mm are arranged in a row in the flow direction of the cooling water through the slit 29 (interval: 1 mm). The ones arranged and constructed were examined.

As a result, in the V-shaped recess formation type heat sink (FIG. 8) according to the present invention, the heat transfer coefficient is 36400 W / m ² K, whereas in FIGS. 10 (a) and 10 (b). It was clarified that the heat transfer coefficients of the conventional simple flat type heat sink and the heat radiation fin split type heat sink shown are 10120 W / m ² K and 20050 W / m ² K, respectively.

Further, as shown in FIG. 8, in a V-shaped recess forming type heat sink according to the present invention, a simulation is performed by variously changing the interval S of the V-shaped gradual deepening recesses 10 and the angle θ formed by the V-shape. The heat transfer coefficient was calculated. The obtained results are shown in Tables 2 and 3 below.

As is clear from the above evaluation results, regardless of whether the heat transfer member according to the present invention has a tubular shape or a plate shape, both have excellent heat exchange characteristics. Among them, it was confirmed that even better heat transfer characteristics or heat exchange characteristics can be exhibited by using it as a plate-shaped heat transfer member rather than a tubular heat transfer member. Can be done.

10 Gradual deepening recess 10a Base 10b Opening end 12 Wall 14 Heat transfer surface 20 Base plate 22 Heat transfer fin 24 Heat transfer tube 26 Smooth fin 28 Divided fin 29 Slit

Claims (8)

A heat transfer member having a heat transfer surface that is brought into contact with the flow of the liquid refrigerant and exchanges heat with the liquid refrigerant.
The liquid is narrowed from the upstream side to the downstream side of the flow of the liquid refrigerant, is formed so that the depth is gradually increased, and is raised at the end point of the gradual change in the depth. A heat transfer member characterized in that a plurality of gradually deepened recesses having a V-shaped planar shape that expand toward the upstream side of the flow of the refrigerant are arranged on the heat transfer surface. The heat transfer member according to claim 1, wherein a plurality of the gradually deepened recesses are linearly arranged in a direction parallel to the flow direction of the liquid refrigerant. The heat transfer member according to claim 1 or 2, wherein a plurality of the gradual deepening recesses are linearly arranged in a direction orthogonal to the flow direction of the liquid refrigerant. The heat transfer member according to any one of claims 1 to 3, wherein a plurality of the gradually deepened recesses are linearly arranged in two directions intersecting each other. Claims 1 to claim that the heat transfer surface is composed of two corresponding plate surfaces of a plate-like body, and a plurality of the gradual deepening recesses are arranged on at least one of the two plate surfaces. The heat transfer member according to any one of 4. Claims 1 to 1 to claim 1, wherein the heat transfer surface is formed by an inner peripheral surface of a pipe body through which the liquid refrigerant is circulated in the pipe, and a plurality of the gradual deepening recesses are arranged on the inner peripheral surface. The heat transfer member according to any one of claims 4. In a heat sink provided with a plate-shaped base plate in which heat-generating components are thermally connected to one surface and arranged, and plate-shaped fins erected on the other surface of the base plate, the plate-shaped fins are used as the plate-shaped fins. A heat sink according to claim 5, wherein the heat transfer member is used. A heat exchanger according to claim 6, wherein the heat transfer member according to claim 6 is used as a heat transfer tube through which a predetermined liquid refrigerant is circulated in the tube.

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