JP2011247432A - Laminated heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated heat exchanger capable of forming a heat medium flow in the lamination direction of a duct even if flow speed of the heat medium in the duct is slow.SOLUTION: The Reynolds number of heat medium that flows a thin duct 333 is configured to be 1,000 or less. An inner fin 33 includes a plate part 331 that extends in the length direction of a duct and a top part 332 for connecting adjoining plate parts 331 together. It has a cross sectional shape which is orthogonal to the length direction of the duct and is wavelike, with the plate part 331 shaped in a wave fin bending wavelike in the length direction of the duct when viewed along the lamination direction of the duct. A fin inclination angle α[°] is so set as to satisfy the relationship of tan(2H/W)≤α<90. The wave angle β[°] and wave depth D [mm] are so set as to satisfy the relationship of 90<β<158, and, D≥13.096×W×β, and, D≥W×0.7.

Description

  The present invention relates to a stacked heat exchanger in which flow channel tubes through which a heat medium flows and heat exchange objects are alternately stacked.

  Conventionally, in order to dissipate heat from a heating element such as a semiconductor module incorporating a semiconductor element, a multilayer heat exchanger is known in which a flow path tube is disposed so as to sandwich the heating element from both sides. . Such a stacked heat exchanger has a configuration in which heating elements and flow path tubes are alternately stacked. The plurality of stacked flow path tubes are communicated by a communication member, and a cooling medium flows in each flow. It is configured to circulate in the road pipe.

  In this type of stacked heat exchanger, in order to improve heat exchange performance, a partition member is provided in the flow path pipe, and the heat medium flow path is arranged in two stages in the thickness direction of the flow path pipe. In addition to this, there is disclosed a structure in which inner fins are arranged in each of the heat medium channels formed in two stages (see, for example, Patent Document 1).

  By the way, in this type of stacked heat exchanger, since the heat medium is distributed from the communicating member to each flow pipe, the flow rate of the heat medium in the flow pipe becomes slow. In order to improve the heat exchange performance in the minute flow rate region in such a flow channel tube, a wave fin having a function of promoting mixing of the heat medium in the flow channel tube is used as the inner fin, and the wave fin is connected to the flow channel tube. What laminated | stacked multiple steps | paragraphs in the thickness direction is disclosed (for example, refer patent document 2).

JP 2005-191527 A JP 2010-10418 A

  In the stacked heat exchanger described in Patent Document 2, the heat medium flow in the width direction of the flow path tube is formed in the flow path tube by using the wave fin as the inner fin. However, since the movement of the heat medium in the stacking direction of the flow path tubes is slight, the effect of promoting the mixing of the heat medium in the flow path tubes cannot be sufficiently obtained.

  In view of the above points, the present invention provides a stacked heat exchanger capable of forming a heat medium flow in the stacking direction of flow channel tubes in the flow channel tube even when the flow rate of the heat medium in the flow channel tube is low. Objective.

In order to achieve the above object, the invention according to claim 1 is configured such that the Reynolds number of the heat medium flowing through the narrow channel (333) is 1000 or less, and the inner fin (33) It has a plate portion (331) extending in the longitudinal direction of the channel pipe (3) and a top portion (332) connecting between the adjacent plate portions (331), and the cross-sectional shape perpendicular to the longitudinal direction is wavy and laminated. When viewed from the direction, the plate portion (331) is a wave fin that refracts into a waveform in the longitudinal direction, and the direction perpendicular to both the longitudinal direction and the stacking direction of the channel tube (3) In the cross section perpendicular to the flow direction of the heat medium in the narrow channel (333) of the inner fin (33), the dimension in the stacking direction of the narrow channels (333) is defined as the channel height H [mm], the narrow channel ( 333) in the narrow channel (3 Top facing the 3) (maximum flow path dimension perpendicular to the flow direction of the heat medium in the most distant sites from 332) (314) width W _{1 [mm],} in the direction perpendicular to the flow direction of the heat medium When the angle formed by the imaginary line connecting the adjacent top portions (332) and the plate portion (331) is defined as the fin inclination angle α [°], the fin inclination angle α is expressed by the following formula 1.
(Equation 1)
tan ⁻¹ (2H / W ₁ ) ≦ α <90
In the cross section of the inner fin (33) perpendicular to the stacking direction and passing through the center of the narrow channel (333) in the stacking direction, the plate portion (332) is set. The wave-shaped refraction angle is the wave angle β [°], the amplitude of the plate portion (332) in the amplitude direction is the wave depth D [mm], and the channel width direction between the adjacent plate portions (331) when the distance was set to the plate portion a distance W _{2 [mm]} and in the wave angle β and wave depth D, to equation 2 to 4
(Equation 2)
90 <β <158
(Equation 3)
D ≧ 13.096 × W ₂ × β− ^0.5785
(Equation 4)
D ≧ W ₂ × 0.7
It is characterized by being set so as to satisfy the relationship shown in.

  In this way, by setting the fin inclination angle α so as to satisfy the relationship represented by Formula 1, the plate portion (331) can be inclined with respect to the stacking direction of the flow channel pipe (3). For this reason, when the narrow channel (333) is viewed from the flow direction of the heat medium, the wall surface of the plate portion (331) exists on the downstream side in the flow direction of the heat medium, and therefore flows through the narrow channel (333). The heat medium comes into contact with the wall surface of the plate portion (331), thereby forming a heat medium flow in the stacking direction of the flow path pipe (3). Therefore, even when the flow rate of the heat medium in the flow path pipe (3) is low, it is possible to form a heat medium flow in the stacking direction of the flow path pipe (3) in the flow path pipe (3).

  Further, by setting the wave angle β and the wave depth D so as to satisfy the above formulas 2 to 4, the Reynolds number of the heat medium flowing through the narrow channel (333) is 1000 or less as shown in an embodiment described later. In this case, it is possible to prevent the heat medium from flowing through the narrow channel (333) without colliding with the plate portion (331) in the cross section perpendicular to the stacking direction of the channel tube (3). Thereby, even when the flow rate of the heat medium in the flow path pipe (3) is low, it is possible to sufficiently obtain the effect of promoting the mixing of the heat medium by the inner fin (33).

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a front view which shows the laminated heat exchanger 1 which concerns on embodiment of this invention. It is AA sectional drawing of FIG. (A) is sectional drawing which shows the cross-sectional shape orthogonal to the flow-path pipe longitudinal direction of the inner fin 33, (b) is the top view which looked at the inner fin 33 from the flow-path pipe lamination direction. 4 is an enlarged perspective view showing an inner fin 33. FIG. It is a B arrow view of FIG. It is CC sectional drawing of FIG. 6 is a graph showing the relationship between the wave angle β of the inner fin 33 and the wave depth D.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view showing a stacked heat exchanger 1 according to the present embodiment.

  As shown in FIG. 1, the laminated heat exchanger 1 of the present embodiment cools a plurality of electronic components 2 as heat exchange objects from both sides, and a heat medium flow path 30 (see FIG. 2) and a communication member 4 that communicates the plurality of flow channel tubes 3 with each other. A plurality of flow path tubes 3 are arranged in a stacked manner so that the electronic component 2 can be sandwiched from both sides.

  In the present embodiment, as the electronic component 2, a semiconductor module incorporating a semiconductor element such as an IGBT and a diode is used. The semiconductor module can be used for an inverter for automobiles, a motor drive inverter for industrial equipment, an air conditioner inverter for building air conditioning, and the like. In addition to the semiconductor module, for example, a power transistor, a power FET, an IGBT, or the like can be used as the electronic component 2.

  FIG. 2 is a cross-sectional view taken along the line AA of FIG. As shown in FIG. 2, the channel tube 3 of this embodiment has a so-called drone cup structure. That is, the flow path pipe 3 is configured to have a pair of outer shell plates 31, and the heat medium flow path 30 is formed between the pair of outer shell plates 31.

  An inner fin 33 that divides the heat medium flow path 30 into a plurality of narrow flow paths 333 and increases the heat transfer area between the heat medium and the flow path pipe 3 is provided in the flow path pipe 3. In the present embodiment, two inner fins 33 are arranged between the pair of outer shell plates 31, that is, in the heat medium flow path 30, in a stacking direction of the flow path pipes 3 (hereinafter referred to as a flow path pipe stacking direction). Has been. Details of the inner fin 33 will be described later.

  Returning to FIG. 1, two electronic components 2 are provided for each of the pair of outer shell plates 31 of the channel tube 3. The two electronic components 2 provided on each outer shell plate 31 are arranged in series in the flow direction of the heat medium.

  Further, at both ends in the longitudinal direction of the outer shell plate 31 of the flow channel tube 3, a substantially cylindrical flange portion 300 that protrudes to the outside, that is, the side of the other adjacent flow channel tube 3 is formed. And the communication member 4 which connects the several flow path pipes 3 is formed by joining the flange parts 300 of the adjacent flow path pipes 3 by brazing.

  When the channel tube 3 disposed on the outermost side in the stacking direction among the plurality of channel tubes 3 is an outer channel tube 3a, both ends in the longitudinal direction of one outer channel tube 3a of the two outer channel tubes 3a. The unit is connected with a heat medium inlet 401 for introducing the heat medium into the laminated heat exchanger 1 and a heat medium outlet 402 for discharging the heat medium from the laminated heat exchanger 1, respectively. Yes. The heat medium introduction port 401 and the heat medium discharge port 402 are joined to one outer flow path pipe 3a by brazing. In addition, the flow path pipe 3, the communication member 4, the heat medium introduction port 401, and the heat medium discharge port 402 of this embodiment are made of aluminum.

  The heat medium introduced from the heat medium introduction port 401 flows into the flow channel pipe 3 from one end portion in the longitudinal direction through the communication member 4, and the inside of each heat medium flow channel 30 to the other end portion. It flows toward. The heat medium is discharged from the heat medium discharge port 402 through the communication member 4. As described above, while the heat medium flows through the heat medium flow path 30, heat exchange is performed with the electronic component 2 to cool the electronic component 2.

  The laminated heat exchanger 1 is configured so that the Reynolds number of the heat medium flowing through the narrow flow path 333 is a laminar flow of 1000 or less. As the heat medium, in this embodiment, water mixed with an ethylene glycol antifreeze is used.

  FIG. 3 shows the inner fins 33 of the laminated heat exchanger 1 according to the present embodiment, in which (a) has a cross-sectional shape orthogonal to the longitudinal direction of the channel tube 3 (hereinafter referred to as the channel tube longitudinal direction). Sectional drawing shown, (b) is the top view seen from the flow-path pipe lamination direction.

  As shown in FIG. 3, wave fins are used as the two inner fins 33 stacked in one flow path pipe 3. Specifically, the inner fin 33 includes a plate portion 331 that extends in the longitudinal direction of the flow channel tube and divides the narrow flow channel 333, and a top portion 332 that connects the adjacent plate portions 331, and in the longitudinal direction of the flow channel tube. The orthogonal cross-sectional shape is formed in a trapezoidal wave shape, and the plate portion 331 is formed so as to be refracted in a triangular waveform in the longitudinal direction of the flow pipe when viewed from the flow pipe stacking direction.

  No other member such as an intermediate plate is disposed between the two inner fins 33, and the top portions 332 of each other are in direct contact with each other. For this reason, in the channel tube 3, there is a portion where the narrow channel 333 formed by one inner fin 33 of the pair of inner fins 33 communicates with the narrow channel 333 formed by the other inner fin 33. Exists.

  FIG. 4 is an enlarged perspective view showing the inner fins 33 in the present embodiment, and FIG. 5 is a view taken in the direction of arrow B in FIG. Here, the direction orthogonal to both the longitudinal direction of the flow channel pipe and the flow channel stacking direction is defined as the flow channel width direction.

  Further, in a cross section (hereinafter, also referred to as a first cross section) orthogonal to the flow direction of the heat medium in the narrow flow path 333 of the inner fin 33, the dimension of the narrow flow path 333 in the flow path stacking direction is defined as a flow path height H [mm] And

In the first cross section, the dimension in the direction perpendicular to the flow direction of the heat medium in the portion 334 farthest from the top 332 facing the narrow channel 333 among the narrow channels 333 is the maximum channel width W ₁ [mm]. To do. That is, the maximum channel width W ₁ can be regarded as the distance between the top 332 adjacent in the direction perpendicular to the flow direction of the heat medium in the first section.

  Further, in the first cross section, the angle formed by the phantom line (broken line 1 in FIG. 4) connecting the adjacent top portions 332 in the direction orthogonal to the flow direction of the heat medium and the plate portion 331 is the fin inclination angle α [°. ].

  The fin inclination angle α is set so as to satisfy the relationship represented by the following mathematical formula 5.

(Equation 5)
tan ⁻¹ (2H / W ₁ ) ≦ α <90
By setting the fin inclination angle α to be less than 90 °, the plate portion 331 of the inner fin 33 is inclined with respect to the flow channel tube stacking direction. Further, when the fin inclination angle α is tan ⁻¹ (2H / W ₁ ), the adjacent plate portions 331 are in direct contact with each other. For this reason, the lower limit of the fin inclination angle α is set to tan ⁻¹ (2H / W ₁ ).

  6 is a cross-sectional view taken along the line CC of FIG. Here, a triangular wave shape of the plate portion 331 in a cross section (hereinafter also referred to as a second cross section) of the inner fin 33 that is orthogonal to the flow path tube stacking direction and passes through the central portion of the narrow flow path 33 in the flow path tube stacking direction. Is the wave angle β [°]. That is, the wave angle β can be said to be an angle formed by the straight portions 331a adjacent to each other in the longitudinal direction of the flow path pipe in one plate portion 331 in the second cross section.

  In the second cross section, the dimension in the amplitude direction of the triangular wave shape of the plate portion 331 is defined as a wave depth D [mm]. That is, the wave depth D can also be said to be the distance in the channel tube width direction between adjacent vertex portions 331b in one plate portion 331 in the second cross section.

In the second cross section, the distance between the plate portions 331 adjacent in the flow channel width direction in the flow channel width direction is defined as a distance W ₂ [mm] between the plate portions.

In general, the wave fins, the wave depth optimal value is known to be a quarter of the plate portion between the distance W ₂ of the D (heat transfer engineering materials (Revised Fourth Edition) (Japan Society of Mechanical Engineers) reference) . However, in a laminar flow region where the Reynolds number (Re) is 1000 or less, if the wave depth D of the wave fin is not set to 70% or more of the distance W ₂ between the plate portions, the heat medium is not It is clear from the experimental study of the present inventor that a sufficient mixing promotion effect cannot be obtained because the flow of the heat medium in the direction of the width of the flow path tube is difficult to form without colliding with the flow path 331. It became.

Therefore, the present inventor has examined a range of the wave depth D that is always 70% or more of the inter-plate portion distance W ₂ when the wave angle β is changed. Specifically, the plate-to-plate distance W ₂ is calculated for each wave angle β, and the calculated W ₂ is multiplied by 0.7 (multiplied by 0.7) to obtain the wave depth D at the wave angle β. The minimum value _Dmin was calculated. The examination result is shown in FIG.

As shown in FIG. 7, the minimum value D _min of the wave depth D can be approximated by the following formula 6.

(Equation 6)
D _min = 13.096 × W ₂ × β ^−0.5785
Here, the wave angle β is set to be larger than 90 ° because of its workability. Further, as shown in FIG. 7, when the wave angle β is 158 ° or more, the minimum value D _min of the wave depth D is less than 70% of the plate-to-plate distance W ₂ , so the wave angle β is smaller than 158 °. Is set.

  As described above, the wave angle β and the wave depth D are set so as to satisfy the relationships represented by the following mathematical formulas 7 to 9.

(Equation 7)
90 <β <158
(Equation 8)
D ≧ W ₂ × 0.7
(Equation 9)
D ≧ 13.096 × W ₂ × β− ^0.5785
In the graph of FIG. 7, the solid line a indicates the above formula 6, and the hatched area is a range that satisfies all the relationships represented by the above formulas 7 to 9. It is shown that if the wave angle β and the wave depth D are set in the hatched region, the heat medium flows along the wave shape of the inner fin 33 and a sufficient mixing promotion effect by the inner fin 33 can be obtained. .

When the width dimension of the narrow channel 333 in the second cross section, that is, the dimension in the direction perpendicular to the flow direction of the heat medium passing through the narrow channel 333 in the second section is defined as the channel width W ₃ [mm], the plate portion between the distance W ₂ may be expressed by equation 10.
(Equation 10)
W ₂ = W ₃ / cos (90−β / 2)
As described above, the plate portion 331 can be inclined with respect to the flow channel tube stacking direction by setting the fin inclination angle α so as to satisfy the relationship expressed by the above mathematical formula 5. For this reason, when the narrow flow path 333 is viewed from the flow direction of the heat medium, the wall surface of the plate portion 331 exists on the downstream side in the flow direction of the heat medium, so that the heat medium flowing through the narrow flow path 333 is the plate portion 331. The heat medium flow in the stacking direction of the flow path pipes 3 is formed by contacting the wall surfaces of the flow path tubes 3. Therefore, even when the flow rate of the heat medium in the flow channel tube 3 is low, it is possible to form a heat medium flow in the flow channel tube stacking direction in the flow channel tube 3. As a result, it is possible to improve the heat exchange performance in the minute flow rate region in the flow channel tube 3.

  In addition, by setting the wave angle β and the wave depth D so as to satisfy the above formulas 7 to 9, when the Reynolds number of the heat medium flowing through the narrow flow path 333 is 1000 or less, it is orthogonal to the flow path tube stacking direction. In the cross section, the heat medium can be prevented from flowing through the narrow channel 333 without colliding with the plate portion 331. Thereby, even when the flow rate of the heat medium in the flow path pipe 3 is low, it is possible to sufficiently obtain the heat medium mixing effect by the inner fins 33.

(Other embodiments)
In the above-described embodiment, an example in which two inner fins 33 are stacked in one flow channel pipe 3 has been described. However, the present invention is not limited thereto, and three or more inner fins 33 are formed in one flow channel tube 3. May be arranged in layers, or only one inner fin 33 may be arranged.

2 Electronic components (objects for heat exchange)
3 Channel pipe 4 Communication member 33 Inner fin 331 Plate part 332 Top part 333 Narrow channel

Claims (1)

A plurality of flow pipes (3) having a heat medium flow path (30) through which the heat medium flows;
A communication member (4) communicating with the plurality of flow path pipes (3),
The plurality of flow channel pipes (3) are arranged so as to sandwich the heat exchange object (2) alternately arranged with the flow channel pipes (3) from both sides,
The heat medium flow path (30) is divided into a plurality of narrow flow paths (333) in the flow path pipe (3), and the heat transfer area between the heat medium and the flow path pipe (3) is increased. A laminated heat exchanger in which a plurality of inner fins (33) are laminated in the lamination direction of the flow path pipe (3),
The Reynolds number of the heat medium flowing through the narrow channel (333) is configured to be 1000 or less,
The inner fin (33) includes a plate portion (331) extending in the longitudinal direction of the flow channel tube (3) and a top portion (332) connecting between the adjacent plate portions (331), and the longitudinal direction. A wave fin in which the cross-sectional shape orthogonal to the wave shape is wavy and the plate portion (331) is refracted into a waveform in the longitudinal direction when viewed from the stacking direction,
When the direction perpendicular to both the longitudinal direction of the flow pipe (3) and the stacking direction is the flow pipe width direction,
In the cross section perpendicular to the flow direction of the heat medium in the narrow channel (333) of the inner fin (33), the dimension in the stacking direction of the narrow channels (333) is the channel height H [mm], and the narrow channel (333), the dimension in the direction perpendicular to the flow direction of the heat medium at the portion (314) farthest from the top (332) facing the narrow channel (333) is the maximum channel width W ₁ [mm]. When the angle formed between the imaginary line connecting the apexes (332) adjacent to each other in the direction orthogonal to the flow direction of the heat medium and the plate portion (331) is a fin inclination angle α [°], the fin The inclination angle α is expressed by the following formula 1.
(Equation 1)
tan ⁻¹ (2H / W ₁ ) ≦ α <90
It is set to satisfy the relationship shown in
In the cross section of the inner fin (33) perpendicular to the stacking direction and passing through the central portion of the narrow channel (333) in the stacking direction, the wave-shaped refraction angle of the plate portion (332) is a wave angle. β [°], the dimension in the amplitude direction of the wave shape of the plate part (332) is the wave depth D [mm], and the distance between the adjacent plate parts (331) in the flow channel width direction is the distance between the plate parts. When the distance is W ₂ [mm], the wave angle β and the wave depth D are expressed by the following formulas 2 to 4.
(Equation 2)
90 <β <158
(Equation 3)
D ≧ 13.096 × W ₂ × β− ^0.5785
(Equation 4)
D ≧ W ₂ × 0.7
It is set so that the relationship shown by may be satisfy | filled, The laminated | stacked heat exchanger characterized by the above-mentioned.

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