WO2014077316A1

WO2014077316A1 - Heat exchanger

Info

Publication number: WO2014077316A1
Application number: PCT/JP2013/080785
Authority: WO
Inventors: 直毅鹿園; 洋介長谷川
Original assignee: 国立大学法人東京大学
Priority date: 2012-11-15
Filing date: 2013-11-14
Publication date: 2014-05-22
Also published as: JPWO2014077316A1; JP6206975B2

Abstract

Multiple wave-like concavities and convexities, which are formed in corrugated fins, are formed from a smooth curved surface such that the angle γ formed by the crest lines (43) linking the crests of the waves and the trough lines (44) linking the troughs of the waves and the main flow of a first heat exchange fluid (air) is an acute angle, and the crest lines (43) and the trough lines (44) are repeated continuously multiple times in a V-shape, and the height of the bend region (43a) of the crest lines (43) is greater than the height of the slanted region (43b) of the V-shape in the crest lines (43). Thus, separation and a localized increase in the speed can be suppressed and a secondary flow of fluid can be generated, the region having a large local thermal flow speed can be reinforced and heat transfer can be promoted, the shear stress at a region having a large local shear stress can be reduced, and flow resistance can be reduced.

Description

Heat exchanger

More specifically, the present invention relates to a heat exchanger, and more specifically, a smooth curved surface is used on the surface of a heat transfer member, and a top line in which a cross section is corrugated and a wave top is continuous and a bottom line in which a wave bottom is continuous are V-shaped. The present invention relates to a heat exchanger in which a plurality of corrugations are formed so as to exchange heat by flowing a first heat exchange fluid in a vertical direction in a V shape with respect to the plurality of corrugations.

Conventionally, in this type of heat exchanger, an angle formed by a line connecting the top of the wave and a line connecting the bottom of the wave to the heat exchange tube or fin with respect to the main flow of air is 10 to 60 degrees. There has been proposed a method in which corrugated irregularities are formed that are symmetrically folded by folding lines at predetermined intervals along the main flow of air (see, for example, Patent Documents 1 to 3). In this heat exchanger, separation of air flow and local acceleration are suppressed, and an effective secondary flow is generated in the air flow to improve heat transfer efficiency, and overall heat exchange efficiency is improved. .

JP 2008-180468 A JP 2008-232592 A JP 2012-137288 A

In the heat exchanger described above, the waves in the corrugated irregularities formed on the heat exchanging tubes and fins are formed so as to have a constant amplitude at a constant wavelength, and with respect to the flow of heat exchanging fluid such as air. Thus, it is not certain whether the shape has the optimal flow resistance of the heat transfer promotion or heat exchange fluid.

The heat exchanger according to the present invention proposes a heat exchanger in which corrugated irregularities are formed in heat exchange members such as heat exchange tubes and fins, in which heat transfer promotion is higher and flow resistance is lower. The main purpose.

熱 The heat exchanger of the present invention employs the following means in order to achieve the main object described above.

The heat exchanger of the present invention is
Using a smooth curved surface on the surface of the heat transfer member, a plurality of corrugations are formed so that the top line where the cross section is corrugated and the top of the wave is continuous and the bottom line where the bottom of the wave is continuous are V-shaped. In the heat exchanger for exchanging heat by flowing the first heat exchanging fluid in the vertical direction in the V shape with respect to the plurality of corrugated irregularities,
The plurality of corrugations are formed such that the height of the top at the bent portion of the top line is higher than the height of the top at a portion different from the bent portion of the top line.
It is characterized by that.

In the heat exchanger according to the present invention, the plurality of corrugated irregularities are formed into a corrugated cross section using a smooth curved surface, and further, a top line in which the top of the wave continues and a bottom line in which the bottom of the wave continues. Is formed in a V-shape and the height of the top portion at the bent portion of the top line is higher than the height of the top portion at a portion different from the bent portion of the top line. Similar to the heat exchanger described in the above-mentioned prior art document, in the heat exchanger of the present invention, the top line where the wave top is continuous and the bottom line where the wave bottom is continuous using a smooth curved surface are V-shaped. By forming a plurality of corrugations so as to have a shape, separation and local acceleration are suppressed with respect to the flow of the first heat exchange fluid, and at the same time, with respect to the flow of the first heat exchange fluid A secondary flow effective for heat transfer promotion is generated. Then, the height of the top portion at the bent portion of the top line is made higher than the height of the top portion at a portion different from the bent portion of the top line, thereby further improving the efficiency of the main flow of the first heat exchange fluid. A secondary flow can be generated and heat transfer enhancement can be improved. Here, the “bending part of the top line” means a bending part in the V shape, that is, a bent lowest part. The bent part of the top line is effective for the main flow of the first heat exchanging fluid when the first heat exchanging fluid is caused to flow in the vertical direction with respect to the V-shaped corrugation. Since it becomes the site | part which produces a next flow, it is thought that it is a site | part which contributes greatly to heat transfer promotion. Therefore, by increasing the height of the top portion at this portion, it is possible to more effectively generate a secondary flow with respect to the main flow of the first heat exchange fluid to improve heat transfer. On the other hand, “the height of the top at the bent portion of the top line is formed to be higher than the height of the top at the portion different from the bent portion of the top line”, in other words, “is different from the bent portion of the top line. It is formed so that the height of the top portion at the portion is lower than the height of the top portion at the bent portion of the top line. Thereby, the resistance at the time of the 1st heat exchange fluid in the site | part different from the bending | flexion site | part of a top line getting over a top line can be made small. As a result, a heat exchanger with high heat transfer promotion and low flow resistance can be obtained.

In such a heat exchanger of the present invention, the heat exchanger is a corrugated fin type heat exchanger, the heat transfer member is a corrugated fin, and the corrugated irregularities are formed so that the top and bottom are symmetrical. , Can also be characterized. In other words, the corrugated fin shape of the present invention is applied to the corrugated fin of the corrugated fin heat exchanger. Here, “the corrugated irregularities are formed so that the top and bottom are symmetrical” means that the top and bottom of the wave on one side of the fin are the bottom and top of the wave on the other side of the fin. This means that the shape of the top of the wave on one side of the fin is the same as the shape of the top of the wave on the other side of the fin. By forming the corrugated irregularities in this way, it is possible to form an effective secondary flow for the main flow with respect to the first heat exchange fluid flowing on either the one surface or the other surface of the fin. The heat transfer promotion can be improved.

Further, in the heat exchanger according to the present invention, the heat transfer member is a plurality of flat tubes forming a flow path of a second heat exchange fluid that exchanges heat with the first heat exchange fluid, and the tube The corrugated irregularities are formed on the flat outer surface of the film. That is, the corrugated shape of the present invention is applied to the outer surface of a tube of a heat exchanger having a plurality of tubes. Here, both the “first heat exchange fluid” and the “second heat exchange fluid” mean a heat exchange medium. For example, air or the like is used as the “first heat exchange fluid”. Oil or water may be used as the “second heat exchange fluid”, or conversely, air or the like may be used as the “second heat exchange fluid”, and the “first heat exchange fluid” Oil or water may be used.

Furthermore, in the heat exchanger according to the present invention, the plurality of corrugated irregularities have an amplitude in the waveform of the corrugated irregularities located on the upstream side of the first heat exchange fluid on the upstream side of the first heat exchange fluid. It can also be characterized by being formed so as to be larger than the amplitude in the waveform of the waveform corrugation located. That is, in the heat transfer member, the amplitude of the waveform unevenness formed on the inlet side of the first heat exchange fluid is larger than the amplitude of the waveform unevenness formed on the outlet side of the first heat exchange fluid. Corrugated irregularities are formed so as to be. Here, the “amplitude in the waveform” corresponds to the height of the top and the depth of the bottom of the waveform unevenness.

Alternatively, in the heat exchanger according to the present invention, the top line and the bottom line of the plurality of corrugated irregularities are formed so that a V-shape is continuously repeated a plurality of times. It can also be. Here, “V-shape is repeated continuously over a plurality of times” means that the V-shape is brought into contact with the side so that it becomes a W-shape by repeating the V-shape continuously over two times, for example. This means a shape obtained by arranging a plurality of the components in a state where they are arranged, that is, a zigzag shape. In the heat exchanger of the present invention in which the top line and the bottom line of the plurality of corrugated irregularities are formed so that the V-shape is continuously repeated a plurality of times, the plural corrugated irregularities are formed on the top line. The bent portion is formed so as to be positioned in the vicinity of the end portion of the heat transfer member. That is, the top line and the bottom line of the corrugated irregularities are formed so that the V-shape is continuously repeated a plurality of times, and the bent portion of the top line is positioned near the end of the heat transfer member. It is formed. For example, the end portion (end portion of the heat transfer member) of the top line of the corrugated unevenness formed so that the V shape is continuous is a lower portion in the inclined portion of the V shape. By carrying out like this, the bending | flexion site | part of the top part which is a site | part which contributes largely to heat transfer promotion can be formed more on the surface of a heat transfer member, and heat transfer promotion can be improved.

Further, in the heat exchanger according to the present invention, the plurality of corrugated irregularities are the first as an average of an angle formed by a V-shaped inclined portion of the top line and a main flow of the first heat exchange fluid. The average angle is the second angle as the average of the angle formed by the V-shaped inclined portion and the main flow of the first heat exchange fluid in the intermediate line where the intermediate part between the top part and the bottom part continues. It may be characterized by being formed to be smaller than the average angle. Here, the “intermediate portion between the top portion and the bottom portion” means a portion that is an intermediate position (average height position) in the height direction with respect to the top portion and the bottom portion. The intermediate part line in which the intermediate part continues is V-shaped because the top line and the bottom line are V-shaped. The fact that the corrugated irregularities are formed so that the first average angle is smaller than the second average angle means that the V-shaped bent portion of the top line and the end of the inclined portion (when the V-shape is continuous) It is formed so that the distance from the adjacent bent part) is longer than the distance between the corresponding bent part of the V-shaped intermediate line and the end part of the inclined part (adjacent bent part when V-shaped is continuous). Will be. If formed in this way, the angle of the rising (climbing) of the wave at the bent portion of the top line can be formed so as to increase, thereby further increasing the main flow of the first heat exchange fluid. An effective secondary flow can be generated and heat transfer enhancement can be improved. In addition, since the angle of the rising of the wave at the V-shaped inclined portion of the top line can be reduced, this reduces the resistance when the first heat exchange fluid crosses the top line. Can do. As a result, a heat exchanger with high heat transfer promotion and low flow resistance can be obtained.

It is a block diagram which shows the outline of a structure of the corrugated fin type heat exchanger 20 of 1st Example of this invention. It is an expansion external view which expands and shows the external appearance of the state where the corrugated fin 40 is arrange | positioned between the two flat tubes 30. FIG. 4 is an explanatory view showing a horizontal surface of the corrugated fin 40 together with cross sections of two flat tubes 30. FIG. It is explanatory drawing explaining the waveform unevenness | corrugation of an Example. It is explanatory drawing explaining the waveform unevenness | corrugation of a comparative example. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 2 and FIG. FIG. 4 is a BB cross-sectional view of the BB cross section of FIGS. 2 and 3 as viewed from the direction of the arrow B in the drawings. FIG. 4 is a CC cross-sectional view of the CC cross section of FIGS. 2 and 3 as viewed from the direction of the arrow C in the drawings. FIG. 4 is a DD sectional view of the DD section of FIGS. 2 and 3 as viewed from the direction of the arrow D in the drawings. It is explanatory drawing which shows the secondary flow of the fluid produced on a flat plate when the fluid of a uniform flow is introduce | transduced into a wavy flat plate, and the contour line by temperature. It is explanatory drawing which shows the result of having simulated the relationship between the position of a waveform unevenness | corrugation, the isoline of a local heat flow rate, and the isoline of a local shear stress. A ratio (Hub / Hua) between the height Hua of the bent portion 43a of the top line 43 and the height Hub of the inclined portion 43b of the top line 43, and a dimensionless number j / f factor as a ratio of heat transfer coefficient and flow resistance, An experimental example of the relationship is shown. It is explanatory drawing which shows and shows the waveform unevenness | corrugation of a modification three-dimensionally. It is explanatory drawing which shows the waveform unevenness | corrugation of a comparative example and a reference example in three dimensions. It is explanatory drawing which attached the auxiliary line to the waveform unevenness | corrugation of a comparative example and a reference example. It is explanatory drawing which shows typically the waveform unevenness | corrugation of a modification with an auxiliary line. It is an external view which shows the external appearance of the heat exchanger 120 as 2nd Example of this invention. It is explanatory drawing which shows the flat surface of the tube 130 for heat exchange used for the heat exchanger 120 of 2nd Example.

Next, modes for carrying out the present invention will be described using examples.

FIG. 1 is a block diagram showing an outline of the configuration of the corrugated fin heat exchanger 20 according to the first embodiment of the present invention, and FIG. 2 shows the appearance of the corrugated fin 40 disposed between the flat tubes 30. FIG. 3 is an explanatory view showing a horizontal plane 42 of the corrugated fin 40 together with cross sections of the flat tubes 30 on both sides. FIG. 4 is an explanatory diagram for explaining the corrugated irregularities formed on the corrugated fin 40 of the embodiment, and FIG. 5 is an explanatory diagram for explaining a comparative example for explaining the corrugated irregularities formed on the corrugated fin 40. is there. Further, FIGS. 6 to 9 show the AA, BB, CC, and DD cross sections of the corrugated fin 40 shown in FIGS. 2 and 3 when viewed from the direction of arrows A to D in the drawings. FIG.

The corrugated fin-type heat exchanger 20 of the first embodiment is a heat exchanger used in a refrigeration cycle such as various air conditioners and refrigeration apparatuses, or heat from exhaust gas from an internal combustion engine or off-gas from a fuel cell. It is used as a heat exchanger used in an energy conversion device such as a heat recovery device that recovers energy. As shown in FIG. 1, it is formed as a flat hollow tube and is a heat exchange medium (hydrofluorocarbon, water, oil, etc.) A plurality of flat tubes 30 forming a flow path of the second heat exchange fluid), three

partition walls

28a, 28b, 28c for diverting the second heat exchange fluid as a whole, Between the flat tube 30 and the three

partition walls

28a, 28b, 28c, and between the flat tube 30 and the

side walls

29a, 29b. A plurality of corrugated fins 40 that promote heat transfer by heat exchange in the flow path of the heat exchange medium (first heat exchange fluid), and a second heat exchange fluid that is disposed above the heat exchange section composed of these. The upper header 22 in which the inflow port 23 and the outflow port 24 are formed, and the lower header 26 disposed at the lower portion of the heat exchange unit. The flat tube 30 and the

partition walls

28a, 28b, 28c, the

side walls

29a, 29b, the corrugated fins 40, the upper header 22, and the lower header 26 of the corrugated fin heat exchanger 20 of the first embodiment are the second heat exchange fluid. And a metal material that has corrosion resistance and high thermal conductivity with respect to the first heat exchange fluid, such as aluminum, copper, stainless steel, and the first heat when air is used as the first heat exchange fluid. When exhaust gas from an internal combustion engine or exhaust gas from a fuel cell is used as a replacement fluid, it is made of stainless steel or the like. In the following description, the corrugated fin type heat exchanger 20 is a heat exchanger used in an air conditioner, and includes a flat tube 30,

partition walls

28a, 28b, 28c,

side walls

29a, 29b, corrugated fins 40, and an upper header. 22, each member of the lower header 26 is made of aluminum. The size of the flat tube 30 is 5 mm to 10 mm, and the distance between the horizontal surfaces 42 of the corrugated fins 40 (the height of the vertical surface 48) is 1 mm to 2 mm. A specific example is one in which hydrofluorocarbon is used as the second heat exchange fluid and air is used as the first heat exchange fluid.

Partition walls

25a and 25b are formed on the inner side of the upper header 22 so that the partition walls 28a and 28c extend at positions that align with the partition walls 28a and 28c, and the lower header 26 is aligned with the partition wall 28b. A partition wall 27 is formed so that the partition wall 28b extends at a position where the partition wall 28b extends. Therefore, the second heat exchange fluid (for example, hydrofluorocarbon) flows into the upper header 22 from the inlet 23 as indicated by the arrows in the figure, and vertically passes through the three flat tubes 30 on the right side of the partition wall 28a. The upper header flows vertically downward from above, is supplied to the three flat tubes 30 between the partition walls 28a and 28b by the partition wall 27 in the lower header 26, and flows vertically upward from below the three flat tubes 30. 22 flows into the space between the

partition walls

25a and 25b, flows from the vertically upper side to the vertically lower side in the three flat tubes 30 of the

partition walls

28b and 28c, reaches the space on the right side of the partition wall 28b, and is on the left side of the partition wall 28c. The inside of the three flat tubes 30 flows vertically downward from vertically above and enters the space on the left side of the partition wall 25b of the upper header 22, After, and is discharged from the outlet 24. Note that the first heat exchange fluid (air) is a plurality of flat tubes from the front surface to the back surface in FIG. 1, from diagonally lower left to diagonally upper right in FIG. 2, and from lower to upper in FIG. Flows through 30.

In the corrugated fins 40, the horizontal planes 42 and the vertical planes 48 are alternately formed in a folded shape (bellows shape), and the vertical planes 48 are joined to the flat tube 30 by brazing or the like. On the horizontal plane 42 of the corrugated fin 40, a plurality of corrugated irregularities are formed by a smooth curved surface. As shown in FIG. 3, the plurality of corrugations of the first embodiment are mainly composed of a top line 43 connecting the wave tops and a bottom line 44 connecting the wave bottoms and the first heat exchange fluid (air). The top line 43 and the bottom line 44 are continuously repeated in a V shape a plurality of times so that the angle γ formed with the straight flow is an acute angle (about 30 degrees in the first embodiment). 4, the height of the bent portion 43 a (wave amplitude) in the top line 43 is higher than the height (wave amplitude) of the V-shaped hatched portion 43 b in the top line 43. The shape of the convex portion on one surface of the horizontal surface 42 and the shape of the concave portion on the same surface are integrated so that the bent portion 43a of the line 43 is positioned near the end portion of the horizontal surface 42 of the corrugated fin 40. As shown in FIG. 9, the wave of the inlet side of the first heat exchange fluid (air) As the width is greater than the amplitude of the wave on the outlet side are formed. Hereinafter, the corrugated irregularities formed in the corrugated fin 40 of the embodiment will be described in detail. The top of the wave means the top of the convex part in the repetition of the convex part and the concave part of the wave, and the bottom of the wave means the bottom of the concave part in the repetition of the convex part and the concave part of the wave. .

As shown in FIG. 3, the plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fin 40 has a smooth curved surface and a top line 43 connecting the wave tops and a bottom line 44 connecting the wave bottoms to the first line. The angle γ formed with the main flow of the heat exchange fluid (air) is an acute angle (about 30 degrees in the first embodiment). Here, the angle γ between the top line 43 and the bottom line 44 and the main flow of the first heat exchange fluid (air) is not only the inlet of the first heat exchange fluid, but also the corrugated fin 40. It is generally constant throughout, and the angle is preferably 10 to 60 degrees, more preferably 15 to 45 degrees, and more preferably 25 to 35 degrees (about 30 degrees in the first embodiment). is there. In this way, corrugated irregularities are formed by a smooth curved surface, and the angle γ between the top line 43 and the bottom line 44 and the main flow of the first heat exchange fluid (air) is in the range of 10 to 60 degrees. The corrugated irregularities are formed so that the angle is the same as that of the first heat exchange fluid flow, and the secondary flow of air that is effective in promoting heat transfer is suppressed by suppressing separation and local acceleration. This is because it is generated. FIG. 10 shows a secondary flow (arrow) of the fluid generated on the flat plate when a uniform flow of fluid is introduced into the wavy flat plate and a contour line due to temperature. As shown in the figure, it can be seen that the corrugated unevenness by the smooth curved surface suppresses the separation of fluid and local acceleration to generate a strong secondary flow, and also generates a large temperature gradient near the wall surface. . Thereby, heat transfer promotion can be made higher and flow resistance can be made smaller.

The plurality of corrugated irregularities formed on the horizontal plane 42 of the corrugated fin 40 are formed such that the top line 43 and the bottom line 44 are continuously repeated in a V shape a plurality of times. To repeat continuously in a V shape a plurality of times means, for example, that a plurality of V characters are in lateral contact with each other so that a V shape is formed by continuously repeating a V character twice. It means that it is formed so as to have a shape obtained side by side, that is, a zigzag shape. Thereby, the secondary flow effective for the heat exchange by the first heat exchange fluid can be generated in many parts of the horizontal surface 42, and the heat transfer can be further enhanced.

As shown in FIG. 4, the plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fin 40 is such that the height (wave amplitude) of the bent portion 43 a in the top line 43 is a V-shaped oblique portion 43 b ( It is formed so as to be higher than the height (wave amplitude) of a portion different from the bent portion 43 a in the top line 43. FIG. 4 is an explanatory diagram showing three-dimensional corrugated irregularities formed on the corrugated fin 40 of the first embodiment, and FIG. 5 is an explanatory diagram showing three-dimensional corrugated irregularities formed on the corrugated fin of the comparative example. . The corrugations of the comparative example of FIG. 5 are formed so that the bent portion 943a and the shaded portion 943b have the same height so that the top line 943 and the top line 944 are V-shaped. The corrugated unevenness formed in the corrugated fin 40 of the first embodiment is such that the height of the bent portion 43a in the top line 43 is higher than the height of the shaded portion 43b of the top line 43, in other words, the oblique line of the top line 43. Since the height of the portion 43b is formed to be lower than the height of the bent portion 43a in the top line 43, for example, as a shape in which the bent portion 943a in the corrugated unevenness of the comparative example is slightly raised, or in the comparative example It can be obtained as a shape in which the ridgeline of the shaded portion 943b in the corrugated unevenness is slightly crushed. FIG. 4 shows a shape in which the ridgeline of the shaded portion 943b in the corrugated unevenness of the comparative example is slightly collapsed. FIG. 6 is a cross-sectional view taken along the line AA in the enlarged view of the corrugated irregularities of FIG. As shown in the drawing, the bent portion 43a of the V-shaped top line 43 is formed such that the height Hua from the center position is higher than the height Hub from the center position of the hatched portion 34b.

In this way, the plurality of waveform irregularities are formed so that the height of the bent portion 43 a in the top line 43 is higher than the height of the oblique line portion 43 b in the top line 43. Alternatively, the plurality of waveform irregularities are hatched in the top line 43. The reason why the height of the portion 43b is formed to be lower than the height of the bent portion 43a in the top line 43 is as follows. FIG. 11 is an explanatory diagram showing the result of simulating the relationship between the waveform unevenness position, the contour line of the local heat flow velocity, and the contour line of the local shear stress in the comparative example. As shown in the figure, the local heat flow rate is large in the region from the bottom line 44 to the top line 43 and small in the region from the top line 43 to the bottom line 44 when viewed from the direction of the flow of the first heat exchange fluid. It has become. Further, the part from the bent part 44a of the bottom line 44 to the bent part 43a of the top line 43 is larger than the part from the inclined part 44b of the bottom line 44 to the inclined part 43b of the top line 43. The inflow side of 1 heat exchange fluid is larger than the outflow side. The local shear stress is larger at the top line 43, and the bent portion 43a is larger than the inclined portion 43b. In addition, the outflow side of the first heat exchange fluid is larger than the inflow side. A region where the local heat flow rate is large indicates a region where heat transfer is highly promoted and greatly contributes to heat exchange, and a region where the local shear stress is large indicates a region where resistance to the flow of the first heat exchange fluid is large. Therefore, by emphasizing the shape of the region where the local heat flow rate is large and relaxing the shape of the region where the local shear stress is large, a heat exchanger with high heat transfer promotion and low flow resistance can be obtained. In the corrugated unevenness of the first embodiment, the heat transfer is enhanced by increasing the height of the bent top 43a of the top wire 43, which is the region where the local heat flow rate is large, and the inclined portion of the top wire 43 where the local shear stress is large. The flow resistance is reduced by reducing the height of 43b. FIG. 12 is a dimensionless number as a ratio (Hub / Hua) between the height Hua of the bent portion 43a of the top line 43 and the height Hub of the inclined portion 43b of the top line 43 and the ratio of the heat transfer coefficient and the flow resistance. An experimental example of the relationship with a certain j / f factor is shown. As shown in the figure, the j / f factor increases as the ratio (Hub / Hua) decreases. This indicates that the smaller the ratio (Hub / Hua), the higher the heat transfer rate and the lower the flow resistance.

The plurality of corrugated irregularities formed on the horizontal plane 42 of the corrugated fin 40 are concave portions (on the bottom line 44) on the same plane as the projections on one surface of the horizontal plane 42 (the bent portion 43 a and the inclined portion 43 b on the top line 43). The bent portion 44a and the inclined portion 44b) are formed so as to be integrated with each other. That is, the shape of the bent portion 43a and the inclined portion 43b of the top line 43 on one surface of the horizontal plane 42 and the shape of the bent portion 44a and the inclined portion 44b of the bottom line 44 on the same surface are the same when the front and back sides are integrated, that is, the front and back are interchanged. It is formed as follows. Therefore, the depth of the bent portion 44a in the bottom line 44 is the same as the depth of the bent portion 43a in the top line 43 so that the height of the bent portion 43a in the top line 43 is higher than the height of the hatched portion 43b in the top line 43. It is formed so as to be deeper than the depth of the hatched portion 44b. As shown in FIGS. 7 and 8, the plurality of corrugations are bent on the bottom line 44 such that the height Hua of the bent part 43 a of the top line 43 is higher than the height Hub of the inclined part 43 b of the top line 43. The height Hua of the bent portion 43a of the top line 43 and the depth Hda of the bent portion 44a of the bottom line 44 match so that the depth Hda of the portion 44a is deeper than the depth Hdb of the inclined portion 43b of the bottom line 44. In this way, the height Hub of the inclined portion 43b of the top line 43 and the depth Hdb of the inclined portion 43b of the bottom line 44 are formed to coincide with each other. Thus, heat exchange with the first heat exchange fluid flowing on one surface side of the horizontal surface 42 of the corrugated fin 40 and heat exchange with the first heat exchange fluid flowing on the other surface side of the horizontal surface 42 are performed. This can be done in the same manner, and a heat exchanger with higher heat transfer and lower flow resistance can be obtained.

The plurality of corrugated irregularities formed on the horizontal plane 42 of the corrugated fin 40 are formed such that the bent portion 43 a of the top line 43 is positioned near the end of the horizontal plane 42 of the corrugated fin 40. That is, a plurality of corrugations are formed so that more bent portions 43a of the top line 43 are formed. Thereby, the bending part 43a of the top line 43 which is a site | part with a high local heat flow rate can be formed more in the horizontal surface 42, and it can be set as a heat exchanger with higher heat transfer promotion.

The plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fin 40 are formed such that the amplitude of the wave on the inlet side of the first heat exchange fluid (for example, air) is larger than the amplitude of the wave on the outlet side. . As shown in FIG. 9, the height of the bent portion 43a of the top wire 43 is such that the bent portion 43a closest to the outlet from the height Hin of the bent portion 43a closest to the inlet of the first heat exchange fluid (for example, air). The height is gradually lowered so as to become the height Hout. Similarly, the depth of the bent portion 44a of the bottom line 44 is determined by the depth Hout of the bent portion 44a closest to the outlet from the depth Hin of the bent portion 44a closest to the inlet of the first heat exchange fluid (for example, air). It becomes gradually shallower. In the local shear stress of FIG. 11, since the outflow side of the first heat exchange fluid is larger than the inflow side, the top line 43 on the outlet side of the first heat exchange fluid having a large local shear stress. By making the height lower than the height on the inlet side, the flow resistance against the flow of the first heat exchange fluid can be reduced.

According to the heat exchanger 20 of the first embodiment described above, a plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fin 40 are formed by a smooth curved surface, a top line 43 connecting wave tops, and a wave bottom part. The top line 43 and the bottom line 44 are V-shaped multiple times so that the angle γ formed by the bottom line 44 and the main flow of the first heat exchange fluid is an acute angle. In such a manner that the height of the bent portion 43a in the top line 43 is higher than the height of the hatched portion 43b in the top line 43 so as to be repeated continuously, the flow of the first heat exchange fluid can be reduced. A secondary flow of air that is effective in promoting heat transfer by suppressing separation and local acceleration can be generated, and heat transfer is promoted by emphasizing the part where the local heat flow rate is large, and the part where the local shear stress is large Reduce the shear stress of the first heat It is possible to reduce the flow resistance to the flow of the changeover fluid. As a result, a heat exchanger with higher heat transfer promotion and lower flow resistance can be obtained.

In addition, according to the heat exchanger 20 of the first embodiment, the plurality of corrugated irregularities formed on the horizontal plane 42 of the corrugated fin 40 are formed with a convex shape on one surface of the horizontal plane 42 and a concave shape on the same surface. Is formed so as to be integrated with the front and back, heat exchange with the first heat exchange fluid flowing on one surface side of the horizontal surface 42 of the corrugated fin 40 and first heat flowing on the other surface side of the horizontal surface 42 Heat exchange with the replacement fluid can be performed in the same manner. As a result, a heat exchanger with higher heat transfer acceleration and lower flow resistance can be obtained.

Further, according to the heat exchanger 20 of the first embodiment, the plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fin 40 are arranged so that the bent portion 43 a of the top line 43 is near the end of the horizontal surface 42 of the corrugated fin 40. By forming so that it may be located, the bending part 43a of the top line 43 which is a site | part with a high local heat flow rate can be formed more in the horizontal surface 42, and it can be set as a heat exchanger with higher heat transfer promotion.

Furthermore, according to the heat exchanger 20 of the first embodiment, the wave amplitude on the inlet side of the first heat exchange fluid (for example, air) is changed between the plurality of waveform irregularities formed on the horizontal surface 42 of the corrugated fin 40. By forming it to be larger than the amplitude of the wave on the outlet side, the flow resistance to the flow of the first heat exchange fluid can be reduced.

In the heat exchanger 20 of the first embodiment, the plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fin 40 are formed so that the shape of the convex portion on one surface of the horizontal surface 42 and the shape of the concave portion on the same surface are integrated. However, the shape of the convex portion on one surface of the horizontal surface 42 may be different from the shape of the concave portion on the same surface. For example, the plurality of corrugations are formed so that the height of the bent portion 43a is higher than the height of the shaded portion 43b with respect to the top line 43, but the depth of the bent portion 44a is the height of the shaded portion 44b with respect to the bottom line 44. The bottom line 44 is formed so that the bent part 44a is deeper than the hatched part 44b, whereas the top line 43 is formed with the bent part 43a. The height may be the same as the height of the hatched portion 43b.

In the heat exchanger 20 of the first embodiment, a plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fin 40 are arranged such that the bent portion 43a of the top line 43 is positioned near the end of the horizontal surface 42 of the corrugated fin 40. Although formed, the bent portion 43 a of the top line 43 may be formed so as not to be positioned in the vicinity of the end of the horizontal surface 42 of the corrugated fin 40.

In the heat exchanger 20 of the first embodiment, the plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fins 40 are such that the amplitude of the wave on the inlet side of the first heat exchange fluid is larger than the amplitude of the wave on the outlet side. However, it may be formed such that the amplitude of the wave on the inlet side and the amplitude of the wave on the outlet side of the first heat exchange fluid are the same.

In the heat exchanger 20 of the first embodiment, the plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fin 40 are repeated so that the top line 43 and the bottom line 44 are continuously V-shaped multiple times. The top line 43 and the bottom line 44 may be formed so as to be continuously W-shaped twice in a V shape, or the top line 43 and the bottom line 44 are single. It may be formed so as to have a V shape.

In the heat exchanger 20 of the first embodiment, a plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fin 40 are formed by a smooth curved surface, so that the top line 43 and the bottom line 44 and the main heat exchange fluid are main. The height of the bent portion 43a in the top line 43 is set so that the top line 43 and the bottom line 44 are continuously repeated in a V shape a plurality of times so that the angle γ formed with the flow is an acute angle. Is formed so as to be higher than the height of the hatched portion 43b in the top line 43, and further, as an average of the angle formed by the hatched portion in the top line and the main flow of the first heat exchange fluid. The second average as the average of the angle formed between the V-shaped oblique line portion in the intermediate line where the intermediate part where the average height is the average height in the corrugated irregularities and the first flow is the main flow of the first heat exchange fluid. Smaller than the average angle of It may alternatively be formed. FIG. 13 is an explanatory diagram illustrating the waveform irregularities of the modified example in three dimensions, FIG. 14 is an explanatory diagram illustrating the waveform irregularities of the comparative example and the reference example in three dimensions, and FIG. 15 is a comparative example of FIG. FIG. 16 is an explanatory diagram in which auxiliary lines are added to the corrugated irregularities of the reference example, and FIG. 16 is an explanatory diagram schematically showing the corrugated irregularities of the modification together with the auxiliary lines. 14A and 15A is similar to the waveform unevenness illustrated in FIG. 5 such that the top line 943 and the top line 944 are V-shaped so that the bent portion 943a is bent. The hatched portion 943b is also formed to have the same height. The corrugated irregularities in the reference examples of FIGS. 14B and 15B are the average height of the corrugated irregularities with respect to the top line 943 of the corrugated irregularities of the comparative example, as shown by the auxiliary line in FIG. In order to prevent deformation of the intermediate line 945 where the intermediate part is continuous, the bent part 943a is moved so as to extend slightly up and down in the drawing to be bent part 63a, and a slightly S-shaped curve is applied to the top line 943. The top line 63 is deformed as depicted. Therefore, the corrugated bottom line 64 of the reference example of FIGS. 14B and 15B is the same as the bottom line 944 of the comparative example, and the hatched part 63b is the same height as the bent part 63a. The corrugated unevenness of the modified example illustrated in FIG. 13 is obtained by slightly crushing the inclined portion 63b in the top line 63 of the corrugated unevenness of the reference example of FIG. Therefore, the waveform unevenness of the modified example illustrated in FIG. 13 is arranged such that the bent portion 53a of the top line 53 extends in the vertical direction in the drawing with respect to the waveform unevenness of the comparative example of FIG. In addition, the hatched portion 53b of the top line 53 is formed so as to draw an S-shaped curve so that the height thereof is lower than that of the bent portion 53a. In FIG. 13, only the top line 53 of the corrugated unevenness is shown three-dimensionally for ease of explanation, but the bottom line 54 is also formed in the same manner as the top line 53. The intermediate line 55 is V-shaped because the top line 53 and the bottom line 54 are V-shaped, and the bent part 53a of the top line 53 and the bent part 54a of the bottom line 54 are shown from the position of the comparative example. By setting the position extended in the middle / up / down direction, the position extends slightly in the up / down direction in the figure. As shown in FIG. 16, the first average angle θ1 as an average of the angle formed between the inclined portion 53b of the top line 53 and the main flow of the second heat exchange fluid is, as shown in FIG. When the vertical length L1 and the V-shaped width W are used in the drawing, the angle is expressed as an angle satisfying tan θ1 = (1/2) W / L1, and the inclined portion 55b of the intermediate line 55 and the second heat exchange are expressed. The second average angle θ2 as the average of the angles formed with the main flow of the working fluid is tan θ2 using the vertical length L2 and the V-shaped width W of the hatched portion 55b of the intermediate line 55 in the drawing. = (1/2) Expressed as an angle satisfying W / L2. Even if the intermediate line 55 has a slight extension in the vertical direction in the drawing (length ΔL as the vertical direction in FIG. 16), the intermediate line 55 is prevented from being extended in the vertical direction in FIG. 16 as much as possible. Therefore, since L1> L2 + ΔL, the first average angle θ1 is smaller than the second average angle θ2.

中間 As described above, the intermediate portion line 55 extends slightly in the vertical direction in the figure, but for ease of explanation, it is shown in FIG. 16 as not extending in the vertical direction in the figure. In FIG. 16, the thick solid line is the top line 53, the thin solid line is the top line 943 of the comparative example before stretching, the thick broken line is the bottom line 54, and the thin broken line is the bottom line 944 of the comparative example before stretching. Yes, the thick dotted line is the middle part line 55. When viewed along the flow of the first heat exchange fluid (air), the bent portion 53a of the top wire 53 and the bent portion 55 of the intermediate wire 55 are bent at the inverted V-shaped bent portion of the top wire 53 and the bottom wire 54. The distance from the portion 55a is L11, the distance between the bent portion 55a of the intermediate line 55 and the bent portion 54a of the bottom line 54 is L12, and the distance between the bent portion 54a of the bottom line 54 and the bent portion 55 of the intermediate line 55 is L13, the distance between the bent portion 55a of the intermediate line 55 and the bent portion 53a of the top line 53 is L14, and the bent portion 53a of the top line 53 and the intermediate line are V-shaped bent portions of the top line 53 and the bottom line 54. 55, the distance between the bent portion 55a of the intermediate portion 55 and the bent portion 54a of the bottom portion 54 is L22, the bent portion 54a of the bottom portion 54 and the bent portion 55 of the intermediate portion 55 Distance L23, medium When the distance between the bent portion 53a of the bent portion 55a and the top line 53 of the section line 55 and L24, the following equation (1) is satisfied. For this reason, when the second heat exchanging fluid (air) is flowed from the top to the bottom in the drawing, the corrugated irregularities are formed from the bent portion 54a of the bottom line 54 to the intermediate portion line 55 in the inverted V-shaped bent portion. From the bent portion 53a of the top line 53 to the bent portion 53a of the top line 53, and from the bent portion 53a of the top line 53 to the bent portion 53a of the top line 53. The intermediate line 55 has a relatively gentle downward slope to the bent portion 55a, and the intermediate line 55 has a relatively steep downward slope from the bent portion 55a of the intermediate line 55 to the bent portion 54a of the bottom line 54. Further, in the V-shaped bent portion, a relatively steep upward slope is formed from the bent portion 54a of the bottom line 54 to the bent portion 55a of the intermediate line 55, and the bent portion 55a of the intermediate line 55 is bent from the bent portion 55a. A relatively gentle slope is obtained up to the portion 53a, a relatively steep downward slope is obtained from the bent portion 53a of the top line 53 to the bent portion 55a of the intermediate line 55, and the bent portion 55a of the intermediate line 55 is extended to the bottom line 54. A relatively gentle downward slope is obtained up to the bent portion 54a. Since the portion from the bent portion 55a of the intermediate line 55 to the bent portion 53a of the top line 53 in the inverted V-shaped bent portion is a portion having a large local heat flow rate as described with reference to FIG. 11, this portion is compared. Heat transfer enhancement can be increased by using a steep climb. On the other hand, the top line 53 has a smaller angle with the first heat exchange fluid than the top line 943 of the comparative example, and the top line extends from the bent part 55a of the intermediate part line 55 at the V-shaped bent part. Since the portion up to the bent portion 53a of 53 has a relatively gentle slope, the first heat exchange fluid can easily get over the top line 53. For this reason, the flow resistance with respect to the flow of the first heat exchange fluid is reduced. As a result, a heat exchanger with higher heat transfer acceleration and lower flow resistance can be obtained.

L11 = L13 = L22 = L24> L12 = L14 = L21 = L23 (1)

Even in the corrugated unevenness of such a modified example, the bent portion 53a of the top line 53 may be formed in the vicinity of the end of the horizontal surface 42 of the corrugated fin 40, or on the inlet side of the first heat exchange fluid. It is good also as what forms so that the amplitude of a wave may become larger than the amplitude of the wave of an exit side, and forms so that the top line 53 and the bottom line 54 may become W shape continuously in a V shape only twice. The top line 53 and the bottom line 54 may be formed into a single V-shape, or the shape of the concave portion on the same surface as the shape of the convex portion on one surface of the horizontal surface 42. It is good also as what forms so that it may become different. In addition, the sloped portion 53b of the top line 53 and the sloped portion 54b of the bottom line 54 may have a straight shape instead of an S-curve shape.

FIG. 17 is an external view showing the external appearance of the heat exchanger 120 as the second embodiment of the present invention, and FIG. 18 shows the flat surface of the heat exchange tube 130 used in the heat exchanger 120 of the second embodiment. It is explanatory drawing. As shown in the drawing, the heat exchanger 120 of the second embodiment includes a plurality of heat exchange tubes 130 that are formed as flat hollow tubes and arranged in parallel, and ends of the plurality of heat exchange tubes 130. A pair of

headers

140 and 150 are attached so as to cover and flow heat exchange fluid into and out of the plurality of heat exchange tubes 30.

The heat exchanging tube 130 is formed into a flat tube having a thickness of 0.5 mm by using a plate having a thickness of 0.1 mm made of a material having thermal conductivity, such as a stainless material, by pressing or bending. Has been. On the outer wall surface side of the flat surfaces (front and back surfaces) of the heat exchange tube 130, a plurality of corrugated irregularities are formed by a smooth curved surface. The plurality of corrugated irregularities of the second embodiment are connected to the top line 143 that connects the tops of the waves and the bottom of the waves, similarly to the plurality of corrugated irregularities formed on the horizontal surface 42 of the corrugated fin 40 of the first embodiment. The top wire 143 and the top wire 143 so that the angle γ between the bottom wire 144 and the main flow of the first heat exchange fluid (eg, air) is an acute angle (about 30 degrees in the second embodiment). The height (wave amplitude) of the bent part 143a in the top line 143 is the height of the V-shaped oblique part 143b in the top line 143 (so that the bottom line 144 is continuously repeated in a V shape a plurality of times. The amplitude of the wave on the inlet side of the first heat exchange fluid (air) is such that the bent portion 143a of the top line 143 is positioned in the vicinity of the end of the flat surface so as to be higher than the amplitude of the wave). It is formed so as to be larger than the amplitude of the wave.

The plurality of corrugations of the second embodiment are smooth curved surfaces, and the angle γ between the top line 143 and the bottom line 144 and the main flow of the first heat exchange fluid (air) is an acute angle range. As shown, the height of the bent portion 143a in the top line 143 is such that the top line 143 and the bottom line 144 are continuously repeated in a V shape a plurality of times. The reason why it is formed so as to be higher than the height, the reason why the plurality of corrugated irregularities of the second embodiment are formed so that the bent portion 143a of the top line 143 is located near the end of the flat surface, The reason why the plurality of corrugations in the embodiment are formed so that the amplitude of the wave on the inlet side of the first heat exchange fluid (air) is larger than the amplitude of the wave on the outlet side is the waveform of the first embodiment. It is the same as unevenness.

According to the heat exchanger 120 of the second embodiment described above, a plurality of corrugated irregularities formed on the flat outer wall surface side of the heat exchanging tube 130 are connected to the top of the wave by a smooth curved surface. The top line 143 and the bottom line 144 are such that the angle γ between the line 143 and the bottom line 144 connecting the bottoms of the waves and the main flow of the first heat exchange fluid (air) is an acute angle. Is formed so that the height of the bent portion 143a in the top line 143 is higher than the height of the V-shaped oblique portion 143b in the top line 143 so that the V-shape continuously repeats a plurality of times. Effectively generates a secondary air flow effective for heat transfer promotion by suppressing delamination and local acceleration, and promotes heat transfer by emphasizing the part where the local heat flow rate is large. Reduce the shear stress of large parts It is possible to reduce the flow resistance for the first flow of heat exchange fluid. As a result, a heat exchanger with higher heat transfer promotion and lower flow resistance can be obtained.

Moreover, according to the heat exchanger 120 of the second embodiment, the plurality of corrugated irregularities formed on the outer wall surface side of the flat surface of the heat exchanging tube 130 are the end portions where the bent portions 143a of the top line 143 are flat surfaces. By forming so that it may be located in the vicinity, the bending part 143a of the top line 143 which is a site | part with a high local heat flow rate can be formed more by a flat surface, and it is set as a heat exchanger with higher heat-transfer promotion. it can.

Further, according to the heat exchanger 120 of the second embodiment, the plurality of corrugated irregularities formed on the outer wall surface side of the flat surface of the heat exchanging tube 130 are replaced with the inlet of the first heat exchanging fluid (for example, air). By forming the side wave so that the amplitude of the wave on the side is larger than the amplitude of the wave on the outlet side, the flow resistance to the flow of the first heat exchange fluid can be reduced.

In the heat exchanger 120 of the second embodiment, a plurality of corrugated irregularities formed on the outer flat wall surface side of the heat exchanging tube 130 are arranged such that the bent portion 143a of the top line 143 is located near the end of the flat surface. However, the bent portion 143a of the top line 143 may be formed so as not to be positioned near the end portion of the flat surface.

In the heat exchanger 120 of the second embodiment, a plurality of corrugations formed on the flat outer wall surface side of the heat exchanging tube 130 has a wave amplitude on the inlet side of the first heat exchanging fluid. However, it may be formed such that the amplitude of the wave on the inlet side and the amplitude of the wave on the outlet side of the first heat exchange fluid are the same.

In the heat exchanger 120 of the second embodiment, a plurality of corrugated irregularities formed on the outer wall surface side of the flat surface of the heat exchange tube 130 are formed a plurality of times so that the top line 143 and the bottom line 144 are V-shaped. The top line 143 and the bottom line 144 may be formed so as to be continuously W-shaped twice in a V shape, or the top line 143 and the bottom line 144 may be formed continuously. The bottom line 144 may be formed in a single V shape.

In the heat exchanger 20 of the first embodiment, a plurality of corrugated irregularities formed on the flat outer wall surface side of the heat exchanging tube 130 are formed by a smooth curved surface with a top line 143 connecting the wave tops and The top wire 143 and the bottom wire 144 are V-shaped multiple times so that the angle γ formed by the bottom wire 144 connecting the bottom and the main flow of the first heat exchange fluid is an acute angle. The height of the bent portion 143a in the top line 143 is formed to be higher than the height of the V-shaped hatched portion 143b in the top line 143 so as to repeat continuously. The first average angle as the average of the angle formed by the shaded portion of the character and the main flow of the first heat exchange fluid is the V Shaded area and first heat exchange It may alternatively be formed to be smaller than the second average angle of the average of the angle between the main flow of the fluid. That is, it is good also considering the waveform unevenness formed in the outer wall surface side of the flat surface of the tube 130 for heat exchange as the shape of the waveform unevenness of the modification illustrated in FIG.

As mentioned above, although the form for implementing this invention was demonstrated using 1st Example and 2nd Example, this invention is not limited to these Examples at all, and the range which does not deviate from the summary of this invention Of course, it can be implemented in various forms.

The present invention can be used in the heat exchanger manufacturing industry and the like.

Claims

A plurality of undulations are formed so that the top surface of the heat transfer member has a smooth curved surface and has a V-shaped cross-section with a wave-like top line and a wave-bottom continuous bottom line. In a heat exchanger for exchanging heat by flowing a first heat exchange fluid in a vertical direction in a V shape with respect to the plurality of corrugated irregularities,
The plurality of corrugations are formed such that the height of the top at the bent portion of the top line is higher than the height of the top at a portion different from the bent portion of the top line.
A heat exchanger characterized by that.
The heat exchanger according to claim 1,
The heat exchanger is a corrugated fin heat exchanger,
The heat transfer member is a corrugated fin,
The corrugated irregularities are formed such that the top and bottom are symmetrical.
A heat exchanger characterized by that.
The heat exchanger according to claim 1,
The heat transfer member is a plurality of flat tubes forming a flow path of a second heat exchange fluid that exchanges heat with the first heat exchange fluid,
The corrugated irregularities are formed on the flat outer surface of the tube,
A heat exchanger characterized by that.
The heat exchanger according to claim 1,
In the plurality of corrugations, the amplitude of the corrugations on the upstream side of the first heat exchange fluid is larger than the amplitude of the corrugations on the upstream side of the first heat exchange fluid. Formed to be,
A heat exchanger characterized by that.
The heat exchanger according to claim 1,
The top line and the bottom line of the plurality of corrugated irregularities are formed such that a V-shape is repeated continuously over a plurality of times.
A heat exchanger characterized by that.
The heat exchanger according to claim 5,
The plurality of corrugations are formed such that the bent portion of the top line is located near the end of the heat transfer member,
A heat exchanger characterized by that.
The heat exchanger according to claim 1,
In the plurality of corrugations, a first average angle as an average of an angle formed between a V-shaped inclined portion of the top line and the main flow of the first heat exchange fluid is intermediate between the top and the bottom. The intermediate portion is formed so as to be smaller than a second average angle as an average of an angle formed by the V-shaped inclined portion in the continuous intermediate portion line and the main flow of the first heat exchange fluid. ,
A heat exchanger characterized by that.