JP2009014220A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact heat exchanger of low costs having superior heat exchanging efficiency. <P>SOLUTION: In this heat exchanger 10 exchanging heat between fluids flowing in a cooling water passage 31 and an exhaust gas passage 32 formed by a plurality of plate members 21, 22, each of the plurality of plate members 21, 22 has first projecting portions 21a, 22a having the projecting shape on its one face side and second projecting portions 21b, 22b having the projecting shape on the other face side in a state of being separated from the first projecting portions in the fluid passing direction, the plurality of plate members are stacked in a state that their one face sides or other face sides are opposed to each other, and the cooling water passage 31 and the exhaust gas passage 32 are formed on one face side and the other face side of the plurality of the plate members 21, 22. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat exchanger, and more particularly to a heat exchanger suitable for exhaust cooling in an exhaust gas recirculation device for an internal combustion engine.

  With the increasing demand for exhaust purification performance of internal combustion engines for vehicles, internal combustion engines equipped with EGR (exhaust gas recirculation) devices that are effective in reducing NOx have become widespread, and fuel is lean relative to the amount of air. In an internal combustion engine in which combustion is possible and the amount of EGR increases, an EGR cooler that reduces the temperature of the recirculated exhaust gas is frequently used.

  For example, the EGR cooler has a flat tube stacked in a shell, and exhaust gas recirculated through the flat tube is passed through the cooling water guided between the shell and the flat tube. By exchanging heat with the passing exhaust gas, the exhaust gas recirculated to the intake side is cooled. That is, the EGR cooler is configured as a heat exchanger.

  As a conventional heat exchanger of this type, for example, a plurality of protrusions are formed on a flat tube so that the protrusions are in contact with each other, and the flat tubes are stacked so that the protrusions are in contact with each other. A water flow direction and flow amount are partially adjusted to prevent problems such as boiling due to cooling water stagnation (for example, see Patent Document 1).

  In addition, in the shell through which exhaust gas passes, a number of flat tubes are arranged in parallel in a direction orthogonal to the exhaust flow direction, and the ends of the flat tubes are sequentially placed on the flat tubes adjacent to the downstream side of the exhaust gas passage in the flow direction. For increasing the heat transfer area inside or outside of the flat tubes that form the zigzag cooling water passages (for example, see Patent Document 2) and the exhaust gas passages (between the flat tubes). The thing which added the fin member is also known (for example, refer patent documents 3, 4, and 5).

Note that an internal combustion engine having an exhaust gas recirculation device with an EGR cooler includes an exhaust gas recirculation device 2 that recirculates a part of the exhaust gas of the engine 1 to the intake manifold 3 side as shown in FIG. 16, for example. The EGR passage 6 bypasses the exhaust gas and connects the exhaust passage in the exhaust manifold 4 and the intake passage in the intake manifold 3. The EGR passage 6 is provided with an EGR valve 7 that adjusts the exhaust gas recirculation amount, and an exhaust cooler that cools the exhaust gas recirculated through the EGR passage 6, that is, an EGR cooler 8. The heat exchange amount for exhaust cooling by the EGR cooler 8 is adjusted by valve-controlling the flow rate of at least one of the EGR gas and the cooling water according to the operating state of the engine. Further, the turbocharger 5 can rotate the intake air compressor by rotating the internal exhaust turbine with the exhaust energy, and can suck positive pressure air into the engine 1.
JP 2004-177060 A JP 2006-057473 A JP 2005-172262 A JP 2005-133981 A JP 2001-342910 A

  However, in the conventional heat exchanger as described above, in the ones described in Patent Documents 1 and 2 in which the circulation of the cooling water is made uniform, the inside of the flat tube having a low passage height (cooling water) On the other hand, a recess is formed on the back side (exhaust gas side) of the convex part to the side) and the gas circulation part expands. On the other hand, the circulation of cooling water is restricted at the contact part of the convex part, and the cooling efficiency There was a problem that would decrease. Further, the stagnation prevention effect of the cooling water greatly changes depending on the position of the flat tube and the cooling conditions, and there is a problem that it is not easy to ensure stable cooling performance and the degree of freedom in design is low.

  In addition, as described in Patent Document 3 (see FIGS. 1 and 3 of the publication), there are a plurality of types of flat tubes in which the inflow direction and the outflow direction of cooling water into the shell intersect or the major axis is different in thickness and uniform. If it is installed, the pressure loss at each part is not constant and it is difficult to evenly flow cooling water, and not only the number of parts increases because of using multiple types of flat tubes with different long diameters, The flow of EGR gas was not constant, and it was difficult to efficiently cool the exhaust gas in accordance with the gas flow.

Furthermore, as described in Patent Documents 3 to 5, when a fin member is provided between a pair of partition plate portions of a flat tube, the fin member easily causes uneven flow in the gas chamber, and the flow uniformity is also reduced. Therefore, the thermal efficiency is likely to decrease. In addition, the partition plate on the upper part of the shell was uneven, and the height of the top surface of the cooling chamber was higher than the opening to the outside of the cooling chamber (see FIG. 10 of Patent Document 5). The steam is difficult to escape and the cooling efficiency is liable to decrease, and there is a problem that the inspection cannot be performed after the upper and lower partition plates are brazed.
On the other hand, it is conceivable to provide an inner fin on the gas passage side in the flat part, but the inner fin cannot contact the inner wall of the concave part of the flat tube located on the back of the convex part on the cooling water side. I can't expect it.

  The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and an object of the present invention is to provide a small and low-cost heat exchanger excellent in heat exchange efficiency.

  In order to achieve the above object, the heat exchanger of the present invention is (1) a heat exchanger that exchanges heat between fluid flowing in one fluid passage and the other fluid passage formed by a plurality of plate-like members. Each of the plurality of plate-like members has a first convex portion convex on one surface side and a convex shape on the other surface side away from the first convex portion in the fluid passage direction of the one or other fluid passage. A second convex portion formed and stacked so as to face each other or the other surface side, and the one fluid passage on the one surface side and the other surface side of the plurality of plate-like members. The other fluid passage is formed.

  With this configuration, the first convex portion and the second convex portion are formed in one and the other fluid passages on both sides of the plate-like member, and the size and arrangement of the first convex portion and the second convex portion. By appropriately setting, it is possible to adjust the flow direction and flow rate of the fluid without providing a fin member separately, and it is possible to sufficiently secure the heat transfer area. Moreover, a plate-shaped member can be manufactured at low cost by press work, and a low-cost and high cooling efficiency heat exchanger can be provided.

  In addition, facing one surface side or the other surface side of the plate-shaped member includes facing the first convex portions or the second convex portions, but the first convex portions or the second convex portions are opposed to each other. Can also be arranged at different positions (positions that differ in the direction of fluid passage). Further, when pressing the plate-like member, it is preferable that irregularities are formed in each fluid passage by the concave portions formed on the back side of the first convex portion and the second convex portion, the first convex portion, It is more preferable that the heat transfer area is increased by the inclined surface around each of the second convex portions so as to form a frustum shape. Furthermore, when exchanging heat between fluids having different specific heats, the size of the heat transfer area of the first and second protrusions is made different so that one of the protrusions is convex toward the fluid passage through which the fluid having a small specific heat flows. It is preferable that the portion is made larger than the other convex portion (the height of one convex portion is made higher than the height of the other convex portion).

  In the heat exchanger having the configuration of (1) above, (2) a plurality of the first protrusions and the second protrusions are alternately arranged in the fluid flow direction in the one fluid passage, It is preferable that a plurality of fluids are alternately arranged in the fluid flow direction in the other fluid passage.

  With this configuration, it is possible to expect a turbulent flow effect and a heat transfer effect in both the one fluid passage and the other fluid passage, and the passage of the fluid on the other fluid passage side at the portion where the cross-sectional area of the one fluid passage is increased. The problem that the cooling capacity is reduced due to the restriction is solved.

  In the case of having the configuration of (2) above, (3) the fluid flow direction in the one fluid passage and the fluid flow direction in the other fluid passage are orthogonal to each other, and the first convex portion The second convex portions are alternately separated in a direction perpendicular to the fluid flow direction in the one fluid passage and alternately separated in a direction perpendicular to the fluid flow direction in the other fluid passage. As described above, it is desirable that a plurality of them are arranged.

  With this configuration, it is possible to further improve the turbulent flow effect and the heat transfer effect in one fluid passage and the other fluid passage, and it is possible to easily arrange the flow path of each fluid to be heat exchanged.

  In the heat exchanger having the configuration of (1) to (3) above, (4) each of the pair of plate members facing each other on the one surface side among the plurality of plate members has the one surface side as an inner surface side. A flat tube having the other surface side as an outer surface side is constituted, and a plurality of the flat tubes constituted by the plurality of plate-like members are laminated so that the second convex portions are in contact with each other. Is good.

  With this configuration, a pair of plate-like members are used in advance as flat tubes to ensure sealing performance and shape accuracy, and assembly can be facilitated by sequentially stacking the flat tubes in the same posture.

  Moreover, the heat exchanger having the configuration of the above (1) to (3) includes (5) a shell that houses the plurality of flat tubes, and provided at both ends of the plurality of flat tubes in the shell, A pair of side wall members that form communication passages that allow the one fluid passages in the plurality of flat tubes to communicate with each other between the plurality of flat tubes, and the plurality of the plurality of flat tubes includes the plurality of side walls. It is preferable that the other fluid passage is formed between the flat tubes.

  With this configuration, one or the other fluid passage and the communication passage can be formed by the plurality of flat tubes and the pair of side wall members, and the number of parts can be reduced.

  In the heat exchanger of the above (4) or (5), (6) the first convex portion has a longitudinal direction intersecting with the inflow / outflow direction of the fluid to the one fluid passage, The flow of the fluid in the fluid passage is preferably biased toward the fluid inflow side in the other fluid passage.

  With this configuration, the low temperature side fluid is biased toward the high temperature side fluid inflow side where heat exchange is not proceeding, or the high temperature side fluid is biased toward the low temperature side fluid inflow side where heat exchange is not proceeding. As a result, the heat exchange efficiency is increased.

  In the heat exchanger of the above (4) or (5), (7) the second convex portion has a longitudinal direction intersecting with the flow direction of the fluid into and out of the other fluid passage, It is also preferable that the fluid flow in the fluid passage is biased toward the fluid inflow side in the one fluid passage.

  Even in this configuration, the high temperature side fluid is biased toward the low temperature side fluid inflow side where heat exchange has not progressed, or the low temperature side fluid is biased toward the high temperature side fluid inlet side where heat exchange has not progressed. As a result, the heat exchange efficiency is increased.

  In the heat exchanger of the above (4) or (5), (8) the length of the first protrusion extending over the entire width of the other fluid passage perpendicular to the fluid inflow / outflow direction to the other fluid passage. The fluid in the one fluid passage may be folded back and flow to one side and the other side in the width direction of the other fluid passage with the first convex portion interposed therebetween.

  With this configuration, one fluid passage that is folded back across the first convex portion becomes a folded passage that reciprocates across the entire width direction of the other fluid passage, and heat exchange efficiency is increased.

  In the heat exchangers of the above (1) to (8), (9) the plurality of plate-like members have a protruding height of the first convex portion from the flat portion on the one surface side or a flat surface on the other surface side. A plurality of types of plate-like members having different projecting heights of the second convex portion from the portion, and the cross-sectional area of the low temperature side fluid passage of the one fluid passage and the other fluid passage is the plurality of plates. The cross-sectional area of the high temperature side fluid passage of the one fluid passage and the other fluid passage increases toward the outside in the stacking direction of the plurality of plate-shaped members. As described above, the plurality of types of plate-like members may be laminated.

  With this configuration, the flow rate of the fluid on the cooling side can be increased on the center side in the stacking direction of the plate-shaped member, and the flow rate of the fluid on the cooled side can be increased on the outer side in the stacking direction of the plate-shaped member. It becomes possible to suppress the heat accumulation in the central part.

  In the heat exchangers (1) to (9), the other fluid passage forms a part of the exhaust gas recirculation passage of the internal combustion engine so as to cool the exhaust gas passing through the exhaust gas recirculation passage of the internal combustion engine. However, it is preferable that the coolant is supplied into the one fluid passage.

  With this configuration, it is possible to provide a high-thermal efficiency, small, and low-cost EGR cooler that can reduce the temperature of exhaust gas recirculated to the intake side of an internal combustion engine and enhance the NOx reduction effect of the exhaust gas recirculation device. it can.

  According to the present invention, each of the one fluid passage and the other fluid passage has a concavo-convex shape corresponding to the first convex portion and the second convex portion. Therefore, these first convex portion and second convex portion. By appropriately setting the size and arrangement, the flow direction and flow rate of the fluid can be adjusted without providing a separate fin member, and a sufficient heat transfer area can be secured. A heat exchanger with high exchange efficiency can be provided.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIGS. 1 to 11 are views showing a heat exchanger according to a first embodiment of the present invention. The heat exchanger according to the present invention is used as an EGR cooler mounted on an exhaust gas recirculation (EGR) device of an internal combustion engine. A configured example is shown. Although the entire configuration of the EGR device itself is not described in detail, a part of the exhaust gas is recirculated to the intake side and recirculated as in the conventional example shown in FIG.

  First, the configuration will be described with reference to FIGS. 1 is a partial cross-sectional plan view of the heat exchanger according to the present embodiment, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, FIG. 3 is a cross-sectional view taken along the line BB in FIG. 4B is a cross-sectional view taken along line FF in FIG. 3, FIG. 5 is a cross-sectional view taken along line CC in FIG. 1, FIG. 6 is a cross-sectional view taken along line DD in FIG. 8 is an explanatory view of the shape of the gas introduction port shown in FIG. 8, FIG. 8 is an explanatory view of the shape of a modification of the gas introduction port, and FIG. 9 is a plan view of the side wall member inside the heat exchanger.

  As shown in FIGS. 1 to 4, the heat exchanger 10 of the present embodiment includes a shell 11 that is an outer shell and a plurality of flat tubes 12 that are housed in the shell 11.

  The shell 11 is connected to an exhaust pipe that forms an EGR passage (corresponding to the EGR passage 6 of the conventional example shown in FIG. 16) (not shown) by the flange portions 11a and 11b at both ends.

  As shown in FIG. 5 and FIG. 6, the plurality of flat tubes 12 includes a pair of plate-like members 21 and 22 facing each other on one surface side, and the one surface side of the plate-like members 21 and 22 is set as an inner surface side. The other members 21 and 22 are formed in a flat cylindrical shape having the other surface side as the outer surface side. In addition, the some plate-shaped members 21 and 22 are the vertical attitude | positions (a horizontal attitude | position or an inclination attitude | position) which orient | assigned the plate | board surface direction to the perpendicular direction, for example. These plate-like members 21 and 22 are made of sheet metal made of a metal having high thermal conductivity.

  Specifically, as shown in FIGS. 1 to 6, the plate-like members 21, 22 are first convex portions 21 a, 22 a each having a convex shape on one surface side and a second convex shape on the other surface side. Convex portions 21b and 22b and flat plate portions 21c and 22c are provided. Each of the plate-like members 21 and 22 is made of, for example, a pressed metal sheet, and the first convex portions 21a and 22a and the second convex portions 21b and 22b have concave shapes on the convex back side. The first convex portions 21a and 22a and the second convex portions 21b and 22b are each formed in, for example, a substantially truncated cone shape (may be a substantially truncated pyramid shape with rounded corner portions). The plurality of flat tubes 12 are joined so that the first convex portions 21a and 22a of the plate-like members 21 and 22 are opposed to each other so as to be in contact with each other, thereby connecting the plate-like members 21 and 22 on the inner surface side thereof. In FIG. 2, a cooling water passage 31 (one fluid passage extending in the D1 direction) extending in the D1 and D2 directions is formed.

  Further, the plurality of flat tubes 12 are laminated in the D3 direction (see FIG. 3) perpendicular to the D1 and D2 directions in FIG. 2 so that the second convex portions 21b and 22b on the outer surface side thereof are brought into contact with each other. An exhaust gas passage 32 (the other fluid passage extending in the D2 direction) extending in the D2 direction is formed between each pair of adjacent flat tubes 12. That is, in the heat exchanger 10 of the present embodiment, the cooling water passage 31 that is one fluid passage and the exhaust gas that is the other fluid passage on one surface side and the other surface side of each plate-like member 21 and 22. A passage 32 is formed. The size, shape, arrangement position and pitch of the first and second convex portions 21a, 22a and 21b, 22b are the flow rate and pressure loss of the fluid flowing in the fluid passage, and the EGR cooler requirements required by the engine. Although it is determined according to the cooling performance or the like, basically, the first protrusion on the plate surface of the flat plate portions 21c, 22c of the plate members 21, 22 is considered in consideration of the specific heat of the fluid passing through the fluid passages 31, 32. The height (hereinafter also referred to as height Hw) and the diameter of the portions 21a and 22a are smaller than the height (hereinafter also referred to as height Hg) and the diameter of the second convex portions 21b and 22b (for example, Hg / Hw> 1) is set.

  As shown in FIG. 4 to FIG. 6, the cooling water passage 31 is more specifically a passage height (a pair of first in the stacking direction) corresponding to the distance between the opposing planes on one surface side of the plate-like members 21 and 22. A flat portion 31f having a height corresponding to the height of the convex portions 21a and 22a) and surrounding the contact portion of the first convex portions 21a and 22a, and the flat portions 31f to the second convex portions 21b and 22b. It has a plurality of bulging portions 31e that bulge to the back surface, and a plurality of immersing portions 31c that are recessed from the flat portion 31f into holes corresponding to the shapes of the first convex portions 21a and 22a. The exhaust gas passage 32 has a passage height corresponding to the distance between the opposing flat surfaces on the other surface side of the plate-like members 21 and 22 (the passage height corresponding to the height of the pair of second convex portions 21b and 22b in the stacking direction). A flat portion 32f surrounding the contact portion of the second convex portions 21b and 22b, and a plurality of bulged portions 32e bulging from the flat portion 32f to the back surfaces of the first convex portions 21a and 22a, The flat portion 32f has a plurality of recessed portions 32c that are recessed into holes corresponding to the shapes of the second convex portions 21b and 22b.

  Moreover, the 1st convex parts 21a and 22a and the 2nd convex parts 21b and 22b are the fluids in the cooling water channel | path 31 which is one fluid channel | path, as shown in FIG. A plurality of them are alternately arranged in the flow direction (D1 direction), and a plurality of fluids are alternately arranged in the flow direction (D2 direction) of the fluid in the exhaust gas passage 32 which is the other fluid passage. Furthermore, in this embodiment, the flow direction of the fluid in the cooling water passage 31 and the flow direction of the fluid in the exhaust gas passage 32 are orthogonal to each other as shown in the D1 direction and the D2 direction in FIG. The first convex portions 21a and 22a and the second convex portions 21b and 22b are alternately separated in the flow direction D2 orthogonal to the fluid flow direction D1 in the cooling water passage 31 and the fluid flow in the exhaust gas passage 32. The flow direction D1 perpendicular to the direction D2 is also alternately spaced. That is, the 1st convex parts 21a and 22a and the 2nd convex parts 21b and 22b are staggered so that the opposite arrangement may be taken at the same pitch, respectively.

On the other hand, between the shell 11 and the plurality of flat tubes 12, as shown in FIGS. 5 and 6, a pair of side wall members 41 that support both side ends 12 a and 12 b of the plurality of flat tubes 12 in the D1 direction, The side wall members 41 and 42 form communication passages 33 and 34 that allow the cooling water passages 31 in the plurality of flat tubes 12 to communicate with each other between the side wall members 41 and 42.
Further, the exhaust gas passage 32 is a flat passage sandwiched between opposed inner wall surfaces of the pair of side wall members 41, 42 between the plurality of flat tubes 12. In other words, the exhaust gas passage 32 is formed between the plurality of flat tubes 12 by the pair of side wall members 41 and 42 and the plurality of flat tubes 12.

  The communication passages 33 and 34 pass the cooling water after heat dissipation from the radiator that cools the engine through the cooling water introduction port 11c, the cooling water discharge port 11d formed in the shell 11, and the cooling water passage 31 in the plurality of flat tubes 12. It is made to pass in the direction D1. The flow rates of the cooling water and the EGR gas passing through the heat exchanger 10 are variably controlled according to the operating state of the engine by a control valve (not shown).

  The heat exchanger 10 of the present embodiment has a heat conductive fluid flowing through the cooling water passage 31 and the exhaust gas passage 32 formed by the plurality of plate-like members 21 and 22 as described above, that is, the cooling water and the intake air of the engine. This is an EGR cooler that exchanges heat with exhaust gas (EGR gas) recirculated to the side.

  The shell 11 shown in FIGS. 1 and 2 has a cross-sectional shape (for example, a circular cross-section) corresponding to the cross-sectional shape of the EGR passage in the openings 11h and 11i at both ends, but a plurality of flat tubes 12 and a pair of side walls. The heat exchange chamber portion 11k that houses the members 41 and 42 has a square cross section. Further, as shown in FIGS. 1 and 2, the connection between the openings 11h and 11i and the heat exchange chamber 11k is such that the passage sectional area is changed so that the passage sectional area becomes larger toward the heat exchange chamber 11k. The connecting pipe part 11m on the inflow side of the EGR gas is offset to the cooling water inlet 11c side from the center of the heat exchange chamber part 11k, and the connecting pipe part 11n on the outflow side is the heat exchange chamber. It is offset from the center of the part 11k to the cooling water discharge port 11d side.

  Further, as shown in FIGS. 3, 4 and 7, D2 (longitudinal length) of the flat tube 12 at the center in the stacking direction is provided at the entrances and exits of a plurality of layers, for example, four layers of the exhaust gas passage 32 in the heat exchange chamber 11k. ) The both end portions in the direction are supported and the both end portions in the D2 direction of the communication passages 33 and 34 are closed, and the laminated thickness of the laminated flat tubes 12 (for example, the thickness at the both end portions in the D2 direction). And end plates 51 and 52 that define the positions of the plurality of flat tubes 12 in the D1 direction. As shown in FIG. 7, the end plates 51 and 52 are inserted into the slits 51 b and 52 b of the intermediate support portions 51 a and 52 a by inserting both longitudinal ends of the flat tube 12 at the center in the stacking direction, thereby Although it supports to the intermediate support parts 51a and 52a, as shown in FIG. 8, the opening shape (gas passage port shape as a whole) which does not have the support parts 51a and 52a of the center part of a lamination direction may be sufficient.

  As shown in FIG. 9, each of the side wall members 41 and 42 includes a plurality of parallel plate holding holes 41a and 42a into which both ends of the flat tube 12 in the D1 direction are inserted, and the flat tubes 12 and shells on both sides in the stacking direction. 11, a plurality of communication holes 41b, 41c, 41d, 41e, 41f and 42b, 42c, 42d, 42e having different diameters for guiding the cooling water in the communication passages 33, 34 into the spaces 35, 36 formed between them. 42f is formed. These communication holes 41b to 41f and 42b to 42f are spaced apart at a predetermined interval in the D2 direction, and the hole diameter is larger as the distance from the cooling water inlet 11c side of the shell 11 is closer to the D2 direction.

  Note that the side wall members 41 and 42 and the end plates 51 and 52 are assembled in advance into a set of flat tubes 12 and loaded into the heat exchange chamber portion 11 k in the shell 11. In addition, the shell 11 is, for example, a lid portion that is closed after the plurality of flat tubes 12 are stored in the heat exchange chamber portion 11k (for example, a portion in which the cooling water introduction port 11c and the cooling water discharge port 11d of the shell 11 are formed). have.

  Next, the operation will be described.

  In the heat exchanger 10 of the present embodiment configured as described above, when exhaust gas recirculation is performed according to the engine load or the like, heat is radiated from the radiator into the communication path 33 from the cooling water inlet 11c of the shell 11. When the later cooling water flows in and flows from the communication path 33 to the communication path 34 through the plurality of cooling water paths 31, the cooling water branches and flows to the cooling water paths 31 in the plurality of flat tubes 12. Merge in the passage 34. Further, the cooling water merged in the communication path 34 flows to the radiator side through the cooling water discharge port 11d and is cooled again. Further, the amount of the cooling water is variably controlled by a control valve or the like disposed in the cooling water circulation path, or the exhaust gas flow rate is controlled by the EGR valve, whereby the cooling water and the exhaust gas path 32 flowing through the cooling water passage 31 are controlled. The amount of heat exchange with the EGR gas flowing through is controlled.

  10 to 11 are action explanatory views showing the state of fluid flow in the heat exchanger 10 in a state where such heat exchange is performed, and FIG. 10A is a cross-sectional view taken along the line EE of FIG. Correspondingly, FIG. 10B corresponds to the GG cross section of FIG. FIG. 11A is an operation explanatory view showing the state of the flow of fluid during heat exchange in the heat exchanger according to the first embodiment in the same cross section as FIG. 5, and FIG. 11B is the flow of the fluid. FIG. 7 is an operation explanatory view showing the state of FIG.

  As shown in FIG. 10, the EGR gas passes through the exhaust gas passage 32 between the plurality of flat tubes 12 in the direction D <b> 2 and passes through the heat exchange chamber portion 11 k of the heat exchanger 10. As shown in FIG. 4, the heat exchange chamber portion 11k of the heat exchanger 10 passes through the cooling water passages 31 in the plurality of flat tubes 12 in the D1 direction.

  In such a heat exchanger 10 of this embodiment, the plate-like members 21 and 22 are formed with the first convex portions 21a and 22a and the second convex portions 21b and 22b and the concave portions corresponding to these, thereby cooling. Unevenness is alternately formed in each of the water passage 31 and the exhaust gas passage 32. Therefore, by appropriately setting the size and arrangement of the first protrusions 21a and 22a and the second protrusions 21b and 22b, the cooling water and the exhaust gas in the cooling water passage 31 can be provided without providing a fin member as in the prior art. The direction and flow rate of the EGR gas in the gas passage 32 can be adjusted. Moreover, the plate-like members 21 and 22 can be manufactured at low cost by press working. As a result, it is possible to provide a small and low-cost EGR cooler with high heat exchange efficiency that can reduce the temperature of the EGR gas and enhance the NOx reduction effect of the EGR device.

  In the present embodiment, a plurality of first protrusions 21a, 22a and second protrusions 21b, 22b are alternately arranged in the direction D1 which is the flow direction of the cooling water in the cooling water passage 31, and the exhaust gas is exhausted. 2 are alternately arranged in the direction D2 which is the flow direction of the EGR gas in the gas passage 32, so that the turbulent flow as shown in FIG. The heat transfer efficiency can be improved.

  Furthermore, in this embodiment, the flow direction of the cooling water in the cooling water passage 31 and the flow direction of the EGR gas in the exhaust gas passage 32 are orthogonal to each other, and the first convex portions 21a and 22a and the second convex portions 21b, 22b are arranged so as to be alternately separated in each of the D1 direction and the D2 direction, so that further improvement of the turbulent flow effect and the heat transfer effect in the cooling water passage 31 and the exhaust gas passage 32 can be expected. . Moreover, since the passage directions of the cooling water and the EGR gas into the shell 11 are orthogonal to each other, both the circulation path of the cooling water and the circulation path of the EGR gas into the shell 11 can be easily arranged.

  In addition, since the first convex portions 21a and 22a and the second convex portions 21b and 22b are each formed in a frustum shape and arranged in a staggered manner, not only the heat transfer area increases, but also the flow of cooling water Both the flow of EGR gas are moderately disturbed in the vertical and horizontal directions on the fluid passage cross section, and the heat transfer efficiency is improved.

  In addition, each of the pair of plate-like members 21, 22 facing each other on one surface side among the plurality of plate-like members 21, 22 constitutes the flat tube 12, and a plurality of pairs of plate-like members 21, 22 are configured. Since the flat tube 12 is laminated so that the second convex portions 21b and 22b are opposed to each other, if the pair of plate-like members 21 and 22 are preliminarily formed as the flat tube 12 and the sealing performance and shape accuracy are secured, The heat exchanger 10 can be easily assembled by sequentially laminating the flat tubes 12 in the same posture.

  In addition, the cooling water passages 31 in the plurality of flat tubes 12 are formed by the shell 11 that houses the plurality of flat tubes 12 and the pair of side wall members 41, 42 provided on both ends of the flat tube 12 in the shell 11. Since the communication passages 33 and 34 that communicate with each other are formed, the cooling water passage 31, the exhaust gas passage 32, and the communication passage 33 are formed by the plurality of flat tubes 12, the pair of side wall members 41 and 42, and the end plates 51 and 52. , 34 can be formed with a small number of parts.

  In addition, although the several flat tube 12 in this embodiment becomes a structure which joins each pair of opposing plate-shaped members 21 and 22 so that those 1st convex parts 21a and 22a may contact | abut, The exhaust gas passage 32 which is the other fluid passage is formed in the flat tube (between the plate-like members 21 and 22) by joining the second convex portions 21b and 22b of the member 21 and 22 so as to contact each other. It can also be formed. In this case, the plurality of flat tubes 12 form a pipe line in the extending direction of the exhaust gas passage 32 (left and right direction in FIG. 4).

(Second Embodiment)
FIG. 12 is a view showing a heat exchanger according to the second embodiment of the present invention. In addition, each embodiment described below has an overall configuration similar to that of the first embodiment described above, and only the convex shape provided on the flat tube (plate-like member) is different from the above-described example. . Therefore, the same or similar configurations as those of the above-described embodiment are denoted by the reference numerals shown in FIGS. 1 to 11 and the differences will be described in detail.

  In the heat exchanger 60 of this embodiment, a part of 2nd convex part 21b, 22b provided in the plate-shaped members 21 and 22 which comprise the flat tube 12 is an oval convex part or the protrusion of predetermined length. A plurality of deformed second convex portions 61c or similar non-illustrated deformed second convex portions (hereinafter referred to as deformed second convex portions 61c, etc.) facing each other are replaced by these deformed second convex portions 61c. The part 61c and the like have a longitudinal direction that intersects the D2 direction, which is the direction in which the EGR gas flows into and out of the exhaust gas passage 32 (exhaust gas passage), at a predetermined angle θ1. Note that the bulging portion 31e of the cooling water passage 31 is formed on the back side of the deformed second convex portion 61c or the like in the form of an oval shape or a protrusion having a predetermined length. In addition, you may provide a deformed 2nd convex part only in the one side of the plate-shaped members 21 and 22. FIG.

  These irregularly shaped second convex portions 61c and the like change the direction of the flow of EGR gas in the exhaust gas passage 32 in the vicinity of the cooling water inlet 11c so that the EGR gas flows into and out of the exhaust gas passage 32 as shown in FIG. It is biased toward the cooling water inlet 11c side, that is, the cooling water inflow side in the cooling water passage 31 with respect to the D2 direction (passing) direction (intention to tilt the EGR gas flow direction toward the low temperature side of the cooling water). The heat transfer area is also increased by the side wall surface portion such as the deformed second convex portion 61c along the flow of the EGR gas.

  In the present embodiment, in addition to the effects of the first embodiment described above, the flow of the EGR gas on the high temperature side becomes a flow that is biased toward the inflow side of the cooling water on the low temperature side where heat exchange is not progressing. Heat exchange is promoted in a region where the temperature difference between the EGR gas and the cooling water is large, and the heat exchange efficiency is increased.

(Third embodiment)
FIG. 13 is a view showing a heat exchanger according to the third embodiment of the present invention.

  In the heat exchanger 70 of this embodiment, some of the first convex portions 21a and 22a provided on the plate-like members 21 and 22 constituting the flat tube 12 are oval convex portions or protrusions having a predetermined length. It is replaced by a certain deformed first convex portion 71c or a similar deformed first convex portion (not shown) opposite to the first convex portion 71c (hereinafter referred to as the deformed first convex portion 71c or the like together). And the like have a longitudinal direction that intersects the direction D1 that is the inflow / outflow (passage) direction of the cooling water into the cooling water passage 31 at a predetermined angle θ2. Note that the bulging portion 32e of the exhaust gas passage 32 is formed in the shape of an oval shape or a protrusion having a predetermined length on the back side of the deformed first convex portion 71c and the like.

  The deformed first convex portion 71c or the like biases the flow of the cooling water in the cooling water passage 31 toward the inflow side of EGR gas (exhaust gas) in the exhaust gas passage 32 (ie, as shown in FIG. The direction of the flow is inclined toward the inflow side of the exhaust gas into the exhaust gas passage 32 with respect to the direction D1 which is the inflow direction into the shell 11 from the cooling water inlet 11c.

  In the present embodiment, in addition to the effects of the first embodiment described above, the cooling water that is the low temperature side fluid is biased toward the high temperature side fluid in which heat exchange does not proceed, that is, the EGR gas inflow side. Therefore, heat exchange is promoted in a region where the temperature difference between the cooling water and the EGR gas is large, and the heat exchange efficiency is increased.

(Fourth embodiment)
FIG. 14 is a view showing a heat exchanger according to the fourth embodiment of the present invention.

  In the heat exchanger 80 of the present embodiment, the first protrusions 21a and 22a provided on the plate-like members 21 and 22 constituting the flat tube 12 are partly bent in a zigzag manner as shown in FIG. However, it is replaced with a plurality of deformed first convex portions 81c that are spaced apart from each other in the D2 direction, or similar non-illustrated deformed first convex portions (hereinafter referred to as the deformed first convex portions 81c, etc.) that oppose each other. ing.

  These deformed first convex portions 81c and the like have a length extending over the entire width of the exhaust gas passage 32 in the D1 direction orthogonal to the D2 direction, which is the flow direction of EGR gas into and out of the exhaust gas passage 32. The cooling water in the cooling water passage 31 is folded back from one side to the other side in the passage width direction (D1 direction) of the exhaust gas passage 32 or from the other side to the one side across each of the deformed first convex portions 81c and the like. Is flowing. In addition, the bulging portion 32e of the exhaust gas passage 32 is formed in the shape of a bent ridge on the back side of the deformed first convex portion 81c and the like.

  Further, the communication passages 33 and 34 are partitioned at predetermined positions, and a zigzag cooling water passage 31 from the cooling water introduction port 11c to the cooling water discharge port 11d is formed between the shell 11 and the side wall members 41 and 42. Partition members 53, 54, and 55 that define the direction in which the cooling water passage 31 is folded back are provided. The partition members 53, 54, and 55 are brazed integrally with the plurality of flat tubes 12, the side wall members 41 and 42, and the end plates 51 and 52.

  In the present embodiment, since the cooling water passage 31 that turns back with the deformed first convex portion 81c and the like interposed therebetween becomes a turning passage that reciprocates in the entire width direction of the exhaust gas passage 32, the heat exchange efficiency is increased.

(Fifth embodiment)
FIG. 15 is a view showing a heat exchanger according to the fifth embodiment of the present invention.

  In the heat exchanger 90 of the present embodiment, the plate-like members 21 and 22 constituting the flat tube 12 are protruded heights or flat plate portions of the first convex portions 21a and 22a from one surface side of the flat plate portions 21c and 22c. Plural types with different protrusion heights of the second convex portions 21b, 22b from the other surface side of 21c, 22c, for example, three types of plate-like members 21S, 21T, 21U, 22S, 22T, 22U (hereinafter referred to as these) It is generally referred to as plate-like members 21 and 22).

  Then, the outermost flat tube 12S in the stacking direction is composed of the same type of plate-like members 21S and 22S having the same protruding height of the first protruding portions 21a and 22a and the protruding height of the second protruding portions 21b and 22b. The projecting height of the first protrusions 21a and 22a is larger than the plate-like members 21S and 22S, and the plate-like members 21T and 22T smaller than the plate-like members 21U and 22U are the second flat tubes 12T from the outside in the stacking direction. The flat tube 12U at the center in the stacking direction is configured by the plate-like members 21U and 22U having the largest protruding heights of the first convex portions 21a and 22a.

  On the other hand, the stacking pitch of the flat tubes 12S, 12T, and 12U is constant at the pitch PA as shown in FIG. 15, and the protruding heights of the second convex portions 21b, 22b of the plate-like members 21S, 22S are the plate-like members 21T. , Larger than the projecting height of the second projecting portions 21b, 22b of 22T, and the projecting height of the second projecting portions 21b, 22b of the plate-like members 21T, 22T is the second projecting portion 21b of the plate-like members 21U, 22U, It is larger than the protruding height of 22b.

  That is, in the heat exchanger 90 of the present embodiment, the cross-sectional area of the cooling water passage 31 that is the low temperature side fluid passage of the cooling water passage 31 and the exhaust gas passage 32 is the flat tube 12 (the plurality of plate-like members 21. 15) so that the cross-sectional area of the exhaust gas passage 32, which is a high temperature side fluid passage, becomes larger toward the outer side in the laminating direction of the flat tubes 12, so that the outer side in the laminating direction of FIG. The flat portion heights B0, B1, B2 of the flat tube 12 corresponding to the thickness of the flat portion 31f of the water passage are set to the relationship of B2> B1> B0, and the thickness G1 of the flat portion 32f of the exhaust gas passage 32 is set. , G2 are set in a relationship of G1> G2.

  In the present embodiment configured as described above, in addition to the effects of the first embodiment described above, heat is accumulated at the center of the heat exchanger 90 because heat exchange at the center of the heat exchanger 90 is not sufficient. In other words, so-called heat accumulation is suppressed.

  In each of the above-described embodiments, the first convex portions and the second convex portions are not alternately arranged one by one in the fluid passage direction, but are alternately arranged every plural numbers or alternately in a different number. May be. Further, if the bulging portion and the immersion portion are present at different positions in the same passage in the fluid passage direction, at least one of the fluid passage on the one surface side of the plate-like member and the fluid passage on the other surface side passes through the fluid. Unevenness may be formed only on the surface. Furthermore, the convex shapes of the first convex portion and the second convex portion are both frustoconical shapes, but are convex portions having a circumferential wall surface inclined in a spherical shape, curved protrusions having a predetermined length, and the like. Of course, as exemplified in the second to fourth embodiments, it is needless to say that a plurality of types of convex portions having different shapes may be combined on the same surface of the same plate-like member.

  As described above, according to the present invention, one of the first convex portion and the second convex portion and the corresponding concave portion are formed in each of the one fluid passage and the other fluid passage. Therefore, by appropriately setting the size and arrangement of the first convex portion and the second convex portion, it is possible to adjust the fluid flow direction and the flow rate balance without providing a fin member separately, and the heat transfer area is sufficient. It is possible to provide a heat exchanger having a low cost and high cooling efficiency, and suitable for exhaust cooling in a heat exchanger, particularly an exhaust gas recirculation device for an internal combustion engine. Useful for heat exchangers in general.

It is a partial cross section top view of the heat exchanger which concerns on the 1st Embodiment of this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. (A) is EE sectional drawing of FIG. 3, (b) is FF sectional drawing of FIG. It is CC sectional drawing of FIG. It is DD sectional drawing of FIG. It is shape explanatory drawing of the exhaust-gas inlet shown by FIG. It is shape explanatory drawing of the deformation | transformation aspect of the exhaust-gas inlet shown by FIG. It is a top view of the side wall member inside the heat exchanger which concerns on 1st Embodiment. FIG. 4 is an operation explanatory view showing the state of fluid flow in a state where heat is exchanged in the heat exchanger according to the first embodiment in a plane cross section having different height positions, and (a) is a cross section taken along line EE in FIG. 3. (B) corresponds to the GG cross section of FIG. (A) is an action explanatory view showing the state of fluid flow at the time of heat exchange in the heat exchanger according to the first embodiment in the same cross section as FIG. 5, and (b) shows the state of fluid flow. 6 is an operation explanatory view showing the same cross section as FIG. It is side surface sectional drawing of the heat exchanger which concerns on the 2nd Embodiment of this invention. It is side surface sectional drawing of the heat exchanger which concerns on the 3rd Embodiment of this invention. It is side surface sectional drawing of the heat exchanger which concerns on the 4th Embodiment of this invention. It is a principal part plane sectional view of the heat exchanger concerning a 5th embodiment of the present invention. It is a schematic block diagram of the internal combustion engine provided with the exhaust gas recirculation apparatus with an EGR cooler of a prior art example.

Explanation of symbols

10, 60, 70, 80, 90 Heat exchanger (EGR cooler)
11 shell 11a, 11b flange part 11c cooling water inlet 11d cooling water outlet 11h, 11i opening 11k heat exchange chamber part 11m, 11n connecting pipe part 12, 12S, 12T, 12U flat tube 12a, 12b both end parts 21, 22 , 21S, 22S, 21T, 22T, 21U, 22U Plate-like member 21a, 22a First convex portion 21b, 22b Second convex portion 21c, 22c Flat plate portion 31 Cooling water passage 31c Immersion portion 31e Swelling portion 31f, 32f Flat portion 32 Exhaust gas passage 32c Immersion part 32e Expansion part 32f Flat part 33, 34 Communication path 35, 36 Space 41, 42 Side wall member 41a, 42a Plate holding hole part 41b, 41c, 41d, 41e, 41f Communication hole 51, 52 End Plate 53, 54, 55 Partition member 61c etc. Modified second convex portion 71c etc. Modified first convex 81c such variant the first convex portion B0, B1, B2 of the flat portion of the flat tube thickness D1 coolant passage direction of the cooling water passage (inflow out direction of the fluid in the one fluid passage)
D2 EGR gas passage direction of exhaust gas passage (flow direction of fluid in the other fluid passage)
G1, G2 Thickness of flat part of exhaust gas passage θ1, θ2 Predetermined angle

Claims (10)

In a heat exchanger for exchanging heat between fluid flowing in one fluid passage and the other fluid passage formed by a plurality of plate-like members,
Each of the plurality of plate-like members has a first convex portion convex on one surface side and a convex shape on the other surface side away from the first convex portion in the fluid passage direction of the one or other fluid passage. A second convex portion formed and stacked so as to face each other or the other surface side, and the one fluid passage on the one surface side and the other surface side of the plurality of plate-like members. A heat exchanger characterized in that the other fluid passage is formed.   A plurality of the first convex portions and the second convex portions are alternately arranged in the fluid flow direction in the one fluid passage, and the plurality of the first convex portions and the second convex portions are alternately arranged in the fluid flow direction in the other fluid passage. The heat exchanger according to claim 1, wherein the heat exchanger is arranged.   The flow direction of the fluid in the one fluid passage and the flow direction of the fluid in the other fluid passage are orthogonal to each other, and the first protrusion and the second protrusion are in the one fluid passage. 3. A plurality of elements are arranged so as to be alternately spaced in a direction orthogonal to the fluid flow direction and alternately spaced in a direction orthogonal to the fluid flow direction in the other fluid passage. The heat exchanger as described in. Each of the pair of plate members facing each other on the one surface side among the plurality of plate members constitutes a flat tube having the one surface side as an inner surface side and the other surface side as an outer surface side,
The said flat tube comprised by these several plate-shaped members was laminated | stacked so that said 2nd convex part might contact | abut, The Claim 1 characterized by the above-mentioned. Heat exchanger. A shell for storing the plurality of flat tubes;
A pair of side wall members that are provided at both ends of the plurality of flat tubes in the shell and that form communication passages between the shells and the one fluid passages in the plurality of flat tubes. Prepared,
The heat exchanger according to claim 4, wherein the other fluid passage is formed between the plurality of flat tubes by the pair of side wall members and the plurality of flat tubes.   The first convex portion has a longitudinal direction intersecting with the inflow / outflow direction of the fluid into the one fluid passage, and the flow of the fluid in the one fluid passage is changed to the inflow of the fluid in the other fluid passage. The heat exchanger according to claim 4 or 5, wherein the heat exchanger is biased to the side.   The second convex portion has a longitudinal direction that intersects the inflow / outflow direction of the fluid into the other fluid passage, and the flow of the fluid in the other fluid passage is changed to the inflow of fluid in the one fluid passage. The heat exchanger according to claim 4 or 5, wherein the heat exchanger is biased to the side.   The first convex portion has a length extending over the entire width of the other fluid passage width orthogonal to the fluid inflow / outflow direction to the other fluid passage, and the fluid in the one fluid passage is the first convex portion. 6. The heat exchanger according to claim 4, wherein the heat exchanger is configured to flow while being folded back to one side and the other side in the width direction of the other fluid passage. The plurality of plate-shaped members are different from each other in the protruding height of the first convex portion from the flat portion on the one surface side or the protruding height of the second convex portion from the flat portion on the other surface side. It consists of a plate-shaped member
Of the one fluid passage and the other fluid passage, the cross-sectional area of the fluid passage on the low temperature side becomes smaller toward the outside in the stacking direction of the plurality of plate-like members, or the one fluid passage and the other fluid passage 2. The plurality of types of plate-like members are stacked so that a cross-sectional area of a fluid passage on a high temperature side of the fluid passages increases toward the outside in the stacking direction of the plurality of plate-like members. The heat exchanger according to claim 8. The other fluid passage forms part of the exhaust gas recirculation passage of the internal combustion engine so as to cool the exhaust gas passing through the exhaust gas recirculation passage of the internal combustion engine;
The heat exchanger according to any one of claims 1 to 9, wherein a coolant is supplied into the one fluid passage.

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