JP2014020608A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger which has high heat transfer efficiency.SOLUTION: A heat exchanger 20 includes a heat exchange tube 40 which is hollow and has a thin and long section the longitudinal dimension of which is larger than the lateral dimension, a core case which houses a plurality of heat exchange tubes 40 one over another, a first heat medium introduction pipe 26 which is provided at one end of the core case 23 and allows a first heat medium to flow in between adjacent heat exchange tubes 40, and a first heat medium discharge tube 27 which is provided at the other end of the core case 23 and discharges the first heat medium. The heat exchange tubes 40 each have a projection part 51a, projecting toward an adjacent heat exchange tube 40, formed from a position of overlapping with the first heat medium introduction tube 40 to a position of overlapping with the first heat medium discharge tube 27 along a flow direction of a second heat medium.

Description

  The present invention relates to a heat exchanger that performs heat exchange between a first heat medium that flows on the outer periphery of a heat exchange tube and a second heat medium that flows on the inner periphery of the heat exchange tube.

  A heat exchanger in which exhaust gas flowing through the inner periphery of the heat exchange tube is cooled by flowing cooling water around the outer periphery of the heat exchange tube is employed in an EGR (Exhaust Gas Recirculation) cooler (for example, Patent Document 1). (See FIGS. 2 and 3).

Patent Document 1 will be described with reference to FIG.
As shown in FIG. 12A, in the EGR cooler 100, a plurality of heat exchange tubes 102 are housed in a core case 101, and a cooling water introduction pipe 103 into which cooling water is introduced and cooling water are contained in the core case 101. A cooling water discharge pipe 104 is attached.

  As indicated by the arrows, the cooling water introduced from the cooling water introduction pipe 103 flows through the flow path having the shortest distance toward the cooling water discharge pipe 104. For this reason, as indicated by a one-dot chain line, a portion having a small flow rate of the cooling water is generated on the outer periphery of the heat exchange tube 102. In order to solve such a problem, according to the invention of the cited document 1, a plurality of protrusions are formed toward the outer periphery of the heat exchange tube 102. Details will be described with reference to FIG.

  As illustrated in FIG. 12B, the EGR cooler 110 has a plurality of protruding portions 115 that protrude toward the outer periphery of the heat exchange tube 112. Since the protrusion 115 is resistant to the flow of water, the water can be allowed to flow so as to bypass the protrusion 115. That is, by restricting the flow of water by the protrusion 115, the cooling water can be flowed over the entire outer periphery of the heat exchange tube 112.

  However, according to the EGR cooler 110, since the protrusion 115 is formed to meander the cooling water, the resistance when the cooling water flows is large. Since the resistance is large, for example, when the cooling water is circulated by a pump having the same output, the flow rate of the cooling water decreases. As the flow rate of the cooling water decreases, the efficiency of heat transfer with the exhaust gas also decreases.

JP 2004-177060 A

  An object of the present invention is to provide a heat exchanger with high heat transfer efficiency.

The invention according to claim 1 is provided at one end of the core case, which is hollow and has a heat exchange tube having an elongated cross section whose vertical dimension is larger than the horizontal dimension, a core case for storing a plurality of the heat exchange tubes in a stacked manner, and A first heat medium introduction pipe for allowing the first heat medium to flow in between the adjacent heat exchange tubes, and a first heat medium discharge pipe provided at the other end of the core case for discharging the first heat medium. Consists of
In the heat exchanger that performs heat exchange with the first heat medium that flows on the outer periphery of the heat exchange tube and the second heat medium that flows on the inner periphery of the heat exchange tube,
In the heat exchange tube, a convex portion protruding toward the adjacent heat exchange tube is continuously formed along the flow direction of the second heat medium.

  In the invention according to claim 2, the convex portion is formed from a position overlapping the first heat medium introduction pipe to a position overlapping the first heat medium discharge pipe, and at least in the width direction of the heat exchange tube. It is formed in both ends.

  In the invention which concerns on Claim 3, a heat exchange tube is a corrugated tube comprised with a corrugated sheet, It is characterized by the above-mentioned.

  In the invention according to claim 4, in the heat exchange tube, the trough portion of the corrugated plate is continuously deepened from upstream to downstream with reference to the flow direction of the second heat medium. .

  The invention according to claim 5 is characterized in that the heat exchanging tube is formed with a contact recess that is recessed toward the flow path of the second heat medium and that contacts the opposite surface.

According to a sixth aspect of the present invention, the heat exchange tube is composed of a first tube half and a second tube half both of which are substantially U-shaped in cross section, and the first tube half and the second tube half. , And
The first tube half and the second tube half are both composed of a bottom portion and an upright portion raised from both ends of the bottom portion,
More than half of the upright portion of the first tube half and the upright portion of the second tube half are overlapped with respect to the height direction.

  In the invention which concerns on Claim 7, the fin for enlarging a heat-transfer area is accommodated in the heat exchange tube, It is characterized by the above-mentioned.

In the invention which concerns on Claim 1, the convex part which regulates the flow path of a 1st heat medium is continuously formed along the flow direction of a 2nd heat medium.
Since the 2nd heat carrier flows linearly, the convex part formed along this flow is also formed linearly. That is, the convex part is formed linearly and continuously so as not to be resistant to the flow of the first heat medium. Since the convex portion does not become a resistance, the flow rate of the first heat medium can be increased. By increasing the flow rate, heat exchange can be performed efficiently.

  In the invention which concerns on Claim 2, while a convex part is formed from the position which overlaps with a 1st heat-medium introduction pipe to the position which overlaps with a 1st heat-medium discharge pipe, it is at least at the both ends of the width direction of a heat exchange tube Is formed. The first heat medium introduced from the first heat medium introduction pipe is introduced into the heat exchanger so as to avoid the end of the convex portion. Further, the first heat medium that has flowed through the heat exchanger bypasses the end of the convex portion, and is then guided to the first heat medium discharge pipe. That is, the convex portion is formed from the position overlapping the first heat medium introduction pipe to the position overlapping the first heat medium discharge pipe, thereby suppressing the first heat medium from flowing through the shortest flow path. The first heat medium can be caused to flow through the entire core case without adding parts such as a current plate.

  In the invention which concerns on Claim 3, a heat exchange tube is a corrugated tube comprised with a corrugated sheet. A large heat transfer area can be ensured by forming the heat exchange tube with a corrugated plate. Since the heat transfer area is large, the heat transfer efficiency can be further increased.

In the invention which concerns on Claim 4, the trough part of a corrugated sheet is continuously deepening toward the downstream from the upstream on the basis of the flow direction of a 2nd heat medium. In other words, a wide flow path area is secured upstream, and the heat transfer area increases toward the downstream. In the upstream before heat exchange is performed, the temperature of the second heat medium is higher than in the downstream after heat exchange is performed. The volume flow rate of the second heat medium increases in proportion to the temperature of the second heat medium. Pressure loss increases as the volumetric flow rate increases. On the other hand, the pressure loss decreases as the flow path area increases.
In the upstream where the temperature of the second heat medium is high, the pressure loss is reduced by increasing the flow path area. By reducing the pressure loss, the flow rate can be increased and the heat transfer efficiency can be increased.
Note that the temperature difference between the first heat medium and the second heat medium is larger in the upstream than in the downstream. Even if the heat transfer area is made smaller than that in the downstream, the heat transfer efficiency equivalent to that in the downstream can be obtained.
The temperature of the second heat medium is lower in the downstream than in the upstream. When the temperature of the second heat medium is low, the volume flow rate of the second heat medium decreases. In the downstream where the volume flow rate is small, even if the flow path area is reduced, the pressure loss can be the same as that in the upstream. In the downstream where the temperature of the second heat medium is low, the heat transfer efficiency is increased by increasing the heat transfer area compared to the upstream.
That is, heat transfer efficiency can be increased by increasing the heat transfer area while suppressing pressure loss.

  In addition, the wavy valley of the heat exchange tube is continuously deepened from the upstream to the downstream with respect to the flow direction of the second heat medium, resulting in a smooth cross-section, and the flow velocity is also downstream. Because it is maintained, soot is hard to accumulate.

  In the invention which concerns on Claim 5, the contact recessed part which contacts the surface which is dented toward the flow path of a 2nd heat medium and contacts is formed in the heat exchange tube. Since the contact recess is in contact with the opposing surface, the rigidity of the heat exchange tube can be increased with respect to the pressure received from the first heat medium. Moreover, when a contact recessed part is joined to the surface which opposes, the rigidity of a heat exchange tube can be improved with respect to the pressure received from a 2nd heat medium.

  In the invention according to claim 6, more than half of the upright portion of the first tube half and the upright portion of the second tube half are superposed on the basis of the height direction. The corner of the heat exchange tube is a part whose shape changes greatly, and particularly high stress is generated in the heat exchange tube. By largely overlapping the first and second tube halves, they can reinforce each other and increase the rigidity of the heat exchange tube.

  In the invention which concerns on Claim 7, the fin for enlarging a heat-transfer area is accommodated in the heat exchange tube. By storing the fins, the heat transfer area is increased. Heat transfer efficiency can be increased by increasing the heat transfer area.

It is a schematic diagram at the time of employ | adopting the heat exchanger by Example 1 for an EGR cooler. FIG. 2 is a left side view of the EGR cooler shown in FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. It is sectional drawing of the EGR cooler shown by FIG. It is a top view of the heat exchange tube shown by FIG. It is a perspective view of the heat exchange tube shown by FIG. It is sectional drawing of the heat exchange tube shown by FIG. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 5. FIG. 9 is a view taken along arrow 9 in FIG. 5. 6 is a plan view of a heat exchange tube used in a heat exchanger according to Embodiment 2. FIG. It is a perspective view of the heat exchange tube used for the heat exchanger by Example 3. It is a figure explaining the basic composition of the conventional technology.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

First, Embodiment 1 of the present invention will be described with reference to the drawings.
As shown in FIG. 1, an EGR (Exhaust Gas Recirculation) cooler 20 (heat exchanger 20) is used by being connected to an intake port 11 and an exhaust port 12 formed in a diesel engine 10 for a vehicle.

  More specifically, a part of the exhaust gas (second heat medium) discharged from the exhaust port 12 is sent into the EGR cooler 20. The sent exhaust gas is cooled by cooling water (first heat medium) and discharged from the EGR cooler 20. The cooled exhaust gas is sent again into the diesel engine 10 together with air. This is an exhaust gas recirculation device that suppresses the generation of NOx (nitrogen oxides) by reducing the oxygen concentration of air sent into the diesel engine 10.

It should be noted that the EGR cooler 20 is not limited to the diesel engine but can be applied to a gasoline engine, and the application is not limited to these.
Details of the EGR cooler 20 will be described with reference to FIG.

  As shown in FIG. 2, the EGR cooler 20 includes an exhaust gas introduction member 21 (second heat medium introduction member 21) into which exhaust gas is introduced, and an upstream end plate connected to the exhaust gas introduction member 21. 22, a substantially rectangular tube-shaped core case 23 connected to the upstream end plate 22, a downstream end plate 24 attached to the downstream end of the core case 23, and the downstream end An exhaust gas discharge member 25 (second heat medium discharge member 25) connected to the plate 24, and a cooling water introduction pipe 26 (introduced on the upper surface of the core case 23 in the vicinity of the exhaust gas discharge member 25). A first heat medium introduction pipe 26) and a cooling water discharge pipe 27 (attached to the upper surface of the core case 23 in order to discharge the cooling water introduced from the cooling water introduction pipe 26) It consists first heat medium discharge pipe 27) and.

  The cooling water introduction pipe 26 and the cooling water discharge pipe 27 are both attached to the same surface of the core case 23, and are respectively attached to opposite ends with respect to the flow direction of the exhaust gas.

  The core case 23 is formed by overlapping and bonding an upper case half 32 having a substantially U-shaped cross section with a lower case half 31 having a substantially U-shaped cross section. On the upper surface of the upper case half 32, a cooling water inlet 32a (first heat medium inlet 32a) into which the cooling water inlet pipe 26 is inserted, and a cooling water outlet 32b (first) into which the cooling water outlet pipe 27 is inserted. And a heat medium discharge port 32b).

The exhaust gas introduction member 21 and the exhaust gas discharge member 25 are respectively provided with flanges 21a and 25a for attachment to other components.
Details of the inside of the core case 23 will be described with reference to FIG.

  As shown in FIG. 3, seven heat exchange tubes 40 are stacked inside the EGR cooler 20. The heat exchange tube 40 is a rectangular tube-shaped member having a substantially rectangular cross section whose longitudinal side is longer than the lateral side, and extends in the horizontal direction along the axis CC of the core case 23.

  The heat exchange tube 40 in which the exhaust gas flows is composed of a first tube half 50 and a second tube half 60 that are substantially U-shaped in cross-section, and these first tube half 50 and second tube half. The body 60 is joined. As a joining method, any method such as welding or brazing can be selected.

  An axis FC of the cooling water introduction pipe 26 extends in the vertical direction and is substantially orthogonal to the axis CC of the core case 23. The vertical side of the heat exchange tube 40 extends along the axis FC of the cooling water introduction pipe 26.

  The first tube half 50 is composed of a corrugated bottom 51 and standing parts 52 raised from both ends of the bottom 51. The same applies to the second tube half 60. That is, the second tube half 60 includes a corrugated bottom 61 and standing parts 62 raised from both ends of the bottom 61. The heat exchange tube 40 is a corrugated tube in which the standing portions 52 and 62 are superposed and joined.

  A large heat transfer area can be ensured by forming the heat exchange tube 40 with a corrugated plate. Since the heat transfer area is large, the heat transfer efficiency can be increased.

  Referring also to FIG. 5, the bottom 51 of the first tube half 50 has a convex portion 51 a that protrudes toward the adjacent heat exchange tube 40, and a surface that is recessed toward the inside of the heat exchange tube 40 and that faces the same. A contact recess 51b is formed. It can also be said that the contact recess 51b is recessed toward the flow path of the exhaust gas.

The same applies to the second tube half 60. On the bottom 61 of the second tube half 60, there are a protrusion 61a that protrudes toward the adjacent heat exchange tube 40, and a contact recess 61b that is recessed toward the inside of the heat exchange tube 40 and that contacts the opposite surface. Is formed.
The mutual contact recesses 51b and 61b are in contact with each other and joined.

  The cooling water flowing on the outer periphery of the heat exchange tube 40 applies water pressure toward the inner periphery of the heat exchange tube 40. The contact recesses 51b and 61b come into contact with the opposing surfaces, thereby preventing the heat exchange tube 40 from being deformed by water pressure. That is, since the contact recesses 51b and 61b are in contact with the opposed surfaces, the rigidity of the heat exchange tube 40 can be increased with respect to the pressure received from the cooling water.

  Further, the exhaust gas flowing along the inner periphery of the heat exchange tube 40 applies pressure in the direction in which the heat exchange tube 40 opens. The contact recesses 51b and 61b are joined to the opposing surfaces, thereby preventing the heat exchange tube 40 from being deformed by the exhaust gas. That is, when the contact recesses 51b and 61b are joined to the opposing surfaces, the rigidity of the heat exchange tube 40 can be increased with respect to the pressure received from the exhaust gas.

In addition, it is desirable that contact recesses 51b and 61b are formed at positions facing the first tube half 50 and the second tube half 60, respectively, and the contact recesses 51b and 61b are brought into contact with each other. Usually, the first tube half 50 and the second tube half 60 are formed by press molding. If the contact recess 51b is formed only in the first tube half 50 and is brought into contact with the second tube half 60, the depth of the contact recess 51b becomes very deep. When the contact recess 51b is deep, the thickness of the first tube half 50 is reduced only at the portion where the contact recess 51b is formed. Since the plate pressure is thin, the strength of the contact recess 51b is weaker than other portions. In this regard, when the contact concave portions 51b and 61b are brought into contact with each other, a portion having an extremely thin plate thickness does not occur. That is, the heat exchange tube 40 can be maintained at a high strength.
The detail of the heat exchange tube 40 is demonstrated based on FIG.

  As shown in FIG. 4, the convex portion 51 a is continuously formed from the position overlapping the cooling water introduction pipe 26 to the position overlapping the cooling water discharge pipe 27 along the exhaust gas flow direction. The length that the convex portion 51 a overlaps is longer than the length that overlaps the cooling water introduction pipe 26 and the length that overlaps the cooling water discharge pipe 27. That is, the overlapping length of the convex portions 51a is set longer on the cooling water introduction side. By forming the convex portion 51a, the flow path of the cooling water is narrowed, and the cooling water is restricted in the flow path.

  The axis RC of the cooling water discharge pipe 27 extends parallel to the axis FC of the cooling water introduction pipe 26 and perpendicular to the axis CC of the core case 23. That is, the axis RC of the cooling water discharge pipe 27 extends in the vertical direction.

The center of the exhaust gas introduction member 21 and the center of the exhaust gas discharge member 25 coincide with the axis CC of the core case 23. Further, the central portion in the height direction of the heat exchange tube 40 also coincides with the axis CC of the core case 23.
The detail of the convex part 51a is demonstrated based on FIG.

As shown in FIG. 5, when the height direction of the heat exchange tube 40 is used as a reference, the length L1 between the convex portion 51a and the convex portion 51a is the length L2 from the convex portion 51a to the end portion. Longer than That is, the area of the flow path of the cooling water is formed wider in the part between the convex part 51a and the convex part 51a than in the part from the convex part 51a to the end part.
The operation of the EGR cooler according to the present invention will be described with reference to FIG.

  As shown in FIG. 6, the cooling water introduced to the outer periphery of the heat exchange tube 40 is divided into three flow paths by the convex portions 51a as indicated by the arrows (1). The introduced cooling water flows along the convex portion 51a and is discharged as indicated by an arrow (2). At this time, as indicated by the white arrow, exhaust gas is caused to flow through the inner periphery of the heat exchange tube 40. The exhaust gas is cooled by cooling water that flows around the outer periphery of the heat exchange tube 40. That is, heat exchange is performed between the exhaust gas and the cooling water via the heat exchange tube 40.

  The convex portion 51a is formed linearly and continuously so as not to be resistant to the flow of the cooling water. Since the convex part 51a does not become resistance, the flow rate of the cooling water can be increased.

  In addition, the convex portions 51 a are formed from a position overlapping the cooling water introduction pipe 26 to a position overlapping the cooling water discharge pipe 27, and are formed at both ends in the width direction of the heat exchange tube 40. The cooling water introduced from the cooling water introduction pipe 26 is introduced into the core case so as to avoid the end of the convex portion 51a. Further, the cooling water that has flowed through the core case bypasses the end of the convex portion 51 a and is guided to the cooling water discharge pipe 27. That is, the convex portion 51a is formed from the position overlapping the cooling water introduction pipe 26 to the position overlapping the cooling water discharge pipe 27, thereby suppressing the cooling water from flowing through the shortest flow path. Without adding parts such as a current plate, the cooling water can flow through the entire core case.

  Moreover, a large amount of cooling water can be flowed toward the exhaust gas introduction part (FIG. 4, reference numeral 21) that becomes high temperature by the convex portions 51a at both ends in the width direction (the convex portion 51a at the lower end in the drawing). Boiling can be suppressed.

  The introduced exhaust gas is introduced into the heat exchange tube 40 at a high temperature. The hot exhaust gas is gradually cooled by the cooling water. In particular, a large amount of high-temperature exhaust gas flows through the center P in the width direction of the heat exchange tube 40 and the upstream portion P1 with respect to the flow of exhaust gas. In such a part P1, the cooling water tends to boil. The boiling of the cooling water inhibits the smooth flow of the cooling water. If the cooling water does not flow smoothly, the heat exchange efficiency decreases. According to the present invention, since the cooling water can be caused to flow through the entire core case by the convex portion 51a, a large amount of cooling water also flows in the portion P1 where the boiling of the cooling water is likely to occur. Can be suppressed.

Referring also to FIG. 4, the convex portion 51 a is formed from a position overlapping the cooling water introduction pipe 26 to a position overlapping the cooling water discharge pipe 27. Since the cooling water introduction pipe 26 is formed at one end of the core case 23 and the cooling water discharge pipe 27 is formed at the other end of the core case, the convex portions 51 a are formed over both ends of the core case 23. Yes. Since the convex part 51a is formed over both ends, the cooling water can flow through the entire core case 23.
According to the present invention, it is possible to flow the cooling water over the entire core case 23 while ensuring the flow rate of the cooling water. That is, it can be said that the EGR cooler 20 has high heat transfer efficiency.

Furthermore, the flow path of the cooling water is widely formed at the center in the height direction. In other words, a wide cooling water flow path is ensured in accordance with the center position of the core case 23 so that a large amount of cooling water can flow. A lot of exhaust gas flows along the axis CC of the core case 23. Heat exchange can be performed more efficiently by flowing a large amount of cooling water in accordance with a portion where the flow rate of exhaust gas is large.
The heat exchange tube 40 will be further described.

As shown in FIGS. 7 and 8, in the heat exchange tube 40, the corrugated valley portions 51 c are continuously deeper from the upstream toward the downstream with respect to the flow direction of the exhaust gas.
As shown in FIG. 7E, the most downstream portion of the heat exchange tube 40 is joined to the end plate (FIG. 4, reference numeral 24), so that the valley portion 51c is shallow.

  The heat exchange member has a larger flow area in the upstream than in the downstream, and a larger heat transfer area in the downstream than in the upstream.

  The temperature of the exhaust gas is higher in the upstream before the heat exchange is performed than in the downstream after the heat exchange is performed. The volumetric flow rate of the exhaust gas increases in proportion to the temperature of the exhaust gas. Pressure loss increases as the volumetric flow rate increases. On the other hand, the pressure loss decreases as the flow path area increases.

  In the upstream where the temperature of the exhaust gas is high, the pressure loss is reduced by increasing the flow path area. By reducing the pressure loss, the flow rate can be increased and the heat transfer efficiency can be increased.

  Note that the temperature difference between the exhaust gas and the cooling water is larger in the upstream than in the downstream. Even if the heat transfer area is made smaller than that in the downstream, the heat transfer efficiency equivalent to that in the downstream can be obtained.

The temperature of the exhaust gas is lower in the downstream than in the upstream. When the temperature of the exhaust gas is low, the volume flow rate of the exhaust gas decreases. In the downstream where the volume flow rate is small, even if the flow path area is reduced, the pressure loss can be the same as that in the upstream. In the downstream where the temperature of the exhaust gas is low, the heat transfer efficiency is increased by increasing the heat transfer area compared to the upstream.
That is, heat transfer efficiency can be increased by increasing the heat transfer area while suppressing pressure loss.

  As shown in FIG. 9, with the height direction as a reference, more than half of the standing portion 52 of the first tube half 50 and the standing portion 62 of the second tube half 60 are overlapped.

  The corner of the heat exchange tube 40 is a part where the shape changes greatly, and particularly high stress occurs in the heat exchange tube 40. When the first and second tube halves 50 and 60 are largely overlapped with each other, they reinforce each other and the rigidity of the heat exchange tube 40 can be increased.

Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 10 is a plan view of a heat exchange tube used in the heat exchanger according to the second embodiment, and corresponds to FIG.

As shown in FIG. 10, the contact recess 51Ab is continuously formed in the first tube half 50A of the heat exchange tube 40A along the flow direction of the exhaust gas.
Similarly, in the second tube half (FIG. 9, reference numeral 60), the contact recess is continuously formed along the flow direction of the exhaust gas.
Thus, in the heat exchange tube 40A, the contact recess 51Ab formed in the first tube half 50A and the contact recess formed in the second tube half are continuous along the exhaust gas flow direction. In contact.

Even when the heat exchange tube 40A configured as described above is used, the predetermined effect of the present invention can be obtained.
In addition, the heat exchange tube 40A receives water pressure from the cooling water flowing on the outer periphery toward the inner periphery. That is, the water pressure acts in a direction that crushes the heat exchange tube 40A. Since the contact recess 51Ab that contacts the second tube half is formed continuously in the exhaust gas flow direction, the strength of the heat exchange tube 40A against the water pressure of the cooling water can be increased.

  Furthermore, a contact recess can be formed in the second tube half, and the contact recess 51Ab of the first tube half 50A can be welded to the contact recess of the second tube half. In the case of welding, the strength of the heat exchange tube 40A can be increased with respect to the force from the exhaust gas applied in the direction in which the first tube half 50A and the second tube half are to be separated.

Next, Embodiment 3 of the present invention will be described with reference to the drawings.
FIG. 11 is a perspective view of a heat exchange tube used in the heat exchanger according to the second embodiment, and corresponds to FIG.

  As shown in FIG. 11, the heat exchange tube 40B includes a first tube half 50B formed from a flat plate shape, and a second tube half 60B joined to the first tube half 50B. Consists of. Convex portions 51a (only the convex portions 51a of the first tube half 50B are shown) are formed on the first tube half 50B and the second tube half 60B, respectively. The heat exchange tube 40B accommodates fins 70 for efficiently taking the heat of the exhaust gas. That is, the heat transfer area is increased by accommodating the fins 70. Even when the heat exchange tube 40B configured as described above is used, the predetermined effect of the present invention can be obtained.

  The heat exchanger of the present invention can be applied to a heat exchanger mounted on an exhaust heat recovery apparatus in addition to an EGR cooler, and can also be applied to a cogeneration system other than a vehicle. Applications of these are not limited.

  The heat exchanger of the present invention is suitable for an EGR cooler connected to a diesel engine.

  20 ... EGR cooler (heat exchanger), 23 ... core case, 26 ... cooling water introduction pipe (first heat medium introduction pipe), 27 ... cooling water discharge pipe (first heat medium discharge pipe), 40, 40A, 40B ... heat exchange tube, 50, 50A, 50B ... first tube half, 51 ... bottom of (first tube half), 51a, 61a ... convex, 51b, 61b, 51Ab ... contact recess, 51c, 61c ... trough , 52 ... standing part (of the first tube half), 60, 60B ... second tube half, 61 ... the bottom part (of the second tube half), 62 ... standing part (of the second tube half).

Claims (7)

A heat exchange tube that is hollow and has an elongated cross section whose longitudinal dimension is larger than the lateral dimension, a core case that houses a plurality of the heat exchange tubes stacked thereon, and a space between the adjacent heat exchange tubes provided at one end of the core case. A first heat medium introduction pipe for allowing the first heat medium to flow toward the first heat medium discharge pipe, and a first heat medium discharge pipe provided at the other end of the core case for discharging the first heat medium,
In the heat exchanger that performs heat exchange with the first heat medium that flows on the outer periphery of the heat exchange tube and the second heat medium that flows on the inner periphery of the heat exchange tube,
The heat exchanger is characterized in that convex portions protruding toward the adjacent heat exchange tubes are continuously formed along the flow direction of the second heat medium.   The protrusions are formed from a position overlapping the first heat medium introduction pipe to a position overlapping the first heat medium discharge pipe, and at least formed at both ends in the width direction of the heat exchange tube. The heat exchanger according to claim 1.   The heat exchanger according to claim 1 or 2, wherein the heat exchange tube is a corrugated tube made of corrugated plates.   4. The heat exchange according to claim 3, wherein in the heat exchange tube, a trough portion of the corrugated plate is continuously deepened from upstream to downstream with reference to the flow direction of the second heat medium. vessel.   5. The contact recess that is recessed toward the flow path of the second heat medium and that contacts the opposite surface is formed in the heat exchange tube. The described heat exchanger. The heat exchange tube is composed of a first tube half and a second tube half both of which are substantially U-shaped in cross-sectional view, and the first tube half and the second tube half are overlapped,
The first tube half and the second tube half are both composed of a bottom portion and an upright portion raised from both ends of the bottom portion,
6. The method according to claim 1, wherein more than half of the upright portion of the first tube half and the upright portion of the second tube half are overlapped with respect to the height direction. The heat exchanger according to claim 1.   The heat exchanger according to claim 1 or 2, wherein fins for increasing a heat transfer area are accommodated in the heat exchange tube.

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