JP2014095503A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger capable of suppressing stress concentration in a joint part of a U-shaped pipe and a support body supporting the U-shaped pipe.SOLUTION: A heat exchanger 10 comprises: a plurality of U-shaped pipes 12 disposed in parallel with each other for passing working fluid; a fin 13 having a plurality of through holes into which the plurality of the U-shaped pipes 12 are inserted and supported by the plurality of the U-shaped pipes 12; and a support body for supporting the plurality of the U-shaped pipes 12. The heat exchanger 10 performs heat exchange between heat exchange fluid around the fin 13 and the working fluid. The phase of the working fluid is changed in the U-shaped pipe 12 by heat exchange with the heat exchange fluid. The plurality of the U-shaped pipes 12 have a first U-shaped pipe 12A containing a before phase change region before the phase of the working fluid is changed in heat exchange, a second U-shaped pipe 12B containing a phase change region in which the phase of the working fluid is changed in heat exchange, and a third U-shaped pipe 12C containing an after phase change region after the phase of the working fluid is changed in heat exchange. The before phase change region and the phase change region are divided in the fin 13.

Description

  The present invention relates to a heat exchanger, and more particularly to a heat exchanger provided with a U-shaped tube for passing a working fluid and a fin for heat exchange fixed to the U-shaped tube.

As a conventional heat exchanger, for example, a heat exchanger 100 having a structure shown in FIG. 10 is known.
A heat exchanger 100 shown in FIG. 10 includes a case 101, a plurality of U-shaped tubes 102 through which a working fluid passes, a number of fins 103 supported by the plurality of U-shaped tubes 102, and an operation returned from the U-shaped tube 102. A header 104 is provided for passing fluid to another U-tube.
In this heat exchanger 100, the heat exchange fluid (indicated by the white arrow in FIG. 10) passes around the U-shaped tube 102 and the fin 103, but heat exchange is performed in a direction intersecting with the working fluid passing through the U-shaped tube 102. Fluid flows.
When the heat exchange fluid passes around the U-shaped tube 102 and the fins 103, heat exchange between the working fluid passing through the U-shaped tube 102 and the heat exchange fluid is performed.
In the case of using a working fluid that changes phase by heat exchange, the plurality of U-shaped tubes 102 includes a U-shaped tube 102 that passes the working fluid before phase change during heat exchange, and a U-shaped tube 102 that includes the working fluid that changes phase. And the U-shaped tube 102 containing the working fluid after the phase change.

On the other hand, as another prior art, for example, a heat exchanger disclosed in Patent Document 1 is known.
The heat exchanger disclosed in Patent Document 1 includes a plurality of plate fins and a medium tube that passes through the plate fins.
A part of the medium pipe is connected to the inlet header part, and another medium pipe of the medium pipe connected to the inlet header part is connected to an outlet header pipe provided in parallel with the inlet header pipe.
An intermediate header pipe connected to all the medium pipes is provided on the opposite side of the inlet pipe section and the outlet header section in the medium pipe.
The plurality of plate fins are respectively divided at portions close to each other among the medium pipes connected to the inlet header portion and the outlet header portion.

JP-A 61-259094

In the heat exchanger 100 shown in FIG. 10, the U-shaped tube 102 that passes the working fluid before the phase change during the heat exchange, the U-shaped tube 102 including the working fluid that changes the phase, and the working fluid after the phase change. A difference in thermal expansion occurs between the U-shaped tube 102 and the U-tube 102.
In particular, the temperature difference is large and the thermal expansion difference is also large between the U-shaped tube 102 through which the working fluid before phase change is passed during heat exchange and the U-shaped tube 102 including the working fluid that changes phase.
Further, in a U-shaped tube that passes a working fluid that changes phase, there may be a significant difference in thermal expansion due to the temperature difference between the forward tube portion and the return tube portion.
However, since all the U-shaped tubes 102 are constrained by the fins 103, deformation of the U-shaped tube 102 is restricted, and stress concentrates on the joint portion with the case 101 in the U-shaped tube 102.
As a result, the joint portion between the U-shaped tube 102 and the case 101 may be broken.

On the other hand, the heat exchanger disclosed in Patent Document 1 merely discloses that the fins are divided at portions where the temperatures in the tubes are different among the plurality of heat medium tubes.
Therefore, even if the heat exchanger disclosed in Patent Document 1 is applied to the heat exchanger shown in FIG. 10, the problem of the heat exchanger shown in FIG. 8 cannot be solved.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a heat exchanger that can relieve stress concentration at a joint portion between a U-shaped tube and a support that supports the U-shaped tube. On offer.

  In order to solve the above-described problems, the present invention includes a plurality of U-shaped tubes that are arranged in parallel to each other and allow a working fluid to pass therethrough, and a plurality of through holes into which the plurality of U-shaped tubes are inserted. A fin that is supported by a U-shaped tube, and a support that supports the plurality of U-shaped tubes, and performs heat exchange between the heat exchange fluid around the fin and the working fluid, and the working fluid is In the heat exchanger that changes phase in the U-shaped tube by heat exchange with the heat exchange fluid, the plurality of U-shaped tubes include a pre-phase change area before the working fluid changes phase during heat exchange. A 1U-shaped tube, a second U-shaped tube including a phase change region in which the working fluid changes phase during heat exchange, and a third U-shaped tube including a phase change post-range after the working fluid undergoes phase change during heat exchange And in the fin, the phase change region and the phase change region are divided. It is characterized in that is.

According to the present invention, since the region before the phase change and the phase change region are divided in the fin, the first U-shaped tube and the second U-shaped tube are not restricted to each other via the fin, Each can be deformed according to the amount of thermal expansion.
Therefore, even if the second U-shaped tube is deformed more than the first U-shaped tube, the stress concentration at the joint between the second U-shaped tube and the support can be relaxed, and the joint can be prevented from being broken. .
In addition, the division | segmentation of a fin includes the case where a fin is not isolate | separated besides the case where a fin is isolate | separated completely.
When the fins are not completely separated, a connection portion that can be deformed independently of each other according to the amount of thermal expansion of the first U-shaped tube and the second U-shaped tube is formed at the separation portion of the fin.

In the heat exchanger described above, the fin may be divided between the phase change area and the phase change area.
In this case, the second U-shaped tube and the third U-shaped tube can be deformed according to the thermal expansion amount without being constrained to each other via the fins.

Further, in the above heat exchanger, the second U-shaped tube has a forward tube portion through which the forward working fluid passes and a return pipe portion through which the return working fluid passes, and the fin returns to the forward tube portion. It is good also as a structure divided | segmented between the pipe parts.
In this case, the forward tube portion and the return tube portion can be deformed according to the amount of thermal expansion without being constrained via fins.

In the heat exchanger, the heat exchange fluid may be exhaust gas of an internal combustion engine.
In this case, exhaust gas that becomes high temperature by combustion in the internal combustion engine can be used as a heat exchange fluid, and can be applied to, for example, an evaporator in a Rankine cycle device.

  ADVANTAGE OF THE INVENTION According to this invention, the heat exchanger which can relieve | moderate the stress concentration in the junction part of the support body which supports a U-shaped tube and a U-shaped tube can be provided.

It is a perspective view which shows the outline | summary of the heat exchanger which concerns on the 1st Embodiment of this invention. It is a front view of the heat exchanger which concerns on the 1st Embodiment of this invention. (A) is an AA arrow view in FIG. 2, (b) is a BB arrow view, (c) is a CC arrow view. It is a perspective view which shows the outline | summary of the heat exchanger which concerns on the 2nd Embodiment of this invention. It is a front view of the heat exchanger which concerns on the 2nd Embodiment of this invention. FIG. 6 is a view taken along line DD in FIG. 5. It is a front view of the heat exchanger which concerns on the 3rd Embodiment of this invention. It is the EE arrow directional view in FIG. It is a front view of the fin which concerns on a modification. It is a perspective view which shows the outline | summary of the conventional heat exchanger.

(First embodiment)
Hereinafter, the heat exchanger according to the first embodiment will be described with reference to the drawings.
The heat exchanger according to the present embodiment is an on-vehicle heat exchanger mounted on a vehicle, and in particular, uses waste heat of an engine as an internal combustion engine mounted on the vehicle, and converts the heat energy of the waste heat into mechanical energy. It is a vehicle-mounted heat exchanger provided in a Rankine cycle circuit that converts to a heat sink.

The heat exchanger 10 shown in FIG. 1 is installed in an exhaust pipe (not shown) through which engine exhaust gas (indicated by the white arrow F in FIG. 1) flows.
The exhaust gas corresponds to a heat exchange fluid.
As shown in FIG. 1 and FIG. 2, the heat exchanger 10 includes a case 11, a plurality of U-shaped tubes 12 through which a refrigerant as a working fluid passes, a plurality of fins 13 brazed to the U-shaped tubes 12, A header 14 that reverses the flow of the refrigerant outside the case 11 is provided.

As shown in FIGS. 1 and 2, the case 11 includes a pair of side plates 15 and 16, a top plate 17, and a bottom plate 18. In the case 11, a plurality of U-shaped tubes 12 and a plurality of U-tubes 12 are provided. A space for accommodating the fins 13 is formed.
The top plate 17 and the bottom plate 18 of the case 11 are not limited to those positioned above and below, but indicate a pair of wall plates that intersect the side plates 15 and 16.
Case 11 of this embodiment is formed of stainless steel.

As shown in FIG. 1, FIG. 3A and FIG. 3B, the U-shaped tube 12 includes a pair of straight pipe portions 19 that are parallel to each other and a curved pipe portion 20 that connects the pair of straight pipe portions 19. I have.
The U-shaped tube 12 of this embodiment is made of stainless steel.
In the present embodiment, the U-tube 12 is disposed horizontally in the case 11 so that the pair of straight pipe portions 19 are in the front-rear position in the exhaust gas flow direction, and the exhaust gas passes through the U-tube 12. It arrange | positions so that it may flow to the direction which cross | intersects the refrigerant | coolant to pass.
Further, a plurality of U-shaped tubes 12 are arranged in parallel in the case 11 so that the adjacent U-shaped tubes 12 are positioned vertically from the top plate 17 toward the bottom plate 18.
In the heat exchanger 10 of the present embodiment, nine U-tubes 12 are arranged in the case 11.

A plurality of through holes (not shown) are formed in one side plate 15 of the case 11, and the straight pipe portion 19 of the U-shaped tube 12 is inserted into the through hole and brazed to the side plate 15.
Therefore, the side plate 15 corresponds to a support that supports the U-shaped tube 12.
An end portion of the straight pipe portion 19 that is inserted through the through hole and protrudes to the outside of the case 11 is connected to a header 14 disposed outside the case 11 by brazing, and forms a base portion of the U-shaped tube 12.
The curved pipe portion 20 of the U-shaped tube 12 faces the other side plate 16 of the case 11 in the case 11.

As shown in FIGS. 1 and 3C, the header 14 is a box body having a space sealed by an outer wall 21 inside, and the inner space is divided into four by partition walls 22, 23, and 24. Have rooms.
The first chamber 26 provided with the inflow port 25 through which the refrigerant flows from the outside is a room partitioned by the partition walls 22 and 23.
The first chamber 26 is formed downstream of the header 14 in the exhaust gas flow direction and on the bottom plate 18 side of the case 11.
The first chamber 26 is formed with three inlet holes 27 communicating with the straight pipe portion 19 on the exhaust gas outlet side in the three U-shaped tubes 12 on the bottom plate 18 side.

The second chamber 28 is a room partitioned and partitioned by the partition walls 23 and 24.
The second chamber 28 is formed on the upstream side in the exhaust gas flow direction in the header 14 and on the bottom plate 18 side of the case 11.
The second chamber 28 is formed with three outlet holes 29 to which the straight pipe portions 19 on the exhaust gas introduction side of the three U-shaped tubes 12 on the bottom plate 18 side are connected.
For this reason, the refrigerant introduced into the first chamber 26 from the inlet 25 passes through the three U-shaped tubes 12 on the bottom plate 18 side from the inlet hole 27 of the first chamber 26 and passes through the outlet hole 29 of the second chamber 28. It is introduced into the second chamber 28.
The second chamber 28 is larger than the first chamber 26, and three inlet holes 30 are formed in the upper portion of the outlet hole 29 in the second chamber 28.
The inlet hole 30 of the second chamber 28 is exhausted in the three U-shaped tubes 12 positioned between the three U-shaped tubes 12 on the bottom plate 18 side and the three U-shaped tubes 12 positioned on the top plate 17 side. It communicates with the straight pipe portion 19 on the gas introduction side.
Accordingly, the refrigerant introduced from the outlet hole 29 of the second chamber 28 into the second chamber 28 flows into the U-shaped tube 12 communicated with the inlet hole 30.

The third chamber 31 is a room partitioned by the partition walls 22 and 23.
The third chamber 31 is formed downstream of the header 14 in the exhaust gas flow direction and closer to the top plate 17 of the case 11 than the first chamber 26.
Three outlet holes 32 are formed in the third chamber 31, and the outlet holes 32 are the three U-shaped tubes 12 on the bottom plate 18 side and the three U-shaped tubes 12 positioned on the top plate 17 side. The straight pipe portions 19 on the exhaust gas outlet side of the three U-shaped pipes 12 positioned between the two are connected.
For this reason, the three U-shaped tubes 12 positioned between the three U-shaped tubes 12 on the bottom plate 18 side and the three U-shaped tubes 12 positioned on the top plate 17 side from the inlet hole 30 of the second chamber 28. The refrigerant introduced into the third chamber 31 is introduced into the third chamber 31 through the outlet hole 32 of the third chamber 31.
The third chamber 31 has the same size space as the second chamber 28, and three inlet holes 33 are formed in the upper portion of the outlet hole 32 in the third chamber 31.
The inlet hole 33 of the third chamber 31 communicates with the straight pipe portion 19 on the exhaust gas outlet side in the three U-shaped tubes 12 on the top plate 17 side.
Therefore, the refrigerant introduced into the third chamber 31 from the outlet hole 32 of the third chamber 31 flows into the U-shaped tube 12 communicated with the inlet hole 33.

The fourth chamber 34 is a room partitioned by the partition walls 23 and 24.
The fourth chamber 34 is formed on the upstream side in the exhaust gas flow direction in the header 14 and on the top plate 17 side of the case 11 with respect to the second chamber 28.
Three outlet holes 35 are formed in the fourth chamber 34, and the outlet hole 35 is connected to the straight pipe portion 19 on the exhaust gas introduction side of the three U-shaped tubes 12 on the top plate 17 side. Is done.
For this reason, the refrigerant introduced into the three U-shaped tubes 12 on the top plate 17 side from the inlet hole 33 of the third chamber 31 is introduced into the fourth chamber 34 from the outlet hole 35 of the fourth chamber 34.
The fourth chamber 34 is provided with an outlet 36 through which the refrigerant in the fourth chamber 34 flows out.

By connecting the header 14 and the U-shaped tube 12, the refrigerant introduced into the first chamber 26 is supplied from the second chamber 28 and the third chamber 31 to the fourth chamber 34 through the U-shaped tube 12. It flows out from the four chambers 34 to the outside.
As shown in FIG. 1, the heat exchanger 10 of the present embodiment includes a plurality of U-shaped tubes 12 and a header 14 to form a continuous refrigerant flow path, and the refrigerant introduced into the header 14 is the case 11. It passes through the inside many times and finally flows out from the header 14.

The refrigerant of the present embodiment has a property of changing phase in the U-shaped tube 12 by heat exchange with exhaust gas.
In this embodiment, the refrigerant passing through the U-shaped tube 12 on the bottom plate 18 side is in a liquid phase during heat exchange.
Then, during heat exchange, the refrigerant passing through the U-shaped tube 12 between the U-shaped tube 12 on the bottom plate 18 side and the U-shaped tube 12 on the top plate 17 side is in a state of phase change from the liquid phase to the gas phase.
During heat exchange, the refrigerant passing through the U-shaped tube 12 on the top plate 17 side is in a gas phase.
In the present embodiment, for convenience of explanation, the three U-shaped tubes 12 on the bottom plate 18 side are referred to as first U-shaped tubes 12A.
For convenience of explanation, the three U-shaped tubes 12 positioned between the three U-shaped tubes 12 on the bottom plate 18 side and the three U-shaped tubes 12 on the top plate 17 side are replaced with the second U-shaped tube 12B. And
Further, the three U-shaped tubes 12 on the top plate 17 side are referred to as third U-shaped tubes 12C.
A first U-shaped tube 12A group, a second U-shaped tube 12B group, and a third U-shaped tube 12C group each having three upper and lower units are configured.

In the three third U-shaped tubes 12C on the top plate 17 side, as shown in FIG. 3A, the straight pipe portion 19 located on the exhaust gas outlet side (downstream side) is connected from the header 14 to the curved pipe portion 20. The going-out refrigerant passes.
Then, the return refrigerant from the curved pipe portion 20 toward the header 14 passes through the straight pipe portion 19 located on the exhaust gas introduction side (upstream side).
In the three second U-shaped pipes 12B, as shown in FIG. 3 (b), the refrigerant that travels from the header 14 to the curved pipe part 20 passes through the straight pipe part 19 positioned on the exhaust gas introduction side (upstream side). Pass through.
Then, the return refrigerant from the curved pipe part 20 toward the header 14 passes through the straight pipe part 19 positioned on the exhaust gas outlet side (downstream side).
Further, in the three first U-shaped pipes 12A on the bottom plate 18 side, the straight pipe part 19 located on the exhaust gas outlet side (downstream side) is connected from the header 14 to the curved pipe part 20 in the same manner as the third U-shaped pipe 12C. The going-out refrigerant passes.
Then, the return refrigerant from the curved pipe portion 20 toward the header 14 passes through the straight pipe portion 19 located on the exhaust gas introduction side (upstream side).

In the present embodiment, a liquid-phase refrigerant passes through the first U-shaped tube 12A.
That is, the first U-shaped tube 12 </ b> A is a U-shaped tube 12 including a region before the phase change (liquid region) before the refrigerant undergoes a phase change.
The refrigerant undergoing phase change from the liquid phase to the gas phase passes through the second U-shaped tube 12B.
That is, the second U-shaped tube 12B is a U-shaped tube 12 including a phase change region (boiling region) in which the refrigerant changes phase.
A gas-phase refrigerant passes through the third U-shaped tube 12C.
That is, the third U-shaped tube 12C is a U-shaped tube 12 including a post-phase change region (superheated steam region) after the refrigerant has undergone a phase change.
For this reason, the temperature of the second U-shaped tube 12B is higher than that of the first U-shaped tube 12A, and deformation due to thermal expansion is larger than that of the first U-shaped tube 12A.
Further, the temperature of the third U-shaped tube 12C is higher than that of the second U-shaped tube 12B.
Therefore, deformation due to thermal expansion in the second U-shaped tube 12B is larger than deformation due to thermal expansion in the first U-shaped tube 12A, and deformation due to thermal expansion in the third U-shaped tube 12C is thermal expansion in the second U-shaped tube 12B. It becomes larger than the deformation by.

In the present embodiment, a large number of fins 13 are attached to the straight tube portion 19 of the U-shaped tube 12 disposed in the case 11.
The fin 13 is a metal plate formed of stainless steel. As shown in FIG. 1, a plurality of through holes 37 through which the straight pipe portion 19 is inserted are formed in the fin 13.
The flow path of the exhaust gas between the side plates 15 and 16 of the case 11 is partitioned by a large number of fins 13, and the surface of the fin 13 is along the flow direction of the exhaust gas.
A gap is formed between the fins 13 adjacent to each other, and the exhaust gas is circulated through the gap to facilitate the transfer of heat of the exhaust gas to the fin 13.

The fins 13 of the present embodiment are physically divided and divided between the first U-shaped tube 12A and the second U-shaped tube 12B, and between the second U-shaped tube 12B and the third U-shaped tube 12C. Is also physically divided and divided.
For this reason, the fin 13 includes a first fin portion 38 attached to the three first U-shaped tubes 12A on the bottom plate 18 side, a second fin portion 39 attached to the second U-shaped tube 12B, and a third U It is divided into three portions of the third fin portion 40 attached to the character tube 12C.
That is, the fins 13 of the present embodiment are divided between the pre-phase change area and the phase change area, and are divided between the phase change area and the post-phase change area.
By dividing the fin 13 into three parts, a first fin part 38 to a third fin part 40, a first U-shaped tube 12 </ b> A group restrained by the first fin part 38 and a second U restrained by the second fin part 39. The character tube 12B group and the third U-shaped tube 12C group constrained by the third fin portion 40 can be deformed independently of each other.

Further, in the present embodiment, the space between the straight pipe portions 19 of the second U-shaped tube 12B in the second fin portion 39 of the fin 13 is divided.
This is because in the present embodiment, the difference in thermal expansion that occurs between the straight pipe portions 19 of the second U-shaped pipe 12B is taken into consideration.
Accordingly, in the second U-shaped tube 12B group of the second fin portion 39, the straight pipe portion 19 through which the forward refrigerant passes and the straight pipe portion 19 through which the return refrigerant passes can be deformed independently of each other.
Incidentally, when the difference in thermal expansion that occurs between the straight pipe portions 19 of the second U-shaped tube 12B is so small that it is not necessary to consider, between the straight pipe portions 19 of the second U-shaped tube 12B in the second fin portion 39. May not be divided.

Next, heat exchange between the refrigerant and the exhaust gas by the heat exchanger 10 of the present embodiment will be described.
In a state where the engine mounted on the vehicle is driven, the exhaust gas of the engine passes through the exhaust pipe (not shown) and passes through the heat exchanger 10.
The exhaust gas passing through the heat exchanger 10 flows along the surfaces of a large number of fins 13, and the fins 13 are heated by the hot exhaust gas.

On the other hand, refrigerant flows through the U-shaped tube 12 of the heat exchanger 10, and the refrigerant is exhausted around the fins 13 through the fins 13, the brazing material that joins the U-shaped tubes 12 and the fins 13, and the straight tube portion 19. Exchange heat with gas.
In the present embodiment, since the refrigerant passing through the first U-shaped tube 12A is introduced from the first chamber 26 of the header 14, the liquid-phase refrigerant is heat-exchanged with high-temperature exhaust gas.
The refrigerant passing through the second U-shaped tube 12B is a refrigerant that has already undergone heat exchange in the first U-shaped tube 12A, and is undergoing a phase change from the liquid phase to the gas phase by heat exchange with the high-temperature exhaust gas in the second U-shaped tube 12B. It is in the state of.
For this reason, the second U-shaped tube 12B is hotter than the first U-shaped tube 12A, and the thermal expansion of the second U-shaped tube 12B is larger than the thermal expansion of the first U-shaped tube 12A.
The refrigerant flowing in the second U-shaped tube 12B is a refrigerant introduced from the second chamber 28 of the header 14, and the ratio of the liquid-phase refrigerant in the refrigerant is high.
On the other hand, in the refrigerant returned from the second U-shaped tube 12B, the ratio of the gas-phase refrigerant in the refrigerant is high.
Therefore, in the second U-shaped tube 12B, the straight pipe portion 19 through which the returning refrigerant passes has a high ratio of the gas-phase refrigerant, the thermal resistance of oil is large, and the thermal expansion of the straight pipe portion 19 through which the forward refrigerant passes. Becomes larger.
Incidentally, the thermal resistance of the oil is small in the first U-shaped tube 12A including the liquid region, and the second U-shaped tube 12B including the boiling region has the same thermal resistance as the third U-shaped tube 12C including the superheated steam region.
Therefore, in the first U-shaped tube 12A, the influence of the phase change is small, and the thermal resistance of the oil is small, so the deformation amount of the first U-shaped tube 12A is the smallest.
Moreover, in the 2nd U-shaped pipe 12B, since the influence by phase change is small and the thermal resistance of oil is large, the deformation amount of the 2nd U-shaped pipe 12B is larger than the deformation amount of the 1st U-shaped pipe 12A.
In the 3rd U-shaped pipe 12C, since the influence by a phase change is large and the thermal resistance of oil is also large, the amount of deformation of the 3rd U-shaped pipe 12C is the largest.

Since the fin 13 is divided into three fin portions 38 to 40, the first U-shaped tube 12A is not constrained between the first U-shaped tube 12A and the second U-shaped tube 12B via the fin 13. Transforms.
The second U-shaped tube 12B is deformed without being constrained by the first U-shaped tube 12A and the third U-shaped tube 12C.
The third U-shaped tube 12C is deformed without being constrained by the second U-shaped tube 12B.
That is, the first U-shaped tube 12A, the second U-shaped tube 12B, and the third U-shaped tube 12C are independently deformed according to the respective thermal expansion amounts.
For this reason, stress concentration is relieved at the joint between the first U-shaped tube 12 </ b> A and the side plate 15 in the case 11.
Further, in the third U-shaped tube 12 </ b> C, stress concentration is reduced at the joint portion between the first U-shaped tube 12 </ b> C and the side plate 15 in the case 11.
Furthermore, since the straight pipe part 19 of the 2nd U-shaped pipe 12B in the 2nd fin part 39 is divided | segmented, in the 2nd U-shaped pipe 12B group of the 2nd fin part 39, the straight pipe part through which the forward refrigerant passes. 19 and the straight pipe portion 19 through which the return refrigerant passes are deformed without being constrained to each other.

The heat exchanger 10 according to the present embodiment has the following operational effects.
(1) Since the first U-shaped tube 12A including the pre-phase change region and the second U-shaped tube 12B including the phase change region are divided in the fin 13, the first U-shaped tube 12A and the second U-shaped tube 12B Can be deformed according to the amount of thermal expansion without being constrained to each other via the fins 13. Therefore, even if the second U-shaped tube 12B is deformed more greatly than the first U-shaped tube 12A, the stress concentration at the joint between the second U-shaped tube 12B and the case 11 can be relaxed, and the joint is prevented from being broken. be able to.
(2) Since the portion between the second U-shaped tube 12B including the phase change region and the third U-shaped tube 12C including the post-phase change region is divided in the fin 13, the second U-shaped tube 12B and the third U-shaped tube 12C Can be deformed according to the amount of thermal expansion without being constrained to each other via the fins 13. Therefore, even if the third U-shaped tube 12C is deformed to a greater extent than the second U-shaped tube 12B, the stress concentration at the joint between the third U-shaped tube 12C and the case 11 can be alleviated, and breakage of the joint is prevented. be able to.

(3) Exhaust gas that becomes high temperature due to combustion in the internal combustion engine can be used as a heat exchange fluid. For example, the heat exchanger 10 can be applied to an evaporator in a Rankine cycle device.
(4) Since the fins 13 attached to the U-shaped tube 12 are divided at positions that take into account the phase change of the refrigerant, stress concentration at the joint between the U-shaped tube 12 and the case 11 can be further relaxed. It is possible to prevent the joint from being broken.

(Second Embodiment)
Next, a heat exchanger according to a second embodiment will be described.
In the heat exchanger of the present embodiment, the configuration of the header and the arrangement state of the U-shaped tube are different from those of the heat exchanger of the first embodiment.
In the present embodiment, the description of the first embodiment is used for the same configuration as that of the first embodiment, and common reference numerals are used.

The heat exchanger 50 shown in FIG. 4 is installed in an exhaust pipe (not shown) through which engine exhaust gas (indicated by the white arrow F in FIG. 1) flows.
As shown in FIGS. 4 and 5, the heat exchanger 50 includes a case 11, a plurality of U-tubes 12 through which refrigerant as a working fluid passes, a plurality of fins 51 brazed to the U-tubes, A header 52 for reversing the refrigerant flow outside the case 11 is provided.

As shown in FIGS. 4 and 5, the U-shaped tube 12 includes a pair of straight pipe portions 19 that are parallel to each other and a curved pipe portion 20 that connects the pair of straight pipe portions 19.
In the present embodiment, the U-shaped tube 12 is horizontally disposed in the case 11 so that the pair of straight tube portions 19 are in the upper and lower positions, and the exhaust gas intersects with the refrigerant passing through the U-shaped tube 12. It is arranged to flow in the direction.
Furthermore, a plurality (two in this embodiment) of U-shaped tubes 12 are arranged in parallel in the case 11 so that the U-shaped tubes 12 adjacent to each other are in the front-rear position in the exhaust gas flow direction.
A plurality of (three in this embodiment) U-shaped tubes 12 are arranged in parallel in the case 11 so that the U-shaped tubes 12 adjacent to each other are vertically positioned from the top plate 17 toward the bottom plate 18. ing.
In the heat exchanger 50 of the present embodiment, six U-tubes 12 are disposed in the case 11.

A plurality of through holes (not shown) are formed in one side plate 15 of the case 11, and the straight pipe portion 19 of the U-shaped tube 12 is inserted into the through hole and brazed to the side plate 15.
An end portion of the straight pipe portion 19 that is inserted into the through hole and protrudes to the outside of the case 11 is connected to a header 52 disposed on the outside of the case 11 by brazing, and forms a base portion of the U-shaped tube 12.

As shown in FIGS. 4 and 6, the header 52 is a box having a space sealed by an outer wall 53 inside, and the inner space is divided into four by partition walls 54, 55, and 56. Have.
The first chamber 58 provided with the inlet 57 through which the refrigerant flows from the outside is a room partitioned by the partition wall 54.
The first chamber 58 is formed on the lowermost side in the header 52.
The first chamber 58 is formed with two inlet holes 59 that communicate with the lower straight pipe portion 19 in the two U-shaped pipes 12 on the bottom plate 18 side, which are front and rear positions in the exhaust gas flow direction. .

The second chamber 60 is a room partitioned and partitioned by the partition walls 54 and 55.
The second chamber 60 is formed above the first chamber 58 in the header 52.
The second chamber 60 is formed with two outlet holes 61 to which the upper straight pipe portions 19 of the two U-shaped pipes 12 on the bottom plate 18 side, which are front and rear positions in the exhaust gas flow direction, are connected. .
For this reason, the refrigerant introduced into the first chamber 58 from the inlet 57 passes through the two U-shaped tubes 12 on the bottom plate 18 side from the inlet hole 59 of the first chamber 58, and from the outlet hole 61 of the second chamber 60. It is introduced into the second chamber 60.
The second chamber 60 is a larger space than the first chamber 58, and two inlet holes 62 are formed in the upper portion of the outlet hole 61 in the second chamber 60.
The inlet hole 62 of the second chamber 60 is located below the two U-shaped tubes 12 positioned between the two U-shaped tubes 12 on the bottom plate 18 side and the two U-shaped tubes 12 positioned on the top plate 17 side. It communicates with the straight pipe part 19 on the side.
Therefore, the refrigerant introduced from the outlet hole 61 of the second chamber 60 into the second chamber 60 flows into the U-shaped tube 12 communicated with the inlet hole 62.

The third chamber 63 is a room partitioned by the partition walls 55 and 56.
The third chamber 63 is formed above the second chamber 60 in the header 52.
Two outlet holes 64 are formed in the third chamber 63, and the outlet holes 64 are two U-shaped tubes 12 on the bottom plate 18 side and two U-shaped tubes 12 positioned on the top plate 17 side. Are connected to the upper straight pipe portion 19 of the two U-shaped pipes 12 positioned between the two.
For this reason, the two U-shaped tubes 12 positioned between the two U-shaped tubes 12 on the bottom plate 18 side and the two U-shaped tubes 12 positioned on the top plate 17 side from the inlet hole 62 of the second chamber 60. The refrigerant introduced into the third chamber 63 is introduced into the third chamber 63 through the outlet hole 64 of the third chamber 63.
The third chamber 63 has the same size space as the second chamber 60, and two inlet holes 65 are formed in the upper portion of the outlet hole 64 in the third chamber 63.
The inlet hole 65 of the third chamber 63 communicates with the lower straight pipe portion 19 in the two U-shaped tubes 12 on the top plate 17 side.
Therefore, the refrigerant introduced from the outlet hole 64 of the third chamber 63 into the third chamber 63 flows into the U-shaped tube 12 communicated with the inlet hole 65.

The fourth chamber 66 is a room partitioned by a partition wall 56.
The fourth chamber 66 is formed above the third chamber 63 in the header 52, that is, at the top of the header 52.
Two outlet holes 67 are formed in the fourth chamber 66, and the outlet holes 67 are connected to the upper straight pipe portion 19 in the two U-shaped tubes 12 on the top plate 17 side.
Therefore, the refrigerant introduced into the two U-shaped tubes 12 on the top plate 17 side from the inlet hole 65 of the third chamber 63 is introduced into the fourth chamber 66 from the outlet hole 67 of the fourth chamber 66.
The fourth chamber 66 is provided with an outlet 68 through which the refrigerant in the fourth chamber 66 flows out.

By connecting the header 52 and the U-shaped tube 12, the refrigerant introduced into the first chamber 58 is supplied to the fourth chamber 66 from the second chamber 60 and the third chamber 63 through the U-shaped tube 12. It flows out from the four chambers 66 to the outside.
In the heat exchanger 50 of the present embodiment, a continuous refrigerant flow path is formed by the configuration of the plurality of U-shaped tubes 12 and the header 52, and the refrigerant introduced into the header 52 passes through the case 11 many times. Finally, it flows out from the header 52.

The refrigerant of the present embodiment has a property of changing phase in the U-shaped tube 12 by heat exchange with exhaust gas.
In this embodiment, the refrigerant passing through the U-shaped tube 12 on the bottom plate 18 side is in a liquid phase during heat exchange.
Then, during heat exchange, the refrigerant passing through the U-shaped tube 12 between the U-shaped tube 12 on the bottom plate 18 side and the U-shaped tube 12 on the top plate 17 side is in a state of phase change from the liquid phase to the gas phase.
During heat exchange, the refrigerant passing through the U-shaped tube 12 on the top plate 17 side is in a gas phase.
In this embodiment, for convenience of explanation, the front and rear U-tubes 12 on the bottom plate 18 side are referred to as first U-tubes 12A.
For convenience of explanation, the two U-shaped tubes 12 positioned between the two front and rear U-shaped tubes 12 on the bottom plate 18 side and the two front and rear U-shaped tubes 12 on the top plate 17 side are replaced by a second U-shaped tube. This is tube 12B.
Further, the two front and rear U-shaped tubes 12 on the top plate 17 side are referred to as third U-shaped tubes 12C.
A first U-shaped tube 12A group, a second U-shaped tube 12B group, and a third U-shaped tube 12C group having two front and rear units as a unit are configured.

The liquid phase refrigerant passes through the straight pipe portion 19 positioned above and below the first U-shaped tube 12A.
That is, the first U-shaped tube 12 </ b> A is a U-shaped tube 12 including a region before the phase change (liquid region) before the refrigerant undergoes a phase change.
In the first U-shaped tube 12 </ b> A, the outgoing refrigerant passes through the lower straight pipe portion 19, and the returning refrigerant passes through the upper straight pipe portion 19.
The upper and lower straight pipe portions 19 of the first U-shaped pipe 12A are in the same position in the exhaust gas flow direction, the difference in thermal expansion between the upper and lower straight pipe sections 19 is small, and the deformation of the first U-shaped pipe 12A is small.

On the other hand, the straight pipe portion 19 in the second U-shaped tube 12B passes the refrigerant undergoing phase change from the liquid phase to the gas phase.
That is, the second U-shaped tube 12B is a U-shaped tube 12 including a phase change region (boiling region) in which the refrigerant changes phase.
In the second U-shaped tube 12B, the lower straight pipe portion 19 through which the forward refrigerant passes corresponds to the forward pipe portion, and the upper straight pipe portion 19 through which the return refrigerant passes corresponds to the return pipe portion.
The temperature of the second U-shaped tube 12B is higher than that of the first U-shaped tube 12A.
Even if the upper and lower straight pipe portions 19 of the second U-shaped pipe 12B are at the same position in the exhaust gas flow direction, the straight pipe sections 19 below the second U-shaped pipe 12B through which refrigerant in a state close to the liquid phase passes, The thermal expansion difference due to the phase change of the refrigerant with the straight pipe part 19 on the second U-shaped pipe 12B through which the refrigerant in a state close to the gas phase passes is large.
Due to the difference in thermal expansion between the upper and lower straight pipe sections 19 in the second U-shaped pipe 12B, the bent pipe section 20 side is deformed toward the bottom plate 18 side.

A gas phase refrigerant passes through the straight pipe portion 19 positioned above and below the third U-shaped tube 12C.
That is, the third U-shaped tube 12C is a U-shaped tube 12 including a post-phase change region (superheated steam region) after the refrigerant has undergone a phase change.
In the third U-shaped tube 12 </ b> C, the outgoing refrigerant passes through the lower straight pipe portion 19, and the returning refrigerant passes through the upper straight pipe portion 19.
The upper and lower straight pipe portions 19 of the third U-shaped pipe 12C are at the same position in the exhaust gas flow direction.
Further, although the temperature of the third U-shaped tube 12C is higher than that of the second U-shaped tube 12B, the difference in thermal expansion between the upper and lower straight tube portions 19 is small.
For this reason, the deformation due to the thermal expansion difference in the second U-shaped tube 12B is larger than the deformation due to the thermal expansion difference in the first U-shaped tube 12A and the third U-shaped tube 12C.
In the present embodiment, since the refrigerant is the heat exchanger 10 that is heated by the exhaust gas, when viewed from the refrigerant flow in the heat exchanger 10, the region before the phase change is located most upstream.
The phase change area is located downstream of the pre-phase change area, and the post-phase change area is located downstream of the phase change area.

In the present embodiment, a large number of fins 51 are attached to the straight tube portion 19 of the U-shaped tube 12 disposed in the case 11.
The fin 51 is a metal plate formed of stainless steel. As shown in FIG. 4, the fin 51 has a plurality of through holes 69 through which the straight pipe portion 19 is inserted.
The flow path of the exhaust gas between the side plates 15 and 16 of the case 11 is partitioned by a large number of fins 51, and the surfaces of the fins 51 are along the flow direction of the exhaust gas.
A gap is formed between the fins 51 adjacent to each other, and the exhaust gas is circulated through the gap to facilitate the transfer of heat of the exhaust gas to the fin 51.

The fin 51 of the present embodiment is physically divided and divided between the first U-shaped tube 12A and the second U-shaped tube 12B, and between the second U-shaped tube 12B and the third U-shaped tube 12C. It is physically divided and divided.
Further, in the present embodiment, the fin 51 is also physically divided and divided between the upper and lower straight pipe portions 19 of the second U-shaped pipe 12B.
For this reason, the fin 51 is divided into four fin portions 70 to 73.
The first fin portion 70 is attached to two front and rear first U-shaped tubes 12A on the bottom plate 18 side.
The second lower fin portion 71 is attached to the straight pipe portion 19 on the lower side of the two front and rear second U-shaped tubes 12B.
The second upper fin portion 72 is attached to the straight pipe portion 19 on the upper side of the two front and rear second U-shaped tubes 12B.
The third fin portion 73 is attached to the two front and rear third U-shaped tubes 12C on the top plate 17 side.
That is, the fin 51 of the present embodiment is divided between the pre-phase change region and the phase change region, and is divided between the phase change region and the post-phase change region.
Further, the fins 51 are also divided in the phase change region.

The amount of deformation associated with the difference in thermal expansion of the first U-shaped tube 12A, the second U-shaped tube 12B, and the third U-shaped tube 12C is different.
By dividing the fin 51 into four fin portions 70 to 73, the fin 51 is restrained by the first U-shaped tube 12 </ b> A restrained by the first fin portion 70, the second lower fin portion 71 and the second upper fin portion 72. The second U-shaped tubes 12B can be deformed independently of each other.
Further, the second U-shaped tube 12B constrained by the second lower fin portion 71 and the second upper fin portion 72 and the third U-shaped tube 12C constrained by the third fin portion 73 can be deformed independently of each other. .
Further, in the second U-shaped tube 12B, the straight pipe portion 19 through which the forward refrigerant passes and the straight pipe portion 19 through which the return refrigerant passes can be deformed without being restricted to each other.

In the present embodiment, when the engine mounted on the vehicle is driven, the exhaust gas of the engine passes through the exhaust pipe (not shown) and passes through the heat exchanger 50.
The exhaust gas passing through the heat exchanger 50 flows along the surfaces of the numerous fins 51, and the fins 51 are heated by the high-temperature exhaust gas.

On the other hand, the refrigerant flows through the U-shaped tube 12 of the heat exchanger 50, and the refrigerant is exhausted around the fins 51 through the fins 51, the brazing material joining the U-shaped tubes 12 and the fins 51, and the straight pipe part 19. Exchange heat with gas.
In the present embodiment, since the refrigerant passing through the first U-shaped tube 12A is introduced from the first chamber 58 of the header 52, the liquid-phase refrigerant exchanges heat with the high-temperature exhaust gas.
The refrigerant passing through the second U-shaped tube 12B is a refrigerant that has already undergone heat exchange in the first U-shaped tube 12A, and is undergoing a phase change from the liquid phase to the gas phase by heat exchange with the high-temperature exhaust gas in the second U-shaped tube 12B. It is in the state of.
For this reason, the second U-shaped tube 12B is hotter than the first U-shaped tube 12A, and the thermal expansion of the second U-shaped tube 12B is larger than the thermal expansion of the first U-shaped tube 12A.
The refrigerant flowing in the second U-shaped tube 12B is a refrigerant introduced from the second chamber 60 of the header 52, and the ratio of the liquid-phase refrigerant in the refrigerant is high.
On the other hand, in the refrigerant returned from the second U-shaped tube 12B, the ratio of the gas-phase refrigerant in the refrigerant is high.
Therefore, in the second U-shaped tube 12B, the straight pipe portion 19 through which the returning refrigerant passes has a high ratio of the gas-phase refrigerant, the thermal resistance of oil is large, and the thermal expansion of the straight pipe portion 19 through which the forward refrigerant passes. Becomes larger.
Incidentally, the thermal resistance of the oil is small in the first U-shaped tube 12A including the liquid region, and the second U-shaped tube 12B including the boiling region has the same thermal resistance as the third U-shaped tube 12C including the superheated steam region.
Therefore, in the first U-shaped tube 12A, the influence of the phase change is small, and the thermal resistance of the oil is small, so the deformation amount of the first U-shaped tube 12A is the smallest.
Moreover, in the 2nd U-shaped pipe 12B, since the influence by phase change is small and the thermal resistance of oil is large, the deformation amount of the 2nd U-shaped pipe 12B is larger than the deformation amount of the 1st U-shaped pipe 12A.
In the 3rd U-shaped pipe 12C, since the influence by a phase change is large and the thermal resistance of oil is also large, the amount of deformation of the 3rd U-shaped pipe 12C is the largest.

Since the fin 51 is divided into four fin portions 70 to 73, the first U-shaped tube 12A is not constrained between the first U-shaped tube 12A and the second U-shaped tube 12B via the fin 51. Transforms.
The second U-shaped tube 12B is deformed without being constrained by the first U-shaped tube 12A and the third U-shaped tube 12C.
The third U-shaped tube 12C is deformed without being constrained by the second U-shaped tube 12B.
That is, the first U-shaped tube 12A, the second U-shaped tube 12B, and the third U-shaped tube 12C are independently deformed according to the respective thermal expansion amounts.
For this reason, stress concentration is relieved at the joint between the first U-shaped tube 12 </ b> A and the side plate 15 in the case 11.
Further, in the third U-shaped tube 12 </ b> C, stress concentration is reduced at the joint portion between the third U-shaped tube 12 </ b> C and the side plate 15 in the case 11.

By the way, in the second U-shaped tube 12B, the second lower fin portion 71 is formed in the straight pipe portion 19 through which the forward refrigerant passes, and the second upper fin portion 72 is formed in the straight pipe portion 19 through which the return refrigerant passes. Yes.
Therefore, in the second U-shaped tube 12B, the straight pipe portion 19 through which the forward refrigerant passes and the straight pipe portion 19 through which the return refrigerant passes are deformed without being constrained to each other.
For this reason, stress concentration is relieved at the joint between the second U-shaped tube 12 </ b> B and the side plate 15 in the case 11.

The heat exchanger 50 of this embodiment has the same effects as the effects (1) to (3) of the first embodiment.
More specifically, the second U-shaped pipe 12B has a straight pipe part 19 through which the forward refrigerant passes and a straight pipe part 19 through which the return refrigerant passes, and the fin 51 returns the straight pipe part 19 through which the forward refrigerant passes. The straight pipe portion 19 through which the refrigerant passes is divided.
The straight pipe portion 19 through which the forward refrigerant passes and the straight pipe portion 19 through which the return refrigerant passes can be deformed according to the amount of thermal expansion without being constrained via the fins 51.

(Third embodiment)
Next, a heat exchanger according to a third embodiment will be described.
The heat exchanger of the present embodiment is different from the first embodiment in the configuration of the header.
In the present embodiment, the description of the first embodiment is used for the same configuration as that of the first embodiment, and common reference numerals are used.

A heat exchanger 80 shown in FIG. 7 includes a header 81 that reverses the flow of the refrigerant outside the case 11.
As shown in FIGS. 7 and 8, the header 81 is a box body having a space sealed by an outer wall 82 inside, and the inner space is divided into four by partition walls 83, 84, 85, and four rooms are formed. Have.
The first chamber 87 provided with the inlet 86 into which the refrigerant flows from the outside is a room partitioned by the partition walls 83 and 84.
The first chamber 87 is formed on the upstream side in the exhaust gas flow direction in the header 81 and on the bottom plate 18 side of the case 11.
In the first chamber 87, three inlet holes 88 communicating with the straight pipe portion 19 on the exhaust gas introduction side in the three first U-shaped tubes 12A on the bottom plate 18 side are formed.

The second chamber 89 is a room partitioned and partitioned by the partition walls 84 and 85.
The second chamber 89 is formed in the header 81 on the downstream side in the exhaust gas flow direction and on the bottom plate 18 side of the case 11.
The second chamber 89 is formed with three outlet holes 90 to which the straight pipe portion 19 on the exhaust gas outlet side in the three first U-shaped tubes 12A on the bottom plate 18 side is connected.
For this reason, the refrigerant introduced into the first chamber 87 from the inlet 86 passes through the three first U-shaped pipes 12A on the bottom plate 18 side from the inlet hole 88 of the first chamber 87, and the outlet hole 90 of the second chamber 89. To the second chamber 89.
The second chamber 89 is larger than the first chamber 87, and three inlet holes 91 are formed in the upper portion of the outlet hole 90 in the second chamber 89.
The inlet hole 91 of the second chamber 89 communicates with the straight pipe portion 19 on the exhaust gas outlet side in the three second U-shaped pipes 12B.
Therefore, the refrigerant introduced into the second chamber 89 from the outlet hole 90 of the second chamber 89 flows into the second U-shaped tube 12 </ b> B communicated with the inlet hole 91.

The third chamber 92 is a room partitioned by the partition walls 83 and 84.
The third chamber 92 is formed on the upstream side of the header 81 in the exhaust gas flow direction and on the top plate 17 side of the case 11 with respect to the first chamber 87.
Three outlet holes 93 are formed in the third chamber 92, and the outlet hole 93 is connected to the straight pipe portion 19 on the exhaust gas introduction side of the three second U-shaped pipes 12B.
For this reason, the refrigerant introduced into the three second U-shaped pipes 12 </ b> B from the inlet hole 91 of the second chamber 89 is introduced into the third chamber 92 from the outlet hole 93 of the third chamber 92.
The third chamber 92 has a space the same size as the second chamber 89, and three inlet holes 94 are formed in the upper portion of the outlet hole 93 in the third chamber 92.
The inlet hole 94 of the third chamber 92 communicates with the straight pipe portion 19 on the exhaust gas introduction side in the three third U-shaped tubes 12C on the top plate 17 side.
Therefore, the refrigerant introduced into the third chamber 92 from the outlet hole 93 of the third chamber 92 flows into the third U-shaped tube 12 </ b> C communicating with the inlet hole 94.

The fourth chamber 95 is a room partitioned by the partition walls 84 and 85.
The fourth chamber 95 is formed downstream of the header 81 in the exhaust gas flow direction and closer to the top plate 17 of the case 11 than the second chamber 89.
Three outlet holes 96 are formed in the fourth chamber 95, and the outlet hole 96 has a straight pipe portion 19 on the exhaust gas outlet side in the three third U-shaped tubes 12 </ b> C on the top plate 17 side. Connected.
Therefore, the refrigerant introduced from the inlet hole 94 of the third chamber 92 into the three third U-shaped tubes 12C on the top plate 17 side is introduced from the outlet hole 96 of the fourth chamber 95 into the fourth chamber 95.
The fourth chamber 95 is provided with an outlet 97 through which the refrigerant in the fourth chamber 95 flows out.

By connecting the header 81 and the U-shaped tube 12, the refrigerant introduced into the first chamber 87 is supplied from the second chamber 89 and the third chamber 92 to the fourth chamber 95 through the U-shaped tube 12. It flows out from the fourth chamber 95 to the outside.
In the heat exchanger 80 of this embodiment, a continuous refrigerant flow path is formed by the configuration of the plurality of U-shaped tubes 12 and the header 81, and the refrigerant introduced into the header 81 passes through the case 11 many times. Finally, it flows out from the header 81.

  The fins 13 of the present embodiment are physically divided and divided between the first U-shaped tube 12A and the second U-shaped tube 12B, and between the second U-shaped tube 12B and the third U-shaped tube 12C. Is also physically divided and divided.

In the present embodiment, the first U-shaped tube 12 </ b> A is disposed close to the bottom plate 18 of the case 11, and the third U-shaped tube 12 </ b> C is disposed close to the top plate 17 of the case 11.
The first fin portion 38 attached to the first U-shaped tube 12A on the bottom plate 18 side is fixed to the bottom plate 18 by brazing.
That is, the first U-shaped tube 12 </ b> A on the bottom plate 18 side is fixed to the bottom plate 18 via the first fin portion 38.
When the first U-shaped tube 12A on the bottom plate 18 side is fixed to the case 11 via the first fin portion 38, the vibration of the first U-shaped tube 12A is suppressed.
In the present embodiment, since the deformation amount of the first U-shaped tube 12A is smaller than the deformation amount of the second U-shaped tube 12B, even if the first U-shaped tube 12B is fixed to the case 11 via the first fin portion 38, the effect of deformation is not affected. small.

The heat exchanger 80 of the present embodiment has the same effects as the effects of the second embodiment.
Furthermore, according to the heat exchanger 80 of the present embodiment, the first U-shaped tube 12 </ b> A on the bottom plate 18 side is fixed to the bottom plate 18 via the first fin portion 38.
For this reason, the vibration of the 1st fin part 38 which restrains 12 A of 1st U-shaped pipes by the side of the baseplate 18 can be suppressed.
Therefore, damage and noise of the first U-shaped tube 12A due to vibrations of the first U-shaped tube 12A and the first fin portion 38 can be reduced, and durability and quietness of the heat exchanger 80 can be improved.

(Modification)
Next, the fin which concerns on a modification is demonstrated.
Here, although the fin of the modification applied to the heat exchanger 10 of 1st Embodiment is demonstrated, the fin which concerns on a modification can also be applied to the heat exchanger 80 of 3rd Embodiment.
The same reference numerals are used as in the first embodiment.

The fins 13 shown in FIG. 9 are connected without being completely completely separated between the first U-shaped tube 12A and the second U-shaped tube 12B and between the second U-shaped tube 12B and the third U-shaped tube 12C. It is a fin.
A connection portion 98 as a stress relaxation portion exists between the first fin portion 38 and the second fin portion 39 and between the second fin portion 39 and the third fin portion 40 in the fin 13.
In this modification, the connection portions 98 provided at the separation locations of the fins 51 are formed on the side edges of the exhaust gas introduction side (upstream side) and the discharge side (downstream side).
The connecting portion 98 is formed by punching out portions in the fin 13 between the first U-shaped tube 12A and the second U-shaped tube 12B and between the second U-shaped tube 12B and the third U-shaped tube 12C in a slit shape. .
The connecting portion 98 is deformed so as to relieve the stress caused by the difference in thermal expansion between the first U-shaped tube 12A and the second U-shaped tube 12B and the difference in thermal expansion between the second U-shaped tube 12B and the third U-shaped tube 12C. Possible shapes and dimensions are set.
In the present modification, the space between the straight pipe portions 19 of the second U-shaped tube 12B in the second fin portion 39 of the fin 13 is not divided, but the second fin portion 39 in the second fin portion 39 as in the first embodiment. You may divide | segment between the straight pipe parts 19 of 2U-shaped pipe 12B.

In the heat exchanger 50 to which the fin 13 according to the modification is applied, the fin 13 is interposed between the first U-shaped tube 12A and the second U-shaped tube 12B or between the second U-shaped tube 12B and the third U-shaped tube 12C. They can be deformed according to the amount of deformation caused by the difference in thermal expansion without being constrained to each other.
Therefore, the stress concentration at the joint between the U-shaped tube 12 and the side plate 15 in the case 11 can be relaxed, and breakage of the joint between the U-shaped tube 12 and the side plate 15 can be prevented.

  The above embodiment shows an embodiment of the present invention, and the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the invention as described below. Is possible.

In the above embodiment, the heat exchange fluid is exhaust gas, and the refrigerant as the working fluid is a heat exchanger that is heated by the exhaust gas. However, a heat exchanger that cools the working fluid with the heat exchange fluid like a condenser is used. There may be. In the case of a heat exchanger that cools the working fluid with a heat exchange fluid, the working fluid is in the gas phase in the region before the phase change, and is in the state of phase change from the liquid phase to the gas phase in the phase change region. It is a liquid phase in the region. That is, the working fluid in the heat exchanger is in the gas phase on the upstream side and in the liquid phase on the downstream side.
○ In the first and third embodiments, the heat exchanger is provided with nine U-shaped tubes, and is configured as a first U-shaped tube group to a third U-shaped tube group in units of three. The number of the 1U-shaped tube group to the third U-shaped tube group is not particularly limited. What is necessary is just the heat exchanger provided with the 1st U-tube-the 3rd U-tube at least one each.
○ In the second embodiment, the heat exchanger is provided with six U-shaped tubes, and is configured as a first U-shaped tube group to a third U-shaped tube group whose front and rear are two units. The number of tube groups to the third U-shaped tube group is not particularly limited. What is necessary is just the heat exchanger provided with the 1st U-tube-the 3rd U-tube at least one each.
In the third embodiment, the fins attached to the first U-shaped tube are fixed to the case by brazing, but the fins are not necessarily fixed to the case by brazing. The fins may be fixed to the case by other means. When the thermal expansion of the third U-shaped tube is small, in addition to the fins of the first U-shaped tube, fins attached to the third U-shaped tube may be brazed to the case.
In the above embodiment, the heat exchanger is a heat exchanger used in the Rankine cycle circuit, but the heat exchanger of the present invention can be used as a heat exchanger other than the Rankine cycle circuit. In the above embodiment, the heat exchanger is an in-vehicle heat exchanger. However, the heat exchanger is not limited to the in-vehicle heat exchanger, and may be, for example, a heat exchanger installed on the ground.
In the above modification, the connecting portion is formed by punching a portion of the fin between the first U-shaped tube and the second U-shaped tube in a slit shape, but the present invention is not limited thereto. The connecting portion may be any shape that can be deformed so as to relieve the stress caused by the difference in thermal expansion between the first U-shaped tube and the second U-shaped tube as a stress relieving portion. Moreover, you may form the connection part as a stress relaxation part in the fin in 1st Embodiment.

10, 50, 80 Heat exchanger 11 Case 12 U-shaped tube 12A First U-shaped tube 12B Second U-shaped tube 12C Third U-shaped tube 13, 51 Fins 14, 52, 81 Header 15, 16 Side plate 17 Top plate 18 Bottom plate 19 Direct Pipe part 20 Curved pipe part 37, 69 Through hole 38, 70 First fin part 39 Second fin part 40, 73 Third fin part 71 Second lower fin part 72 Second upper fin part 81 Header 98 Connection part 100 Heat Exchanger (conventional)
101 Case 102 U-shaped tube 103 Fin 104 Header

Claims (4)

A plurality of U-tubes arranged in parallel to each other and passing the working fluid;
A plurality of through holes into which the plurality of U-shaped tubes are inserted, and fins supported by the plurality of U-shaped tubes;
A support for supporting the plurality of U-shaped tubes,
Heat exchange between the heat exchange fluid around the fin and the working fluid;
In the heat exchanger in which the working fluid undergoes phase change in the U-shaped tube by heat exchange with the heat exchange fluid,
The plurality of U-tubes are
A first U-shaped tube including a pre-phase change region before the working fluid undergoes a phase change during heat exchange;
A second U-shaped tube including a phase change region in which the working fluid changes phase during heat exchange;
A third U-shaped tube including a phase change post-range after the working fluid undergoes a phase change during heat exchange,
The heat exchanger according to claim 1, wherein the fin is divided between the pre-phase change region and the phase change region.   The heat exchanger according to claim 1, wherein the fin is divided between the phase change region and the phase change post region. The second U-shaped pipe has a forward pipe portion for passing the forward working fluid and a return pipe portion for passing the return working fluid;
The heat exchanger according to claim 1 or 2, wherein the forward pipe part and the return pipe part are divided in the fin.   The heat exchanger according to claim 1 or 2, wherein the heat exchange fluid is exhaust gas of an internal combustion engine.

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