JP4533308B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger in which a partition material is provided in a heat exchange part.

As a conventional heat exchanger, the thing of patent document 1 is proposed. The heat exchanger described in Patent Document 1 has a structure in which a plurality of circular passages having a circular cross section are arranged in a cylindrical housing.
JP-A-6-294593 (FIG. 2)

  However, the heat exchanger described in Patent Document 1 has the advantage that thermal stress is less likely to be concentrated by making the housing cylindrical, and heat flow is achieved by arranging a large number of circular passages in the cylindrical housing. Although it is excellent in terms of improving the conversion efficiency, a large number of circular flow paths are required, which increases the number of parts and complicates the manufacturing process. Therefore, it is possible to reduce the number of parts by arranging a plurality of elongated flow passages in a cylindrical housing in parallel, but in the case of a cylindrical housing, the flow is applied to both end portions of the flow passage arrangement direction. A wide flow path portion where the path cannot be arranged is generated, and the flow velocity (uneven flow rate) is increased only by that portion, and the temperature distribution becomes uneven.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a heat exchanger that does not generate stress concentration with a simple configuration and can prevent temperature unevenness.

Invention, a plurality of heating fluid path channel cross section is formed in an elongated shape pressurizing heat fluid flows, and has a heated fluid pathway heated fluid flows, each heating fluid path according to claim 1 A substantially cylindrical casing that covers heat exchange portions that are arranged in parallel and spaced apart from each other in the heated fluid path, and a cylindrical housing in which the casing is inserted, and the heating fluid The path is formed such that the length of the heating fluid path becomes shorter from the center to the both ends so that the center of the heating fluid path is the longest in the center and the both ends of the heating direction are the shortest. The casing is formed such that both ends of the heating fluid path in the arrangement direction are flat and is positioned between an inflow portion into which the heated fluid is introduced and an outflow portion from which the heated fluid flows out. Now Arcuate partition portions provided at both ends of the heating fluid path in the arrangement direction, and arc-shaped partition portions provided at both ends in the longitudinal direction of the flow path cross section of the heating fluid path, A partition member configured such that a hole is formed in a central portion of the plate, wherein the partition member is formed integrally with the casing at an edge portion on the inflow portion side and is in close contact with the housing; It is arranged.

According to the invention which concerns on Claim 1 , stress concentration can be prevented by making a housing cylindrical. In this way, when the housing is cylindrical and a plurality of elongated heating fluid paths are arranged in parallel, a wide heated fluid path portion where heating fluid paths cannot be arranged at both ends in the arrangement direction of the heating fluid paths occurs. By providing the partition material in the wide heated fluid path portion, the flow of the heated fluid is blocked, thereby making the flow distribution uniform and making the temperature distribution uniform.

The invention according to claim 1 is characterized in that a tubular casing that wraps the heat exchanging portion inside the housing is provided, and the casing and the partition member have an integral structure.
According to the first aspect of the invention, since the housing and the casing have a double tube structure, the casing serves as a jig for fixing the heat exchanging portion, and the manufacturability when the heat exchanging portion is attached to the housing is improved. Can be improved.

The invention according to claim 1 is characterized in that the partition member has a shape having a hole for disposing the heat exchange part in a central part.
According to the invention which concerns on Claim 1 , it becomes possible to raise heat conversion efficiency in the whole outer periphery by using the partition material which surrounds an outer periphery.

According to a second aspect of the present invention, the partition member is provided on an edge portion on the outflow portion side together with an edge portion on the inflow portion side of the casing, and is sealed with the partition members between the casing and the housing. It is characterized by having an annular heat insulating layer.

According to the invention which concerns on Claim 2 , the thermal radiation from a heat exchange part can be suppressed, and heat conversion efficiency can be improved.

The invention according to claim 3 is characterized in that at least the outermost layer path of the fluid to be heated has a fin structure.

According to the third aspect of the present invention, the fin structure itself serves as a cushioning material, and the stress generated when the heated fluid path is thermally deformed can be released by the fin structure. In addition, by providing the fins in the outermost layer path, heat loss due to heat radiation from the inside can be suppressed, and an effect as a heat insulating layer can be given to suppress thermal deformation of the fin outer peripheral portion.

  According to the present invention, it is possible to provide a heat exchanger that does not generate stress concentration with a simple configuration and can prevent temperature unevenness.

  FIG. 1 is a block diagram showing an example of a system equipped with a heat exchanger according to this embodiment, and FIG. 2 is an external perspective view showing a combustion heater provided with the heat exchanger according to this embodiment.

  The system shown in FIG. 1 is a fuel cell system 1 and includes a fuel cell FC, an anode system 2, a cathode system 3, a cooling system 4, a warm-up system 5, and the like. In the present embodiment, the fuel cell system 1 is mounted on a vehicle, for example, and when the vehicle is used in a low temperature environment, the fuel cell FC is warmed up by the warm-up system 5 when the fuel cell system 1 is started. It has become so.

  The fuel cell FC is a solid polymer type PEM (Proton Exchange Membrane) type fuel cell, and a membrane electrode structure (MEA;) comprising an electrolyte membrane m sandwiched between an anode electrode An and a cathode electrode Ca. It has a structure in which a plurality of single cells configured by sandwiching a membrane electrode assembly) with a conductive separator are stacked in the thickness direction. In addition, in the fuel cell FC, separately from the flow path through which hydrogen as the fuel gas flows and the flow path through which air (oxygen) as the oxidant flows, the heated object used when the fuel cell FC is warmed up. A flow path through which the fluid flows is formed. The heated fluid is also used as a cooling medium when cooling the fuel cell FC. In this type of fuel cell FC, hydrogen is supplied to the anode electrode An and air is supplied to the cathode electrode Ca, whereby electric power is generated by an electrochemical reaction between hydrogen and oxygen in the air, and electric power is supplied to the traveling motor and the like. Supplied.

  The anode system 2 includes a hydrogen tank 2a, a regulator 2b, a purge valve 2c, an ejector 2d, and the like. The hydrogen tank 2a is filled with high-purity hydrogen at a high pressure. When a shut-off valve (not shown) is opened, the hydrogen is decompressed by the regulator 2b and then supplied to the inlet of the anode pole An of the fuel cell FC. It has come to be. The purge valve 2c is a shut-off valve. When the valve is closed, unreacted hydrogen discharged from the outlet of the anode electrode An is supplied again to the inlet of the anode electrode An by the ejector 2d. When the valve is opened, it is accumulated in the anode electrode An. Impurities are discharged.

  The cathode system 3 includes an air compressor 3a and the like. The air compressor 3a is composed of a mechanical supercharger or the like driven by a motor, takes in external air (air) and compresses it, and supplies air to the inlet of the cathode electrode Ca of the fuel cell FC.

  The anode off-gas discharged from the anode electrode An and the cathode off-gas discharged from the cathode electrode Ca are sent to the diluter 6, where the hydrogen in the anode off-gas is diluted with the cathode off-gas and then into the atmosphere. Discharged.

  The cooling system 4 has a function of dissipating heat generated by the fuel cell FC by power generation, and includes a radiator 4a, pipes 4b, 4c, 4d, a circulation pump 4e, a thermostat valve 4f, and the like. In the cooling system 4, when it is necessary to cool the fuel cell FC, the circulation pump 4e is activated and the thermostat valve 4f is switched to the radiator 4a side, so that the cooling medium heated by the fuel cell FC is supplied to the radiator. Cooled in 4a. Further, when it is not necessary to cool the fuel cell FC, the thermostat valve 4f is switched to the pipe 4d side.

The warm-up system 5 includes a combustion heater 10, a mixer 11, pipes 5a and 5b, a three-way valve 5c, gas supply pipes 5d and 5e, and the like. The combustion heater 10 is provided with a combustor 20 and a heat exchanger 30A (30B, 30C) adjacent to each other. Note that the combustor 20 is configured such that a combustion portion 22 in which a catalyst is supported on a honeycomb structure or the like is supported in a case 21 (see FIG. 3). Hereinafter, the heat exchangers 30A, 30B, and 30C of the reference example, the first embodiment , and the second embodiment will be described.

( Reference example )
3 is a cross-sectional view taken along the line AA in FIG. 2, and FIG. 4 is a cross-sectional view taken along the line BB in FIG. FIG. 2 is common to the first embodiment and the second embodiment. In FIG. 3, the illustration of the fins is omitted .
As shown in FIG. 3, the heat exchanger 30A includes a heat exchange part 31A, a housing 32, and partition members 33a, 33b, 33c, and 33d (refer to FIG. 4 for the partition members 33a and 33b). I have.

  As shown in FIG. 4, the heat exchanging portion 31 </ b> A has a plurality (five in the present embodiment) in which the cross section of the flow path is formed in an elongated shape in the space inside the housing 32 formed in a cylindrical shape. Heating fluid pipe portions 31a, 31a, 31a, 31a, 31a. More specifically, each heating fluid pipe portion 31a is formed to have a constant width and is elongated in the vertical direction and the same length, and is arranged with a space between each other. In addition, the elongate space enclosed by these heating fluid pipe | tube parts 31a is equivalent to heating fluid path | route S1 in this embodiment. A space surrounded by the housing 32 outside the heated fluid pipe portion 31a corresponds to the heated fluid path S2 in the present embodiment.

  As shown in FIG. 3, the housing 32 includes a cylindrical cylinder 32a, and circular blocking plates 32b and 32c that block the openings at both ends of the cylinder 32a except for the heating fluid path S1. Yes. The housing 32 is connected to a pipe 5a for allowing the fluid to be heated to flow into the heat exchanging portion 31A at the lower part near the combustor 20, and heats the fluid to be heated at the upper part opposite to the combustor 20. A pipe 5b for flowing out from the exchange part 31A is connected. As shown in FIG. 1, the pipe 5a is connected in the middle of the pipe 4c via a three-way valve 5c, and the pipe 5b is connected to the downstream side of the three-way valve 5c of the pipe 4c. The three-way valve 5c causes a control unit (not shown) to circulate the heated fluid between the fuel cell FC and the heat exchanger 30A, and a normal operation position where the heated fluid bypasses the heat exchanger 30A. Switching to the warm-up operation position is possible.

  As shown in FIG. 4, the partition members 33a, 33b, 33c, and 33d are formed of arcuate plates, and are arranged near the center in the longitudinal direction of the heat exchanging portion 31A (see FIG. 3). Further, the partition members 33a and 33b are joined to both ends of the heating fluid pipe portions 31a in the arrangement direction so that the curved surfaces thereof are in close contact with the inner wall surface of the housing 32, while the partition members 33c and 33d are Different from the both end portions, the curved surfaces are joined to both end portions in the longitudinal direction of the cross section of the heating fluid pipe portion 31 a (vertical direction in FIG. 4) so that the curved surfaces are in close contact with the inner wall surface of the housing 32. Further, a corrugated fin (fin structure) 34A is provided between the heating fluid pipe part 31a and the heating fluid pipe part 31a, and the cross-sectional waveform is similarly provided in the outermost layer path of the heat exchange part 31A. Fins (fin structure) 34B are provided. The fins 34A and 34B are provided within a range indicated by reference numeral E1 in FIG. 3, and in particular, the range E1 functions as a heat exchanging portion 31A that actively exchanges heat. In the following, the region during which the heated fluid is introduced from the pipe 5a to the heat exchanging portion 31A is referred to as an inflow portion E2, and the region during which the heated fluid is discharged from the heat exchanging portion 31A to the pipe 5b is referred to as the outflow portion. This will be described as E3.

Next , the operation of the fuel cell system 1 including the heat exchanger 30A will be described. When the above-described fuel cell system 1 is started, if a control unit (not shown) determines that the fuel cell FC needs to be warmed up, the three-way valve 5c is switched to the warm-up operation position and the circulation pump 4e is driven. To do. Then, a shut-off valve (not shown) is opened to supply hydrogen from the hydrogen tank 2a to the mixer 11 via the gas supply pipe 5d, and to the mixer 11 via the gas supply pipe 5e by driving the air compressor 3a. Supply air (oxygen). The mixed gas of hydrogen and air mixed in the mixer 11 is sent to the combustor 20 of the combustion heater 10, and catalytic combustion is performed in the combustor 20. The heating fluid (high-temperature combustion off gas) generated by catalytic combustion flows through the heating fluid path S1 formed by each heating fluid pipe portion 31a of the heat exchanger 30A as indicated by the white arrow. The combustion off gas that has passed through the heat exchanger 30A is discharged into the atmosphere together with the cathode off gas discharged from the outlet of the cathode electrode Ca of the fuel cell FC.

  On the other hand, by the driving of the circulation pump 4e, the heated fluid flows from the pipe 5a into the heat exchanging portion 31A, heat exchange is performed with the heated fluid flowing through the heated fluid path S1, and the heated fluid is heated. By the way, in the case where the heating fluid path S1 having a narrow channel cross section is formed in the cylindrical housing 32, if the partition members 33a to 33d are not provided, both ends of the heating fluid path S1 in the alignment direction are provided. Since a large heated fluid path is formed, the flow of the surrounding heated fluid becomes faster than the flow of the central heated fluid, and the temperature is lowered to cause temperature unevenness. Therefore, as in the present embodiment, by providing the partition members 33a to 33d at the outer peripheral edge portion of the heated fluid path S2 of the heat exchanging portion 31A, the flow of the heated fluid is blocked, so the center of the heat exchanging portion 31A The flow (distribution) of the heated fluid can be made uniform between the portion and the outer peripheral edge, and it becomes possible to prevent uneven temperature of the heated fluid.

Further , in the heat exchanger 30A, stagnation occurs in the fluid to be heated on the upstream side and the downstream side with the partition members 33a to 33d interposed therebetween. be able to.

Further , in the heat exchanger 30A, by providing the fin 34B (see FIG. 4) in the outermost layer path of the heated fluid path S2, the fin 34B itself serves as a buffer material, and the heated fluid pipe portions 31e to 31g are heated. Even if it is deformed, the stress can be released. Further, by providing the fins 34B, heat loss due to heat radiation from the internal heating fluid path S1 can be suppressed, and an effect as a heat insulating layer can be provided to suppress thermal deformation of the outer peripheral portion of the fins 34B.

  If the control unit (not shown) determines that the fuel cell FC is in a state capable of self-power generation, the three-way valve 5c is switched to the normal operation position and the warm-up operation is terminated. In addition, when the temperature of the heated fluid discharged from the fuel cell FC exceeds a predetermined temperature, the thermostat valve 4f is switched, and the heated fluid flowing out from the fuel cell FC is cooled by the radiator 4a, and the fuel cell. Returned to FC.

As shown in FIG. 5, partition members 33a and 33b are provided only at both ends of the heating fluid path S1 in the arrangement direction. In this case, the length of the heating fluid pipe portion in the vertical direction is not made uniform as shown in FIG. 4, but the cross section of the flow path is vertically arranged at the center (position with the longest diameter) in the arrangement direction as shown in FIG. The heating fluid pipe section 31b that is the longest in the direction, the second longest heating fluid pipe sections 31c and 31c outside the arrangement direction, and the shortest heating fluid pipe sections 31d and 31d outside the arrangement direction further increase heating. The heat transfer area of the heated fluid received from the fluid can be obtained.

  Moreover, although not shown in figure, all of the partition materials 33a-33d may be integrally formed with one plate. Alternatively, it may be a punching metal in which a plurality of holes are formed in the partition members 33a to 33d as long as it can block the flow of the heated fluid and make the flow uniform. This makes it possible to reduce the weight of the heat exchanger 30A.

(First Embodiment)
6 is a cross-sectional view showing a combustion heater provided with the heat exchanger of the first embodiment, FIG. 7 is a cross-sectional view taken along the line CC of FIG. 6, and FIG. 8 is a perspective perspective view showing the heat exchanger of the first embodiment. is there. In addition, illustration of a fin is abbreviate | omitted in FIG.
As shown in FIG. 6, the heat exchanger 30 </ b> B of the first embodiment includes a heat exchange part 31 </ b> B, a housing 32, a partition member 37, and a casing 38. The partition member 37 and the casing 38 have an integral structure.

  As shown in FIG. 7, the heat exchanging portion 31 </ b> B includes a substantially cylindrical casing 38 inside thereof, and a heating fluid having a different flow path cross-sectional length in the space inside the casing 38 as in FIG. 5. Tube portions 31e, 31f, 31f, 31g, and 31g are provided, and a heated fluid path S1 and a heated fluid path S2 are configured.

  The partition members 37 are provided at both ends in the longitudinal direction (vertical direction) of the cross section of the flow path of the heating fluid path S1 and arcuate partition parts 37a and 37b provided at both ends in the arrangement direction of the heating fluid path S1. The arc-shaped partitioning portions 37c and 37d are configured such that a hole 37s is formed in the center portion with a single plate.

  The casing 38 has a cylindrical shape in which both end portions in the arrangement direction are formed flat. As shown in FIG. 8, the casing 38 is integrally formed with the partition member 37, that is, by press molding or the like. Further, the casing 38 is formed with a length that is located approximately between the inflow portion E2 into which the fluid to be heated is introduced from the pipe 5a and the outflow portion E3 from which the fluid to be heated flows out from the pipe 5b. The partition member 37 is formed outward with respect to the edge portion of the casing 38 on the inflow portion E2 side.

  Further, in the casing 38, a fin (fin structure) 34A is disposed between the heating fluid path S1 and the heating fluid path S1, and a fin (fin structure) 34B is disposed in the outermost layer path (see FIG. 7). ).

In the heat exchanger 30B of the first embodiment described above, similarly to the reference example , the flow distribution of the flow of the heated fluid introduced from the inflow portion E2 by the partition member 37 can be made uniform, and the temperature unevenness Can be prevented.

Further, according to the first embodiment, the heated fluid that has flowed out of the casing 38 to the outflow portion E3 stays in the space formed between the casing 38 and the housing 32 (tubular body 32a). It is possible to suppress heat dissipation from 31B and increase heat conversion efficiency.

In addition, according to the first embodiment, the partition portions 37a and 37b and the partition portions 37c and 37d are provided in portions different from the arrangement direction of the heating fluid path S1, so that the entire outer periphery of the heat exchange portion 31B is enclosed. , Heat conversion efficiency can be improved.

Further, according to the first embodiment, as shown in FIG. 8, the heating fluid pipe portions 31e, 31f, 31f, 31g, and 31g are inserted into the casing 38, and the fins 34A are interposed between the heating fluid pipe portions 31e to 31g. In the state where the fins 34B are brazed to the outermost layer path, the casing 38 can be attached to the housing 32 as a jig of the heat exchanging portion 31B, so that the manufacturability can be improved. Further, since it is not necessary to join the fins 34A and 34B to the housing 32, the joining rate of the brazing of the fins 34A and 34B can be increased. In the manufacturing process, after the casing 38 to which the heated fluid pipe portions 31e to 31g and the fins 34A and 34B are attached is inserted into the cylindrical body 32a, the blocking plates 32b and 32c are welded to both sides of the cylindrical body 32a. Thus, the heat exchanger 30B is obtained.

Further, according to the first embodiment, like the first embodiment, by providing the fins 34B in the outermost path, the fins 34B itself without the role of buffer material, a heating fluid pipe portion 31e~31g thermal deformation Even so, the stress can be released.

( Second Embodiment)
FIG. 9 is a cross-sectional view showing a combustion heater provided with the heat exchanger of the second embodiment, and FIG. 10 is a cross-sectional view taken along the line DD of FIG. In FIG. 9, the fins are not shown.
The heat exchanger 30C according to the second embodiment includes a partition member 39 having the same shape as the partition member 37 according to the first embodiment, and the partition member 39 is connected to the casing 38 at an end opposite to the partition member 37. It is comprised so that it may be integrally formed in a part. That is, as shown in FIG. 10, the partition member 39 includes arcuate partition portions 39a and 39b provided at both ends in the arrangement direction of the heating fluid path S1, and the longitudinal direction of the flow path cross section of the heating fluid path S1 (see FIG. Arc-shaped partition portions 39c and 39d provided at both end portions in the vertical direction (10) are formed by a single plate. Other configurations are the same as those of the first embodiment, and the same reference numerals are given and description thereof is omitted.

  As shown in FIG. 9, the space between the housing 32 and the casing 38 is hermetically sealed with partition members 37 and 39, so that an annular heat insulating layer Q (not shown) is formed. The heat insulating layer Q may be an air layer or a heat insulating material such as glass wool.

Thus, according to the heat exchanger 30C of 2nd Embodiment, since the heat insulation layer Q is formed, the thermal radiation from 31 C of heat exchange parts can be prevented, and heat conversion efficiency can be improved. Further, by providing the partition members 37 and 39, temperature unevenness can be prevented.

It is a lineblock diagram showing an example of a system carrying a heat exchanger of this embodiment. It is an external appearance perspective view which shows the combustion heater provided with the heat exchanger of 1st Embodiment. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is sectional drawing which shows the heat exchange part as a reference example . It is sectional drawing which shows the combustion heater provided with the heat exchanger of 1st Embodiment. It is CC sectional drawing of FIG. It is a see-through | perspective perspective view which shows the heat exchanger of 1st Embodiment. It is sectional drawing which shows the combustion heater provided with the heat exchanger of 2nd Embodiment. It is DD sectional drawing of FIG.

Explanation of symbols

30A, 30B, 30C Heat exchanger 31A, 31B, 31C Heat exchange part 32 Housing 33a-33d, 37, 39 Partition material 34A, 34B Fin 37s Hole 38 Casing Q Heat insulation layer S1 Heating fluid path S2 Heated fluid path

Claims (3)

A plurality of heating fluid paths in which a cross section of the flow path through which the heated fluid flows is formed in an elongated shape; and a heated fluid path through which the heated fluid flows; and each of the heated fluid paths is mutually in the heated fluid path A substantially cylindrical casing covering the heat exchanging portions arranged in parallel with a gap therebetween,
A cylindrical housing into which the casing is inserted, and
The heating fluid path is configured such that the length of the heating fluid path is shortened from the center to the both ends so that the center of the heating fluid path is longest and both ends of the heating direction are shortest. Formed into
The casing is formed such that both ends of the heating fluid path in the arrangement direction are flat and is positioned between an inflow portion into which the heated fluid is introduced and an outflow portion from which the heated fluid flows out. Formed with
An arcuate partition provided at both ends of the heating fluid path in the arrangement direction and an arcuate partition provided at both ends in the longitudinal direction of the flow path cross section of the heating fluid path are arranged in the center with one plate. It further comprises a partition material configured to form a hole in the part,
The heat exchanger according to claim 1, wherein the partition member is formed integrally with the casing at an edge portion on the inflow portion side so as to be in close contact with the housing. The partition material is provided on the edge portion on the outflow portion side together with the edge portion on the inflow portion side of the casing, and has an annular heat insulating layer sealed with the partition materials between the casing and the housing. The heat exchanger according to claim 1 . At least the outermost layer path of the heated fluid, the heat exchanger according to claim 1 or claim 2, characterized in that it has a fin structure.

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